A Multiscale and Comparative Model for Receptor Binding of 2019 Novel Coronavirus and the Implication of its Life Cycle in Host Cells

The relevant information about the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the five-question approach (when, where, what, why, and how) and its impact on the environment

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is regarded as a threat because it spreads quickly across the world without requiring a passport or establishing an identity. This tiny virus has wreaked havoc on people's lives, killed people, and created psychological problems all over the world. The viral spike protein (S) significantly contributes to host cell entry, and mutations associated with it, particularly in the receptor-binding protein (RBD), either facilitate the escape of virus from neutralizing antibodies or enhance its transmission by increasing the affinity for cell entry receptor, angiotensin-converting enzyme 2 (ACE2). The initial variants identified in Brazil, South Africa, and the UK have spread to various countries. On the other hand, new variants are being detected in India and the USA. The viral genome and proteome were applied for molecular detection techniques, and nanotechnology particles and materials were utilized in protection and prevention strategies. Consequently, the SARS-CoV-2 pandemic has resulted in extraordinary scientific community efforts to develop detection methods, diagnosis tools, and effective antiviral drugs and vaccines, where prevailing academic, governmental, and industrial institutions and organizations continue to engage themselves in large-scale screening of existing drugs, both in vitro and in vivo. In addition, COVID-19 pointed on the possible solutions for the environmental pollution globe problem. Therefore, this review aims to address SARS-CoV-2, its transmission, where it can be found, why it is severe in some people, how it can be stopped, its diagnosis and detection techniques, and its relationship with the environment.

The role of 5-lipoxygenase in the pathophysiology of COVID-19 and its therapeutic implications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, known as coronavirus disease 2019 (COVID-19) causes cytokine release syndrome (CRS), leading to acute respiratory distress syndrome (ARDS), acute kidney and cardiac injury, liver dysfunction, and multiorgan failure. Although several studies have discussed the role of 5-lipoxygenase (5-LOX) in viral infections, such as influenzae and SARS, it remains unexplored in the pathophysiology of COVID-19. 5-LOX acts on free arachidonic acid (AA) to form proinflammatory leukotrienes (LTs). Of note, numerous cells involved with COVID-19 (e.g., inflammatory and smooth muscle cells, platelets, and vascular endothelium) widely express leukotriene receptors. Moreover, 5-LOX metabolites induce the release of cytokines (e.g., tumour necrosis factor-α [TNF-α], interleukin-1α [IL-1α], and interleukin-1β [IL-1β]) and express tissue factor on cell membranes and activate plasmin. Since macrophages, monocytes, neutrophils, and eosinophils can express lipoxygenases, activation of 5-LOX and the subsequent release of LTs may contribute to the severity of COVID-19. This review sheds light on the potential implications of 5-LOX in SARS-CoV-2-mediated infection and the anticipated therapeutic role of 5-LOX inhibitors.

A Journey From SARS-CoV-2 to COVID-19 and Beyond: A Comprehensive Insight of Epidemiology, Diagnosis, Pathogenesis, and Overview of the Progress into Its Therapeutic Management

The 2019 novel coronavirus (2019-nCoV), commonly known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19), was first revealed in late 2019 in Wuhan city, Hubei province, China. It was subsequently spread globally and thereby declared as a pandemic by WHO in March 2020. The disease causes severe acute respiratory illness and is highly contagious due to the fast-onward transmission. As of the mid of November 2020, the disease has affected 220 countries with more than 16 million active cases and 1.3 million deaths worldwide. Males, pregnant women, the elderly, immunosuppressed patients, and those with underlying medical conditions are more vulnerable to the disease than the general healthy population. Unfortunately, no definite treatment is available. Although remdesivir as an antiviral had been approved for use in those above 12 years of age and 40 kg weight group, it has been observed to be ineffective in large-scale SOLIDARITY trials by WHO. Moreover, dexamethasone has been found to increase the recovery rate of ventilated patients; oxygen and inhaled nitric oxide as a vasodilator have been given emergency expanded access. In addition, more than 57 clinical trials are being conducted for the development of the vaccines on various platforms. Two vaccines were found to be significantly promising in phase III results. It is concluded that till the approval of a specific treatment or development of a vaccine against this deadly disease, the preventive measures should be followed strictly to reduce the spread of the disease.

Structure and Hierarchy of SARS-CoV-2 Infection Dynamics Models Revealed by Reaction Network Analysis

This work provides a mathematical technique for analyzing and comparing infection dynamics models with respect to their potential long-term behavior, resulting in a hierarchy integrating all models. We apply our technique to coupled ordinary and partial differential equation models of SARS-CoV-2 infection dynamics operating on different scales, that is, within a single organism and between several hosts. The structure of a model is assessed by the theory of chemical organizations, not requiring quantitative kinetic information. We present the Hasse diagrams of organizations for the twelve virus models analyzed within this study. For comparing models, each organization is characterized by the types of species it contains. For this, each species is mapped to one out of four types, representing uninfected, infected, immune system, and bacterial species, respectively. Subsequently, we can integrate these results with those of our former work on Influenza-A virus resulting in a single joint hierarchy of 24 models. It appears that the SARS-CoV-2 models are simpler with respect to their long term behavior and thus display a simpler hierarchy with little dependencies compared to the Influenza-A models. Our results can support further development towards more complex SARS-CoV-2 models targeting the higher levels of the hierarchy.

SARS-CoV-2: Pathogenesis, and Advancements in Diagnostics and Treatment

The emergence and rapid spread of SARS-CoV-2 in December 2019 has brought the world to a standstill. While less pathogenic than the 2002-2003 SARS-CoV, this novel betacoronavirus presents a global threat due to its high transmission rate, ability to invade multiple tissues, and ability to trigger immunological hyperactivation. The identification of the animal reservoir and intermediate host were important steps toward slowing the spread of disease, and its genetic similarity to SARS-CoV has helped to determine pathogenesis and direct treatment strategies. The exponential increase in cases has necessitated fast and reliable testing procedures. Although RT-PCR remains the gold standard, it is a time-consuming procedure, paving the way for newer techniques such as serologic tests and enzyme immunoassays. Various clinical trials using broad antiviral agents in addition to novel medications have produced controversial results; however, the advancement of immunotherapy, particularly monoclonal antibodies and immune modulators is showing great promise in clinical trials. Non-orthodox medications such as anti-malarials have been tested in multiple institutions but definitive conclusions are yet to be made. Adjuvant therapies have also proven to be effective in decreasing mortality in the disease course. While no formal guidelines have been established, the multitude of ongoing clinical trials as a result of unprecedented access to research data brings us closer to halting the SARS-CoV-2 pandemic.

A comprehensive review on drug repositioning against coronavirus disease 2019 (COVID19)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is the reason for this ongoing pandemic infection diseases termed coronavirus disease 2019 (COVID-19) that has emerged since early December 2019 in Wuhan City, Hubei Province, China. In this century, it is the worst threat to international health and the economy. After 4 months of COVID-19 outbreak, there is no certain and approved medicine against it. In this public health emergency, it makes sense to investigate the possible effects of old drugs and find drug repositioning that is efficient, economical, and riskless process. Old drugs that may be effective are from different pharmacological categories, antimalarials, anthelmintics, anti-protozoal, anti-HIVs, anti-influenza, anti-hepacivirus, antineoplastics, neutralizing antibodies, immunoglobulins, and interferons. In vitro, in vivo, or preliminary trials of these drugs in the treatment of COVID-19 have been encouraging, leading to new research projects and trials to find the best drug/s. In this review, we discuss the possible mechanisms of these drugs against COVID-19. Also, it should be mentioned that in this manuscript, we discuss preliminary rationales; however, clinical trial evidence is needed to prove them. COVID-19 therapy must be based on expert clinical experience and published literature and guidelines from major health organizations. Moreover, herein, we describe current evidence that may be changed in the future.

Relevance of SARS-CoV-2 in food safety and food hygiene: potential preventive measures, suggestions and nanotechnological approaches

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is easily transmitted from person to person, which has fueled the ongoing pandemic. Governments in different countries have taken drastic actions such as complete lockdown. However, little attention has been paid to food safety and its potential linkage with the coronavirus disease (COVID-19) pandemic. SARS-CoV-2 spread from staff to food products or food surfaces is conceivable. At least, instead of consuming unpackaged or uncovered foods, consumption of boiled or canned foods processed at high temperatures should be preferred. Before consumption, consumers should clean the surface of canned foods. In addition to recommending or enforcing simple precautions, such as using masks, governments must conduct mandatory SARS-CoV-2 tests regularly and intermittently for personnel who handle food materials or supporting materials (e.g., plastic pouches). Local markets, such as those in Wuhan, which sell live animals and exotic foods for consumption, are a concern. Trade of exotic or wild animals, unhygienic marketplace conditions, and not cooking at high temperatures ought to be prohibited. The consumption of vitamins, minerals, and other food-derived compounds such as omega fatty acids is a prudent way to improve the performance of the immune system. In addition, nano-encapsulated materials with controlled release properties may be useful in protecting food products and packaging from SARS-CoV-2 contamination.

Hydroxychloroquine as an aerosol might markedly reduce and even prevent severe clinical symptoms after SARS-CoV-2 infection

Covid-19 is a new coronavirus disease first described in December 2019. This respiratory illness is severe and potentially fatal. Severe cases make up to 15%, lethality ranges between 1.5 and more than 10%. What is urgently needed is an efficient pharmacological treatment for the treatment of severe cases. During the infection of alveolar epithelial cells of the lung, the ACE2 receptor has a central function. The antimalarial drugs chloroquine phosphate (CQ) and hydroxychloroquine (HCQ) impair in vitro the terminal glycosylation of ACE2 without significant change of cell-surface ACE2 and, therefore, might be potent inhibitors of SARS-CoV-2 infections. Starting inhibition at 0.1 µM, CQ completely prevented in vitro infections at 10 µM, suggesting a prophylactic effect and preventing the virus spread 5 h after infection. In a first clinical trial, CQ was effective in inhibiting exacerbation of pneumonia, improving lung imaging findings, promotion of virus-negative conversion, and shortening the disease. In addition, HCQ, which is three times more potent than CQ in SARS-CoV-2 infected cells (EC50 0.72 µM), was significantly associated with viral load reduction/disappearance in COVID-19 patients compared to controls. Theoretically, CQ and HCQ could thus be effectively used in the treatment of SARS-CoV pneumonia. From a pharmacological standpoint, however, the major problems of oral treatment with these drugs are possible severe side effects and toxicity. Concretely, this relates to (a) the inconsistent individual bioavailability of these drugs at the alveolar target cells, depending on intestinal resorption, hepatic first-pass metabolism and accumulation in liver, spleen and lung, and (b) the need for a relatively high concentration of 1–5 µM at the alveolar surface.

Therefore, we propose in a first dose estimation the use of HCQ as an aerosol in a dosage of 2–4 mg per inhalation in order to reach sufficient therapeutic levels at the alveolar epithelial cells. By using a low-dose non-systemic aerosol, adverse drug reactions will markedly be reduced compared with oral application. This increase in tolerability enables a broader use for prevention and after contact with an infected person, which would be an advantage especially for the high-risk, often multi-morbid and elderly patients.

Empirical data on self-medication with a one-week aerosol application by two of the authors is presented. Inhalation was well tolerated without relevant side effects.