Rapid discovery and classification of inhibitors of coronavirus infection by pseudovirus screen and amplified luminescence proximity homogeneous assay

Unraveling the structural and functional dimensions of SARS-CoV2 proteins in the context of COVID-19 pathogenesis and therapeutics

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) has emerged as the causative agent behind the global pandemic of Coronavirus Disease 2019 (COVID-19). As the scientific community strives to comprehend the intricate workings of this virus, a fundamental aspect lies in deciphering the myriad proteins it expresses. This knowledge is pivotal in unraveling the complexities of the viral machinery and devising targeted therapeutic interventions. The proteomic landscape of SARS-CoV2 encompasses structural, non-structural, and open-reading frame proteins, each playing crucial roles in viral replication, host interactions, and the pathogenesis of COVID-19. This comprehensive review aims to provide an updated and detailed examination of the structural and functional attributes of SARS-CoV2 proteins. By exploring the intricate molecular architecture, we have highlighted the significance of these proteins in viral biology. Insights into their roles and interplay contribute to a deeper understanding of the virus's mechanisms, thereby paving the way for the development of effective therapeutic strategies. As the global scientific community strives to combat the ongoing pandemic, this synthesis of knowledge on SARS-CoV2 proteins serves as a valuable resource, fostering informed approaches toward mitigating the impact of COVID-19 and advancing the frontier of antiviral research.

Retrospective Analysis of the Effect of Postmenopausal Women Medications on SARS-CoV-2 Infection Progression

Since the beginning of the COVID-19 pandemic, it has been evident that women and young people were less susceptible to severe infections compared to males. In a previous study, we observed a reduced prevalence of SARS-CoV-2 infections in hormonal-driven breast cancer patients undergoing SERM (selective estrogen receptor modulator) therapy with respect to other treatments inhibiting estrogen synthesis. In addition to being used in anticancer therapy, SERMs are also prescribed for postmenopausal osteoporosis prevention and treatment. Therefore, in this study, a retrospective analysis of the clinical outcomes of SARS-CoV-2 infections in a population of women over 50 years who were treated for the management of menopausal symptoms was performed. SARS-CoV-2 infections, hospitalizations, and death rates were evaluated in women residing in the Italian north-eastern Veneto Region who were undergoing treatment with Estrogen Modulators (EMs); Estrogen or Progestin, and their combination (EPs); Bisphosphonates (BIs); or cholecalciferol (vitamin D3) ± calcium supplementation (CC). The final cohort study included 124,393 women, of whom 6412 were found to be SARS-CoV-2 infected (CoV2+ve). The results indicated that only women treated with vitamin D3 alone or in combination with calcium showed a significant reduction in their SARS-CoV-2 infection risk by 26% (OR 0.74; 95%CI 0.60-0.91). On the other hand, an increased risk of hospitalization (OR 2.69; 95%CI 1.77-4.07) was shown for the same treatments. The results highlighted in this work contribute to shedding some light on the widely debated role of vitamin D in the prevention of SARS-CoV-2 infections and the disease's treatment.

Docking and other computing tools in drug design against SARS-CoV-2

The use of computer simulation methods has become an indispensable component in identifying drugs against the SARS-CoV-2 coronavirus. There is a huge body of literature on application of molecular modelling to predict inhibitors against target proteins of SARS-CoV-2. To keep our review clear and readable, we limited ourselves primarily to works that use computational methods to find inhibitors and test the predicted compounds experimentally either in target protein assays or in cell culture with live SARS-CoV-2. Some works containing results of experimental discovery of corresponding inhibitors without using computer modelling are included as examples of a success. Also, some computational works without experimental confirmations are also included if they attract our attention either by simulation methods or by databases used. This review collects studies that use various molecular modelling methods: docking, molecular dynamics, quantum mechanics, machine learning, and others. Most of these studies are based on docking, and other methods are used mainly for post-processing to select the best compounds among those found through docking. Simulation methods are presented concisely, information is also provided on databases of organic compounds that can be useful for virtual screening, and the review itself is structured in accordance with coronavirus target proteins.

Mapping the Lipid Signatures in COVID-19 Infection: Diagnostic and Therapeutic Solutions

The COVID-19 pandemic ignited research centered around the identification of robust biomarkers and therapeutic targets. SARS-CoV-2, the virus responsible, hijacks the metabolic machinery of the host cells. It relies on lipids and lipoproteins of host cells for entry, trafficking, immune evasion, viral replication, and exocytosis. The infection causes host cell lipid metabolic remodelling. Targeting lipid-based processes is thus a promising strategy for countering COVID-19. Here, we review the role of lipids in the different steps of the SARS-CoV-2 pathogenesis and identify lipid-centric targetable avenues. We discuss lipidome changes in infected patients and their relevance as potential clinical diagnostic or prognostic biomarkers. We summarize the emerging direct and indirect therapeutic approaches for targeting COVID-19 using lipid-inspired approaches. Given that viral protein-targeted therapies may become less effective due to mutations in emerging SARS-CoV-2 variants, lipid-inspired interventions may provide additional and perhaps better means of combating this and future pandemics.

Discovery of PLpro and Mpro Inhibitors for SARS-CoV-2

There are very few small-molecule antivirals for SARS-CoV-2 that are either currently approved (or emergency authorized) in the US or globally, including remdesivir, molnupiravir, and paxlovid. The increasing number of SARS-CoV-2 variants that have appeared since the outbreak began over three years ago raises the need for continual development of updated vaccines and orally available antivirals in order to fully protect or treat the population. The viral main protease (Mpro) and the papain-like protease (PLpro) are key for viral replication; therefore, they represent valuable targets for antiviral therapy. We herein describe an in vitro screen performed using the 2560 compounds from the Microsource Spectrum library against Mpro and PLpro in an attempt to identify additional small-molecule hits that could be repurposed for SARS-CoV-2. We subsequently identified 2 hits for Mpro and 8 hits for PLpro. One of these hits was the quaternary ammonium compound cetylpyridinium chloride with dual activity (IC50 = 2.72 ± 0.09 μM for PLpro and IC50 = 7.25 ± 0.15 μM for Mpro). A second inhibitor of PLpro was the selective estrogen receptor modulator raloxifene (IC50 = 3.28 ± 0.29 μM for PLpro and IC50 = 42.8 ± 6.7 μM for Mpro). We additionally tested several kinase inhibitors and identified olmutinib (IC50 = 0.54 ± 0.04 μM), bosutinib (IC50 = 4.23 ± 0.28 μM), crizotinib (IC50 = 3.81 ± 0.04 μM), and dacominitinib (IC50 = IC50 3.33 ± 0.06 μM) as PLpro inhibitors for the first time. In some cases, these molecules have also been tested by others for antiviral activity for this virus, or we have used Calu-3 cells infected with SARS-CoV-2. The results suggest that approved drugs can be identified with promising activity against these proteases, and in several cases we or others have validated their antiviral activity. The additional identification of known kinase inhibitors as molecules targeting PLpro may provide new repurposing opportunities or starting points for chemical optimization.

The Circulation of Common Respiratory Viruses and Their Co-infection with Severe Acute Respiratory Syndrome Coronavirus 2 Before and After Coronavirus Disease of 2019 Vaccination

Background: Respiratory viruses play important roles in respiratory tract infections; they are the major cause of diseases such as the common cold, bronchiolitis, pneumonia, etc., in humans that circulate more often in the cold seasons. During the COVID-19 pandemic, many strict public health measures, such as hand hygiene, the use of face masks, social distancing, and quarantines, were implemented worldwide to control the pandemic. Besides controlling the COVID-19 pandemic, these introduced measures might change the spread of other common respiratory viruses. Moreover, with COVID-19 vaccination and reducing public health protocols, the circulation of other respiratory viruses probably increases in the community. Objectives: This study aims to explore changes in the circulation pattern of common respiratory viruses during the COVID-19 pandemic. Methods: In the present study, we evaluated the circulation of seven common respiratory viruses (influenza viruses A and B, rhinovirus, and seasonal human Coronaviruses (229E, NL63, OC43, and HKU1) and their co-infection with SARS-CoV-2 in suspected cases of COVID-19 in two time periods before and after COVID-19 vaccination. Clinical nasopharyngeal swabs of 400 suspected cases of COVID-19 were tested for SARS-CoV-2 and seven common respiratory viruses by reverse transcription real-time polymerase chain reaction. Results: Our results showed common respiratory viruses were detected only in 10% and 8% of SARS-CoV-2-positive samples before and after vaccination, respectively, in which there were not any significant differences between them (P-value = 0.14). Moreover, common viral respiratory infections were found only in 12% and 32% of SARS-CoV-2-negative specimens before and after vaccination, respectively, in which there was a significant difference between them (P-value = 0.041). Conclusions: Our data showed a low rate of co-infection of other respiratory viruses with SARS-CoV-2 at both durations, before and after COVID-19 vaccination. Moreover, the circulation of common respiratory viruses before the COVID-19 vaccination was lower, probably due to non-pharmaceutical interventions (NPI), while virus activity (especially influenza virus A) was significantly increased after COVID-19 vaccination with reducing strict public health measures.