Antiviral drugs suppress infection of 2019-nCoV spike pseudotyped virus by interacting with ACE2 protein.

The outbreak of coronavirus disease 2019 (COVID-19) has induced a large number of deaths worldwide. Angiotensin-converting enzyme 2 (ACE2) is the entry receptor for the 2019 novel coronavirus (2019-nCoV) to infect the host cells. Therefore, ACE2 may be an important target for the prevention and treatment of COVID-19. The aim of this study was to investigate the inhibition effect of valaciclovir hydrochloride (VACV), zidovudine (ZDV), saquinavir (SQV), and efavirenz (EFV) on 2019-nCoV infection. The results of molecule docking and surface plasmon resonance showed that VACV, ZDV, SQV, and EFV could bind to ACE2 protein, with the KD value of (4.33 ± 0.09) e-8 , (6.29 ± 1.12) e-6 , (2.37 ± 0.59) e-5 , and (4.85 ± 1.57) e-5 M, respectively. But only ZDV and EFV prevent the 2019-nCoV spike pseudotyped virus to enter ACE2-HEK293T cells with an EC50 value of 4.30 ± 1.46 and 3.92 ± 1.36 µM, respectively. ZDV and EFV also have a synergistic effect on preventing entry of virus into cells. In conclusion, ZDV and EFV suppress 2019-nCoV infection of ACE2-HEK293T cells by interacting with ACE2.

[The RAAS and SARS-CoV-2: A riddle to solve]. / El SRAA y el SARS-CoV-2: el acertijo a resolver.

The first case of COVID-19 was reported on 31 December 2019 in Wuhan, China. Ever since there has been unprecedented and growing interest in learning about all aspects of this new disease. Debate has been generated as to the association between antihypertensive therapy with renin-angiotensin-aldosterone system (RAAS) inhibitors and SARS-CoV-2 infection. While many questions as yet remain unanswered, the aim of this report is to inform health professionals about the current state of knowledge. Because this is an ever-evolving topic, the recommendation is that it be updated as new evidence becomes available. Below, we provide a review of pre-clinical and clinical studies that link coronavirus to the RAAS.

Candidate drugs against SARS-CoV-2 and COVID-19.

Outbreak and pandemic of coronavirus SARS-CoV-2 in 2019/2020 will challenge global health for the future. Because a vaccine against the virus will not be available in the near future, we herein try to offer a pharmacological strategy to combat the virus. There exists a number of candidate drugs that may inhibit infection with and replication of SARS-CoV-2. Such drugs comprise inhibitors of TMPRSS2 serine protease and inhibitors of angiotensin-converting enzyme 2 (ACE2). Blockade of ACE2, the host cell receptor for the S protein of SARS-CoV-2 and inhibition of TMPRSS2, which is required for S protein priming may prevent cell entry of SARS-CoV-2. Further, chloroquine and hydroxychloroquine, and off-label antiviral drugs, such as the nucleotide analogue remdesivir, HIV protease inhibitors lopinavir and ritonavir, broad-spectrum antiviral drugs arbidol and favipiravir as well as antiviral phytochemicals available to date may limit spread of SARS-CoV-2 and morbidity and mortality of COVID-19 pandemic.

Glycyrrhizin: An old weapon against a novel coronavirus.

Currently, over 100 countries are fighting against a common enemy, the severe acute respiratory syndrome coronavirus (SARS-CoV)-2, which causes COVID-19. This has created a demand for a substance whose effectiveness has already been demonstrated in a similar scenario. Glycyrrhizin (GZ) is a promising agent against SARS-CoV-2 as its antiviral activity against SARS-CoV has already been confirmed. It is worthwhile to extrapolate from its proven therapeutic effects as there is a high similarity in the structure and genome of SARS-CoV and SARS-CoV-2. There are many possible mechanisms through which GZ acts against viruses: increasing nitrous oxide production in macrophages, affecting transcription factors and cellular signalling pathways, directly altering the viral lipid-bilayer membrane, and binding to the ACE2 receptor. In this review, we discuss the possible use of GZ in the COVID-19 setting, where topical administration appears to be promising, with the nasal and oral cavity notably being the potent location in terms of viral load. The most recently published papers on the distribution of ACE2 in the human body and documented binding of GZ to this receptor, as well as its antiviral activity, suggest that GZ can be used as a therapeutic for COVID-19 and as a preventive agent against SARS-CoV-2.

Drugs acting on renin angiotensin system and use in ill patients with COVID-19.

Some concerns about the prescription of drugs acting on the renin-angiotensin system (angiotensin-converting enzyme 1 (ACE1) inhibitors, ACEi; angiotensin II type 1 receptor blockers, ARB) have emerged due to SARS COV2 and COVID-19 pandemic. These very legitimate questions are directly the consequence of the recent recognition of the fundamental role of ACE2 (angiotensin-converting enzyme 2) in COVID-19 infection. Indeed, SARS COV2 utilizes ACE2 as a membrane receptor to enter target cells. Consequently, the putative impact of drugs modulating the renin-angiotensin system on the risk of developing severe or fatal severe acute respiratory syndrome in case of COVID-19 infection emerged. As a membrane-bound enzyme (carboxypeptidase), ACE2 inactivates angiotensin II and therefore physiologically counters its effects. Due to a different structure compared with ACE1, ACE2 is insensitive to ACEIs. In vitro, both ARBs and ACEi appear able to upregulate ACE2 tissue expression and activity but these results were not confirmed in Humans. The exact impact of both ARBs and ACEis on COVID-19 infection is definitively known and preliminary results are even in favor of a protective role confers by these drugs. Due to the crucial role of ACE2, some groups support the hypothesis that a modulation of ACE2 expression could represent a valuable therapeutic target could confer protective properties against inflammatory tissue damage in COVID-19 infection. So, studies are currently ongoing to test the impact of elevated ACE2 membrane expression, administration of ARB and infusion of soluble ACE2. In summary, based on the currently available evidences and as recommended by several medical societies, ACEi or ARB should not be systematically discontinued because to date no safety signal was raised with the use of these drugs.

Recognition of Potential COVID-19 Drug Treatments through the Study of Existing Protein-Drug and Protein-Protein Structures: An Analysis of Kinetically Active Residues.

We report the results of our in silico study of approved drugs as potential treatments for COVID-19. The study is based on the analysis of normal modes of proteins. The drugs studied include chloroquine, ivermectin, remdesivir, sofosbuvir, boceprevir, and α-difluoromethylornithine (DMFO). We applied the tools we developed and standard tools used in the structural biology community. Our results indicate that small molecules selectively bind to stable, kinetically active residues and residues adjoining them on the surface of proteins and inside protein pockets, and that some prefer hydrophobic sites over other active sites. Our approach is not restricted to viruses and can facilitate rational drug design, as well as improve our understanding of molecular interactions, in general.

On the whereabouts of SARS-CoV-2 in the human body: A systematic review.

Since SARS-CoV-2 appeared in the human population, the scientific community has scrambled to gather as much information as possible to find good strategies for the containment and treatment of this pandemic virus. Here, we performed a systematic review of the current (pre)published SARS-CoV-2 literature with a focus on the evidence concerning SARS-CoV-2 distribution in human tissues and viral shedding in body fluids. In addition, this evidence is aligned with published ACE2 entry-receptor (single cell) expression data across the human body to construct a viral distribution and ACE2 receptor body map. We highlight the broad organotropism of SARS-CoV-2, as many studies identified viral components (RNA, proteins) in multiple organs, including the pharynx, trachea, lungs, blood, heart, vessels, intestines, brain, male genitals and kidneys. This also implicates the presence of viral components in various body fluids such as mucus, saliva, urine, cerebrospinal fluid, semen and breast milk. The main SARS-CoV-2 entry receptor, ACE2, is expressed at different levels in multiple tissues throughout the human body, but its expression levels do not always correspond with SARS-CoV-2 detection, indicating that there is a complex interplay between virus and host. Together, these data shed new light on the current view of SARS-CoV-2 pathogenesis and lay the foundation for better diagnosis and treatment of COVID-19 patients.

Outcome of patients hospitalized for COVID-19 and exposure to angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers in France: results of the ACE-CoV study.

Data are lacking on the impact of ACEI/ARB exposure on unfavorable outcome in the population of patients hospitalized for COVID-19 with hypertension/cardiovascular disease, particularly in Europe. The ACE-CoV study was designed to assess this question. The study was conducted in the Covid-Clinic-Toul cohort, which contains data about all patients hospitalized at Toulouse University hospital, France with a SARS-CoV-2 infection since March, 2020. We selected the patients with a history of cardiovascular disease (heart failure or coronary disease) and/or arterial hypertension. We conducted a subgroup analysis in patients with arterial hypertension. ACEI/ARB exposures at admission were assessed. The outcome was composite: admission to intensive care unit, need of mechanical ventilation or death during the 14 days after admission to hospital. We used logistic regression models with propensity scores (PS) weighted by overlap weighting (OW) and inverse probability of treatment weighting (IPTW). Between March 2020 and April 20, 2020, the Covid-Clinic-Toul included 263 patients. Among them, 111 were included in the ACE-CoV study population. In OW-PS-adjusted analyses, the association of exposure to ACEIs or ARBs with outcome occurrence was OR: 1.56 (95% CI: 0.73-3.33). It was 0.99 (95% CI: 0.68-1.45) for ACEIs and 1.64 (95% CI: 0.77-3.50) for ARBs. Analyses with weighting by the IPTW-PS method gave similar results. Results were similar when considering the subgroup of patients with arterial hypertension. The ACE-CoV study found no association between exposure to ACEIs or ARBs and unfavorable outcome in hospitalized patients for COVID-19 with a history of cardiovascular disease/arterial hypertension.

Current targets and drug candidates for prevention and treatment of SARS-CoV-2 (COVID-19) infection.

Angiotensin-converting enzyme 2 (ACE2), the host cell-binding site for SAR-CoV-2, poses two-fold drug development problems. First, the role of ACE2 itself is still a matter of investigation, and no specific drugs are available targeting ACE2. Second, as a consequence of SARS-CoV-2 interaction with ACE2, there is an impairment of the renin-angiotensin system (RAS) involved in the functioning of vital organs like the heart, kidney, brain, and lungs. In developing antiviral drugs for COVID-19, ACE2, RNA-dependent RNA polymerase (RdRp), and the specific enzymes involved in the viral and cellular gene expression have been the primary targets. SARS-CoV-2 being a new virus with unusually high mortality, there has been a need to get medicines in an emergency, and the drug repurposing has been a primary strategy. Considering extensive mortality and morbidity throughout the world, we have made a maiden attempt to discover the drugs interacting with RAS and identify the lead compounds from herbal plants using molecular docking. Both host ACE2 and viral RNA-dependent RNA polymerase (RdRp) and ORF8 appear to be the primary targets for the treatment of COVID-19. While the drug repurposing of currently approved drugs seems to be one strategy for the treatment of COVID-19, purposing phytochemicals may be another essential strategy for discovering lead compounds. Using in silico molecular docking, we have identified a few phytochemicals that may provide insights into designing herbal and synthetic therapeutics to treat COVID-19.

Twenty years of progress in angiotensin converting enzyme 2 and its link to SARS-CoV-2 disease.

The virulence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the aggressive nature of the disease has transformed the universal pace of research in the desperate attempt to seek effective therapies to halt the morbidity and mortality of this pandemic. The rapid sequencing of the SARS-CoV-2 virus facilitated identification of the receptor for angiotensin converting enzyme 2 (ACE2) as the high affinity binding site that allows virus endocytosis. Parallel evidence that coronavirus disease 2019 (COVID-19) disease evolution shows greater lethality in patients with antecedent cardiovascular disease, diabetes, or even obesity questioned the potential unfavorable contribution of angiotensin converting enzyme (ACE) inhibitors or angiotensin II (Ang II) receptor blockers as facilitators of adverse outcomes due to the ability of these therapies to augment the transcription of Ace2 with consequent increase in protein formation and enzymatic activity. We review, here, the specific studies that support a role of these agents in altering the expression and activity of ACE2 and underscore that the robustness of the experimental data is associated with weak clinical long-term studies of the existence of a similar regulation of tissue or plasma ACE2 in human subjects.

Spontaneous Hinge-Bending Motions of Angiotensin I Converting Enzyme: Role in Activation and Inhibition.

The inhibition of human angiotensin I converting enzyme (ACE) has been regarded as a promising approach for the treatment of hypertension. Despite research attempts over many years, our understanding the mechanisms of activation and inhibition of ACE is still far from complete. Here, we present results of all atom molecular dynamics simulations of ACE with and without ligands. Two types of inhibitors, competitive and mixed non-competitive, were used to model the ligand bound forms. In the absence of a ligand the simulation showed spontaneous large hinge-bending motions of multiple conversions between the closed and open states of ACE, while the ligand bound forms were stable in the closed state. Our simulation results imply that the equilibrium between pre-existing backbone conformations shifts in the presence of a ligand. The hinge-bending motion of ACE is considered as an essential to the enzyme function. A mechanistic model of activation and the inhibition may provide valuable information for novel inhibitors of ACE.

The therapeutic potential of targeting ACE2 in COVID-19.

OBJECTIVE: ACE2 long served as the human gateway for multiple coronaviruses, including the currently pandemic SARS-CoV-2. This mini-review explores the potential of targeting ACE2 in blocking viral penetrance. MATERIALS AND METHODS: PubMed search was conducted using the terms: "coronaviridae", "peptidyl-dipeptidase A", "ACE2", "SARS", and "SARS-CoV-2". References of relevant articles were further screened by the author. RESULTS: Four main methods of blocking ACE2-mediated viral penetrance were identified: receptor blockage, receptor decoying, receptor shedding, and co-receptor inhibition. CONCLUSIONS: Drugs that inhibit viral binding to ACE2 present a strong choice for the current, and if necessary, future outbreaks. Further research is needed to establish the clinical and pharmacological aspects of the identified candidate molecules.

A Retrospective Study from 2 Centers in China on the Effects of Continued Use of Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers in Patients with Hypertension and COVID-19.

BACKGROUND Use of renin-angiotensin-aldosterone system inhibitors in coronavirus disease 2019 (COVID-19) patients lacks evidence and is still controversial. This study was designed to investigate effects of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) on clinical outcomes of COVID-19 patients and to assess the safety of ACEIs/ARBs medication. MATERIAL AND METHODS COVID-19 patients with hypertension from 2 hospitals in Wuhan, China, from 17 Feb to 18 Mar 2020 were retrospectively screened and grouped according to in-hospital medication. We performed 1: 1 propensity score matching (PSM) analysis to adjust for confounding factors. RESULTS We included 210 patients and allocated them to ACEIs/ARBs (n=81; 46.91% males) or non-ACEIs/ARBs (n=129; 48.06% males) groups. The median age was 68 [interquartile range (IQR) 61.5-76] and 66 (IQR 59-72.5) years, respectively. General comparison showed mortality in the ACEIs/ARBs group was higher (8.64% vs. 3.88%) but the difference was not significant (P=0.148). ACEIs/ARBs was associated with significantly more cases 7-categorical ordinal scale >2 at discharge, more cases requiring Intensive Care Unit (ICU) stay, and increased values and ratio of days that blood pressure (BP) was above normal range (P<0.05). PSM analysis showed no significant difference in mortality, cumulative survival rate, or other clinical outcomes such as length of in-hospital/ICU stay, BP fluctuations, or ratio of adverse events between groups after adjustment for confounding parameters on admission. CONCLUSIONS We found no association between ACEIs/ARBs and clinical outcomes or adverse events, thus indicating no evidence for discontinuing use of ACEIs/ARBs in the COVID-19 pandemic.

Currently prescribed drugs in the UK that could upregulate or downregulate ACE2 in COVID-19 disease: a systematic review.

OBJECTIVE: To review evidence on routinely prescribed drugs in the UK that could upregulate or downregulate ACE2 and potentially affect COVID-19 disease. DESIGN: Systematic review. DATA SOURCE: MEDLINE, EMBASE, CINAHL, the Cochrane Library and Web of Science. STUDY SELECTION: Any design with animal or human models examining a currently prescribed UK drug compared with a control, placebo or sham group, and reporting an effect on ACE2 level, activity or gene expression. DATA EXTRACTION AND SYNTHESIS: MEDLINE, EMBASE, CINAHL, the Cochrane Library, Web of Science and OpenGrey from inception to 1 April 2020. Methodological quality was assessed using the SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) risk-of-bias tool for animal studies and Cochrane risk-of-bias tool for human studies. RESULTS: We screened 3360 titles and included 112 studies with 21 different drug classes identified as influencing ACE2 activity. Ten studies were in humans and one hundred and two were in animal models None examined ACE2 in human lungs. The most frequently examined drugs were angiotensin receptor blockers (ARBs) (n=55) and ACE inhibitors (ACE-I) (n=22). More studies reported upregulation than downregulation with ACE-I (n=22), ARBs (n=55), insulin (n=8), thiazolidinedione (n=7) aldosterone agonists (n=3), statins (n=5), oestrogens (n=5) calcium channel blockers (n=3) glucagon-like peptide 1 (GLP-1) agonists (n=2) and Non-steroidal anti-inflammatory drugs (NSAIDs) (n=2). CONCLUSIONS: There is an abundance of the academic literature and media reports on the potential of drugs that could attenuate or exacerbate COVID-19 disease. This is leading to trials of repurposed drugs and uncertainty among patients and clinicians concerning continuation or cessation of prescribed medications. Our review indicates that the impact of currently prescribed drugs on ACE2 has been poorly studied in vivo, particularly in human lungs where the SARS-CoV-2 virus appears to enact its pathogenic effects. We found no convincing evidence to justify starting or stopping currently prescribed drugs to influence outcomes of COVID-19 disease.

Chloroquine and hydroxychloroquine as ACE2 blockers to inhibit viropexis of 2019-nCoV Spike pseudotyped virus.

BACKGROUND: The novel coronavirus disease (2019-nCoV) has been affecting global health since the end of 2019 and there is no sign that the epidemic is abating . The major issue for controlling the infectious is lacking efficient prevention and therapeutic approaches. Chloroquine (CQ) and Hydroxychloroquine (HCQ) have been reported to treat the disease, but the underlying mechanism remains controversial. PURPOSE: The objective of this study is to investigate whether CQ and HCQ could be ACE2 blockers and used to inhibit 2019-nCoV virus infection. METHODS: In our study, we used CCK-8 staining, flow cytometry and immunofluorescent staining to evaluate the toxicity and autophagy of CQ and HCQ, respectively, on ACE2 high-expressing HEK293T cells (ACE2h cells). We further analyzed the binding character of CQ and HCQ to ACE2 by molecular docking and surface plasmon resonance (SPR) assays, 2019-nCoV spike pseudotyped virus was also used to observe the viropexis effect of CQ and HCQ in ACE2h cells. RESULTS: Results showed that HCQ is slightly more toxic to ACE2h cells than CQ. Both CQ and HCQ could bind to ACE2 with KD = (7.31 ± 0.62)e-7 M and (4.82 ± 0.87)e-7 M, respectively. They exhibit equivalent suppression effect for the entrance of 2019-nCoV spike pseudotyped virus into ACE2h cells. CONCLUSIONS: CQ and HCQ both inhibit the entrance 2019-nCoV into cells by blocking the binding of the virus with ACE2. Our findings provide novel insights into the molecular mechanism of CQ and HCQ treatment effect on virus infection.

Ivermectin Docks to the SARS-CoV-2 Spike Receptor-binding Domain Attached to ACE2.

BACKGROUND/AIM: Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). One drug that has attracted interest is the antiparasitic compound ivermectin, a macrocyclic lactone derived from the bacterium Streptomyces avermitilis. We carried out a docking study to determine if ivermectin might be able to attach to the SARS-CoV-2 spike receptor-binding domain bound with ACE2. MATERIALS AND METHODS: We used the program AutoDock Vina Extended to perform the docking study. RESULTS: Ivermectin docked in the region of leucine 91 of the spike and histidine 378 of the ACE2 receptor. The binding energy of ivermectin to the spike-ACE2 complex was -18 kcal/mol and binding constant was 5.8 e-08. CONCLUSION: The ivermectin docking we identified may interfere with the attachment of the spike to the human cell membrane. Clinical trials now underway should determine whether ivermectin is an effective treatment for SARS-Cov2 infection.