- Spike N354 glycosylation augments SARS-CoV-2 fitness for human adaptation through multiple mechanisms -
Selective pressures have given rise to a number of SARS-CoV-2 variants during the prolonged course of the COVID-19 pandemic. Recently evolved variants differ from ancestors in additional glycosylation within the spike protein receptor-binding domain (RBD). Details of how the acquisition of glycosylation impacts viral fitness and human adaptation are not clearly understood. Here, we dissected the role of N354-linked glycosylation, acquired by BA.2.86 sub-lineages, as a RBD conformational control element in attenuating viral infectivity. The reduced infectivity could be recovered in the presence of heparin sulfate, which targets the N354 pocket to ease restrictions of conformational transition resulting in a RBD-up state, thereby conferring an adjustable infectivity. Furthermore, N354 glycosylation improved spike cleavage and cell-cell fusion, and in particular escaped one subset of ADCC antibodies. Together with reduced immunogenicity in hybrid immunity background, these indicate a single spike amino acid glycosylation event provides selective advantage in humans through multiple mechanisms.
- A general platform for targeting MHC-II antigens via a single loop -
Class-II major histocompatibility complexes (MHC-IIs) are central to the communications between CD4+ T cells and antigen presenting cells (APCs), but intrinsic structural features associated with MHC-II make it difficult to develop a general targeting system with high affinity and antigen specificity. Here, we introduce a protein platform, Targeted Recognition of Antigen-MHC Complex Reporter for MHC-II (TRACeR-II), to enable the rapid development of peptide-specific MHC-II binders. TRACeR-II has a small helical bundle scaffold and uses an unconventional mechanism to recognize antigens via a single loop. This unique antigen-recognition mechanism renders this platform highly versatile and amenable to direct structural modeling of the interactions with the antigen. We demonstrate that TRACeR-II binders can be rapidly evolved across multiple alleles, while computational protein design can produce specific binding sequences for a SARS-CoV-2 peptide of unknown complex structure. TRACeR-II sheds light on a simple and straightforward approach to address the MHC peptide targeting challenge, without relying on combinatorial selection on complementarity determining region (CDR) loops. It presents a promising basis for further exploration in immune response modulation as well as a broad range of theragnostic applications.
- Some mechanistic underpinnings of molecular adaptations of SARS-COV-2 spike protein by integrating candidate adaptive polymorphisms with protein dynamics -
We integrate evolutionary predictions based on the neutral theory of molecular evolution with protein dynamics to generate mechanistic insight into the molecular adaptations of the SARS-COV-2 Spike (S) protein. With this approach, we first identified Candidate Adaptive Polymorphisms (CAPs) of the SARS-CoV-2 Spike protein and assessed the impact of these CAPs through dynamics analysis. Not only have we found that CAPs frequently overlap with well-known functional sites, but also, using several different dynamics-based metrics, we reveal the critical allosteric interplay between SARS-CoV-2 CAPs and the S protein binding sites with the human ACE2 (hACE2) protein. CAPs interact far differently with the hACE2 binding site residues in the open conformation of S protein compared to the closed form. In particular, the CAP sites control the dynamics binding residues in the open state, suggesting an allosteric control of hACE2 binding. We also explored the characteristic mutations of different SARS-CoV-2 strains to find dynamic hallmarks and potential effects of future mutations. Our analyses reveal that Delta strain-specific variants have non-additive (i.e., epistatic) interactions with CAP sites, whereas the less pathogenic Omicron strains have mostly compensatory variants. Finally, our dynamics-based analysis suggests that the novel mutations observed in the Omicron strain epistatically interact with the CAP sites to help escape antibody binding.
- Low-coverage whole genome sequencing for a highly selective cohort of severe COVID-19 patients -
Despite advances in identifying genetic markers associated to severe COVID-19, the full genetic characterisation of the disease remains elusive. This study explores the use of imputation in low-coverage whole genome sequencing for a severe COVID-19 patient cohort. We generated a dataset of 79 imputed variant call format files using the GLIMPSE1 tool, each containing an average of 9.5 million single nucleotide variants. Validation revealed a high imputation accuracy (squared Pearson correlation {approx}0.97) across sequencing platforms, showing GLIMPSE1's ability to confidently impute variants with minor allele frequencies as low as 2% in Spanish ancestry individuals. We conducted a comprehensive analysis of the patient cohort, examining hospitalisation and intensive care utilisation, sex and age-based differences, and clinical phenotypes using a standardised set of medical terms developed to characterise severe COVID-19 symptoms. The methods and findings presented here may be leveraged in future genomic projects, providing vital insights for health challenges like COVID-19.
- Discovery of orally active SARS-CoV-2 papain-like protease (PLpro) inhibitors -
Vaccines and first-generation antiviral therapeutics have provided important protection against coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there remains a need for additional therapeutic options that provide enhanced efficacy and protection against potential viral resistance. The SARS-CoV-2 papain-like protease (PLpro) is one of two essential cysteine proteases involved in viral replication. While inhibitors of the SARS-CoV-2 main protease (Mpro) have demonstrated clinical efficacy, known PLpro inhibitors have to date lacked the inhibitory potency and requisite pharmacokinetics to demonstrate that targeting PLpro translates to in vivo efficacy in a preclinical setting. Herein, we report the machine learning-driven discovery of potent, selective, and orally available SARS-CoV-2 PLpro inhibitors, with lead compound PF-07957472 (4) providing robust efficacy in a mouse-adapted model of COVID-19 infection.
- Multiple layers of innate immune response antagonism of SARS-CoV-2 -
Several SARS-CoV-2 proteins have been shown to counteract the host innate immune response, mostly using in vitro protein expression, which may not fully reflect their role in the context of viral infection. In addition, while each viral protein was characterized in a different experimental system, their relative contribution in immunosuppression remains unclear. Here we used a SARS-CoV-2 bacterial artificial chromosome with en passant mutagenesis to recover a panel of twelve infectious recombinant SARS-CoV-2 viruses, each with mutations in either NSP1, NSP2, NSP3, NSP6, NSP12, NSP13, NSP14, NSP15, NSP16, ORF3a, ORF6 or ORF8. We used the interferon-stimulated response element (ISRE)-driven luciferase assay in 293T-ACE2/TMPRSS2 cells to test the panel, demonstrating that mutations in many proteins, especially in NSP1 and NSP15, increased the type I interferon response relative to the parental wild-type virus. RNA-seq analysis of mutant-virus infected Calu-3 cells showed that the mutations in NSP1 or NSP15 lead to higher expression of multiple genes involved in innate immune response, cytokine-mediated signaling and regulation of lymphocyte proliferation. Furthermore, mutations in either NSP1 or NSP15 resulted in a greater maturation of human monocyte-derived dendritic cells in vitro. Infection of K18 hACE2 transgenic mice with either NSP1 or NSP15 mutated viruses demonstrated attentuated respiratory tract replication. Analysis of lung immune cells from infected mice by single-cell RNA-seq identified 15 populations of major myeloid and lymphoid cells with changes in the pattern of their activation associated with viral infection. The effects of mutations in NSP1 or NSP15 on these responses are consistent with differences in the immunosuppressive mechanisms utilized by the two proteins. Overall, these data demonstrate different and redundant mechanisms of innate immune antagonism by SARS-CoV-2 and suppression of activation of antigen presenting cells and T and B lymphocytes mediated by multiple viral proteins.
- Nanobody repertoire generated against the spike protein of ancestral SARS-CoV-2 remains efficacious against the rapidly evolving virus -
To date, all major modes of monoclonal antibody therapy targeting SARS-CoV-2 have lost significant efficacy against the latest circulating variants. As SARS-CoV-2 omicron sublineages account for over 90% of COVID-19 infections, evasion of immune responses generated by vaccination or exposure to previous variants poses a significant challenge. A compelling new therapeutic strategy against SARS-CoV-2 is that of single domain antibodies, termed nanobodies, which address certain limitations of monoclonal antibodies. Here we demonstrate that our high-affinity nanobody repertoire, generated against wild-type SARS-CoV-2 spike protein (Mast, Fridy et al. 2021), remains effective against variants of concern, including omicron BA.4/BA.5; a subset is predicted to counter resistance in emerging XBB and BQ.1.1 sublineages. Furthermore, we reveal the synergistic potential of nanobody cocktails in neutralizing emerging variants. Our study highlights the power of nanobody technology as a versatile therapeutic and diagnostic tool to combat rapidly evolving infectious diseases such as SARS-CoV-2.
- Economic precarity and changing levels of anxiety and stress among Canadians with disabilities and chronic health conditions throughout the COVID-19 pandemic -
Early in the COVID-19 pandemic, multiple event stressors converged to exacerbate a growing mental health crisis in Canada with differing effects across status groups. However, less is known about changing mental health situations throughout the pandemic, especially among individuals more likely to experience chronic stress because of their disability and health status. Using data from two waves of a targeted online survey of people with disabilities and chronic health conditions in Canada (N = 563 individuals, June 2020 and July 2021), we find that approximately 25% of respondents experienced additional increases in stress and anxiety levels in 2021. These increases were partly explained by worsening perceived financial insecurity and, in the case of stress, additional negative financial effects tied to the pandemic. This paper understands mental health disparities as a function of social status and social group membership. By linking stress process models and a minority stress framework with a social model of disability, we allude to how structural and contextual barriers make functional limitations disabling and in turn, life stressors.
- Impact of the COVID-19 Pandemic on Undergraduate Research in the Department of Biology at Western University: Effect on project types, learning outcomes, and student perceptions. -
Undergraduate research is a high impact practice that offers numerous benefits to students, academic institutions, and the wider scientific community. Unfortunately, undergraduate research has faced restrictions due to the COVID-19 pandemic. This study aimed to assess how the COVID-19 pandemic has impacted: (1) the number and types of undergraduate research projects performed in the Department of Biology at the University of Western Ontario, and (2) the satisfaction-levels and perceived learning outcomes of students performing these projects. This study also aimed to incorporate a One Health framework through an emphasis on stakeholder involvement and the need for future action. A survey of 33 students who completed an undergraduate research project in the Department of Biology in the 2020/2021 academic year, and 68 students who completed an undergraduate research project in the 5 years prior was conducted. In keeping with the One Health approach, key stakeholders were identified, and a stakeholder map was constructed. The number of projects performed did not change dramatically despite COVID-19 restrictions. However, a shift towards dry research was observed with 87.9% of students in the 2020/2021 academic year conducting dry research, compared to 16.4% of students in the 5 years prior. Students who conducted research in the 2020/2021 academic year indicated lower overall levels of satisfaction and enjoyment, though their perceived learning outcomes were consistent with students who completed their projects in the 5 years prior. 53 key stakeholders from academia, government, industry, media, and the public were identified. Students provided invaluable feedback on their undergraduate research experiences that can be used to improve the quality of undergraduate research courses in the Department of Biology in the future. Findings may be of use to other departments and educational institutions that are seeking to improve their own undergraduate research courses amidst the COVID-19 pandemic or looking to incorporate experiential-based learning techniques into existing online courses.
- Case of Myocarditis, Pericarditis, and Fatal Aortic Dissection following Covid-19 mRNA Vaccination -
We present a case study of a 34-year-old male who was in apparent good health prior to his COVID-19 mRNA vaccination. Sixteen days after his first dose, he experienced acute inflammation, sudden thoracic aortic dissection, and pericardial tamponade, rapidly leading to his death. Studies suggest that young males, in particular, appear to be at increased risk of adverse cardiac events following COVID-19 mRNA vaccination. However, we propose that certain information gaps exist in the criteria that inform both public health agencies and the public on incidence rates in certain presentations of even severe myocarditis and cardiac adverse events following COVID-19 vaccination, as is often mentioned within COVID-19 vaccine myocarditis studies and is evident within the findings of this young man’s important case presentation.
- nf-core/airrflow: an adaptive immune receptor repertoire analysis workflow employing the Immcantation framework -
Adaptive Immune Receptor Repertoire sequencing (AIRR-seq) is a valuable experimental tool to study the immune state in health and following immune challenges such as infectious diseases, (auto)immune diseases, and cancer. Several tools have been developed to reconstruct B cell and T cell receptor sequences from AIRR-seq data and infer B and T cell clonal relationships. However, currently available tools offer limited parallelization across samples, scalability or portability to high-performance computing infrastructures. To address this need, we developed nf-core/airrflow, an end-to-end bulk and single-cell AIRR-seq processing workflow which integrates the Immcantation Framework following BCR and TCR sequencing data analysis best practices. The Immcantation Framework is a comprehensive toolset, which allows the processing of bulk and single-cell AIRR-seq data from raw read processing to clonal inference. nf-core/airrflow is written in Nextflow and is part of the nf-core project, which collects community contributed and curated Nextflow workflows for a wide variety of analysis tasks. We assessed the performance of nf-core/airrflow on simulated sequencing data with sequencing errors and show example results with real datasets. To demonstrate the applicability of nf-core/airrflow to the high-throughput processing of large AIRR-seq datasets, we validated and extended previously reported findings of convergent antibody responses to SARS-CoV-2 by analyzing 97 COVID-19 infected individuals and 99 healthy controls, including a mixture of bulk and single-cell sequencing datasets. Using this dataset, we extended the convergence findings to 20 additional subjects, highlighting the applicability of nf-core/airrflow to validate findings in small in-house cohorts with reanalysis of large publicly available AIRR datasets. nf-core/airrflow is available free of charge, under the MIT license on GitHub (https://github.com/nf-core/airrflow). Detailed documentation and example results are available on the nf-core website at (https://nf-co.re/airrflow).
- Development and validation of a federated learning framework for detection of subphenotypes of multisystem inflammatory syndrome in children -
Background Multisystem inflammatory syndrome in children (MIS-C) is a severe post-acute sequela of SARS-CoV-2 infection. The highly diverse clinical features of MIS-C necessities characterizing its features by subphenotypes for improved recognition and treatment. However, jointly identifying subphenotypes in multi-site settings can be challenging. We propose a distributed multi-site latent class analysis (dMLCA) approach to jointly learn MIS-C subphenotypes using data across multiple institutions. Methods We used data from the electronic health records (EHR) systems across nine U.S. childrens hospitals. Among the 3,549,894 patients, we extracted 864 patients < 21 years of age who had received a diagnosis of MIS-C during an inpatient stay or up to one day before admission. Using MIS-C conditions, laboratory results, and procedure information as input features for the patients, we applied our dMLCA algorithm and identified three MIS-C subphenotypes. As validation, we characterized and compared more granular features across subphenotypes. To evaluate the specificity of the identified subphenotypes, we further compared them with the general subphenotypes identified in the COVID-19 infected patients. Findings Subphenotype 1 (46.1%) represents patients with a mild manifestation of MIS-C not requiring intensive care, with minimal cardiac involvement. Subphenotype 2 (25.3%) is associated with a high risk of shock, cardiac and renal involvement, and an intermediate risk of respiratory symptoms. Subphenotype 3 (28.6%) represents patients requiring intensive care, with a high risk of shock and cardiac involvement, accompanied by a high risk of >4 organ system being impacted. Importantly, for hospital-specific clinical decision-making, our algorithm also revealed a substantial heterogeneity in relative proportions of these three subtypes across hospitals. Properly accounting for such heterogeneity can lead to accurate characterization of the subphenotypes at the patient-level. Interpretation Our identified three MIS-C subphenotypes have profound implications for personalized treatment strategies, potentially influencing clinical outcomes. Further, the proposed algorithm facilitates federated subphenotyping while accounting for the heterogeneity across hospitals.
- In silico assessment of immune cross protection between BCoV and SARS-CoV-2 -
Background: Humans have long shared infectious agents with cattle, and the bovine-derived human common cold OC-43 CoV is a not-so-distant example of cross-species viral spill over of coronaviruses. Human exposure to the Bovine Coronavirus (BCoV) is certainly common, as the virus is endemic in most high-density cattle-raising regions. Since BCoVs are phylogenetically close to SARS-CoV-2, it is possible that cross-protection against COVID-19 occurs in people exposed to BCoV. Methods: This article shows an in silico investigation of human cross-protection to SARS-CoV-2 due to BCoV exposure. We determined HLA recognition and human B lymphocyte reactivity to BCoV epitopes using bioinformatics resources. A retrospective geoepidemiological analysis of COVID-19 was then performed to verify if BCoV/SARS-CoV-2 cross-protection could have occurred in the field. Brazil was used as a model for the epidemiological analysis of the impact of livestock density, as a proxy for human exposure to BCoV, on the prevalence of COVID-19 in people. Results: As could be expected from their classification in the same Betacoronavirus genus, we show that several human B and T epitopes are shared between BCoV and SARS-CoV-2. This raised the possibility of cross-protection of people from exposure to the bovine coronavirus. Analysis of field data added partial support to the hypothesis of viral cross-immunity from human exposure to BCoV. There was a negative correlation between livestock geographical density and COVID-19. Whole-Brazil data showed areas in the country in which COVID-19 prevalence was disproportionally low (controlled by normalization by transport infrastructure). Areas with high cattle density had lower COVID-19 prevalence in these low-risk areas. Conclusions: These data are hypothesis-raising indications that cross-protection is possibly being induced by human exposure to the Bovine Coronavirus.
- No Substitute for the Real Thing? Physical and Digital Cultural Participation in Denmark during the COVID-19 Pandemic: A Research Note -
In this research note, we analyze the impact of the COVID-19 pandemic on cultural participation. We use rich survey data from Denmark to construct pooled time-series cross-sectional data for each month of the years 2019-2021 and report three findings. First, participation in physical cultural activities (e.g., attending a concert or a museum) plummeted during two lockdowns and did not return to its pre-pandemic level by the end of 2021. Second, participation in digital activities (e.g., reading a digital book or following a museum on social media) did not change much during the pandemic. Overall, we find little evidence of substitution from physical to digital cultural participation during the COVID-19 lockdown in Denmark. Third, socioeconomic gradients in cultural participation decreased during the pandemic for physical cultural participation, but did not change for digital cultural participation. We end by discussing what we can learn from our results about how social disruptions affect patterns of cultural participation and inequality.
- Stratification in Parents’ Selection of Developmentally Appropriate Books for Children: Register-based Evidence from Danish Public Libraries -
This paper studies socioeconomic gradients in selecting developmentally appropriate children’s books from public libraries. I draw on research on developmental gradients in parental inputs to hypothesize that families with high socioeconomic status (SES) are more likely to select books that match children’s developmental stage in order to best improve children’s learning environments. In contrast to previous survey-based research, I use behavioral data on the actual books families have selected from libraries. Based on Danish registry data that cover all books borrowed from public libraries in 2020, I find that highly educated families are more likely to use libraries and borrow more books when they use libraries, but they do not select a larger share of developmentally appropriate books; in fact, they select a slightly lower share. In contrast, I find only a weak positive income gradient for the amount of books borrowed and the share of developmentally appropriate books. The supplementary analyses show that results are robust across families with children of different ages and to account for nonrandom selection into the sample of library users, socioeconomic differences in children’s reading skills, and the impact of library lockdowns due to Covid-19. I conclude that stratification in library book selection is more prominent concerning the voraciousness with which highly educated parents provide reading inputs (more books) than how discriminating they are in terms of selecting developmentally appropriate books.
Study on the Effect of Incentive Spirometer-based Respiratory Training on the Long COVID-19 - Conditions: COVID-19 Pandemic; Diabetes; Hypertension; Cardiac Disease; Long COVID
Interventions: Behavioral: Incentive Spirometer respiratory training
Sponsors: National Taipei University of Nursing and Health Sciences; Tri-Service General Hospital
Not yet recruiting
Balance Acceptance and Commitment Therapy for Long COVID - Conditions: Post-COVID-19 Syndrome; Long COVID
Interventions: Behavioral: Balance Acceptance and Commitment Therapy
Sponsors: King’s College London
Not yet recruiting
Predict + Protect Study: Exploring the Effectiveness of a Predictive Health Education Intervention on the Adoption of Protective Behaviors Related to ILI - Conditions: Influenza; Influenza A; Influenza B; COVID-19; Respiratory Syncytial Virus (RSV)
Interventions: Behavioral: ILI Predictive Alerts, Reactive Content, and Proactive Content; Behavioral: ILI Predictive Alerts, Reactive Content; Behavioral: Proactive Content; Behavioral: No Intervention
Sponsors: Evidation Health; Biomedical Advanced Research and Development Authority
Not yet recruiting
Long COVID-19 [11C]CPPC Study - Conditions: COVID Long-Haul
Interventions: Drug: [11C]CPPC Injection; Drug: [11C]CPPC Injection
Sponsors: Johns Hopkins University; Radiological Society of North America
Recruiting
Thrombohemorrhagic Complications of COVID-19 - Conditions: COVID-19 (Coronavirus Disease 2019)
Interventions: Diagnostic Test: Prevention algorithm
Sponsors: Volgograd State Medical University
Active, not recruiting
Combined Use of Immunoglobulin and Pulse Steroid Therapies in Severe Covid-19 Patients - Conditions: Pulse Steroid and Immunoglobulins Drugs in Covid 19 Patients
Interventions: Drug: pulse steroid and nanogam
Sponsors: Konya City Hospital
Completed
Eficacia Ventilatoria y Remolacha - Conditions: SARS CoV 2 Infection; Muscle Disorder; Fatigue
Interventions: Dietary Supplement: Remolacha
Sponsors: Hospital de MatarĂł
Recruiting
Beneficial Effects of Natural Products on Management of Xerostomia - Conditions: Xerostomia; Diabetes Mellitus; Hypertension; Post COVID-19 Condition
Interventions: Other: (Manuka honey-green tea- ginger)
Sponsors: British University In Egypt
Completed
Diet and Fasting for Long COVID - Conditions: Long Covid19; Long COVID
Interventions: Other: Low sugar diet and 10-12 hour eating window; Other: Low sugar diet, 8 hour eating window and fasting
Sponsors: Pacific Northwest University of Health Sciences
Recruiting
The Effectiveness of a Health Promotion Program for Older People With Post-Covid-19 Sarcopenia - Conditions: Post COVID-19 Condition
Interventions: Other: Protein powder and Resistance exercise
Sponsors: Mahidol University; National Health Security Office, Thailand
Not yet recruiting
Chronic-disease Self-management Program in Patients Living With Long-COVID in Puerto Rico - Conditions: Long Covid19
Interventions: Other: “Tomando control de su salud” (Spanish Chronic Disease Self-Management)
Sponsors: University of Puerto Rico; National Institutes of Health (NIH)
Recruiting
Treatment of Persistent Post-Covid-19 Smell and Taste Disorders - Conditions: Post-covid-19 Persistent Smell and Taste Disorders
Interventions: Drug: Cerebrolysin; Other: olfactory and gustatory trainings
Sponsors: Sherifa Ahmed Hamed
Completed
High-throughput screening for a SARS-CoV-2 frameshifting inhibitor using a cell-free protein synthesis system - Programmed-1 ribosomal frameshifting (-1 PRF) is a translational mechanism adopted by some viruses, including SARS-CoV-2. To find a compound that can inhibit -1 PRF in SARS-CoV-2, we set up a high-throughput screening system using a HeLa cell extract-derived cell-free protein synthesis (CFPS) system. A total of 32,000 compounds were individually incubated with the CFPS system programmed with a -1 PRF-EGFP template. Several compounds were observed to decrease the -1 PRF-driven fluorescence, and…
Prevention of lipid droplet accumulation by DGAT1 inhibition ameliorates sepsis-induced liver injury and inflammation - CONCLUSIONS: Our results indicate that sepsis triggers lipid metabolism alterations that culminate in increased liver LD accumulation. Increased LDs are associated with disease severity and liver injury. Moreover, inhibition of LD accumulation decreased the production of inflammatory mediators and lipid peroxidation while improving tissue function, suggesting that LDs contribute to the pathogenesis of liver injury triggered by sepsis.
Pharmacokinetic analysis of placental transfer of ritonavir as a component of paxlovid using microdialysis in pregnant rats - BACKGROUND: Ritonavir is one of the most potent CYP3A4 inhibitor currently on the market, and is often used together with other antiviral drugs to increase their bioavailability and efficacy. Paxlovid, consisting of nirmatrelvir and ritonavir, was approved for the treatment of COVID-19. As previous studies regarding the use of ritonavir during pregnancy were limited to ex-vivo experiments and systemic safety data, to fully explore the detailed pharmacokinetics of ritonavir in pregnant rats’…
Efficacy and safety of aniseed powder for treating gastrointestinal symptoms of COVID-19: a randomized, placebo-controlled trial - Background: Gastrointestinal symptoms are prevalent amongst patients with a confirmed diagnosis of COVID-19 and may be associated with an increased risk of disease severity. This trial aimed to evaluate the efficacy and safety of aniseed (Pimpinella anisum L.) powder as an add-on therapy to standard care for treating gastrointestinal symptoms experienced by adults with an acute SARS-CoV-2 infection. Methods: The study was a randomized parallel-group double-blinded placebo-controlled add-on…
A narrative review on tofacitinib: The properties, function, and usefulness to treat coronavirus disease 2019 - In coronavirus disease 2019 (COVID-19), the formation of cytokine storm may have a role in worsening of the disease. By attaching the cytokines like interleukin-6 to the cytokine receptors on a cell surface, Janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathway will be activated in the cytoplasm lead to hyperinflammatory conditions and acute respiratory distress syndrome. Inhibition of JAK/STAT pathway may be useful to prevent the formation of cytokine storm….
A critical review of advances on tumor metabolism abnormalities induced by nitrosamine disinfection by-products in drinking water - Intensified sanitation practices amid the recent SARS-CoV-2 outbreak might result in the increased release of chloramine disinfectants into surface water, significantly promoting the formation of nitrosamine disinfection by-products (DBPs) in drinking water. Unfortunately, these nitrosamine DBPs exhibit significant genotoxic, carcinogenic, and mutagenic properties, while chlorinating disinfectants remain in global practice. The current review provides valuable insights into the occurrence,…
Cleavage of HDAC6 to dampen its antiviral activity by nsp5 is a common strategy of swine enteric coronaviruses - HDAC6, a structurally and functionally unique member of the histone deacetylase (HDAC) family, is an important host factor that restricts viral infection. The broad-spectrum antiviral activity of HDAC6 makes it a potent antiviral agent. Previously, we found that HDAC6 functions to antagonize porcine deltacoronavirus (PDCoV), an emerging enteropathogenic coronavirus with zoonotic potential. However, the final outcome is typically a productive infection that materializes as cells succumb to viral…
Campesterol and dithymoquinone as a potent inhibitors of SARS cov-2 main proteases-promising drug candidates for targeting its novel variants - The sudden outbreak of the COVID-19 pandemic has currently taken approximately 2.4 million lives, with no specific medication and fast-tracked tested vaccines for prevention. These vaccines have their own adverse effects, which have severely affected the global healthcare system. The discovery of the main protease structure of coronavirus (Mpro/Clpro) has resulted in the identification of compounds having antiviral potential, especially from the herbal system. In this study, the…
SARS-CoV-2 NSP2 as a Potential Delivery Vehicle for Proteins - The development of biomolecule delivery systems is essential for the treatment of various diseases such as cancer, immunological diseases, and metabolic disorders. For the first time, we found that SARS-CoV-2-encoded nonstructural protein 2 (NSP2) can be secreted from the cells, where it is synthesized. Brefeldin A and H89, inhibitors of ER/Golgi secretion pathways, did not inhibit NSP2 secretion. NSP2 is likely secreted via an unconventional secretory pathway. Moreover, both secreted and…
AI-driven covalent drug design strategies targeting main protease (mpro) against SARS-CoV-2: structural insights and molecular mechanisms - The emergence of new SARS-CoV-2 variants has raised concerns about the effectiveness of COVID-19 vaccines. To address this challenge, small-molecule antivirals have been proposed as a crucial therapeutic option. Among potential targets for anti-COVID-19 therapy, the main protease (M^(pro)) of SARS-CoV-2 is important due to its essential role in the virus’s life cycle and high conservation. The substrate-binding region of the core proteases of various coronaviruses, including SARS-CoV-2,…
Inhibition of multiple SARS-CoV-2 variants entry by Lycium barbarum L. polysaccharides through disruption of spike protein-ACE2 interaction - Viral respiratory infections are major human health concerns. The most striking epidemic disease, COVID-19 is still on going with the emergence of fast mutations and drug resistance of pathogens. A few polysaccharide macromolecules from traditional Chinese medicine (TCM) have been found to have direct anti-SARS-CoV-2 activity but the mechanism remains unclear. In this study, we evaluated the entry inhibition effect of Lycium barbarum polysaccharides (LBP) in vitro and in vivo. We found LBP…
Proposing of fungal endophyte secondary metabolites as a potential inhibitors of 2019-novel coronavirus main protease using docking and molecular dynamics - In this study, the inhibitory potential of 99 fungal derived secondary metabolites was predicted against SARS-CoV-2 main protease by using of computational approaches. This protein plays an important role in replication and is one of the important targets to inhibit viral reproduction. Among the 99 reported compounds, the 9 of them with the highest binding energy to Mpro obtained from the molecular docking method were selected for the molecular dynamic simulations. The compounds were then…
DON/DRP-104 as potent serine protease inhibitors implicated in SARS-CoV-2 infection: Comparative binding modes with human TMPRSS2 and novel therapeutic approach - Human transmembrane serine protease 2 (TMPRSS2) is an important member of the type 2 transmembrane serine protease (TTSP) family with significant therapeutic markings. The search for potent TMPRSS2 inhibitors against severe acute respiratory syndrome coronavirus 2 infection with favorable tissue specificity and off-site toxicity profiles remains limited. Therefore, probing the anti-TMPRSS2 potential of enhanced drug delivery systems, such as nanotechnology and prodrug systems, has become…
Fluoxetine exerts anti-inflammatory effects on human epidermal keratinocytes and suppresses their endothelin release - Fluoxetine is a safe antidepressant with remarkable anti-inflammatory actions; therefore, we aimed to investigate its effects on immortalized (HaCaT) as well as primary human epidermal keratinocytes in a polyinosinic-polycytidylic acid (p(I:C))-induced inflammatory model. We found that a non-cytotoxic concentration (MTT-assay, CyQUANT-assay) of fluoxetine significantly suppressed p(I:C)-induced expression and release of several pro-inflammatory cytokines (Q-PCR, cytokine array, ELISA), and it…
Flavonoids derived from medicinal plants as a COVID-19 treatment - The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 disease. Through its viral spike (S) protein, the virus enters and infects epithelial cells by utilizing angiotensin-converting enzyme 2 as a host cell’s receptor protein. The COVID-19 pandemic had a profound impact on global public health and economies. Although various effective vaccinations and medications are now available to prevent and treat COVID-19, natural compounds derived from medicinal plants,…