SARS-CoV-2: From the pathogenesis to potential anti-viral treatments

Potential therapeutic effects and nano-based delivery systems of mesenchymal stem cells and their isolated exosomes to alleviate acute respiratory distress syndrome caused by COVID-19

The severe respiratory effects of the coronavirus disease 2019 (COVID-19) pandemic have necessitated the immediate development of novel treatments. The majority of COVID-19-related fatalities are due to acute respiratory distress syndrome (ARDS). Consequently, this virus causes massive and aberrant inflammatory conditions, which must be promptly managed. Severe respiratory disorders, notably ARDS and acute lung injury (ALI), may be treated safely and effectively using cell-based treatments, mostly employing mesenchymal stem cells (MSCs). Since the high potential of these cells was identified, a great deal of research has been conducted on their use in regenerative medicine and complementary medicine. Multiple investigations have demonstrated that MSCs and their products, especially exosomes, inhibit inflammation. Exosomes serve a critical function in intercellular communication by transporting molecular cargo from donor cells to receiver cells. MSCs and their derived exosomes (MSCs/MSC-exosomes) may improve lung permeability, microbial and alveolar fluid clearance, and epithelial and endothelial repair, according to recent studies. This review focuses on COVID-19-related ARDS clinical studies involving MSCs/MSC-exosomes. We also investigated the utilization of Nano-delivery strategies for MSCs/MSC-exosomes and anti-inflammatory agents to enhance COVID-19 treatment.

Specific binding of G-quadruplex in SARS-CoV-2 RNA by RHAU peptide

G-quadruplexes (G4s) are reported to present on the SARS-CoV-2 RNA genome and control various viral activities. Specific ligands targeting those viral nucleic acid structures could be investigated as promising detection methods or antiviral reagents to suppress this menacing virus. Herein, we demonstrate the binding between a G4 structure in the RNA of SARS-CoV-2 and a fluorescent probe created by fusing a parallel-G4 specific RHAU53 and a cyan fluorescent protein. The specific binding of G4 in SARS-CoV-2 by RHAU peptide was easily detected under the fluorescence spectrometer. The drawbacks of this approach and potential solutions are also discussed.

Inhibition of SARS-CoV-2 3CL protease by the anti-viral chimeric protein RetroMAD1

COVID-19 results from SARS-CoV-2, which mutates frequently, challenging current treatments. Therefore, it is critical to develop new therapeutic drugs against this disease. This study explores the interaction between SARS-CoV-2 3CLpro and RetroMAD1, a well-characterized coronavirus protein and potential drug target, using in-silico methods. The analysis through the HDOCK server showed stable complex formation with a binding energy of -12.3, the lowest among reference drugs. The RetroMAD1-3CLpro complex underwent a 100 ns molecular dynamics simulation (MDS) in an explicit solvation system, generating various trajectories, including RMSD, RMSF, hydrogen bonding, radius of gyration, and ligand binding energy. MDS results confirmed intact interactions within the RetroMAD1-3CLpro complex during simulations. In vitro experiments validated RetroMAD1's ability to inhibit 3CLpro enzyme activity and prevent SARS-CoV-2 infection in human bronchial cells. RetroMAD1 exhibited antiviral efficacy comparable to Remdesivir without cytotoxicity at effective concentrations. These results suggest RetroMAD1 as a potential drug candidate against SARS-CoV-2, warranting further in vivo and clinical studies to assess its efficiency.

Immunosenescence and inflamm-ageing in COVID-19

The destructive effects of coronavirus disease 2019 (COVID-19) on the elderly and people with cardiovascular disease have been proven. New findings shed light on the role of aging pathways on life span and health age. New therapies that focus on aging-related pathways may positively impact the treatment of this acute respiratory infection. Using new therapies that boost the level of the immune system can support the elderly with co-morbidities against the acute form of COVID-19. This article discusses the effect of the aging immune system against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the pathways affecting this severity of infection.

A Review of the Potential Effects of Melatonin in Compromised Mitochondrial Redox Activities in Elderly Patients With COVID-19

Melatonin, an endogenous indoleamine, is an antioxidant and anti-inflammatory molecule widely distributed in the body. It efficiently regulates pro-inflammatory and anti-inflammatory cytokines under various pathophysiological conditions. The melatonin rhythm, which is strongly associated with oxidative lesions and mitochondrial dysfunction, is also observed during the biological process of aging. Melatonin levels decline considerably with age and are related to numerous age-related illnesses. The signs of aging, including immune aging, increased basal inflammation, mitochondrial dysfunction, significant telomeric abrasion, and disrupted autophagy, contribute to the increased severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. These characteristics can worsen the pathophysiological response of the elderly to SARS-CoV-2 and pose an additional risk of accelerating biological aging even after recovery. This review explains that the death rate of coronavirus disease (COVID-19) increases with chronic diseases and age, and the decline in melatonin levels, which is closely related to the mitochondrial dysfunction in the patient, affects the virus-related death rate. Further, melatonin can enhance mitochondrial function and limit virus-related diseases. Hence, melatonin supplementation in older people may be beneficial for the treatment of COVID-19.

Efficacy of a multiple-indication antiviral herbal drug (Saliravira®) for COVID-19 outpatients: A pre-clinical and randomized clinical trial study

Background

The scientific researches on COVID-19 pandemic topics are headed to an explosion of scientific literature. Despite these global efforts, the efficient treatment of patients is an in-progress challenge. Based on a meta-study of published shreds of evidence about compounds and their botanic sources in the last six decades, a novel multiple-indication herbal compound (Saliravira®) has been developed. Based on the antiviral, anti-inflammatory, and immune-enhancing properties of its ingredients, we hypothesized that Saliravira® has the potential to act as an antiviral agent, accelerate treatment, and reduce undesirable effects of COVID-19.

Methods

In this randomized, controlled, open-label clinical trial, COVID-19 outpatients were included by RT-PCR test or diagnosis of physicians according to the symptoms. Participants were randomly divided into intervention and control groups to receive Saliravira® package plus routine treatments of COVID-19 or routine treatments of COVID-19 alone, respectively. Saliravira® package includes tablets, nasal-sinuses spray, oral-pharynx spray, and inhaler drops. The treatment was for 10 days and followed up till 23 days after admission.

Results

On the 8th day, the “mean reduction rates” of viral load of the patients in the intervention group was 50% lower compared to the control group with a p-value < 0.05. The improvement of 10 out of 14 COVID-19 symptoms in the intervention group was significantly accelerated. The mean treatment duration of patients in the intervention group was 4.9 days less than the control group. In addition, no patients in the intervention group were hospitalized compared to 28% of the control group needed to be hospitalized.

Recent and advanced nano-technological strategies for COVID-19 vaccine development

The outbreak of the COVID-19 pandemic in 2019 has been one of the greatest challenges modern medicine and science has ever faced. It has affected millions of people around the world and altered human life and activities as we once knew. The high prevalence as well as an extended period of incubations which usually does not present with symptoms have played a formidable role in the transmission and infection of millions. A lot of research has been carried out on developing suitable treatment and effective preventive measures for the control of the pandemic. Preventive strategies which include social distancing, use of masks, washing of hands, and contact tracing have been effective in slowing the spread of the virus; however, the infectious nature of the SARS-COV-2 has made these strategies unable to eradicate its spread. In addition, the continuous increase in the number of cases and death, as well as the appearance of several variants of the virus, has necessitated the development of effective and safe vaccines in a bid to ensure that human activities can return to normalcy. Nanotechnology has been of great benefit in the design of vaccines as nano-sized materials have been known to aid the safe and effective delivery of antigens as well as serve as suitable adjuvants to potentiate responses to vaccines. There are only four vaccine candidates currently approved for use in humans while many other candidates are at various levels of development. This review seeks to provide updated information on the current nano-technological strategies employed in the development of COVID-19 vaccines.

Recent Research in Cell Stress and Microbial Infection

Microbial infection, including bacterial, viral, fungal, and parasitic, is a common human disease leading to various cell stresses [...]

Fluvoxamine Treatment of Patients with Symptomatic COVID-19 in a Community Treatment Center: A Preliminary Result of Randomized Controlled Trial

Background

This study aimed to evaluate whether fluvoxamine reduces clinical deterioration in adult patients with mild to moderate coronavirus disease 2019 (COVID-19), and to identify risk factors for clinical deterioration in patients admitted to a community treatment center (CTC).

Materials and Methods

A randomized, placebo-controlled trial was conducted in a CTC, in Seoul, Korea from January 15, 2021, to February 19, 2021. Symptomatic adult patients with positive results of severe acute respiratory syndrome coronavirus 2 real time-polymerase chain reaction within 3 days of randomization were assigned at random to receive 100 mg of fluvoxamine or placebo twice daily for 10 days. The primary outcome was clinical deterioration defined by any of the following criteria: oxygen requirement to keep oxygen saturation over 94.0%, aggravation of pneumonia with dyspnea, or World Health Organization clinical progression scale 4 or greater.

Results

Of 52 randomized participants [median (interquartile range) age, 53.5 (43.3 - 60.0) years; 31 (60.0%) men], 44 (85.0%) completed the trial. Clinical deterioration occurred in 2 of 26 patients in each group (P >0.99). There were no serious adverse events in either group. Clinical deterioration occurred in 15 (6.0%) of 271 patients admitted to the CTC, and all of them were transferred to a hospital. In multivariate analysis, age between 55 and 64, fever and pneumonia at admission were independent risk factors for clinical deterioration.

Conclusion

In this study of adult patients with symptomatic COVID-19 who were admitted to the CTC, there was no significant differences in clinical deterioration between patients treated with fluvoxamine and placebo (ClinicalTrials.gov Identifier: NCT04711863).

Investigational antiviral drugs for the treatment of COVID-19 patients

In the current pandemic of coronavirus disease 2019 (COVID-19), antiviral drugs are at the center of attention because of their critical role against severe acute respiratory disease syndrome coronavirus 2 (SARS-CoV-2). In addition to designing new antivirals against SARS-COV-2, a drug repurposing strategy is a practical approach for treating COVID-19. A brief insight about antivirals would help clinicians to choose the best medication for the treatment of COVID-19. In this review, we discuss both novel and repurposed investigational antivirals, focusing on in vitro, in vivo, and clinical trial studies.

Efficacy of mRNA, adenoviral vector, and perfusion protein COVID-19 vaccines

Coronavirus disease 2019 (COVID-19) has a devastating impact on global populations triggered by a highly infectious viral sickness, produced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The third major cause of mortality in the United States, following heart disease and cancer in 2020, was undoubtedly COVID-19. The centers for disease control and prevention (CDC) and the world health organization (WHO) separately developed a categorization system for differentiating new strains of SARS-CoV-2 into variants of concern (VoCs) and variants of interest (VoIs) with the continuing development of various strains SARS-CoV-2. By December 2021, five of the SARS-CoV-2 VoCs were discovered from the onset of the pandemic depending on the latest epidemiologic report by the WHO: Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.1.529). Mutations in the receptor-binding domain (RBD) and n-terminal domain (NTD) have been found throughout all five identified VoCs. All strains other than the delta mutant are often found with the N501Y mutation situated on the RBD, resulting in higher binding between the spike protein and angiotensin-converting enzyme 2 (ACE2) receptors, enhanced viral adhesion, and following the entrance to host cells. The introduction of these new strains of SRAS-CoV-2 is likely to overcome the remarkable achievements gained in restricting this viral disease to the point where it is presented with remarkable vaccine developments against COVID-19 and strong worldwide mass immunization initiatives. Throughout this literature review, the effectiveness of current COVID-19 vaccines for managing and prohibiting SARS-CoV-2 strains is thoroughly described.

The Role of Unfolded Protein Response in Coronavirus Infection and Its Implications for Drug Design

Coronavirus is an important pathogen with a wide spectrum of infection and potential threats to humans and animals. Its replication occurs in the cytoplasm and is closely related to the endoplasmic reticulum (ER). Studies reported that coronavirus infection causes ER stress, and cells simultaneously initiate unfolded protein response (UPR) to alleviate the disturbance of ER homeostasis. Activation of the three branches of UPR (PERK, IRE1, and ATF6) modulates various signaling pathways, such as innate immune response, microRNA, autophagy, and apoptosis. Therefore, a comprehensive understanding of the relationship between coronavirus and ER stress is helpful to understand the replication and pathogenesis of coronavirus. This paper summarizes the current knowledge of the complex interplay between coronavirus and UPR branches, focuses on the effect of ER stress on coronavirus replication and coronavirus resistance to host innate immunity, and summarizes possible drug targets to regulate the impact of coronavirus infection.

Screening Potential Drugs for COVID-19 Based on Bound Nuclear Norm Regularization

The novel coronavirus pneumonia COVID-19 infected by SARS-CoV-2 has attracted worldwide attention. It is urgent to find effective therapeutic strategies for stopping COVID-19. In this study, a Bounded Nuclear Norm Regularization (BNNR) method is developed to predict anti-SARS-CoV-2 drug candidates. First, three virus-drug association datasets are compiled. Second, a heterogeneous virus-drug network is constructed. Third, complete genomic sequences and Gaussian association profiles are integrated to compute virus similarities; chemical structures and Gaussian association profiles are integrated to calculate drug similarities. Fourth, a BNNR model based on kernel similarity (VDA-GBNNR) is proposed to predict possible anti-SARS-CoV-2 drugs. VDA-GBNNR is compared with four existing advanced methods under fivefold cross-validation. The results show that VDA-GBNNR computes better AUCs of 0.8965, 0.8562, and 0.8803 on the three datasets, respectively. There are 6 anti-SARS-CoV-2 drugs overlapping in any two datasets, that is, remdesivir, favipiravir, ribavirin, mycophenolic acid, niclosamide, and mizoribine. Molecular dockings are conducted for the 6 small molecules and the junction of SARS-CoV-2 spike protein and human angiotensin-converting enzyme 2. In particular, niclosamide and mizoribine show higher binding energy of −8.06 and −7.06 kcal/mol with the junction, respectively. G496 and K353 may be potential key residues between anti-SARS-CoV-2 drugs and the interface junction. We hope that the predicted results can contribute to the treatment of COVID-19.

7-Ketocholesterol: Effects on viral infections and hypothetical contribution in COVID-19

7-Ketocholesterol, which is one of the earliest cholesterol oxidization products identified, is essentially formed by the auto-oxidation of cholesterol. In the body, 7-ketocholesterol is both provided by food and produced endogenously. This pro-oxidant and pro-inflammatory molecule, which can activate apoptosis and autophagy at high concentrations, is an abundant component of oxidized Low Density Lipoproteins. 7-Ketocholesterol appears to significantly contribute to the development of age-related diseases (cardiovascular diseases, age-related macular degeneration, and Alzheimer's disease), chronic inflammatory bowel diseases and to certain cancers. Recent studies have also shown that 7-ketocholesterol has anti-viral activities, including on SARS-CoV-2, which are, however, lower than those of oxysterols resulting from the oxidation of cholesterol on the side chain. Furthermore, 7-ketocholesterol is increased in the serum of moderately and severely affected COVID-19 patients. In the case of COVID-19, it can be assumed that the antiviral activity of 7-ketocholesterol could be counterbalanced by its toxic effects, including pro-oxidant, pro-inflammatory and pro-coagulant activities that might promote the induction of cell death in alveolar cells. It is therefore suggested that this oxysterol might be involved in the pathophysiology of COVID-19 by contributing to the acute respiratory distress syndrome and promoting a deleterious, even fatal outcome. Thus, 7-ketocholesterol could possibly constitute a lipid biomarker of COVID-19 outcome and counteracting its toxic effects with adjuvant therapies might have beneficial effects in COVID-19 patients.

A systematic review of pregnant women with COVID-19 and their neonates

BACKGROUND

In December 2019, a novel coronavirus disease (COVID-19) emerged in Wuhan, China, with an incredible contagion rate. However, the vertical transmission of COVID-19 is uncertain.

OBJECTIVES

This is a systematic review of published studies concerning pregnant women with confirmed COVID-19 and their neonates.

SEARCH STRATEGY

We carried out a systematic search in multiple databases, including PubMed, Web of Science, Google Scholar, Scopus, and WHO COVID-19 database using the following keywords: (Coronavirus) OR (novel coronavirus) OR (COVID-19) OR (COVID19) OR (COVID 19) OR (SARS-CoV2) OR (2019-nCoV)) and ((pregnancy) OR (pregnant) OR (vertical transmission) OR (neonate) OR (newborn) OR (placenta) OR (fetus) OR (Fetal)). The search took place in April 2020.

SELECTION CRITERIA

Original articles published in English were eligible if they included pregnant patients infected with COVID-19 and their newborns.

DATA COLLECTION AND ANALYSES

The outcomes of interest consisted of clinical manifestations of COVID-19 in pregnant patients with COVID-19 and also the effect of COVID-19 on neonatal and pregnancy outcomes.

MAIN RESULTS

37 articles involving 364 pregnant women with COVID-19 and 302 neonates were included. The vast majority of pregnant patients were in their third trimester of pregnancy, and only 45 cases were in the first or second trimester (12.4%). Most mothers described mild to moderate manifestations of COVID-19. Of 364 pregnant women, 25 were asymptomatic at the time of admission. The most common symptoms were fever (62.4%) and cough (45.3%). Two maternal deaths occurred. Some pregnant patients (12.1%) had a negative SARS-CoV-2 test but displayed clinical manifestations and abnormalities in computed tomography (CT) scan related to COVID-19. Twenty-two (6.0%) pregnant patients developed severe pneumonia. Two maternal deaths occurred from severe pneumonia and multiple organ dysfunction. Studies included a total of 302 neonates from mothers with COVID-19. Of the studies that provided data on the timing of birth, there were 65 (23.6%) preterm neonates. One baby was born dead from a mother who also died from COVID-19. Of the babies born alive from mothers with COVID-19, five newborns faced critical conditions, and two later died. A total of 219 neonates underwent nasopharyngeal specimen collection for SARS-CoV-2, of which 11 tested positive (5%). Seventeen studies examined samples of the placenta, breast milk, umbilical cord, and amniotic fluid, and all tested negative except one amniotic fluid sample.

CONCLUSIONS

A systematic review of published studies confirm that the course of COVID-19 in pregnant women resembles that of other populations. However, there is not sufficient evidence to establish an idea that COVID-19 would not complicate pregnancy.

Altered immunoemotional regulatory system in COVID-19: From the origins to opportunities

The emergence of the novel coronavirus (SARS-CoV-2) and the worldwide spread of the coronavirus disease (COVID-19) have led to social regulations that caused substantial changes in manners of daily life. The subsequent loneliness and concerns of the pandemic during social distancing, quarantine, and lockdown are psychosocial stressors that negatively affect the immune system. These effects occur through mechanisms controlled by the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenocortical (HPA) axis that alter immune regulation, namely the conserved transcriptional response to adversity (CTRA), which promotes inflammation and diminishes antiviral responses, leading to inadequate protection against viral disease. Unhealthy eating habits, physical inactivity, sleep disturbances, and mental health consequences of COVID-19 add on to the pathological effects of loneliness, making immunity against this ferocious virus an even tougher fight. Therefore, social isolation, with its unintended consequences, has inherently paradoxical effects on immunity in relation to viral disease. Though this paradox can present a challenge, its acknowledgment can serve as an opportunity to address the associated issues and find ways to mitigate the adverse effects. In this review, we aim to explore, in detail, the pathological effects of the new social norms on immunity and present suggested methods to improve our physical, psychological, and healthcare abilities to fight viral infection in the context of the COVID-19 pandemic.

Potential therapeutic agents to COVID-19: An update review on antiviral therapy, immunotherapy, and cell therapy

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, in December 2020 and coronavirus disease 19 (COVID-19) was later announced as pandemic by the World Health Organization (WHO). Since then, several studies have been conducted on the prevention and treatment of COVID-19 by potential vaccines and drugs. Although, the governments and global population have been attracted by some vaccine production projects, the presence of SARS-CoV-2-specific antiviral drugs would be an urge necessity in parallel with the efficient preventive vaccines. Various nonspecific drugs produced previously against other bacterial, viral, and parasite infections were recently evaluated for treating patients with COVID-19. In addition to therapeutic properties of these anti-COVID-19 compounds, some adverse effects were observed in different human organs as well. Not only several attentions were paid to antiviral therapy and treatment of COVID-19, but also nanomedicine, immunotherapy, and cell therapy were conducted against this viral infection. In this review study, we planned to introduce the present and potential future treatment strategies against COVID-19 and define the advantages and disadvantages of each treatment strategy.

Biosensing surfaces and therapeutic biomaterials for the central nervous system in COVID-19

COVID-19 can affect the central nervous system (CNS) indirectly by inflammatory mechanisms and even directly enter the CNS. Thereby, COVID-19 can evoke a range of neurosensory conditions belonging to infectious, inflammatory, demyelinating, and degenerative classes. A broad range of non-specific options, including anti-viral agents and anti-inflammatory protocols, is available with varying therapeutic. Due to the high mortality and morbidity in COVID-19-related brain damage, some changes to these general protocols, however, are necessary for ensuring the delivery of therapeutic(s) to the specific components of the CNS to meet their specific requirements. The biomaterials approach permits crossing the blood-brain barrier (BBB) and drug delivery in a more accurate and sustained manner. Beyond the BBB, drugs can protect neural cells, stimulate endogenous stem cells, and induce plasticity more effectively. Biomaterials for cell delivery exist, providing an efficient tool to improve cell retention, survival, differentiation, and integration. This paper will review the potentials of the biomaterials approach for the damaged CNS in COVID-19. It mainly includes biomaterials for promoting synaptic plasticity and modulation of inflammation in the post-stroke brain, extracellular vesicles, exosomes, and conductive biomaterials to facilitate neural regeneration, and artificial nerve conduits for treatment of neuropathies. Also, biosensing surfaces applicable to the first sensory interface between the host and the virus that encourage the generation of accelerated anti-viral immunity theoretically offer hope in solving COVID-19.

COVID-19 and human papillomavirus: Paradoxical immunity

Coronavirus disease 2019 (COVID‐19) is a multisystemic disease that can cause progressive lung failure, organ dysfunction, and coagulation disorder associated with high mortality and morbidity. COVID‐19 is known to either primarily cause skin symptoms or increase existing skin diseases. Human papillomavirus (HPV) is a DNA virus that can cause benign and malignant neoplasms. Mucocutaneous verruca vulgaris are common benign lesions of HPV. Here, we report a case of verruca vulgaris regressed after COVID‐19.

SARS-CoV-2 and other coronaviruses negatively influence mitochondrial quality control: beneficial effects of melatonin

Coronaviruses (CoVs) are a group of single stranded RNA viruses, of which some of them such as SARS-CoV, MERS-CoV, and SARS-CoV-2 are associated with deadly worldwide human diseases. Coronavirus disease-2019 (COVID-19), a condition caused by SARS-CoV-2, results in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) associated with high mortality in the elderly and in people with underlying comorbidities. Results from several studies suggest that CoVs localize in mitochondria and interact with mitochondrial protein translocation machinery to target their encoded products to mitochondria. Coronaviruses encode a number of proteins; this process is essential for viral replication through inhibiting degradation of viral proteins and host misfolded proteins including those in mitochondria. These viruses seem to maintain their replication by altering mitochondrial dynamics and targeting mitochondrial-associated antiviral signaling (MAVS), allowing them to evade host innate immunity. Coronaviruses infections such as COVID-19 are more severe in aging patients. Since endogenous melatonin levels are often dramatically reduced in the aged and because it is a potent anti-inflammatory agent, melatonin has been proposed to be useful in CoVs infections by altering proteasomal and mitochondrial activities. Melatonin inhibits mitochondrial fission due to its antioxidant and inhibitory effects on cytosolic calcium overload. The collective data suggests that melatonin may mediate mitochondrial adaptations through regulating both mitochondrial dynamics and biogenesis. We propose that melatonin may inhibit SARS-CoV-2-induced cell damage by regulating mitochondrial physiology.