A comprehensive review on clinical and mechanistic pathophysiological aspects of COVID-19 Malady: How far have we come?

Proteomic snapshot of saliva samples predicts new pathways implicated in SARS-CoV-2 pathogenesis

BACKGROUND

Information on the microbiome's human pathways and active members that can affect SARS-CoV-2 susceptibility and pathogenesis in the salivary proteome is very scarce. Here, we studied a unique collection of samples harvested from April to June 2020 from unvaccinated patients.

METHODS

We compared 10 infected and hospitalized patients with severe (n = 5) and moderate (n = 5) coronavirus disease (COVID-19) with 10 uninfected individuals, including non-COVID-19 but susceptible individuals (n = 5) and non-COVID-19 and nonsusceptible healthcare workers with repeated high-risk exposures (n = 5).

RESULTS

By performing high-throughput proteomic profiling in saliva samples, we detected 226 unique differentially expressed (DE) human proteins between groups (q-value ≤ 0.05) out of 3376 unambiguously identified proteins (false discovery rate ≤ 1%). Major differences were observed between the non-COVID-19 and nonsusceptible groups. Bioinformatics analysis of DE proteins revealed human proteomic signatures related to inflammatory responses, central cellular processes, and antiviral activity associated with the saliva of SARS-CoV-2-infected patients (p-value ≤ 0.0004). Discriminatory biomarker signatures from human saliva include cystatins, protective molecules present in the oral cavity, calprotectins, involved in cell cycle progression, and histones, related to nucleosome functions. The expression levels of two human proteins related to protein transport in the cytoplasm, DYNC1 (p-value, 0.0021) and MAPRE1 (p-value, 0.047), correlated with angiotensin-converting enzyme 2 (ACE2) plasma activity. Finally, the proteomes of microorganisms present in the saliva samples showed 4 main microbial functional features related to ribosome functioning that were overrepresented in the infected group.

CONCLUSION

Our study explores potential candidates involved in pathways implicated in SARS-CoV-2 susceptibility, although further studies in larger cohorts will be necessary.

Differential abundance of lipids and metabolites related to SARS-CoV-2 infection and susceptibility

The mechanisms driving SARS-CoV-2 susceptibility remain poorly understood, especially the factors determining why unvaccinated individuals remain uninfected despite high-risk exposures. To understand lipid and metabolite profiles related with COVID-19 susceptibility and disease progression. We collected samples from an exceptional group of unvaccinated healthcare workers heavily exposed to SARS-CoV-2 but not infected ('non-susceptible') and subjects who became infected during the follow-up ('susceptible'), including non-hospitalized and hospitalized patients with different disease severity providing samples at early disease stages. Then, we analyzed their plasma metabolomic profiles using mass spectrometry coupled with liquid and gas chromatography. We show specific lipids profiles and metabolites that could explain SARS-CoV-2 susceptibility and COVID-19 severity. More importantly, non-susceptible individuals show a unique lipidomic pattern characterized by the upregulation of most lipids, especially ceramides and sphingomyelin, which could be interpreted as markers of low susceptibility to SARS-CoV-2 infection. This study strengthens the findings of other researchers about the importance of studying lipid profiles as relevant markers of SARS-CoV-2 pathogenesis.

Structural and non-structural proteins in SARS-CoV-2: potential aspects to COVID-19 treatment or prevention of progression of related diseases

Coronavirus disease 2019 (COVID-19) is caused by a new member of the Coronaviridae family known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are structural and non-structural proteins (NSPs) in the genome of this virus. S, M, H, and E proteins are structural proteins, and NSPs include accessory and replicase proteins. The structural and NSP components of SARS-CoV-2 play an important role in its infectivity, and some of them may be important in the pathogenesis of chronic diseases, including cancer, coagulation disorders, neurodegenerative disorders, and cardiovascular diseases. The SARS-CoV-2 proteins interact with targets such as angiotensin-converting enzyme 2 (ACE2) receptor. In addition, SARS-CoV-2 can stimulate pathological intracellular signaling pathways by triggering transcription factor hypoxia-inducible factor-1 (HIF-1), neuropilin-1 (NRP-1), CD147, and Eph receptors, which play important roles in the progression of neurodegenerative diseases like Alzheimer's disease, epilepsy, and multiple sclerosis, and multiple cancers such as glioblastoma, lung malignancies, and leukemias. Several compounds such as polyphenols, doxazosin, baricitinib, and ruxolitinib could inhibit these interactions. It has been demonstrated that the SARS-CoV-2 spike protein has a stronger affinity for human ACE2 than the spike protein of SARS-CoV, leading the current study to hypothesize that the newly produced variant Omicron receptor-binding domain (RBD) binds to human ACE2 more strongly than the primary strain. SARS and Middle East respiratory syndrome (MERS) viruses against structural and NSPs have become resistant to previous vaccines. Therefore, the review of recent studies and the performance of current vaccines and their effects on COVID-19 and related diseases has become a vital need to deal with the current conditions. This review examines the potential role of these SARS-CoV-2 proteins in the initiation of chronic diseases, and it is anticipated that these proteins could serve as components of an effective vaccine or treatment for COVID-19 and related diseases. Video Abstract.

Social capital's impact on COVID-19 outcomes at local levels

Over the past thirty years, disaster scholars have highlighted that communities with stronger social infrastructure-including social ties that enable trust, mutual aid, and collective action-tend to respond to and recover better from crises. However, comprehensive measurements of social capital across communities have been rare. This study adapts Kyne and Aldrich's (Risk Hazards Crisis Public Policy 11, 61-86, 2020) county-level social capital index to the census-tract level, generating social capital indices from 2011 to 2018 at the census-tract, zipcode, and county subdivision levels. To demonstrate their usefulness to disaster planners, public health experts, and local officials, we paired these with the CDC's Social Vulnerability Index to predict the incidence of COVID-19 in case studies in Massachusetts, Wisconsin, Illinois, and New York City. We found that social capital predicted 41-49% of the variation in COVID-19 outbreaks, and up to 90% with controls in specific cases, highlighting its power as diagnostic and predictive tools for combating the spread of COVID.

Common Molecular Pathways Between Post-COVID19 Syndrome and Lung Fibrosis: A Scoping Review

The pathogenetic mechanism of post-Covid-19 pulmonary fibrosis is currently a topic of intense research interest, but still largely unexplored. The aim of this work was to carry out a systematic exploratory search of the literature (Scoping review) to identify and systematize the main pathogenetic mechanisms that are believed to be involved in this phenomenon, in order to highlight the same molecular aspect of the lung. These aims could be essential in the future for therapeutic management. We identified all primary studies involving in post COVID19 syndrome with pulmonary fibrosis as a primary endpoint by performing data searches in various systematic review databases. Two reviewers independently reviewed all abstracts (398) and full text data. The quality of study has been assess through SANRA protocol. A total of 32 studies involving were included, included the possible involvement of inflammatory cytokines, concerned the renin-angiotensin system, the potential role of galectin-3, epithelial injuries in fibrosis, alveolar type 2 involvement, Neutrophil extracellular traps (NETs) and the others implied other specific aspects (relationship with clinical and mechanical factors, epithelial transition mesenchymal, TGF-β signaling pathway, midkine, caspase and macrophages, genetics). In most cases, these were narrative reviews or letters to the editor, except for 10 articles, which presented original data, albeit sometimes in experimental models. From the development of these researches, progress in the knowledge of the phenomenon and hopefully in its prevention and therapy may originate.

[Omicron Variant of SARS-CoV-2 and Its Potential Impact on Dental Practice]

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been raging across the world for over two years, but the daily reported numbers of new infections and deaths are still increasing. The newly identified Omicron variant has significant changes in its transmissibility and pathogenicity due to the multiple mutations in the spike protein, posing new challenges to the global public health. World Health Organization has categorized Omicron as a variant of concern (VOC). The spread of SARS-CoV-2 and its variants has caused disruptions to the dental practice worldwide. During the course of diagnosis and treatment of dental care, face-to-face communication at close quarters, droplets, aerosols, and exposure to saliva and blood increase the risks of SARS-CoV-2 transmission. The emergence of new variants, especially the Omicron variant, has formed new challenges to dental healthcare provision. In addition, oral tissues, including the tongue and oral mucosa, can overexpress the angiotensin converting enzyme 2 (ACE2), which is also the binding receptors of SARS-CoV-2. As a result, the oral cavity is one of the target sites of SARS-CoV-2 infection. SARS-CoV-2 infection in oral cavity may cause different oral complications, such as loss of taste. However, there are few reports about Omicron and the other variants of SARS-CoV-2 and their impacts on dental healthcare provision. Herein we made an overview of the Omicron variant and its characteristics, including its pathogenicity and immune evasion, and its potential impact on dental practice. We also proposed some control measures with the aim of reducing the possible transmission of SARS-CoV-2 and its variants during dental care.

Viral and Host Genetic and Epigenetic Biomarkers Related to SARS-CoV-2 Cell Entry, Infection Rate, and Disease Severity

The rapid spread of COVID-19 outbreak lead to a global pandemic declared in March 2020. The common features of corona virus family helped to resolve structural characteristics and entry mechanism of SARS-CoV-2. However, rapid mutagenesis leads to the emergence of new strains that may have different reproduction rates or infectivity and may impact the course and severity of the disease. Host related factors may also play a role in the susceptibility for infection as well as the severity and outcomes of the COVID-19. We have performed a literature and database search to summarize potential viral and host-related genomic and epigenomic biomarkers, such as genetic variability, miRNA, and DNA methylation in the molecular pathway of SARS-CoV-2 entry into the host cell, that may be related to COVID-19 susceptibility and severity. Bioinformatics tools may help to predict the effect of mutations in the spike protein on the binding to the ACE2 receptor and the infectivity of the strain. SARS-CoV-2 may also target several transcription factors and tumour suppressor genes, thus influencing the expression of different host genes and affecting cell signalling. In addition, the virus may interfere with RNA expression in host cells by exploiting endogenous miRNA and its viral RNA. Our analysis showed that numerous human miRNA may form duplexes with different coding and non-coding regions of viral RNA. Polymorphisms in human genes responsible for viral entry and replication, as well as in molecular damage response and inflammatory pathways may also contribute to disease prognosis and outcome. Gene ontology analysis shows that proteins encoded by such polymorphic genes are highly interconnected in regulation of defense response. Thus, virus and host related genetic and epigenetic biomarkers may help to predict the course of the disease and the response to treatment.

Sophorolipid: a glycolipid biosurfactant as a potential therapeutic agent against COVID-19

Biosurfactants are natural surfactants produced by a variety of microorganisms. In recent years, biosurfactants have garnered a lot of interest due to their biomedical and pharmaceutical applications. Sophorolipids are glycolipid types of biosurfactants produced by selected nonpathogenic yeasts. In addition to the detergent activity (reduction in surface and interfacial tension), which is commonly utilized by biomedical applications, sophorolipids have shown some unique properties such as, antiviral activity against enveloped viruses, immunomodulation, and anticancer activity. Considering their antiviral activity, the potential of sophorolipids as an antiviral therapy for the treatment of COVID-19 is discussed in this review. Being a surfactant molecule, sophorolipid could solubilize the lipid envelope of SARS-CoV-2 and inactivate it. As an immunomodulator, sophorolipid could attenuate the cytokine storm caused by the SARS-CoV-2 upon infection, and inhibit the progression of COVID-19 in patients. Sophorolipids could also be used as an effective treatment strategy for COVID-19 patients suffering from cancer. However, there is limited research on the use of sophorolipid as a therapeutic agent for the treatment of cancer and viral diseases, and to modulate the immune response. Nevertheless, the multitasking capabilities of sophorolipids make them potential therapeutic candidates for the bench-to-bedside research for the treatment of COVID-19.