Tratamientos y bioterapias para COVID-19 / Therapeutics and biotherapies for covid-19

INTRODUCCIÓN: Un nuevo brote de coronavirus surgió en 2019 en Wuhan, China, causando conmoción en el sistema sanitario de todo el mundo; el Comité Internacional de Taxonomía de Virus lo denominó SARS-CoV-2, agente causante de la enfermedad COVID-19.El espectro de gravedad de la enfermedad es muy amplio: la mayoría de los pacientes no presentan gravedad, pero otros pueden desarrollar neumonías, y la insuficiencia respiratoria aguda es la causa más frecuente de mortalidad. Objetivo: analizar y desarrollar las distintas alternativas terapéuticas aportadas por la Biotecnología para tratar los síntomas de aquellos pacientes con COVID-19. Metodología: se realizó una revisión de la bibliografía disponible, a partir de enero de 2020 en PubMed, acerca de los tratamientos que se encuentran aún en ensayos clínicos y aquellos que cuentan con aprobación bajo uso de emergencia para la enfermedad COVID-19. También se realizaron búsquedas a través de Google y Google Académico para publicaciones de organismos de Salud en referencia a políticas de salud establecidas para la terapéutica durante dicha pandemia. Resultados: este trabajo aborda las nuevas alternativas terapéuticas para COVID-19 derivadas de la Biotecnología, que se encuentran tanto en uso como en etapas de ensayos clínicos comprendidos dentro del segmento de los biofármacos y las bioterapias. Se incluye un breve resumen del estatus regulatorio de entidades de salud, el mecanismo de acción de dichas terapias y características generales de cada uno. Se incluyen novedosas bioterapias que se empezaron a implementar para afrontar la pandemia. Conclusiones: la pandemia de coronavirus está poniendo a prueba el sistema sanitario internacional, para brindar soluciones tanto desde el diagnóstico y prevención como para el tratamiento de la población a fin de disminuir la mortalidad. Esto incluyó, obviamente también, al área de la Biotecnología aplicada a la salud, que ha aportado en los tres aspectos mencionados; el presente trabajo se centra en las respuestas de tipo terapéutico que ha brindado y que están comercializadas o en fases clínicas. (AU)

INTRODUCTION: A new coronavirus outbreak emerged in 2019 in Wuhan, China, causing a shock to the healthcare system around the world; the International Committee on Taxonomy of Viruses named it SARS-CoV- 2, the infectious agent of the COVID-19 disease. The spectrum of severity of the disease is very wide, most patients are not serious, but others can develop pneumonia, with acute respiratory failure being the most frequent cause of mortality. Objective: to analyze and develop the different therapeutic alternatives provided by Biotechnology dedicated to Health, to treat the symptoms of those COVID-19 patients who require it, and thus reduce mortality.Methodology: a review of the available literature from January 2020 in PubMed of the treatments that are still in clinical trials and those that have been approved under emergency use for the disease COVID-19 was performed. Searches were also carried out through Google and Google Scholar for publications of Health organizations in reference to health policies established for therapeutics during the mentioned pandemic. Results: this work addresses the new therapeutic alternatives derived from Biotechnology, which are both in use and in stages of clinical trials, to treat patients who developed COVID-19 included within the segment of biopharmaceuticals and biotherapies. A brief summary of the regulatory status of health entities, the mechanism of action of said therapies and general characteristics of each one is included. Innovative biotherapies that began to be implemented to face the pandemic are included. Conclusions: The coronavirus pandemic has driven the international health system to the test, to provide solutions both from the diagnosis, prevention and treatment of the population to reduce the mortality of patients. This obviously also included the area of Biotechnology applied to health, which has contributed in the three aspects mentioned. The present work focuses on the therapeutic responses that it has provided and that are commercialized or in clinical phases. (AU)

Probing the Requirements for Dual Angiotensin-Converting Enzyme C-Domain Selective/Neprilysin Inhibition.

Selective inhibition of the angiotensin-converting enzyme C-domain (cACE) and neprilysin (NEP), leaving the ACE N-domain (nACE) free to degrade bradykinin and other peptides, has the potential to provide the potent antihypertensive and cardioprotective benefits observed for nonselective dual ACE/NEP inhibitors, such as omapatrilat, without the increased risk of adverse effects. We have synthesized three 1-carboxy-3-phenylpropyl dipeptide inhibitors with nanomolar potency based on the previously reported C-domain selective ACE inhibitor lisinopril-tryptophan (LisW) to probe the structural requirements for potent dual cACE/NEP inhibition. Here we report the synthesis, enzyme kinetic data, and high-resolution crystal structures of these inhibitors bound to nACE and cACE, providing valuable insight into the factors driving potency and selectivity. Overall, these results highlight the importance of the interplay between the S1' and S2' subsites for ACE domain selectivity, providing guidance for future chemistry efforts toward the development of dual cACE/NEP inhibitors.

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.

A Novel Angiotensin-I-Converting Enzyme (ACE) Inhibitory Peptide from Takifugu flavidus.

Alcalase, neutral protease, and pepsin were used to hydrolyze the skin of Takifugu flavidus. The T. flavidus hydrolysates (TFHs) with the maximum degree of hydrolysis (DH) and angiotensin-I-converting enzyme (ACE)-inhibitory activity were selected and then ultra-filtered to obtain fractions with components of different molecular weights (MWs) (<1, 1-3, 3-10, 10-50, and >50 kDa). The components with MWs < 1 kDa showed the strongest ACE-inhibitory activity with a half-maximal inhibitory concentration (IC50) of 0.58 mg/mL. Purification and identification using semi-preparative liquid chromatography, Sephadex G-15 gel chromatography, RP-HPLC, and LC-MS/MS yielded one new potential ACE-inhibitory peptide, PPLLFAAL (non-competitive suppression mode; IC50 of 28 µmmol·L-1). Molecular docking and molecular dynamics simulations indicated that the peptides should bind well to ACE and interact with amino acid residues and the zinc ion at the ACE active site. Furthermore, a short-term assay of antihypertensive activity in spontaneously hypertensive rats (SHRs) revealed that PPLLFAAL could significantly decrease the systolic blood pressure (SBP) and diastolic blood pressure (DBP) of SHRs after intravenous administration. These results suggested that PPLLFAAL may have potential applications in functional foods or pharmaceuticals as an antihypertensive agent.

Protective and Anti-Aging Effects of 5 Cosmeceutical Peptide Mixtures on Hydrogen Peroxide-Induced Premature Senescence in Human Skin Fibroblasts.

Skin aging usually leads to the excessive deterioration of the dermal extracellular matrix, loss of antimicrobial function, loss of skin barrier function, and a series of inflammatory processes. Bioactive peptides have been widely used in cosmetics due to their protective effects on skin and efficient absorption. Combination of different peptides may lead to synergistic or antagonistic effects, so different formulas need to be designed and tested properly. In this study, 5 functional cosmeceutical peptides were tested on their individual and mixed activities to detect a suitable anti-aging and protective formula from our experiments. After the individual activity test, the optimal concentration is 200 µg/mL of carnosine for the superoxide dismutase (SOD) activity, 200 µg/mL of GHK peptide for the hydroxyproline (HYP) content activity, 100 µg/mL of acetyl tetrapeptide-5 for the angiotensin-converting enzyme 1 activity, 400 µg/mL of hexapeptide-11 for the HYP content activity, and 400 µg/mL of acetyl hexapeptide-3 for the catecholamine content activity. According to the optimal concentration of these 5 cosmeceutical peptides, 6 formulations of peptide mixtures were designed and tested for their anti-aging activities and protective effects against hydrogen peroxide-induced premature senescence in human skin fibroblasts. One of the cosmeceutical peptide mixtures (carnosine + acetyl tetrapeptide-5 + hexapeptide-11 + acetyl hexapeptide-3) significantly reduced the intracellular malondialdehyde and hydroxyl free radical contents and increased the HYP and human elastin contents as well as the enzymatic activities of SOD and glutathione peroxidase. Our study suggests that this formula of cosmeceutical peptide mixtures could be a promising agent for use in anti-aging and protective cosmetics.

Antioxidant properties and inhibition of angiotensin-converting enzyme by highly active peptides from wheat gluten.

This study aimed to focus on the high-value utilization of raw wheat gluten by determining the potent antioxidant peptides and angiotensin I-converting enzyme (ACE) inhibitory peptides from wheat gluten oligopeptides (WOP). WOP were analyzed for in vitro antioxidant activity and inhibition of ACE, and the identification of active peptides was performed by reversed-phase high-performance liquid chromatography and mass spectrometry. Quantitative analysis was performed for highly active peptides. Five potent antioxidant peptides, Leu-Tyr, Pro-Tyr, Tyr-Gln, Ala-Pro-Ser-Tyr and Arg-Gly-Gly-Tyr (6.07 ± 0.38, 7.28 ± 0.29, 11.18 ± 1.02, 5.93 ± 0.20 and 9.04 ± 0.47 mmol 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) equivalent/g sample, respectively), and five potent ACE inhibitory peptides, Leu-Tyr, Leu-Val-Ser, Tyr-Gln, Ala-Pro-Ser-Tyr and Arg-Gly-Gly-Tyr (half maximal inhibitory concentration (IC50) values = 0.31 ± 0.02, 0.60 ± 0.03, 2.00 ± 0.13, 1.47 ± 0.08 and 1.48 ± 0.11 mmol/L, respectively), were observed. The contents of Leu-Tyr, Pro-Tyr, Tyr-Gln, Ala-Pro-Ser-Tyr, Arg-Gly-Gly-Tyr, and Leu-Val-Ser were 155.04 ± 8.36, 2.08 ± 0.12, 1.95 ± 0.06, 22.70 ± 1.35, 0.25 ± 0.01, and 53.01 ± 2.73 µg/g, respectively, in the WOP. Pro-Tyr, Tyr-Gln, Ala-Pro-Ser-Tyr, Arg-Gly-Gly-Tyr, and Leu-Val-Ser are novel antioxidative/ACE inhibitory peptides that have not been previously reported. The results suggest that WOP could potentially be applied in the food industry as a functional additive.

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.

Metabolites of the ellagitannin, geraniin inhibit human ACE; in vitro and in silico evidence.

Hypertension is defined as the persistence of elevated blood pressure in the circulation system. The renin-angiotensin-aldosterone system is a major modulator of blood pressure. Among the risk factors of cardiovascular disease, hypertension is the most preventable and treatable, with drugs such as ACE inhibitors. Many ACE inhibitors are known to have undesirable side effects and hence, natural alternatives are being sought. Dietary polyphenols, particularly ellagitannins, are derived from plant products and are known to exhibit a variety of bioactivities. Geraniin, an ellagitannin has been shown to have antihypertensive activity in animal experiments. It is speculated that the metabolites of geraniin are responsible for its ACE inhibitory activity. We have performed in vitro ACE inhibition and in silico studies with geraniin and its metabolites (ellagic acid, urolithins). Our studies confirm that ellagic acid exhibited similar inhibitory potential to ACE as the positive control captopril.

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.

Explorative Screening of Bioactivities Generated by Plant-Based Proteins after In Vitro Static Gastrointestinal Digestion.

The gastrointestinal digestion of food proteins can generate peptides with a wide range of biological activities. In this study, we screened various potential bioactivities generated by plant-based proteins. Whey protein as an animal protein reference, five grades of pea protein, two grades of wheat protein, and potato, fava bean, and oat proteins were submitted to in vitro SGID. They were then tested in vitro for several bioactivities including measures on: (1) energy homeostasis through their ability to modulate intestinal hormone secretion, to inhibit DPP-IV activity, and to interact with opioid receptors; (2) anti-hypertensive properties through their ability to inhibit ACE activity; (3) anti-inflammatory properties in Caco-2 cells; (4) antioxidant properties through their ability to inhibit production of reactive oxygen species (ROS). Protein intestinal digestions were able to stimulate intestinal hormone secretion by enteroendocrine cells, to inhibit DPP-IV and ACE activities, to bind opioid receptors, and surprisingly, to decrease production of ROS. Neither pro- nor anti-inflammatory effects have been highlighted and some proteins lost their pro-inflammatory potential after digestion. The best candidates were pea, potato, and fava bean proteins.

Caffeic and chlorogenic acids modulate altered activity of key enzymes linked to hypertension in cyclosporine-induced hypertensive rats.

OBJECTIVES: This study aimed to explore the protective mechanism of caffeic acid (CAA) and chlorogenic acid (CHA) on cyclosporine (CSA) induced hypertensive rats. METHODS: Effect of CAA and CHA on diastolic blood pressure (DBP), mean arterial pressure (MAP), angiotensin-converting enzyme (ACE), e-nucleotide triphosphate dephosphorylase (e-NTPDase), 5' nucleotidase and adenosine deaminase (ADA) activity in CSA-induced hypertensive rats were determined. RESULTS: CAA and CHA administration stabilized hypertensive effect caused by CSA administration. Also, altered activity of ACE (lung), e-NTPDase, 5' nucleotidase, ADA as well as elevated malondiadehyde (MDA) level was restored in all the treated hypertensive rats in comparison with the untreated hypertensive rats. CONCLUSION: Hence, these observed results could underlie some of the mechanisms through which CAA and CHA could offer antihypertensive effect.

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.

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.

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.

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.

Scaffold morphing of arbidol (umifenovir) in search of multi-targeting therapy halting the interaction of SARS-CoV-2 with ACE2 and other proteases involved in COVID-19.

The rapid emergence of novel coronavirus, SARS-coronavirus 2 (SARS-CoV-2), originated from Wuhan, China, imposed a global health emergency. Angiotensin-converting enzyme 2 (ACE2) receptor serves as an entry point for this deadly virus while the proteases like furin, transmembrane protease serine 2 (TMPRSS2) and 3 chymotrypsin-like protease (3CLpro) are involved in the further processing and replication of SARS-CoV-2. The interaction of SP with ACE2 and these proteases results in the SARS-CoV-2 invasion and fast epidemic spread. The small molecular inhibitors are reported to limit the interaction of SP with ACE2 and other proteases. Arbidol, a membrane fusion inhibitor approved for influenza virus is currently undergoing clinical trials against COVID-19. In this context, we report some analogues of arbidol designed by scaffold morphing and structure-based designing approaches with a superior therapeutic profile. The representative compounds A_BR4, A_BR9, A_BR18, A_BR22 and A_BR28 restricted the interaction of SARS-CoV-2 SP with ACE2 and host proteases furin and TMPRSS2. For 3CLPro, Compounds A_BR5, A_BR6, A_BR9 and A_BR18 exhibited high binding affinity, docking score and key residue interactions. Overall, A_BR18 and A_BR28 demonstrated multi-targeting potential against all the targets. Among these top-scoring molecules A_BR9, A_BR18, A_BR22 and A_BR28 were predicted to confer favorable ADME properties.

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.

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.

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.