A screen of approved drugs and molecular probes identifies therapeutics with anti-Ebola virus activity

Two-way pharmacodynamic modeling of drug combinations and its application to pairs of repurposed Ebola and SARS-CoV-2 agents

Existing pharmacodynamic (PD) mathematical models for drug combinations discriminate antagonistic, additive, multiplicative, and synergistic effects, but fail to consider how concentration-dependent drug interaction effects may vary across an entire dose-response matrix. We developed a two-way pharmacodynamic (TWPD) model to capture the PD of two-drug combinations. TWPD captures interactions between upstream and downstream drugs that act on different stages of viral replication, by quantifying upstream drug efficacy and concentration-dependent effects on downstream drug pharmacodynamic parameters. We applied TWPD to previously published in vitro drug matrixes for repurposed potential anti-Ebola and anti-SARS-CoV-2 drug pairs. Depending on the drug pairing, the model recapitulated combined efficacies as or more accurately than existing models and can be used to infer efficacy at untested drug concentrations. TWPD fits the data slightly better in one direction for all drug pairs, meaning that we can tentatively infer the upstream drug. Based on its high accuracy, TWPD could be used in concert with PK models to estimate the therapeutic effects of drug pairs in vivo.

Multicomponent Synthesis of α-Branched Amines via a Zinc-Mediated Carbonyl Alkylative Amination Reaction

Methods for the synthesis of α-branched alkylamines are important due to their ubiquity in biologically active molecules. Despite the development of many methods for amine preparation, C(sp3)-rich nitrogen-containing compounds continue to pose challenges for synthesis. While carbonyl reductive amination (CRA) between ketones and alkylamines is the cornerstone method for α-branched alkylamine synthesis, it is sometimes limited by the sterically demanding condensation step between dialkyl ketones and amines and the more restricted availability of ketones compared to aldehydes. We recently reported a "higher-order" variant of this transformation, carbonyl alkylative amination (CAA), which utilized a halogen atom transfer (XAT)-mediated radical mechanism, enabling the streamlined synthesis of complex α-branched alkylamines. Despite the efficacy of this visible-light-driven approach, it displayed scalability issues, and competitive reductive amination was a problem for certain substrate classes, limiting applicability. Here, we report a change in the reaction regime that expands the CAA platform through the realization of an extremely broad zinc-mediated CAA reaction. This new strategy enabled elimination of competitive CRA, simplified purification, and improved reaction scope. Furthermore, this new reaction harnessed carboxylic acid derivatives as alkyl donors and facilitated the synthesis of α-trialkyl tertiary amines, which cannot be accessed via CRA. This Zn-mediated CAA reaction can be carried out at a variety of scales, from a 10 μmol setup in microtiter plates enabling high-throughput experimentation, to the gram-scale synthesis of medicinally-relevant compounds. We believe that this transformation enables robust, efficient, and economical access to α-branched alkylamines and provides a viable alternative to the current benchmark methods.

Design, synthesis and antiviral evaluation of novel conjugates of the 1,7,7-trimethylbicyclo[2.2.1]heptane scaffold and saturated N-heterocycles via 1,2,3-triazole linker

A new series of heterocyclic derivatives with a 1,7,7-trimethylbicyclo[2.2.1]heptane fragment was designed, synthesised and biologically evaluated. Synthesis of the target compounds was performed using the Cu(I) catalysed cycloaddition reaction. The key starting substances in the click reaction were an alkyne containing a 1,7,7-trimethylbicyclo[2.2.1]heptane fragment and a series of azides with saturated nitrogen-containing heterocycles. Some of the derivatives were found to exhibit strong antiviral activity against Marburg and Ebola pseudotype viruses. Lysosomal trapping assays revealed the derivatives to possess lysosomotropic properties. The molecular modelling study demonstrated the binding affinity between the compounds investigated and the possible active site to be mainly due to hydrophobic interactions. Thus, combining a natural hydrophobic structural fragment and a lysosome-targetable heterocycle may be an effective strategy for designing antiviral agents.

Calcium Influx Regulates the Replication of Several Negative-Strand RNA Viruses Including Severe Fever with Thrombocytopenia Syndrome Virus

Negative-strand RNA viruses (NSVs) represent one of the most threatening groups of emerging viruses globally. Severe fever with thrombocytopenia syndrome virus (SFTSV) is a highly pathogenic emerging virus that was initially reported in 2011 from China. Currently, no licensed vaccines or therapeutic agents have been approved for use against SFTSV. Here, L-type calcium channel blockers obtained from a U.S. Food and Drug Administration (FDA)-approved compound library were identified as effective anti-SFTSV compounds. Manidipine, a representative L-type calcium channel blocker, restricted SFTSV genome replication and exhibited inhibitory effects against other NSVs. The result from the immunofluorescent assay suggested that manidipine inhibited SFTSV N-induced inclusion body formation, which is believed to be important for the virus genome replication. We have shown that calcium possesses at least two different roles in regulating SFTSV genome replication. Inhibition of calcineurin, the activation of which is triggered by calcium influx, using FK506 or cyclosporine was shown to reduce SFTSV production, suggesting the important role of calcium signaling on SFTSV genome replication. In addition, we showed that globular actin, the conversion of which is facilitated by calcium from filamentous actin (actin depolymerization), supports SFTSV genome replication. We also observed an increased survival rate and a reduction of viral load in the spleen in a lethal mouse model of SFTSV infections after manidipine treatment. Overall, these results provide information regarding the importance of calcium for NSV replication and may thereby contribute to the development of broad-scale protective therapies against pathogenic NSVs. IMPORTANCE SFTS is an emerging infectious disease and has a high mortality rate of up to 30%. There are no licensed vaccines or antivirals against SFTS. In this article, L-type calcium channel blockers were identified as anti-SFTSV compounds through an FDA-approved compound library screen. Our results showed the involvement of L-type calcium channel as a common host factor for several different families of NSVs. The formation of an inclusion body, which is induced by SFTSV N, was inhibited by manidipine. Further experiments showed that SFTSV replication required the activation of calcineurin, a downstream effecter of the calcium channel. In addition, we identified that globular actin, the conversion of which is facilitated by calcium from filamentous actin, supports SFTSV genome replication. We also observed an increased survival rate in a lethal mouse model of SFTSV infection after manidipine treatment. These results facilitate both our understanding of the NSV replication mechanism and the development of novel anti-NSV treatment.

Design, synthesis and anti-Chikungunya virus activity of lomerizine derivatives

Chikungunya fever is an acute infectious disease caused by Chikungunya virus (CHIKV) and transmitted by Aedes mosquito. It is characterized by fever, rash and arthralgia with no effective drugs. Lomerizine (Lom) is a new generation calcium antagonist, which is mainly used in the treatment of migraine. Certain antiviral function of Lom was shown by some research. In our study, a series of new derivatives of Lom were designed and synthesized, and their in-vitro anti-CHIKV activity was tested. The results showed that Lom and its derivatives had potent anti-CHIKV activity and low cytotoxicity. Among them, compounds B1 and B7 showed most potent antiviral activity. Besides, structure-activity relationships, in-silico ADMET properties were also analyzed. Molecular docking study was performed to rationalize the SAR and analyze the possible binding modes between B1 and amino acid residues in the active site of nsP3 protein to enhance the understanding of their action as antiviral agents. These finding provides research basis for the design and synthesis of effective anti-CHIKV drugs with Lom as the lead compound.

β-arrestins and G protein-coupled receptor kinases in viral entry: A graphical review

Viruses rely on host-cell machinery in order to invade host cells and carry out a successful infection. G-protein coupled receptor (GPCR)-mediated signaling pathways are master regulators of cellular physiological processing and are an attractive target for viruses to rewire cells during infection. In particular, the GPCR-associated scaffolding proteins β-arrestins and GPCR signaling effectors G-protein receptor kinases (GRKs) have been identified as key cellular factors that mediate viral entry and orchestrate signaling pathways that reprogram cells for viral replication. Interestingly, a broad range of viruses have been identified to activate and/or require GPCR-mediated pathways for infection, including polyomaviruses, flaviviruses, influenza virus, and SARS-CoV-2, demonstrating that these viruses may have conserved mechanisms of host-cell invasion. Thus, GPCR-mediated pathways highlight an attractive target for the development of broad antiviral therapies.

Pseudotyped Viruses for Marburgvirus and Ebolavirus

Marburg virus (MARV) and Ebola virus (EBOV) of the Filoviridae family are the most lethal viruses in terms of mortality rate. However, the development of antiviral treatment is hampered by the requirement for biosafety level-4 (BSL-4) containment. The establishment of BSL-2 pseudotyped viruses can provide important tools for the study of filoviruses. This chapter summarizes general information on the filoviruses and then focuses on the construction of replication-deficient pseudotyped MARV and EBOV (e.g., lentivirus system and vesicular stomatitis virus system). It also details the potential applications of the pseudotyped viruses, including neutralization antibody detection, the study of infection mechanisms, the evaluation of antibody-dependent enhancement, virus entry inhibitor screening, and glycoprotein mutation analysis.

Sertraline Is an Effective SARS-CoV-2 Entry Inhibitor Targeting the Spike Protein

The global spread of the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the continuously emerging new variants underscore an urgent need for effective therapeutics for the treatment of coronavirus disease 2019 (COVID-19). Here, we screened several FDA-approved amphiphilic drugs and determined that sertraline (SRT) exhibits potent antiviral activity against infection of SARS-CoV-2 pseudovirus (PsV) and authentic virus in vitro. It effectively inhibits SARS-CoV-2 spike (S)-mediated cell-cell fusion. SRT targets the early stage of viral entry. It can bind to the S1 subunit of the S protein, especially the receptor binding domain (RBD), thus blocking S-hACE2 interaction and interfering with the proteolysis process of S protein. SRT is also effective against infection with SARS-CoV-2 PsV variants, including the newly emerging Omicron. The combination of SRT and other antivirals exhibits a strong synergistic effect against infection of SARS-CoV-2 PsV. The antiviral activity of SRT is independent of serotonin transporter expression. Moreover, SRT effectively inhibits infection of SARS-CoV-2 PsV and alleviates the inflammation process and lung pathological alterations in transduced mice in vivo. Therefore, SRT shows promise as a treatment option for COVID-19. IMPORTANCE The study shows SRT is an effective entry inhibitor against infection of SARS-CoV-2, which is currently prevalent globally. SRT targets the S protein of SARS-CoV-2 and is effective against a panel of SARS-CoV-2 variants. It also could be used in combination to prevent SARS-CoV-2 infection. More importantly, with long history of clinical use and proven safety, SRT might be particularly suitable to treat infection of SARS-CoV-2 in the central nervous system and optimized for treatment in older people, pregnant women, and COVID-19 patients with heart complications, which are associated with severity and mortality of COVID-19.

Phosphatidylserine clustering by the Ebola virus matrix protein is a critical step in viral budding

Phosphatidylserine (PS) is a critical lipid factor in the assembly and spread of numerous lipid-enveloped viruses. Here, we describe the ability of the Ebola virus (EBOV) matrix protein eVP40 to induce clustering of PS and promote viral budding in vitro, as well as the ability of an FDA-approved drug, fendiline, to reduce PS clustering and subsequent virus budding and entry. To gain mechanistic insight into fendiline inhibition of EBOV replication, multiple in vitro assays were run including imaging, viral budding and viral entry assays. Fendiline lowers PS content in mammalian cells and PS in the plasma membrane, where the ability of VP40 to form new virus particles is greatly lower. Further, particles that form from fendiline-treated cells have altered particle morphology and cannot significantly infect/enter cells. These complementary studies reveal the mechanism by which EBOV matrix protein clusters PS to enhance viral assembly, budding, and spread from the host cell while also laying the groundwork for fundamental drug targeting strategies.

Dihydropyridine-derived calcium channel blocker as a promising anti-hantavirus entry inhibitor

Hantaviruses, the causative agent for two types of hemorrhagic fevers, hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS), are distributed from Eurasia to America. HFRS and HPS have mortality rates of up to 15% or 45%, respectively. Currently, no certified therapeutic has been licensed to treat hantavirus infection. In this study, we discovered that benidipine hydrochloride, a calcium channel blocker, inhibits the entry of hantaviruses in vitro. Moreover, an array of calcium channel inhibitors, such as cilnidipine, felodipine, amlodipine, manidipine, nicardipine, and nisoldipine, exhibit similar antiviral properties. Using pseudotyped vesicular stomatitis viruses harboring the different hantavirus glycoproteins, we demonstrate that benidipine hydrochloride inhibits the infection by both HFRS- and HPS-causing hantaviruses. The results of our study indicate the possibility of repurposing FDA-approved calcium channel blockers for the treatment of hantavirus infection, and they also indicate the need for further research in vivo.

Selective serotonin reuptake inhibitor (SSRI) antidepressants reduce COVID-19 infection: prospects for use

Purpose

The absence of specific treatments for COVID-19 leads to an intense global effort in the search for new therapeutic interventions and better clinical outcomes for patients. This review aimed to present a selection of accepted studies that reported the activity of antidepressant drugs belonging to the selective serotonin receptor inhibitor (SSRI) class for treating the novel coronavirus.

Methods

A search was performed in PubMed and SciELO databases using the following search strategies: [(coronavirus) OR (COVID) OR (SARS-CoV-2) AND (antidepressant) OR (serotonin) OR (selective serotonin receptor inhibitors)]. In the end, eleven articles were included. We also covered information obtained from ClinicalTrials.gov in our research.

Results

Although several clinical trials are ongoing, only a few drugs have been officially approved to treat the infection. Remdesivir, an antiviral drug, despite favorable preliminary results, has restricted the use due to the risk of toxicity and methodological flaws. Antidepressant drugs were able to reduce the risk of intubation or death related to COVID-19, decrease the need for intensive medical care, and severely inhibit viral titers by up to 99%. Among the SSRIs studied so far, fluoxetine and fluvoxamine have shown to be the most promising against SARS-CoV-2.

Conclusion

If successful, these drugs can substantially reduce hospitalization and mortality rates, as well as allow for fully outpatient treatment for mild-to-moderate infections. Thus, repositioning SSRIs can provide benefits when faced with a rapidly evolving pandemic such as COVID-19.

Enhancing autophagy in Alzheimer's disease through drug repositioning

Alzheimer's disease (AD) is one of the biggest human health threats due to increases in aging of the global population. Unfortunately, drugs for treating AD have been largely ineffective. Interestingly, downregulation of macroautophagy (autophagy) plays an essential role in AD pathogenesis. Therefore, targeting autophagy has drawn considerable attention as a therapeutic approach for the treatment of AD. However, developing new therapeutics is time-consuming and requires huge investments. One of the strategies currently under consideration for many diseases is "drug repositioning" or "drug repurposing". In this comprehensive review, we have provided an overview of the impact of autophagy on AD pathophysiology, reviewed the therapeutics that upregulate autophagy and are currently used in the treatment of other diseases, including cancers, and evaluated their repurposing as a possible treatment option for AD. In addition, we discussed the potential of applying nano-drug delivery to neurodegenerative diseases, such as AD, to overcome the challenge of crossing the blood brain barrier and specifically target molecules/pathways of interest with minimal side effects.

Therapeutic Strategies against Ebola Virus Infection

Since the 2014–2016 epidemic, Ebola virus (EBOV) has spread to several countries and has become a major threat to global health. EBOV is a risk group 4 pathogen, which imposes significant obstacles for the development of countermeasures against the virus. Efforts have been made to develop anti-EBOV immunization and therapeutics, with three vaccines and two antibody-based therapeutics approved in recent years. Nonetheless, the high fatality of Ebola virus disease highlights the need to continuously develop antiviral strategies for the future management of EBOV outbreaks in conjunction with vaccination programs. This review aims to highlight potential EBOV therapeutics and their target(s) of inhibition, serving as a summary of the literature to inform readers of the novel candidates available in the continued search for EBOV antivirals.

Difficulty in Repurposing Selective Serotonin Reuptake Inhibitors and Other Antidepressants with Functional Inhibition of Acid Sphingomyelinase in COVID-19 Infection

The rapid spread of COVID-19 has become a health emergency causing an urgent need for drug treatments to control the outbreak, especially in more vulnerable individuals. This is reinforced by the fact that prophylactic vaccines and neutralizing monoclonal antibodies may not be fully effective against emerging variants. Despite all efforts made by the scientific community, efficient therapeutic options currently remain scarce, either in the initial, as well as in the advanced forms of the disease. From retrospective observational studies and prospective clinical trials, selective serotonin reuptake inhibitors (SSRIs), and other antidepressants with functional inhibition of acid sphingomyelinase (FIASMAs), have emerged as potential treatments of COVID-19. This has led to some prematurely optimistic points of view, promoting a large prescription of fluvoxamine in patients with COVID-19, that we think should be reasonably tempered.

The Interactions among Hypertension, Cancer, and COVID-19: Perspectives from Ca2+/cAMP Signalling

BACKGROUND

The hypothesis that hypertension is clinically associated with an enhanced risk for developing cancer has been highlighted. However, the working principles involved in this link are still under intensive discussion. A correlation among inflammation, hypertension, and cancer could accurately describe the clinical link between these diseases. In addition, a dyshomeostasis of Ca²⁺ has been considered as a topic involved in both cancer and hypertension and inflammation. There is a strong link between Ca²⁺ signalling, e.g. enhanced Ca²⁺ signals, and inflammatory outcomes. cAMP also modulates pro- and anti-inflammatory outcomes: pharmaceuticals, which increase intracellular cAMP levels, can decrease the production of proinflammatory mediators and enhance the production of anti-inflammatory outcomes.

OBJECTIVE

This article has discussed the participation of Ca²⁺/cAMP signalling in the clinical association among inflammation, hypertension, and an enhanced risk for the development of cancer. In addition, considering coronavirus disease 2019 (COVID-19) is a rapidly evolving field, this article also reviews recent reports about the role of Ca²⁺ channel blockers for restoring Ca²⁺ signalling disruption due to COVID-19, including the relationship among COVID-19, cancer, and hypertension.

CONCLUSION

Understanding the association among these diseases could expand current pharmacotherapy, including that involving Ca²⁺ channel blockers and pharmaceuticals which rise cAMP levels.

Antidepressant and Antipsychotic Drugs Reduce Viral Infection by SARS-CoV-2 and Fluoxetine Shows Antiviral Activity Against the Novel Variants in vitro

Repurposing of currently available drugs is a valuable strategy to tackle the consequences of COVID-19. Recently, several studies have investigated the effect of psychoactive drugs on SARS-CoV-2 in cell culture models as well as in clinical practice. Our aim was to expand these studies and test some of these compounds against newly emerged variants. Several antidepressants and antipsychotic drugs with different primary mechanisms of action were tested in ACE2/TMPRSS2-expressing human embryonic kidney cells against the infection by SARS-CoV-2 spike protein-dependent pseudoviruses. Some of these compounds were also tested in human lung epithelial cell line, Calu-1, against the first wave (B.1) lineage of SARS-CoV-2 and the variants of concern, B.1.1.7, B.1.351, and B.1.617.2. Several clinically used antidepressants, including fluoxetine, citalopram, reboxetine, imipramine, as well as antipsychotic compounds chlorpromazine, flupenthixol, and pimozide inhibited the infection by pseudotyped viruses with minimal effects on cell viability. The antiviral action of several of these drugs was verified in Calu-1 cells against the B.1 lineage of SARS-CoV-2. By contrast, the anticonvulsant carbamazepine, and novel antidepressants ketamine, known as anesthetic at high doses, and its derivatives as well as MAO and phosphodiesterase inhibitors phenelzine and rolipram, respectively, showed no activity in the pseudovirus model. Furthermore, fluoxetine remained effective against pseudoviruses with common receptor binding domain mutations, N501Y, K417N, and E484K, as well as B.1.1.7 (alpha), B.1.351 (beta), and B.1.617.2 (delta) variants of SARS-CoV-2. Our study confirms previous data and extends information on the repurposing of these drugs to counteract SARS-CoV-2 infection including different variants of concern, however, extensive clinical studies must be performed to confirm our in vitro findings.

Modeling viral infection with tissue engineering: COVID-19 and the next outbreaks

Pandemics caused by respiratory viruses have impacted millions of lives and caused massive destruction to global infrastructure. With their emergence, it has become a priority to develop platforms to rapidly dissect host/pathogen interactions, develop diagnostics, and evaluate therapeutics. Traditional viral culture methods do not faithfully recapitulate key aspects of infection. Tissue engineering as a discipline has developed techniques to produce three-dimensional human tissues which can serve as platforms to study respiratory viruses in vitro. In this chapter, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been used as a representative respiratory virus motivating the use of tissue engineering to generate in vitro culture models. SARS-CoV-2 pathophysiology, traditional cell culture, tissue engineering-based cell culture, and future directions for the field are highlighted.

Neuroinflammation, diabetes, and COVID-19: Perspectives coming from Ca2+/cAMP signalling

BACKGROUND

A link between inflammatory diseases, e.g., epilepsy, dementia, diabetes, and COVID-19, has been established. For instance, observational studies with several individuals established that people with epilepsy have shown an enhanced incidence of manifesting dysfunctions related to cognition, e.g., dementia, while people with dementia have a higher incidence of manifesting epilepsy, thus an evident bidirectional relationship between epilepsy and dementia might occur. In addition, epilepsy commonly cooccurs in patients with diabetes, so an association between these two disorders is also discussed. Intriguingly, some reports have also observed a poor prognosis for people with both diabetes and COVID-19. It is recognized that a dyshomeostasis of both Ca2+ and cAMP signalling pathways could be a molecular connection for these disorders.

OBJECTIVES

Therefore, clarifying this clinical relationship among epilepsy, dementia, diabetes, and COVID-19 may outcome in novel hypotheses for identifying the etiology of these disorders.

Drug Combinations as a First Line of Defense against Coronaviruses and Other Emerging Viruses

The world was unprepared for coronavirus disease 2019 (COVID-19) and remains ill-equipped for future pandemics. While unprecedented strides have been made developing vaccines and treatments for COVID-19, there remains a need for highly effective and widely available regimens for ambulatory use for novel coronaviruses and other viral pathogens. We posit that a priority is to develop pan-family drug cocktails to enhance potency, limit toxicity, and avoid drug resistance. We urge cocktail development for all viruses with pandemic potential both in the short term (<1 to 2 years) and longer term with pairs of drugs in advanced clinical testing or repurposed agents approved for other indications. While significant efforts were launched against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in vitro and in the clinic, many studies employed solo drugs and had disappointing results. Here, we review drug combination studies against SARS-CoV-2 and other viruses and introduce a model-driven approach to assess drug pairs with the highest likelihood of clinical efficacy. Where component agents lack sufficient potency, we advocate for synergistic combinations to achieve therapeutic levels. We also discuss issues that stymied therapeutic progress against COVID-19, including testing of agents with low likelihood of efficacy late in clinical disease and lack of focus on developing virologic surrogate endpoints. There is a need to expedite efficient clinical trials testing drug combinations that could be taken at home by recently infected individuals and exposed contacts as early as possible during the next pandemic, whether caused by a coronavirus or another viral pathogen. The approach herein represents a proactive plan for global viral pandemic preparedness.

Analysis of the impact of antidepressants and other medications on COVID-19 infection risk in a chronic psychiatric in-patient cohort

BACKGROUND

During the first wave of the coronavirus disease 2019 (COVID-19) pandemic, patients with confirmed cases in New York State accounted for roughly 25% of total US cases, with psychiatric hospital in-patients at particularly high risk for COVID-19 infection.

AIMS

The beneficial effects of mental health medications, such as selective serotonin reuptake inhibitors (SSRIs), on the severity of COVID-19 disease outcomes have been documented. Protective effects against infection have also been suggested for these medications. We therefore tested the hypothesis that medication use modifies the risk of COVID-19 infection in a long-stay, chronic in-patient psychiatry setting, where the potential for exposure was likely uniform across the facility, and where these medications were routinely prescribed.

METHOD

This was a retrospective cohort study of an adult psychiatric facility operated by the New York State Office of Mental Health. Current medication information and COVID-19 status was collected from electronic medical records for 165 people who were in-patients during the period January to July 2020, and logistic regression was employed to model the main effects of medication use on COVID-19 infection.

RESULTS

A significant protective association was observed between antidepressant use and COVID-19 infection (odds ratio (OR) = 0.33, 95% CI 0.15-0.70, adjusted P < 0.05). Analysis of individual antidepressant classes showed that SSRI, serotonin-norepinephrine reuptake inhibitor and the serotonin-2 antagonist reuptake inhibitor classes of antidepressants, drove this protective effect. Exploratory analyses of individual antidepressants demonstrated an association between lower risk of infection and fluoxetine use (P = 0.023), as well as trazodone use (P = 0.001).

CONCLUSIONS

The novel finding of reduced COVID-19 infection risk for psychiatric in-patients taking antidepressants, suggests that antidepressants may be an important weapon in the continued fight against COVID-19 disease. This finding may become particularly salient for in-patient settings if vaccine-resistant strains of the virus appear.

Investigating the binding affinity, interaction, and structure-activity-relationship of 76 prescription antiviral drugs targeting RdRp and Mpro of SARS-CoV-2

SARS-CoV-2 virus outbreak poses a major threat to humans worldwide due to its highly contagious nature. In this study, molecular docking, molecular dynamics, and structure-activity relationship are employed to assess the binding affinity and interaction of 76 prescription drugs against RNA dependent RNA polymerase (RdRp) and Main Protease (Mpro) of SARS-CoV-2. The RNA-dependent RNA polymerase is a vital enzyme of coronavirus replication/transcription complex whereas the main protease acts on the proteolysis of replicase polyproteins. Among 76 prescription antiviral drugs, four drugs (Raltegravir, Simeprevir, Cobicistat, and Daclatasvir) that are previously used for human immunodeficiency virus (HIV), hepatitis C virus (HCV), Ebola, and Marburg virus show higher binding energy and strong interaction with active sites of the receptor proteins. To explore the dynamic nature of the interaction, 100 ns molecular dynamics (MD) simulation is performed on the selected protein-drug complexes and apo-protein. Binding free energy of the selected drugs is performed by MM/PBSA. Besides docking and dynamics, partial least square (PLS) regression method is applied for the quantitative structure activity relationship to generate and predict the binding energy for drugs. PLS regression satisfactorily predicts the binding energy of the effective antiviral drugs compared to binding energy achieved from molecular docking with a precision of 85%. This study highly recommends researchers to screen these potential drugs in vitro and in vivo against SARS-CoV-2 for further validation of utility.

Dysregulation of host cell calcium signaling during viral infections: Emerging paradigm with high clinical relevance

Viral infections are one of the leading causes of human illness. Viruses take over host cell signaling cascades for their replication and infection. Calcium (Ca2+) is a versatile and ubiquitous second messenger that modulates plethora of cellular functions. In last two decades, a critical role of host cell Ca2+ signaling in modulating viral infections has emerged. Furthermore, recent literature clearly implicates a vital role for the organellar Ca2+ dynamics (influx and efflux across organelles) in regulating virus entry, replication and severity of the infection. Therefore, it is not surprising that a number of viral infections including current SARS-CoV-2 driven COVID-19 pandemic are associated with dysregulated Ca2+ homeostasis. The focus of this review is to first discuss the role of host cell Ca2+ signaling in viral entry, replication and egress. We further deliberate on emerging literature demonstrating hijacking of the host cell Ca2+ dynamics by viruses. In particular, a variety of viruses including SARS-CoV-2 modulate lysosomal and cytosolic Ca2+ signaling for host cell entry and replication. Moreover, we delve into the recent studies, which have demonstrated the potential of several FDA-approved drugs targeting Ca2+ handling machinery in inhibiting viral infections. Importantly, we discuss the prospective of targeting intracellular Ca2+ signaling for better management and treatment of viral pathogenesis including COVID-19. Finally, we highlight the key outstanding questions in the field that demand critical and timely attention.

Antiviral fungal metabolites and some insights into their contribution to the current COVID-19 pandemic

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak, which started in late 2019, drove the scientific community to conduct innovative research to contain the spread of the pandemic and to care for those already affected. Since then, the search for new drugs that are effective against the virus has been strengthened. Featuring a relatively low cost of production under well-defined methods of cultivation, fungi have been providing a diversity of antiviral metabolites with unprecedented chemical structures. In this review, we present viral RNA infections highlighting SARS-CoV-2 morphogenesis and the infectious cycle, the targets of known antiviral drugs, and current developments in this area such as drug repurposing. We also explored the metabolic adaptability of fungi during fermentation to produce metabolites active against RNA viruses, along with their chemical structures, and mechanisms of action. Finally, the state of the art of research on SARS-CoV-2 inhibitors of fungal origin is reported, highlighting the metabolites selected by docking studies.

Targeting Two-Pore Channels: Current Progress and Future Challenges

Two-pore channels (TPCs) are cation-permeable channels located on endolysosomal membranes and important mediators of intracellular Ca²⁺ signalling. TPCs are involved in various pathophysiological processes, including cell growth and development, metabolism, and cancer progression. Most studies of TPCs have used TPC^–/– cell or whole-animal models, or Ned-19, an indirect inhibitor. The TPC activation mechanism remains controversial, which has made it difficult to develop selective modulators. Recent studies of TPC structure and their interactomes are aiding the development of direct pharmacological modulators. This process is still in its infancy, but will facilitate future research and TPC targeting for therapeutical purposes. Here, we review the progress of current research into TPCs, including recent insights into their structures, functional roles, mechanisms of activation, and pharmacological modulators.

Two-pore channel (TPC)-mediated endolysosomal Ca²⁺ signalling regulates a variety of processes, including cell proliferation, differentiation, metabolism, viral infection, and cardiac function.

Despite the well-established model that TPCs are Ca²⁺-selective channels indirectly activated by nicotinic acid adenine dinucleotide phosphate (NAADP), it has also been proposed that TPCs as Na⁺ channels are activated directly by phosphatidylinositol 3,5-bisphosphate [PI(3,5)P₂].

3D structures of mouse TPC1 and human TPC2 were recently determined, which made it possible for structure-based virtual screening methods to identify pharmacological modulators of TPC.

Recent identification by high-throughput screens of pharmacological modulators that target TPCs will help reveal the molecular mechanisms underlying the role of endolysosomal Ca²⁺ signalling in different pathophysiological processes, and to develop new therapeutics.

Comprehensive Consensus Analysis of SARS-CoV-2 Drug Repurposing Campaigns

The current COVID-19 pandemic has elicited extensive repurposing efforts (both small and large scale) to rapidly identify COVID-19 treatments among approved drugs. Herein, we provide a literature review of large-scale SARS-CoV-2 antiviral drug repurposing efforts and highlight a marked lack of consistent potency reporting. This variability indicates the importance of standardizing best practices-including the use of relevant cell lines, viral isolates, and validated screening protocols. We further surveyed available biochemical and virtual screening studies against SARS-CoV-2 targets (Spike, ACE2, RdRp, PLpro, and Mpro) and discuss repurposing candidates exhibiting consistent activity across diverse, triaging assays and predictive models. Moreover, we examine repurposed drugs and their efficacy against COVID-19 and the outcomes of representative repurposed drugs in clinical trials. Finally, we propose a drug repurposing pipeline to encourage the implementation of standard methods to fast-track the discovery of candidates and to ensure reproducible results.

Repurposing Psychotropic Agents for Viral Disorders: Beyond Covid

Recent reports have highlighted the possible role of the antipsychotic chlorpromazine and the antidepressant fluvoxamine as anti-coronavirus disease 2019 (COVID-19) agents. The objective of this narrative review is to explore what is known about the activity of psychotropic medications against viruses in addition to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). PubMed was queried for "drug repurposing, antiviral activity," and for "antiviral activity" with "psychotropic drugs" and individual agents, through November 2020. Of more than 100 psychotropic agents, 37 drugs, including 27 with a history of pediatric use were identified, which had been studied in the preclinical setting and found to have activity against viruses which are human pathogens. Effects were evaluated by type of virus and by category of psychotropic agent. Activity was identified both against viruses known to cause epidemics such as SARS-CoV-2 and Ebola and against those that are the cause of rare disorders such as Human Papillomatosis Virus-related respiratory papillomatosis. Individual drugs and classes of psychotropics often had activity against multiple viruses, with promiscuity explained by shared viral or cellular targets. Safety profiles of psychotropics may be more tolerable in this context than when they are used long-term in the setting of psychiatric illness. Nonetheless, translation of in vitro results to the clinical arena has been slow. Psychotropic medications as a class deserve further study, including in clinical trials for repurposing as antiviral drugs for children and adults.

A human-airway-on-a-chip for the rapid identification of candidate antiviral therapeutics and prophylactics

The rapid repurposing of antivirals is particularly pressing during pandemics. However, rapid assays for assessing candidate drugs typically involve in vitro screens and cell lines that do not recapitulate human physiology at the tissue and organ levels. Here we show that a microfluidic bronchial-airway-on-a-chip lined by highly differentiated human bronchial-airway epithelium and pulmonary endothelium can model viral infection, strain-dependent virulence, cytokine production and the recruitment of circulating immune cells. In airway chips infected with influenza A, the co-administration of nafamostat with oseltamivir doubled the treatment-time window for oseltamivir. In chips infected with pseudotyped severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), clinically relevant doses of the antimalarial drug amodiaquine inhibited infection but clinical doses of hydroxychloroquine and other antiviral drugs that inhibit the entry of pseudotyped SARS-CoV-2 in cell lines under static conditions did not. We also show that amodiaquine showed substantial prophylactic and therapeutic activities in hamsters challenged with native SARS-CoV-2. The human airway-on-a-chip may accelerate the identification of therapeutics and prophylactics with repurposing potential.

Drug-induced phospholipidosis confounds drug repurposing for SARS-CoV-2

Repurposing drugs as treatments for COVID-19, the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has drawn much attention. Beginning with sigma receptor ligands and expanding to other drugs from screening in the field, we became concerned that phospholipidosis was a shared mechanism underlying the antiviral activity of many repurposed drugs. For all of the 23 cationic amphiphilic drugs we tested, including hydroxychloroquine, azithromycin, amiodarone, and four others already in clinical trials, phospholipidosis was monotonically correlated with antiviral efficacy. Conversely, drugs active against the same targets that did not induce phospholipidosis were not antiviral. Phospholipidosis depends on the physicochemical properties of drugs and does not reflect specific target-based activities-rather, it may be considered a toxic confound in early drug discovery. Early detection of phospholipidosis could eliminate these artifacts, enabling a focus on molecules with therapeutic potential.

Screening and Identification of Lujo Virus Inhibitors Using a Recombinant Reporter Virus Platform

Lujo virus (LUJV), a highly pathogenic arenavirus, was first identified in 2008 in Zambia. To aid the identification of effective therapeutics for LUJV, we developed a recombinant reporter virus system, confirming reporter LUJV comparability with wild-type virus and its utility in high-throughput antiviral screening assays. Using this system, we evaluated compounds with known and unknown efficacy against related arenaviruses, with the aim of identifying LUJV-specific and potential new pan-arenavirus antivirals. We identified six compounds demonstrating robust anti-LUJV activity, including several compounds with previously reported activity against other arenaviruses. These data provide critical evidence for developing broad-spectrum antivirals against high-consequence arenaviruses.

Potential pharmacological strategies targeting the Niemann-Pick C1 receptor and Ebola virus glycoprotein interaction

Niemann-Pick C1 (NPC1) receptor is an intracellular protein located in late endosomes and lysosomes whose main function is to regulate intracellular cholesterol trafficking. Besides being postulated as necessary for the infection of highly pathogenic viruses in which the integrity of cholesterol transport is required, this protein also allows the entry of the Ebola virus (EBOV) into the host cells acting as an intracellular receptor. EBOV glycoprotein (EBOV-GP) interaction with NPC1 at the endosomal membrane triggers the release of the viral material into the host cell, starting the infective cycle. Disruption of the NPC1/EBOV-GP interaction could represent an attractive strategy for the development of drugs aimed at inhibiting viral entry and thus infection. Some of the today available EBOV inhibitors were proposed to interrupt this interaction, but molecular and structural details about their mode of action are still preliminary thus more efforts are needed to properly address these points. Here, we provide a critical discussion of the potential of NPC1 and its interaction with EBOV-GP as a therapeutic target for viral infections.

Estrogen Receptor Modulators in Viral Infections Such as SARS-CoV-2: Therapeutic Consequences

COVID-19 is a pandemic respiratory disease caused by the SARS-CoV-2 coronavirus. The worldwide epidemiologic data showed higher mortality in males compared to females, suggesting a hypothesis about the protective effect of estrogens against severe disease progression with the ultimate end being patient's death. This article summarizes the current knowledge regarding the potential effect of estrogens and other modulators of estrogen receptors on COVID-19. While estrogen receptor activation shows complex effects on the patient's organism, such as an influence on the cardiovascular/pulmonary/immune system which includes lower production of cytokines responsible for the cytokine storm, the receptor-independent effects directly inhibits viral replication. Furthermore, it inhibits the interaction of IL-6 with its receptor complex. Interestingly, in addition to natural hormones, phytestrogens and even synthetic molecules are able to interact with the estrogen receptor and exhibit some anti-COVID-19 activity. From this point of view, estrogen receptor modulators have the potential to be included in the anti-COVID-19 therapeutic arsenal.

Drug repurposing of selective serotonin reuptake inhibitors: Could these drugs help fight COVID-19 and save lives?

The current 2019 novel coronavirus disease (COVID-19), an emerging infectious disease, is undoubtedly the most challenging pandemic in the 21st century. A total of 92,977,768 confirmed cases of COVID-19 and 1,991,289 deaths were reported globally up to January 14, 2021. COVID-19 also affects people's mental health and quality of life. At present, there is no effective therapeutic strategy for the management of this disease. Therefore, in the absence of a specific vaccine or curative treatment, it is an urgent need to identify safe, effective and globally available drugs for reducing COVID-19 morbidity and fatalities. In this review, we focus on selective serotonin reuptake inhibitors (SSRIs: a class of antidepressant drugs with widespread availability and an optimal tolerability profile) that can potentially be repurposed for COVID-19 and are currently being tested in clinical trials. We also summarize the existing literature on what is known about the link between serotonin (5-HT) and the immune system. From the evidence reviewed here, we propose fluoxetine as an adjuvant therapeutic agent for COVID-19 based on its known immunomodulatory, anti-inflammatory and antiviral properties. Fluoxetine may potentially reduce pro-inflammatory chemokine/cytokines levels (such as CCL-2, IL-6, and TNF-α) in COVID-19 patients. Furthermore, fluoxetine may help to attenuate neurological complications of COVID-19.

Biological activity-based modeling identifies antiviral leads against SARS-CoV-2

Computational approaches for drug discovery, such as quantitative structure-activity relationship, rely on structural similarities of small molecules to infer biological activity but are often limited to identifying new drug candidates in the chemical spaces close to known ligands. Here we report a biological activity-based modeling (BABM) approach, in which compound activity profiles established across multiple assays are used as signatures to predict compound activity in other assays or against a new target. This approach was validated by identifying candidate antivirals for Zika and Ebola viruses based on high-throughput screening data. BABM models were then applied to predict 311 compounds with potential activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Of the predicted compounds, 32% had antiviral activity in a cell culture live virus assay, the most potent compounds showing a half-maximal inhibitory concentration in the nanomolar range. Most of the confirmed anti-SARS-CoV-2 compounds were found to be viral entry inhibitors and/or autophagy modulators. The confirmed compounds have the potential to be further developed into anti-SARS-CoV-2 therapies.

Antidepressants and Antipsychotic Agents as Repurposable Oncological Drug Candidates

Drug repurposing, also known as drug repositioning/reprofiling, is a relatively new strategy for the identification of alternative uses of well-known therapeutics that are outside the scope of their original medical indications. Such an approach might entail a number of advantages compared to standard de novo drug development, including less time needed to introduce the drug to the market, and lower costs. The group of compounds that could be considered as promising candidates for repurposing in oncology include the central nervous system drugs, especially selected antidepressant and antipsychotic agents. In this article, we provide an overview of some antidepressants (citalopram, fluoxetine, paroxetine, sertraline) and antipsychotics (chlorpromazine, pimozide, thioridazine, trifluoperazine) that have the potential to be repurposed as novel chemotherapeutics in cancer treatment, as they have been found to exhibit preventive and/or therapeutic action in cancer patients. Nevertheless, although drug repurposing seems to be an attractive strategy to search for oncological drugs, we would like to clearly indicate that it should not replace the search for new lead structures, but only complement de novo drug development.

Cyclodextrins in the antiviral therapy

The main antiviral drug-cyclodextrin interactions, changes in physicochemical and physiological properties of the most commonly used virucides are summarized. The potential complexation of antiviral molecules against the SARS-Cov2 also pointed out the lack of detailed information in designing effective and general medicines against viral infections. The principal problem of the current molecules is the 3D structures of the currently active compounds. Improving the solubility or bioavailability of antiviral molecules is possible, however, there is no universal solution, and the complexation experiments dominantly use the already approved cyclodextrin derivatives. This review discusses the basic properties of the different cyclodextrin derivatives, their potential in antiviral formulations, and the prevention and treatment of viral infections. The biologically active new cyclodextrin derivatives are also discussed.

Targeting Ebola virus replication through pharmaceutical intervention

Introduction. The consistent emergence/reemergence of filoviruses into a world that previously lacked an approved pharmaceutical intervention parallels an experience repeatedly played-out for most other emerging pathogenic zoonotic viruses. Investment to preemptively develop effective and low-cost prophylactic and therapeutic interventions against viruses that have high potential for emergence and societal impact should be a priority.Areas covered. Candidate drugs can be characterized into those that interfere with cellular processes required for Ebola virus (EBOV) replication (host-directed), and those that directly target virally encoded functions (direct-acting). We discuss strategies to identify pharmaceutical interventions for EBOV infections. PubMed/Web of Science databases were searched to establish a detailed catalog of these interventions.Expert opinion. Many drug candidates show promising in vitro inhibitory activity, but experience with EBOV shows the general lack of translation to in vivo efficacy for host-directed repurposed drugs. Better translation is seen for direct-acting antivirals, in particular monoclonal antibodies. The FDA-approved monoclonal antibody treatment, Inmazeb™ is a success story that could be improved in terms of impact on EBOV-associated disease and mortality, possibly by combination with other direct-acting agents targeting distinct aspects of the viral replication cycle. Costs need to be addressed given EBOV emergence primarily in under-resourced countries.

Synthesis and Antiviral Activity of Camphene Derivatives against Different Types of Viruses

To date, the 'one bug-one drug' approach to antiviral drug development cannot effectively respond to the constant threat posed by an increasing diversity of viruses causing outbreaks of viral infections that turn out to be pathogenic for humans. Evidently, there is an urgent need for new strategies to develop efficient antiviral agents with broad-spectrum activities. In this paper, we identified camphene derivatives that showed broad antiviral activities in vitro against a panel of enveloped pathogenic viruses, including influenza virus A/PR/8/34 (H1N1), Ebola virus (EBOV), and the Hantaan virus. The lead-compound 2a, with pyrrolidine cycle in its structure, displayed antiviral activity against influenza virus (IC50 = 45.3 µM), Ebola pseudotype viruses (IC50 = 0.12 µM), and authentic EBOV (IC50 = 18.3 µM), as well as against pseudoviruses with Hantaan virus Gn-Gc glycoprotein (IC50 = 9.1 µM). The results of antiviral activity studies using pseudotype viruses and molecular modeling suggest that surface proteins of the viruses required for the fusion process between viral and cellular membranes are the likely target of compound 2a. The key structural fragments responsible for efficient binding are the bicyclic natural framework and the nitrogen atom. These data encourage us to conduct further investigations using bicyclic monoterpenoids as a scaffold for the rational design of membrane-fusion targeting inhibitors.

Outcomes of Hospitalized COVID-19 Patients Receiving Renin Angiotensin System Blockers and Calcium Channel Blockers

INTRODUCTION

Use of certain antihypertensive medications has been an area of interest during the COVID-19 pandemic, and several hypotheses have been developed regarding the effects of renin-angiotensin system blockers as well as calcium channel blockers in those infected with COVID-19. We seek to determine the association between exposure to ACEI, ARB, and CCB and outcomes in those admitted to the hospital with COVID-19 infection.

METHODS

This retrospective cohort study included 841 adult patients hospitalized with COVID-19 infection at the University of Chicago Medical Center between March 25 and June 22, 2020. Out of these 841, 453 patients had a personal history of hypertension. For the first part, we evaluated primary outcomes of in-hospital mortality and ICU admission in hospitalized COVID-19 patients based on their exposure to particular medications regardless of a personal history of hypertension and compared them with those who were not on these medications. For the second part, we evaluated the aforementioned outcomes in 453 patients with a personal history of hypertension based on their medication exposure. Secondary outcomes of length of stay, readmission rate, and new-onset dialysis requirement were also compared across the study groups.

RESULTS

Out of 841 patients, 111 (13.19%) were on ACEI/ARB (median age: 66.1, SD 15.4; 52.25% females) and 730 (86.80%) were not on them (median age: 56.6, SD 20.3; 50.14% females), while 277 (32.93%) used CCB (median age: 64.6, SD 15.2; 57.04% females) and 564 (67.06%) did not use CCB (median age: 54.6, SD 21.2; 47.16% females). After adjusting for demographics and covariates, neither ACEI/ARB nor CCB exposure was associated with any effect on mortality, but ACEI/ARB exposure was associated with 42% reduction in risk of ICU admissions (OR 0.58, 95% CI [0.35, 0.95], p value 0.03). In addition, combined use of ACEI/ARB and CCB was associated with statistically significant (45%) reduction in ICU admission (OR 0.55, 95% CI [0.32, 0.94], p value 0.029). Out of 453 patients with a personal history of hypertension, 85 (18.76%) were taking ACEI/ARB (median age 65, SD 15.6; 56.47% females) and 368 (81.24%) were not on ACEI/ARB (median age 62.8, SD 16.4; 54.89% females), while 208 (45.92%) out of 453 were on CCB (median age 65; SD 14.8; 60.1% females) and 245 (54.08%) were not on CCB (median age 61.7, SD 17.3; 51.02% females). In the fully adjusted model in this group, ACEI use was associated with 71% reduction in in-house mortality (OR 0.29, 95% CI [0.09, 0.93], p value 0.03).

DISCUSSION/CONCLUSION

Among all hospitalized patients with COVID-19 infection, exposure to ACEI/ARB, as well as combined exposure to ACEI/ARB and CCB, were associated with reduced incidence of ICU admissions. In those admitted patients who had a personal history of hypertension, there was a trend towards reduced in-hospital mortality in those exposed to ACEI.

Phospholipidosis is a shared mechanism underlying the in vitro antiviral activity of many repurposed drugs against SARS-CoV-2

Repurposing drugs as treatments for COVID-19 has drawn much attention. A common strategy has been to screen for established drugs, typically developed for other indications, that are antiviral in cells or organisms. Intriguingly, most of the drugs that have emerged from these campaigns, though diverse in structure, share a common physical property: cationic amphiphilicity. Provoked by the similarity of these repurposed drugs to those inducing phospholipidosis, a well-known drug side effect, we investigated phospholipidosis as a mechanism for antiviral activity. We tested 23 cationic amphiphilic drugs-including those from phenotypic screens and others that we ourselves had found-for induction of phospholipidosis in cell culture. We found that most of the repurposed drugs, which included hydroxychloroquine, azithromycin, amiodarone, and four others that have already progressed to clinical trials, induced phospholipidosis in the same concentration range as their antiviral activity; indeed, there was a strong monotonic correlation between antiviral efficacy and the magnitude of the phospholipidosis. Conversely, drugs active against the same targets that did not induce phospholipidosis were not antiviral. Phospholipidosis depends on the gross physical properties of drugs, and does not reflect specific target-based activities, rather it may be considered a confound in early drug discovery. Understanding its role in infection, and detecting its effects rapidly, will allow the community to better distinguish between drugs and lead compounds that more directly impact COVID-19 from the large proportion of molecules that manifest this confounding effect, saving much time, effort and cost.

Inhibition of Arenaviruses by Combinations of Orally Available Approved Drugs

Neglected diseases caused by arenaviruses such as Lassa virus (LASV) and filoviruses like Ebola virus (EBOV) primarily afflict resource-limited countries, where antiviral drug development is often minimal. Previous studies have shown that many approved drugs developed for other clinical indications inhibit EBOV and LASV and that combinations of these drugs provide synergistic suppression of EBOV, often by blocking discrete steps in virus entry. We hypothesize that repurposing of combinations of orally administered approved drugs provides effective suppression of arenaviruses. In this report, we demonstrate that arbidol, an approved influenza antiviral previously shown to inhibit EBOV, LASV, and many other viruses, inhibits murine leukemia virus (MLV) reporter viruses pseudotyped with the fusion glycoproteins (GPs) of other arenaviruses (Junin virus [JUNV], lymphocytic choriomeningitis virus [LCMV], and Pichinde virus [PICV]). Arbidol and other approved drugs, including aripiprazole, amodiaquine, sertraline, and niclosamide, also inhibit infection of cells by infectious PICV, and arbidol, sertraline, and niclosamide inhibit infectious LASV. Combining arbidol with aripiprazole or sertraline results in the synergistic suppression of LASV and JUNV GP-bearing pseudoviruses. This proof-of-concept study shows that arenavirus infection in vitro can be synergistically inhibited by combinations of approved drugs. This approach may lead to a proactive strategy with which to prepare for and control known and new arenavirus outbreaks.

Formulation, Stability, Pharmacokinetic, and Modeling Studies for Tests of Synergistic Combinations of Orally Available Approved Drugs against Ebola Virus In Vivo

Outbreaks of Ebola ebolavirus (EBOV) have been associated with high morbidity and mortality. Milestones have been reached recently in the management of EBOV disease (EVD) with licensure of an EBOV vaccine and two monoclonal antibody therapies. However, neither vaccines nor therapies are available for other disease-causing filoviruses. In preparation for such outbreaks, and for more facile and cost-effective management of EVD, we seek a cocktail containing orally available and room temperature stable drugs with strong activity against multiple filoviruses. We previously showed that (bepridil + sertraline) and (sertraline + toremifene) synergistically suppress EBOV in cell cultures. Here, we describe steps towards testing these combinations in a mouse model of EVD. We identified a vehicle suitable for oral delivery of the component drugs and determined that, thus formulated the drugs are equally active against EBOV as preparations in DMSO, and they maintain activity upon storage in solution for up to seven days. Pharmacokinetic (PK) studies indicated that the drugs in the oral delivery vehicle are well tolerated in mice at the highest doses tested. Collectively the data support advancement of these combinations to tests for synergy in a mouse model of EVD. Moreover, mathematical modeling based on human oral PK projects that the combinations would be more active in humans than their component single drugs.

The Anti-inflammatory Effect of the Tricyclic Antidepressant Clomipramine and Its High Penetration in the Brain Might Be Useful to Prevent the Psychiatric Consequences of SARS-CoV-2 Infection

At the time of writing (December 2020), coronavirus disease 2019 (COVID-19) has already caused more than one million deaths worldwide, and therefore, it is imperative to find effective treatments. The “cytokine storm” induced by Severe Acute Respiratory Syndrome-Coronavirus type 2 (SARS-CoV-2) is a good target to prevent disease worsening, as indicated by the results obtained with tocilizumab and dexamethasone. SARS-CoV-2 can also invade the brain and cause neuro-inflammation with dramatic neurological manifestations, such as viral encephalitis. This could lead to potentially incapacitating long-term consequences, such as the development of psychiatric disorders, as previously observed with SARS-CoV. Several pathways/mechanisms could explain the link between viral infection and development of psychiatric diseases, especially neuro-inflammation induced by SARS-CoV-2. Therefore, it is important to find molecules with anti-inflammatory properties that penetrate easily into the brain. For instance, some antidepressants have anti-inflammatory action and pass easily through the blood brain barrier. Among them, clomipramine has shown very strong anti-inflammatory properties in vitro, in vivo (animal models) and human studies, especially in the brain. The aim of this review is to discuss the potential application of clomipramine to prevent post-infectious mental complications. Repositioning and testing antidepressants for COVID-19 management could help to reduce peripheral and especially central inflammation and to prevent the acute and particularly the long-term consequences of SARS-CoV-2 infection.

Association between Functional Inhibitors of Acid Sphingomyelinase (FIASMAs) and Reduced Risk of Death in COVID-19 Patients: A Retrospective Cohort Study

Given the current scarcity of curative treatment of COVID-19, the search for an effective treatment modality among all available medications has become a priority. This study aimed at investigating the role of functional inhibitors of acid sphingomyelinase (FIASMAs) on in-hospital COVID-19 mortality. In this retrospective cohort study, we included adult in-patients with laboratory-confirmed COVID-19 between 1 March 2020 and 31 August 2020 with definite outcomes (discharged hospital or deceased) from Erasme Hospital (Brussels, Belgium). We used univariate and multivariate logistic regression models to explore the risk factors associated with in-hospital mortality. We included 350 patients (205 males, 145 females) with a mean age of 63.24 years (SD = 17.4, range: 21-96 years). Seventy-two patients died in the hospital and 278 were discharged. The four most common comorbidities were hypertension (184, 52.6%), chronic cardiac disease (110, 31.4%), obesity (96, 27.8%) and diabetes (95, 27.1%). Ninety-three participants (26.6%) received a long-term prescription for FIASMAs. Among these, 60 (64.5%) received amlodipine. For FIASMAs status, multivariable regression showed increasing odds ratio (OR) for in-hospital deaths associated with older age (OR 1.05, 95% CI: 1.02-1.07; p = 0.00015), and higher prevalence of malignant neoplasm (OR 2.09, 95% CI: 1.03-4.22; p = 0.039). Nonsignificant decreasing OR (0.53, 95% CI: 0.27-1.04; p = 0.064) was reported for FIASMA status. For amlodipine status, multivariable regression revealed increasing OR of in-hospital deaths associated with older age (OR 1.04, 95% CI: 1.02-1.07; p = 0.0009), higher prevalence of hypertension (OR 2.78, 95% CI: 1.33-5.79; p = 0.0062) and higher prevalence of malignant neoplasm (OR 2.71, 95% CI: 1.23-5.97; p = 0.013), then secondarily decreasing OR of in-hospital death associated with long-term treatment with amlodipine (OR 0.24, 95% CI: 0.09-0.62; p = 0.0031). Chronic treatment with amlodipine could be significantly associated with low mortality of COVID-19 in-patients.

Identification of candidate repurposable drugs to combat COVID-19 using a signature-based approach

The COVID-19 pandemic caused by the novel SARS-CoV-2 is more contagious than other coronaviruses and has higher rates of mortality than influenza. Identification of effective therapeutics is a crucial tool to treat those infected with SARS-CoV-2 and limit the spread of this novel disease globally. We deployed a bioinformatics workflow to identify candidate drugs for the treatment of COVID-19. Using an "omics" repository, the Library of Integrated Network-Based Cellular Signatures (LINCS), we simultaneously probed transcriptomic signatures of putative COVID-19 drugs and publicly available SARS-CoV-2 infected cell lines to identify novel therapeutics. We identified a shortlist of 20 candidate drugs: 8 are already under trial for the treatment of COVID-19, the remaining 12 have antiviral properties and 6 have antiviral efficacy against coronaviruses specifically, in vitro. All candidate drugs are either FDA approved or are under investigation. Our candidate drug findings are discordant with (i.e., reverse) SARS-CoV-2 transcriptome signatures generated in vitro, and a subset are also identified in transcriptome signatures generated from COVID-19 patient samples, like the MEK inhibitor selumetinib. Overall, our findings provide additional support for drugs that are already being explored as therapeutic agents for the treatment of COVID-19 and identify promising novel targets that are worthy of further investigation.