Inflammation Triggered by SARS-CoV-2 and ACE2 Augment Drives Multiple Organ Failure of Severe COVID-19: Molecular Mechanisms and Implications

S Protein, ACE2 and Host Cell Proteases in SARS-CoV-2 Cell Entry and Infectivity; Is Soluble ACE2 a Two Blade Sword? A Narrative Review

Since the spread of the deadly virus SARS-CoV-2 in late 2019, researchers have restlessly sought to unravel how the virus enters the host cells. Some proteins on each side of the interaction between the virus and the host cells are involved as the major contributors to this process: (1) the nano-machine spike protein on behalf of the virus, (2) angiotensin converting enzyme II, the mono-carboxypeptidase and the key component of renin angiotensin system on behalf of the host cell, (3) some host proteases and proteins exploited by SARS-CoV-2. In this review, the complex process of SARS-CoV-2 entrance into the host cells with the contribution of the involved host proteins as well as the sequential conformational changes in the spike protein tending to increase the probability of complexification of the latter with angiotensin converting enzyme II, the receptor of the virus on the host cells, are discussed. Moreover, the release of the catalytic ectodomain of angiotensin converting enzyme II as its soluble form in the extracellular space and its positive or negative impact on the infectivity of the virus are considered.

Severe COVID-19-A Review of Suggested Mechanisms Based on the Role of Extracellular Matrix Stiffness

The severity of COVID-19 commonly depends on age-related tissue stiffness. The aim was to review publications that explain the effect of microenvironmental extracellular matrix stiffness on cellular processes. Platelets and endothelial cells are mechanosensitive. Increased tissue stiffness can trigger cytokine storm with the upregulated expression of pro-inflammatory cytokines, such as tumor necrosis factor alpha and interleukin IL-6, and tissue integrity disruption, leading to enhanced virus entry and disease severity. Increased tissue stiffness in critically ill COVID-19 patients triggers platelet activation and initiates plague formation and thrombosis development. Cholesterol content in cell membrane increases with aging and further enhances tissue stiffness. Membrane cholesterol depletion decreases virus entry to host cells. Membrane cholesterol lowering drugs, such as statins or novel chitosan derivatives, have to be further developed for application in COVID-19 treatment. Statins are also known to decrease arterial stiffness mitigating cardiovascular diseases. Sulfated chitosan derivatives can be further developed for potential use in future as anticoagulants in prevention of severe COVID-19. Anti-TNF-α therapies as well as destiffening therapies have been suggested to combat severe COVID-19. The inhibition of the nuclear factor kappa-light-chain-enhancer of activated B cells pathway must be considered as a therapeutic target in the treatment of severe COVID-19 patients. The activation of mechanosensitive platelets by higher matrix stiffness increases their adhesion and the risk of thrombus formation, thus enhancing the severity of COVID-19.

Simulation of COVID-19 symptoms in a genetically engineered mouse model: implications for the long haulers

The ongoing pandemic (also known as coronavirus disease-19; COVID-19) by a constantly emerging viral agent commonly referred as the severe acute respiratory syndrome corona virus 2 or SARS-CoV-2 has revealed unique pathological findings from infected human beings, and the postmortem observations. The list of disease symptoms, and postmortem observations is too long to mention; however, SARS-CoV-2 has brought with it a whole new clinical syndrome in "long haulers" including dyspnea, chest pain, tachycardia, brain fog, exercise intolerance, and extreme fatigue. We opine that further improvement in delivering effective treatment, and preventive strategies would be benefited from validated animal disease models. In this context, we designed a study, and show that a genetically engineered mouse expressing the human angiotensin converting enzyme 2; ACE-2 (the receptor used by SARS-CoV-2 agent to enter host cells) represents an excellent investigative resource in simulating important clinical features of the COVID-19. The ACE-2 mouse model (which is susceptible to SARS-CoV-2) when administered with a recombinant SARS-CoV-2 spike protein (SP) intranasally exhibited a profound cytokine storm capable of altering the physiological parameters including significant changes in cardiac function along with multi-organ damage that was further confirmed via histological findings. More importantly, visceral organs from SP treated mice revealed thrombotic blood clots as seen during postmortem examination. Thus, the ACE-2 engineered mouse appears to be a suitable model for studying intimate viral pathogenesis thus paving the way for identification, and characterization of appropriate prophylactics as well as therapeutics for COVID-19 management.

A predicted structure of NADPH Oxidase 1 identifies key components of ROS generation and strategies for inhibition

NADPH oxidase 1 (NOX1) is primarily expressed in epithelial cells and responsible for local generation of reactive oxygen species (ROS). By specifically manipulating the local redox microenvironment, NOX1 actively engages in epithelial immunity, especially in colorectal and pulmonary epithelia. To unravel the structural basis of NOX1 engaged epithelial immune processes, a predicted structure model was established using RaptorX deep learning models. The predicted structure model illustrates a 6-transmembrane domain structure, a FAD binding domain, and an NADPH binding/NOXO1 interacting region. The substrate/cofactor binding scheme with respect to this proposed model highly correlates with published reports and is verified in our site-directed mutagenesis assays. An electron transport chain, from NADPH to FAD and the two heme groups, was well supported by the predicted model. Through molecular docking analysis of various small molecule NOX1 inhibitors and subsequent experimental validation, we identified pronounced active sites for potent NOX1 inhibition. Specifically, LEU60, VAL71, MET181, LEU185, HIS208, PHE211, TYR214, and TYR280 in the transmembrane domain form an active pocket for insertion of the small molecule inhibitors to inhibit electron transfer between the heme groups, thus affecting extracellular ROS generation. Altogether, our study provides structural information to help elucidate the role of NOX1 in epithelial generation of ROS and sheds light on the development of therapeutics for NOX1 related illnesses.

SARS-CoV-2 N Protein Triggers Acute Lung Injury via Modulating Macrophage Activation and Infiltration in in vitro and in vivo

Background

SARS-CoV-2-induced acute lung injury but its nucleocapsid (N) and/or Spike (S) protein involvements in the disease pathology remain elusive.

Methods

In vitro, the cultured THP-1 macrophages were stimulated with alive SARS-CoV-2 virus at different loading dose, N protein or S protein with/without TICAM2-siRNA, TIRAP-siRNA or MyD88-siRNA. The TICAM2, TIRAP and MyD88 expression in the THP-1 cells after N protein stimulation were determined. In vivo, naïve mice or mice with depletion macrophages were injected with N protein or dead SARS-CoV-2. The macrophages in the lung were analyzed with flow cytometry, and lung sections were stained with H&E or immunohistochemistry. Culture supernatants and serum were harvested for cytokines measurements with cytometric bead array.

Results

Alive SARS-CoV-2 virus or N protein but not S protein induced high cytokine releases from macrophages in a time or virus loading dependent manner. MyD88 and TIRAP but not TICAM2 were highly involved in macrophage activation triggered by N protein whilst both inhibited with siRNA decreased inflammatory responses. Moreover, N protein and dead SARS-CoV-2 caused systemic inflammation, macrophage accumulation and acute lung injury in mice. Macrophage depletion in mice decreased cytokines in response to N protein.

Conclusion

SARS-CoV-2 and its N protein but not S protein induced acute lung injury and systemic inflammation, which was closely related to macrophage activation, infiltration and release cytokines.

Semantic and Population Analysis of the Genetic Targets Related to COVID-19 and Its Association with Genes and Diseases

SARS-CoV-2 is a coronavirus responsible for one of the most serious, modern worldwide pandemics, with lasting and multifaceted effects. By late 2021, SARS-CoV-2 has infected more than 180 million people and has killed more than 3 million. The virus gains entrance to human cells through binding to ACE2 via its surface spike protein and causes a complex disease of the respiratory system, termed COVID-19. Vaccination efforts are being made to hinder the viral spread, and therapeutics are currently under development. Toward this goal, scientific attention is shifting toward variants and SNPs that affect factors of the disease such as susceptibility and severity. This genomic grammar, tightly related to the dark part of our genome, can be explored through the use of modern methods such as natural language processing. We present a semantic analysis of SARS-CoV-2-related publications, which yielded a repertoire of SNPs, genes, and disease ontologies. Population data from the 1000 Genomes Project were subsequently integrated into the pipeline. Data mining approaches of this scale have the potential to elucidate the complex interaction between COVID-19 pathogenesis and host genetic variation; the resulting knowledge can facilitate the management of high-risk groups and aid the efforts toward precision medicine.

Severe Acute Respiratory Syndrome Coronavirus-2 Delta Variant Study In Vitro and Vivo

At the end of 2019, an outbreak of a new severe acute respiratory syndrome caused by a coronavirus occurred in Wuhan, China, after which the virus spread around the world. Here, we have described the adaptive capacity and pathogenesis of the SARS-CoV-2 Delta variant, which is widespread in Armenia, in vitro and vivo on Syrian hamsters. We have studied the changes in the SARS-CoV-2genome using viral RNA sequencing during virus adaptation in vitro and in vivo. Our findings revealed that SARS-CoV-2 in Syrian hamsters causes a short-term pulmonary form of the disease, the first symptoms appear within 48 h after infection, reach 5-7 days after infection, and begin to disappear by 7-9 days after infection. The virus induces pathogenesis in the blood and bone marrow, which generally corresponds to the manifestation of the inflammatory process. The pulmonary form of the disease passes faster than changes in blood cells and bone marrow. Our data show that hamster organs do not undergo significant pathological changes in the Delta variant of SARS-CoV-2 infection.

Upregulation of miRNA-200c during Disease Progression in COVID-19 Patients

The COVID-19 pandemic has caused more than 6 million deaths worldwide since its first outbreak in December 2019 and continues to be a major health problem. Several studies have established that the infection by SARS-CoV-2 can be categorized in a viremic, acute and recovery or severe phase. Hyperinflammation during the acute pneumonia phase is a major cause of severe disease progression and death. Treatment of COVID-19 with directly acting antivirals is limited within a narrow window of time between first clinical symptoms and the hyperinflammatory response. Therefore, early initiation of treatment is crucial to assure optimal health care for patients. Molecular diagnostic biomarkers represent a potent tool to predict the course of disease and thus to assess the optimal treatment regimen and time point. Here, we investigated miRNA-200c as a potential marker for the prediction of the severity of COVID-19 to preventively initiate and personalize therapeutic interventions in the future. We found that miRNA-200c correlates with the severity of disease. With retrospective analysis, however, there is no correlation with prognosis at the time of hospitalization. Our study provides the basis for further evaluation of miRNA-200c as a predictive biomarker for the progress of COVID-19.

Intestinal Shedding of SARS-CoV-2 in Children: No Evidence for Infectious Potential

The clinical courses of COVID-19 in children are often mild and may remain undiagnosed, but prolonged intestinal virus shedding has been documented, thus potentially enabling fecal-oral transmission. However, the infectious potential of SARS-CoV-2 viruses excreted with feces has remained unclear. Here, we investigated 247 stool specimens from 213 pediatric patients to assess the prevalence of intestinal SARS-CoV-2 shedding in hospitalized children without or with COVID-19 and determined the infectious capacity of stool-borne viruses. Upon RT-qPCR screening, the infectivity of virus-positive samples was tested in cell culture using the Vero-E6 permissive cell line. SARS-CoV-2 RNA was detected by RT-qPCR in 32 (13%) stool specimens, but the analysis of virus-positive samples in cell culture revealed no cytopathic effects attributable to SARS-CoV-2-related cell damage. Our findings do not support the notion of potential fecal-oral SARS-CoV-2 spreading, thus questioning the role of hygienic measures designed to prevent this mode of viral transmission.

SCUBE1 is associated with thrombotic complications, disease severity, and in-hospital mortality in COVID-19 patients

Introduction

COVID-19 disease, which has recently become an important cause of mortality and morbidity all over the world, is remarkably associated with thrombotic complications. Although many factors are responsible for these increased thrombotic complications in COVID-19 disease, its relationship with a marker that increases the risk of thrombosis such as Signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1) has not yet been clarified. This is the first study to examine the potential diagnostic and prognostic value of SCUBE1 levels in patients with COVID-19. In this study, we aimed to clarify the relationship between the increased risk of thrombosis and SCUBE1 in the course of COVID-19 disease.

Materials and methods

553 patients with COVID-19 and 553 healthy controls were compared in terms of SCUBE1 levels. Additionally, patients with COVID-19 were divided into two groups according to their SCUBE1 levels and compared in terms of severity of disease, thrombotic complications and ın-hospital mortality.

Results

SCUBE1 levels were significantly higher in patients with COVID-19 compared to the control group (p < 0.001). Plasma SCUBE1 levels were significantly higher in patients with severe disease and thrombotic complications, those with mild to moderate disease, and those without thrombotic complications (p < 0.001, for both). In addition, SCUBE1 was found to be an independent predictor of in-hospital mortality (p < 0.001).

Conclusions

SCUBE1 may be one of the major determinants of thrombotic complications, which is an increased cause of mortality and morbidity in COVID-19 patients so inhibition of this peptide may be among the therapeutic targets in patients with COVID-19.

Cardiac Manifestations of Post-Acute COVID-19 Infection

PURPOSE OF REVIEW

There is emerging evidence that the post-acute and chronic phases of COVID-19 infection are associated with various significant cardiovascular sequelae.

RECENT FINDINGS

Long COVID has been shown to be associated with multiple cardiovascular sequelae including direct myocardial injury, arrhythmias, and cardiomyopathies. Hypotheses on the mechanism of myocardial injury include direct viral infiltration and autoimmune dysregulation. Long COVID is associated with persistent cardiac ischemia in patients with no previous history of coronary disease, atrial and ventricular arrhythmias, and the development of new-onset heart failure in previously healthy patients. Onset of long COVID may be related to severity of the initial SARS-CoV2 infection. Cardiac MRI is a valuable tool in assessing myocarditis and the development of cardiomyopathies in the setting of long COVID. Both patients with and without pre-existing cardiovascular disease are at risk of developing myocardial injury in the setting of long COVID. Future studies will elucidate both cardiovascular mortality and cardiac rehabilitation in the post-acute and chronic phases of COVID-19.

Evidence for Interplay Between the Renin-Angiotensin System and Toll-Like Receptor 4 Signaling Pathways in the Induction of Virus-Induced Acute Lung Injury

Dedication: This article is dedicated to Howard Young, an exceptional scientist who has provided outstanding mentorship to many postbaccalaureates, graduate students, and postdoctoral fellows during his career. Howard has been a colleague to many and was never tired of learning new things. He has brought "thinking out of the box" to the level of an art form and has always provided thoughtful and constructive suggestions to those who have sought his counsel. I am personally greatly indebted to Howard for his guidance in molecular biology over the past 30 years, and hope that we will continue to share a passion for learning and mentoring others for years to come. Thank you, Howard! -Stephanie N. Vogel The SARS-CoV-2 pandemic has led to an unprecedented explosion in studies that have sought to identify key mechanisms that underlie the ravaging aspects of this disease on individuals. SARS-CoV-2 virus gains access to cells by (1) binding of the viral spike (S) protein to cell-associated angiotensin-converting enzyme 2 (ACE2), a key receptor in the renin-angiotensin system (RAS), followed by (2) cleavage of S protein by a cellular serine protease ("S protein priming") to facilitate viral entry. Dysregulation of the RAS system has been implicated in the spectrum of clinical symptoms associated with SARS-CoV-2, including hypercytokinemia, elevated markers of endothelial injury and thrombosis, and both localized and systemic inflammation. However, the underlying mechanisms have yet to be fully delineated.

Antigen-Specific T Cells and SARS-CoV-2 Infection: Current Approaches and Future Possibilities

COVID-19, a significant global health threat, appears to be an immune-related disease. Failure of effective immune responses in initial stages of infection may contribute to development of cytokine storm and systemic inflammation with organ damage, leading to poor clinical outcomes. Disease severity and the emergence of new SARS-CoV-2 variants highlight the need for new preventative and therapeutic strategies to protect the immunocompromised population. Available data indicate that these people may benefit from adoptive transfer of allogeneic SARS-CoV-2-specific T cells isolated from convalescent individuals. This review first provides an insight into the mechanism of cytokine storm development, as it is directly related to the exhaustion of T cell population, essential for viral clearance and long-term antiviral immunity. Next, we describe virus-specific T lymphocytes as a promising and efficient approach for the treatment and prevention of severe COVID-19. Furthermore, other potential cell-based therapies, including natural killer cells, regulatory T cells and mesenchymal stem cells are mentioned. Additionally, we discuss fast and effective ways of producing clinical-grade antigen-specific T cells which can be cryopreserved and serve as an effective "off-the-shelf" approach for rapid treatment of SARS-CoV-2 infection in case of sudden patient deterioration.

Machine learning insights concerning inflammatory and liver-related risk comorbidities in non-communicable and viral diseases

The liver is a key organ involved in a wide range of functions, whose damage can lead to chronic liver disease (CLD). CLD accounts for more than two million deaths worldwide, becoming a social and economic burden for most countries. Among the different factors that can cause CLD, alcohol abuse, viruses, drug treatments, and unhealthy dietary patterns top the list. These conditions prompt and perpetuate an inflammatory environment and oxidative stress imbalance that favor the development of hepatic fibrogenesis. High stages of fibrosis can eventually lead to cirrhosis or hepatocellular carcinoma (HCC). Despite the advances achieved in this field, new approaches are needed for the prevention, diagnosis, treatment, and prognosis of CLD. In this context, the scientific com-munity is using machine learning (ML) algorithms to integrate and process vast amounts of data with unprecedented performance. ML techniques allow the integration of anthropometric, genetic, clinical, biochemical, dietary, lifestyle and omics data, giving new insights to tackle CLD and bringing personalized medicine a step closer. This review summarizes the investigations where ML techniques have been applied to study new approaches that could be used in inflammatory-related, hepatitis viruses-induced, and coronavirus disease 2019-induced liver damage and enlighten the factors involved in CLD development.

Alcohol use disorder as a potential risk factor for COVID-19 severity: A narrative review

In Dec. 2019-January 2020, a pneumonia illness originating in Wuhan, China, designated as coronavirus disease 2019 (COVID-19) was shown to be caused by a novel RNA coronavirus designated as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). People with advanced age, male sex, and/or underlying health conditions (obesity, type 2 diabetes, cardiovascular disease, hypertension, chronic kidney disease, and chronic lung disease) are especially vulnerable to severe COVID-19 symptoms and death. These risk factors impact the immune system and are also associated with poor health, chronic illness, and shortened longevity. However, a large percent of patients without these known risk factors also develops severe COVID-19 disease that can result in death. Thus, there must exist risk factors that promote exaggerated inflammatory and immune response to the SARS-CoV-2 virus leading to death. One such risk factor may be alcohol misuse and alcohol use disorder because these can exacerbate viral lung infections like SARS, influenza, and pneumonia. Thus, it is highly plausible that alcohol misuse is a risk factor for either increased infection rate when individuals are exposed to SARS-CoV-2 virus and/or more severe COVID-19 in infected patients. Alcohol use is a well-known risk factor for lung diseases and ARDS in SARS patients. We propose that alcohol has three key pathogenic elements in common with other COVID-19 severity risk factors: namely, inflammatory microbiota dysbiosis, leaky gut, and systemic activation of the NLRP3 inflammasome. We also propose that these three elements represent targets for therapy for severe COVID-19.

The combination of ciprofloxacin and indomethacin suppresses the level of inflammatory cytokines secreted by macrophages in vitro

PURPOSE

The combined use of antibiotics and anti-inflammatory medicine to manage bacterial endotoxin-induced inflammation following injuries or diseases is increasing. The cytokine level produced by macrophages plays an important role in this treatment course. Ciprofloxacin and indomethacin, two typical representatives of antibiotics and anti-inflammatory medicine, are cost-effective and has been reported to show satisfactory effect. The current study aims to investigate the effect of ciprofloxacin along with indomethacin on the secretion of inflammatory cytokines by macrophages in vitro.

METHODS

Primary murine peritoneal macrophages and RAW 264.7 cells were administrated with lipopolysaccharide (LPS) for 24 h. The related optimal dose and time point of ciprofloxacin or indomethacin in response to macrophage inflammatory response inflammation were determined via macrophage secretion induced by LPS. Then, the effects of ciprofloxacin and indomethacin on the secretory functions and viability of various macrophages were determined by enzyme-linked immunosorbent assay and flow cytometry analysis, especially for the levels of interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor (TNF)-α. The optimal dose and time course of ciprofloxacin affecting macrophage inflammatory response were determined by testing the maximum inhibitory effect of the drugs on pro-inflammatory factors at each concentration or time point.

RESULTS

According to the levels of cytokines secreted by various macrophages (1.2 × 10⁶ cells/well) after administration of 1 μg/mL LPS, the optimal dose and usage timing for ciprofloxacin alone were 80 μg/mL and 24 h, respectively, and the optimal dose for indomethacin alone was 10 μg/mL. Compared with the LPS-stimulated group, the combination of ciprofloxacin and indomethacin reduced the levels of IL-1β (p < 0.05), IL-6 (p < 0.05), IL-10 (p < 0.01)), and TNF-α (p < 0.01). Furthermore, there was greater stability in the reduction of inflammatory factor levels in the combination group compared with those in which only ciprofloxacin or indomethacin was used.

CONCLUSION

The combination of ciprofloxacin and indomethacin suppressed the levels of inflammatory cytokines secreted by macrophages in vitro. This study illustrates the regulatory mechanism of drug combinations on innate immune cells that cause inflammatory reactions. In addition, it provides a new potential antibacterial and anti-inflammatory treatment pattern to prevent and cure various complications in the future.

Analysis of mechanisms of Shenhuang Granule in treating severe COVID-19 based on network pharmacology and molecular docking

OBJECTIVE

Severe cases of coronavirus disease 2019 (COVID-19) are expected to have a worse prognosis than mild cases. Shenhuang Granule (SHG) has been shown to be a safe and effective treatment for severe COVID-19 in a previous randomized clinical trial, but the active chemical constituents and underlying mechanisms of action remain unknown. The goal of this study is to explore the chemical basis and mechanisms of SHG in the treatment of severe COVID-19, using network pharmacology.

METHODS

Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was employed to screen chemical constituents of SHG. Putative therapeutic targets were predicted by searching traditional Chinese medicine system pharmacology database and analysis platform, SwissTargetPrediction, and Gene Expression Omnibus (GEO) databases. The target protein-protein interaction network and enrichment analysis were performed to investigate the hub genes and presumptive mechanisms. Molecular docking and molecular dynamics simulations were used to verify the stability and interaction between the key chemical constituents of SHG and COVID-19 protein targets.

RESULTS

Forty-five chemical constituents of SHG were identified along with 131 corresponding therapeutic targets, including hub genes such as HSP90AA1, MMP9, CXCL8, PTGS2, IFNG, DNMT1, TYMS, MDM2, HDAC3 and ABCB1. Functional enrichment analysis indicated that SHG mainly acted on the neuroactive ligand-receptor interaction, calcium signaling pathway and cAMP signaling pathway. Molecular docking showed that the key constituents had a good affinity with the severe acute respiratory syndrome coronavirus 2 protein targets. Molecular dynamics simulations indicated that ginsenoside Rg4 formed a stable protein-ligand complex with helicase.

CONCLUSION

Multiple components of SHG regulated multiple targets to inhibit virus invasion and cytokine storm through several signaling pathways; this provides a scientific basis for clinical applications and further experiments.

Recovery of functional fitness, lung function, and immune function in healthcare workers with nonsevere and severe COVID-19 at 13 months after discharge from the hospital: a prospective cohort study

OBJECTIVES

This study aimed to evaluate the recovery of functional fitness, lung function, and immune function in healthcare workers (HCWs) with nonsevere and severe COVID-19 at 13 months after discharge from the hospital.

METHODS

The participants of "Rehabilitation Care Project for Medical Staff Infected with COVID-19" underwent a functional fitness test (muscle strength, flexibility, and agility/dynamic balance), lung function test, and immune function test (including cytokines and lymphocyte subsets) at 13 months after discharge.

RESULTS

The project included 779 HCWs (316 nonsevere COVID-19 and 463 severe COVID-19). This study found that 29.1% (130/446) of the HCWs have not yet recovered their functional fitness. The most affected lung function indicator was lung perfusion capacity (34% with diffusion capacity for carbon monoxide-single breath <80%). The increase of interleukin-6 (64/534, 12.0%) and natural killer cells (44/534, 8.2%) and the decrease of CD3⁺ T cells (58/534, 10.9%) and CD4⁺ T cells (26/534, 4.9%) still existed at 13 months after discharge. No significant difference was found in the HCWs with nonsevere and severe COVID-19 regarding recovery of functional fitness, lung function, and immune function at 13 months after discharge.

CONCLUSION

The majority of Chinese HCWs with COVID-19 had recovered their functional fitness, lung function, and immune function, and the recovery status in HCWs with severe COVID-19 is no worse than that in HCWs with nonsevere COVID-19 at 13 months after discharge from the hospital.

Worsening COVID-19 Disease Course After Surgical Trauma: A Case Series

Introduction

Current guidelines from the American Society of Anesthesiologists recommend postponing elective surgery on COVID-19-positive patients for a minimum of four to twelve weeks. However, literature focusing on the outcomes of COVID-19-positive patients undergoing surgery is scarce. In this case series, the outcome of asymptomatic COVID-19 patients undergoing acute or semi-urgent surgery was evaluated.

Case Presentation

A case series of four patients between 32 and 82 years old with a confirmed SARS-CoV-2 infection undergoing acute or semi-urgent surgery was presented here. All four patients were asymptomatic for COVID-19, developing severe respiratory failure following endo CABG, caesarian section, a thyroidectomy, or abdominal surgery. ICU admission, together with invasive ventilation, was necessary for all patients. Two patients required venovenous extracorporeal membrane oxygenation treatment. A mortality of 50% was observed.

Conclusions

In conclusion, the present case series suggests that elective surgery in asymptomatic SARS-CoV-2 infected patients might elicit an exacerbated COVID-19 disease course. This study endorses the current international guidelines recommending postponing elective surgery for SARS-CoV-2-positive patients for seven weeks, depending on the severity of the surgery and perioperative morbidities, to minimize postoperative mortality.

Association of COVID-19 with hepatic metabolic dysfunction

The coronavirus disease 2019 (COVID-19) pandemic continues to be a global problem with over 438 million cases reported so far. Although it mostly affects the respiratory system, the involvement of extrapulmonary organs, including the liver, is not uncommon. Since the beginning of the pandemic, metabolic com-orbidities, such as obesity, diabetes, hypertension, and dyslipidemia, have been identified as poor prognostic indicators. Subsequent metabolic and lipidomic studies have identified several metabolic dysfunctions in patients with COVID-19. The metabolic alterations appear to be linked to the course of the disease and inflammatory reaction in the body. The liver is an important organ with high metabolic activity, and a significant proportion of COVID-19 patients have metabolic comorbidities; thus, this factor could play a key role in orchestrating systemic metabolic changes during infection. Evidence suggests that metabolic dysregulation in COVID-19 has both short- and long-term metabolic implications. Furthermore, COVID-19 has adverse associations with metabolic-associated fatty liver disease. Due to the ensuing effects on the renin-angiotensin-aldosterone system and ammonia metabolism, COVID-19 can have significant implications in patients with advanced chronic liver disease. A thorough understanding of COVID-19-associated metabolic dysfunction could lead to the identification of important plasma biomarkers and novel treatment targets. In this review, we discuss the current understanding of metabolic dysfunction in COVID-19, focusing on the liver and exploring the underlying mechanistic pathogenesis and clinical implications.

Usefulness of KL-6 for Predicting Clinical Outcomes in Hospitalized COVID-19 Patients

Background: Krebs von den Lungen 6 (KL-6) is a novel biomarker for interstitial lung disease, and it reflects acute lung injury. We explored the usefulness of KL-6 to predict clinical outcomes in hospitalized coronavirus disease 2019 (COVID-19) patients. Methods: In a total of 48 hospitalized COVID-19 patients, KL-6 levels were measured using the HISCL KL-6 assay (Sysmex, Kobe, Japan) with the HISCL 5000 automated analyzer (Sysmex). Clinical outcomes (intensive care unit [ICU] admission, ventilator use, extracorporeal membrane oxygenation [ECMO] use, and 30-day mortality) were analyzed according to KL-6 percentiles. Age, initial KL-6 level, Charlson comorbidity index (CCI), and critical disease were compared using the receiver operating characteristic (ROC) curve and Kaplan-Meier methods for clinical outcomes. Results: KL-6 quartiles were associated with ICU admission, ventilator use, and ECMO use (all p < 0.05), except 30-day mortality (p = 0.187). On ROC curve analysis, initial KL-6 level predicted ICU admission, ventilator use, and ECMO use significantly better than age, CCI, and critical disease (all p < 0.05); age, initial KL-6 level, CCI, and critical disease predicted 30-day mortality comparably. On Kaplan−Meier survival analysis, hazard ratios (95% confidence interval) were 4.8 (1.2−19.3) for age, 4.7 (1.1−21.6) for initial KL-6 level, 3.9 (0.9−16.2) for CCI, and 2.1 (0.5−10.3) for critical disease. Conclusions: This study demonstrated that KL-6 could be a useful biomarker to predict clinical outcomes in hospitalized COVID-19 patients. KL-6 may contribute to identifying COVID-19 patients requiring critical care, including ICU admission and ventilator and/or ECMO use.

Deciphering the therapeutical potentials of rosmarinic acid

Lemon balm is herbal tea used for soothing stomach cramps, indigestion, and nausea. Rosmarinic acid (RA) is one of its chemical constituents known for its therapeutic potentials against cancer, inflammatory and neuronal diseases such as the treatment of neurofibromatosis or prevention from Alzheimer’s diseases (AD). Despite efforts, recovery and purification of RA in high yields has not been entirely successful. Here, we report its aqueous extraction with optimal conditions and decipher the structure by nuclear magnetic resonance (NMR) spectroscopy. Using various physical–chemical and biological assays, we highlight its anti-aggregation inhibition potentials against the formation of Tau filaments, one of the hallmarks of AD. We then examine its anti-cancer potentials through reduction of the mitochondrial reductase activity in tumor cells and investigate its electrochemical properties by cyclic voltammetry. Our data demonstrates that RA is a prominent biologically active natural product with therapeutic potentials for drug discovery in AD, cancer therapy and inflammatory diseases.

Network Pharmacology and Bioinformatics Analysis Identifies Potential Therapeutic Targets of Paxlovid Against LUAD/COVID-19

Background

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a pandemic in many countries around the world. The virus is highly contagious and has a high fatality rate. Lung adenocarcinoma (LUAD) patients may have higher susceptibility and mortality to COVID-19. While Paxlovid is the first oral drug approved by the U.S. Food and Drug Administration (FDA) for COVID-19, its specific drug mechanism for lung cancer patients infected with COVID-19 remains to be further studied.

Methods

COVID-19 related genes were obtained from NCBI, GeneCards, and KEGG, and then the transcriptome data for LUAD was downloaded from TCGA. The drug targets of Paxlovid were revealed through BATMAN-TCM, DrugBank, SwissTargetPrediction, and TargetNet. The genes related to susceptibility to COVID-19 in LUAD patients were obtained through differential analysis. The interaction of LUAD/COVID-19 related genes was evaluated and displayed by STRING, and a COX risk regression model was established to screen and evaluate the correlation between genes and clinical characteristics. The Venn diagram was drawn to select the candidate targets of Paxlovid against LUAD/COVID-19, and the functional analysis of the target genes was performed using KEGG and GO enrichment analysis. Finally, Cytoscape was used to screen and visualize the Hub Gene, and Autodock was used for molecular docking between the drug and the target.

Result

Bioinformatics analysis was performed by combining COVID-19-related genes with the gene expression and clinical data of LUAD, including analysis of prognosis-related genes, survival rate, and hub genes screened out by the prognosis model. The key targets of Paxlovid against LUAD/COVID-19 were obtained through network pharmacology, the most important targets include IL6, IL12B, LBP. Furthermore, pathway analysis showed that Paxlovid modulates the IL-17 signaling pathway, the cytokine-cytokine receptor interaction, during LUAD/COVID-19 treatment.

Conclusions

Based on bioinformatics and network pharmacology, the prognostic signature of LUAD/COVID-19 patients was screened. And identified the potential therapeutic targets and molecular pathways of Paxlovid Paxlovid in the treatment of LUAD/COVID. As promising features, prognostic signatures and therapeutic targets shed light on improving the personalized management of patients with LUAD.

Cytokine storm-calming property of the isoquinoline alkaloids in Coptis chinensis Franch

Coronavirus disease (COVID-19) has spread worldwide and its effects have been more devastating than any other infectious disease. Importantly, patients with severe COVID-19 show conspicuous increases in cytokines, including interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, IL-8, tumor necrosis factor (TNF)-α, IL-1, IL-18, and IL-17, with characteristics of the cytokine storm (CS). Although recently studied cytokine inhibitors are considered as potent and targeted approaches, once an immunological complication like CS happens, anti-viral or anti-inflammation based monotherapy alone is not enough. Interestingly, certain isoquinoline alkaloids in Coptis chinensis Franch. (CCFIAs) exerted a multitude of biological activities such as anti-inflammatory, antioxidant, antibacterial, and immunomodulatory etc, revealing a great potential for calming CS. Therefore, in this timeline review, we report and compare the effects of CCFIAs to attenuate the exacerbation of inflammatory responses by modulating signaling pathways like NF-ĸB, mitogen-activated protein kinase, JAK/STAT, and NLRP3. In addition, we also discuss the role of berberine (BBR) in two different triggers of CS, namely sepsis and viral infections, as well as its clinical applications. These evidence provide a rationale for considering CCFIAs as therapeutic agents against inflammatory CS and this suggestion requires further validation with clinical studies.

Lack of Correlation Between Soluble Angiotensin-Converting Enzyme 2 and Inflammatory Markers in Hospitalized COVID-19 Patients with Hypertension

Purpose

This study aimed to investigate the correlation of plasma soluble angiotensin-converting enzyme 2, sACE2, and several inflammatory markers in COVID-19 patients requiring hospitalization with hypertension. Additionally, we analyzed the effects of renin-angiotensin-aldosterone-system, RAAS, inhibitors on the levels of sACE2 and inflammatory marker levels in patients with COVID-19.

Patients and Methods

This cross-sectional study involved patients with COVID-19 who required hospitalization on a stable dose of antihypertensive drugs. The study included three hospitals in Jakarta and Tangerang, Indonesia, between December 2020 and June 2021. We classified eligible subjects into two groups: patients with COVID-19 treated with antihypertensive RAAS inhibitors or non-RAAS inhibitors.

Results

We found no correlation between sACE2 and all the inflammatory and coagulation markers studied (high-sensitivity C-reactive protein, IL-6, IL-10, IL6/IL10, tumor necrosis factor-α, neutrophil-to-lymphocyte ratio, and D-dimer) in COVID-19 patients with hypertension. Further analysis showed lower sACE2 concentrations and IL-6/IL-10 ratio in patients treated with RAAS inhibitors vs those treated with non-RAAS inhibitors.

Conclusion

We found no correlation between ACE2 and inflammatory markers. Using RAAS inhibitors resulted in a lower sACE2 and IL-6/IL-10 ratio. The type of antihypertensive treatments has a neutral effect on disease severity and outcome in COVID-19 patients with hypertension. However, to firmly-established these effects, our findings should be confirmed in a much larger population.

Regulated necrosis in COVID-19: A double-edged sword

COVID-19 caused by SARS-CoV-2 can cause various systemic diseases such as acute pneumonia with cytokine storm. Constituted of necroptosis, pyroptosis, and ferroptosis, regulated necrosis constitutes the cell death patterns under the low apoptosis condition commonly observed in COVID-19. Regulated necrosis is involved in the release of cytokines like TNF-α, IL-1 β, and IL-6 and cell contents such as alarmins, PAMPs, and DAMPs, leading to more severe inflammation. Uncontrolled regulated necrosis may explain the poor prognosis and cytokine storm observed in COVID-19. In this review, the pathophysiology and mechanism of regulated necrosis with the double-edged sword effect in COVID-19 are thoroughly discussed in detail. Furthermore, this review also focuses on the biomarkers and potential therapeutic targets of the regulated necrosis pathway in COVID-19, providing practical guidance to judge the severity, prognosis, and clinical treatment of COVID-19 and guiding the development of clinical anti-SARS-CoV-2 drugs.

The Role of the Gut-Lung Axis in COVID-19 Infections and Its Modulation to Improve Clinical Outcomes

The main entry point of SARS-CoV-2 is the respiratory tract and as such immune defence in this site determines if the virus will spill-over to the systemic circulation and circulate and infect other major organs. The first line of mucosal immune defence is composed of mucins, an epithelial barrier, and immune cells in the nasal cavity. The lung immune defence is carried out by numerous alveoli. The lung microbiota is a key factor in determining the efficacy of lung mucosal immunity protection. The intestinal microbiota has been demonstrated to affect the severity of COVID-19. Gut dysbiosis is involved in hyperinflammation and multiple organ failure through communications with multiple organs. The gut lung axis could be the earliest axis affected in COVID-19. Through the gut-lung axis, gut dysbiosis can affect the pathogenesis of the lung in COVID-19. In this review, we summarise the effects that gut dysbiosis can progress on the lung, and the lung microbiota. The possible mechanisms and approaches for modulation are discussed.

The immune response to COVID-19: Does sex matter?

The coronavirus disease 2019 (COVID-19) pandemic has created unprecedented challenges worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and has a complex interaction with the immune system, including growing evidence of sex-specific differences in the immune response. Sex-disaggregated analyses of epidemiological data indicate that males experience more severe symptoms and suffer higher mortality from COVID-19 than females. Many behavioural risk factors and biological factors may contribute to the different immune response. This review examines the immune response to SARS-CoV-2 infection in the context of sex, with emphasis on potential biological mechanisms explaining differences in clinical outcomes. Understanding sex differences in the pathophysiology of SARS-CoV-2 infection will help promote the development of specific strategies to manage the disease.

Angiotensin-converting enzyme 2 and transmembrane protease serine 2 in female and male patients with end-stage kidney disease

BACKGROUND

Individuals with chronic kidney disease are affected by acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to multiple comorbidities and altered immune system. The first step of the infection process is the binding of SARS-CoV-2 with angiotensin-converting enzyme 2 (ACE2) receptor, followed by its priming by transmembrane protease serine 2 (TMPRSS2). We hypothesized that circulating soluble ACE2 levels, as well as the expressions of ACE2 and TMPRSS2 in the microvasculature, are increased in patients with end-stage kidney disease (ESKD).

METHODS

A total of 210 participants were enrolled, representing 80 ESKD patients and 73 non-CKD controls for soluble ACE2, and 31 ESKD and 26 non-CKD controls for vasculature and fat tissue bioassays. We have assessed ACE2 expression in blood using ELISA and in tissue using immunofluorescence.

RESULTS

Soluble ACE2 levels were higher in ESKD patients compared to controls; however, there is no sex difference observed. In ESKD and controls, soluble ACE2 positively correlated with Interleukin 6 (IL-6) and C-reactive protein (CRP), respectively. Similarly, ACE2 tissue expression in the vasculature was higher in ESKD patients; moreover, this higher ACE2 expression was observed only in male ESKD patients. In addition, TMPRSS2 expression was observed in vessels from males and females but showed no sex difference. The expression of ACE2 receptor was higher in ESKD patients on ACE-inhibitor/angiotensin blocker treatment.

CONCLUSION

ESKD is associated with increased ACE2 levels in the circulation and pronounced in male vasculature; however, further studies are warranted to assess possible sex differences on specific treatment regime(s) for different comorbidities present in ESKD.

Pharmacotherapy consideration of thrombolytic medications in COVID-19-associated ARDS

BACKGROUND

In late 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is responsible for coronavirus disease (COVID-19), was identified as the new pathogen to lead pneumonia in Wuhan, China, which has spread all over the world and developed into a pandemic. Despite the over 1 year of pandemic, due to the lack of an effective treatment plan, the morbidity and mortality of COVID-19 remains high. Efforts are underway to find the optimal management for this viral disease.

MAIN BODY

SARS-CoV-2 could simultaneously affect multiple organs with variable degrees of severity, from mild to critical disease. Overproduction of pro-inflammatory mediators, exacerbated cellular and humoral immune responses, and coagulopathy such as Pulmonary Intravascular Coagulopathy (PIC) contributes to cell injuries. Considering the pathophysiology of the disease and multiple microthrombi developments in COVID-19, thrombolytic medications seem to play a role in the management of the disease. Beyond the anticoagulation, the exact role of thrombolytic medications in the management of patients with COVID-19-associated acute respiratory distress syndrome (ARDS) is not explicit. This review focuses on current progress in underlying mechanisms of COVID-19-associated pulmonary intravascular coagulopathy, the historical use of thrombolytic drugs in the management of ARDS, and pharmacotherapy considerations of thrombolytic therapy, their possible benefits, and pitfalls in COVID-19-associated ARDS.

CONCLUSIONS

Inhaled or intravenous administration of thrombolytics appears to be a salvage therapy for severe ARDS associated with COVID-19 by prompt attenuation of lung injury. Considering the pathogenesis of COVID-19-related ARDS and mechanism of action of thrombolytic agents, thrombolytics appear attractive options in stable patients without contraindications.

Effects of vaccination, new SARS-CoV-2 variants and reinfections on post-COVID-19 complications

Post-COVID-19 complications involve a variety of long-lasting health complications emerging in various body systems. Since the prevalence of post-COVID-19 complications ranges from 8-47% in COVID-19 survivors, it represents a formidable challenge to COVID-19 survivors and the health care system. Post-COVID-19 complications have already been studied in the connection to risk factors linked to their higher probability of occurrence and higher severity, potential mechanisms underlying the pathogenesis of post-COVID-19 complications, and their functional and structural correlates. Vaccination status has been recently revealed to represent efficient prevention from long-term and severe post-COVID-19 complications. However, the exact mechanisms responsible for vaccine-induced protection against severe and long-lasting post-COVID-19 complications remain elusive. Also, to the best of our knowledge, the effects of new SARS-CoV-2 variants and SARS-CoV-2 reinfections on post-COVID-19 complications and their underlying pathogenesis remain to be investigated. This hypothesis article will be dedicated to the potential effects of vaccination status, SARS-CoV-2 reinfections, and new SARS-CoV-2 variants on post-COVID-19 complications and their underlying mechanisms Also, potential prevention strategies against post-COVID complications will be discussed.

Therapeutic potential of P2X7 purinergic receptor modulation in the main organs affected by the COVID-19 cytokine storm

Defined by the World Health Organization as a global public health pandemic, coronavirus 2019 (COVID-19) has a global impact and the death of thousands of people. The "severe acute respiratory syndrome coronavirus 2" virus (SARS-CoV-2) is the etiologic agent of this disease, which uses the angiotensin-converting enzyme receptor 2 (ACE2) to infect the body, so any organ that expresses the gene ACE2 is a possible target for the new coronavirus. In addition, in severe cases of COVID-19, a cytokine storm occurs, which triggers widespread systemic inflammation due to the uncontrolled release of proinflammatory cytokines. In this perspective, the modulation of purinergic receptors are highlighted in the literature as a possible therapy, considering its application in other viral infections and systemic inflammation. Therefore, the objective of this review is to gather information on the modulation of the P2X7 receptor in the main organs directly affected by the virus and by the cytokine storm: heart, brain, lung, liver and kidneys. Thus, demonstrating possible therapies for reducing inflammation, as well as reducing the level of morbidity and mortality of COVID-19.

Vascular Endothelial Growth Factor Receptor, fms-Like Tyrosine Kinase-1 (Flt-1), as a Novel Binding Partner for SARS-CoV-2 Spike Receptor-Binding Domain

Angiotensin-converting enzyme 2 (ACE2) and neuropilin 1, a vascular endothelial growth factor (VEGF) receptor, were identified to bind to the SARS-CoV-2 spike receptor-binding domain (spike RBD). In silico analysis based on 3D structure, multiple sequence alignment, and molecular docking of second domain of soluble Flt-1 (sFlt-1) and spike RBD revealed structural similarities, sequence homology, and protein-protein interaction. Interaction and binding of recombinant spike RBD (rspike RBD) and recombinant sFlt-1 (rsFlt-1) in vitro induced a conformational change, as revealed by spectrofluorimetric data, with increased fluorescence intensity in emission spectra as compared to either of the proteins alone. Results on ELISA confirmed the binding and cross-reactivity of rspike-RBD and rsFlt-1 as determined by using either specific antibodies towards each protein or immunized human serum. We found that polyclonal or monoclonal anti-spike RBD antibodies can recognize either rsFlt-1 or rspike RBD, showing cross-reactivity for the two proteins in a dose-dependent binding response. Recognition of bound rspike RBD or rsFlt-1 by anti-Flt-1 or anti-spike RBD antibodies, respectively, as observed by immunoblotting, further confirmed interaction between the two proteins. Immunoprecipitation and immunoblot analysis demonstrated the identification of rspike RBD binding to the Flt-1 receptor on A549 cells. Further, the binding of rspike RBD to Flt-1 receptor was shown using immunofluorescence on 2D-culture or 3D-spheroid of MDA-MB-231 cells, which over-express Flt-1 receptor. Together, our study concludes that the Flt-1 receptor is a novel binding partner for SARS-CoV-2 spike RBD.

Coronavirus disease 2019 and the cardiologist

PURPOSE OF REVIEW

There continues to be extensive clinical and epidemiological data to suggest that coronavirus disease 2019 (COVID-19) infection is associated with numerous different types of cardiac involvement.

RECENT FINDINGS

Myocardial injury has been reported in over 25% of patients hospitalized due to COVID-19 infection and is not only associated with a worse prognosis but with higher mortality, approaching 40%. Currently proposed mechanisms of myocardial injury include direct viral infection, cytokine storm, endothelial inflammation, demand ischemia, interferon-mediated response and stress cardiomyopathy. COVID-19 infection is associated with new-onset arrhythmias and heart failure regardless of history of previous cardiovascular disease. Echocardiographic findings can be useful to predict mortality in COVID-19 patients and cardiac MRI is an effective tool to both assess COVID-19 induced myocarditis and to follow-up on cardiac complications of COVID-19 long-term. Although there is an association between COVID-19 vaccination and myocarditis, pericarditis or arrhythmias, the risk appears lower when compared to risk attributable to the natural infection.

SUMMARY

Patients with cardiovascular disease are not only more likely to suffer from severe COVID-19 infection but are at increased risk for further complications and higher mortality. Further data compilation on current and emerging treatments of COVID-19 will have additional impact on cardiovascular morbidity and mortality of COVID-19 infection.

Roles of the ACE/Ang II/AT1R pathway, cytokine release, and alteration of tight junctions in COVID-19 pathogenesis

This paper shows how SARS-CoV-2 alters tight junctions (TJs) in human organs. The effect of SARS-CoV-2 on the ACE/Ang II/AT1R pathway and immune cells culminates in the release of numerous pro-inflammatory mediators, leading to the presence of certain symptoms in COVID-19, such as acute lung injury (ALI), pulmonary hypertension, and pulmonary fibrosis. Furthermore, the cytokines released alter different TJs components. The study shows how the irregular release of pro-inflammatory cytokines leads to claudin disruption in various tissues of the body, resulting in different symptoms, such as alveolar fibrosis, pulmonary edema, conjunctivitis, altered fertility in males, gastrointestinal symptoms, Covid toes, and others. SARS-CoV-2 also alters occludin expression in the endothelial and blood-testis barriers (BTB) resulting in edema and altered fertility. Viral disruption of JAM-A leads to activation of the RhoA GTPase, which leads to ALI. Taken together, these results define ACE/Ang II/AT1R pathway receptors and tight junctional components as potential therapeutic targets in COVID-19.

Mechanisms of SARS-CoV-2 Infection-Induced Kidney Injury: A Literature Review

The severe acute respiratory coronavirus 2 (SARS-CoV-2) has become a life-threatening pandemic. Clinical evidence suggests that kidney involvement is common and might lead to mild proteinuria and even advanced acute kidney injury (AKI). Moreover, AKI caused by coronavirus disease 2019 (COVID-19) has been reported in several countries and regions, resulting in high patient mortality. COVID-19-induced kidney injury is affected by several factors including direct kidney injury mediated by the combination of virus and angiotensin-converting enzyme 2, immune response dysregulation, cytokine storm driven by SARS-CoV-2 infection, organ interactions, hypercoagulable state, and endothelial dysfunction. In this review, we summarized the mechanism of AKI caused by SARS-CoV-2 infection through literature search and analysis.

The potential impact of Covid-19 on CNS and psychiatric sequels

Due to its high prevalence and fatality, the current Severe Acute Respiratory Syndrome-coronavirus-2 (SARS-CoV-2) virus, which first emerged in China in 2019, quickly spread around the world and immediately became a serious global health concern. Although respiratory issues were initially the most prominent symptom of coronavirus disease 2019 (COVID-19), it became obvious rapidly that COVID-19, like many other coronavirus family members, could affect the central nervous system (CNS). During the pandemic, CNS involvement expressed itself in a variety of forms, including insomnia, anosmia, headaches, encephalopathies, encephalitis, cerebrovascular accidents, cognitive and memory impairment, and increased psychiatric disorders. Almost everyone who has been infected has at least one of these neurological symptoms, demonstrating that the virus has a high ability to impact the CNS. As the coronavirus pandemic passes its second year, the manifestations it can cause in the long run, such as its psychological sequels, have not yet been thoroughly studied. Given the high importance of this issue in today's society and due to the lack of reliable knowledge about the COVID-19 landscape on psychiatric disorders, we intend to investigate coronavirus's possible effect on mental illnesses based on available literature. Because the majority of the psychological effects of the coronavirus can continue for a long period after the pandemic ends, our research can give insight into potential psychiatric sequels associated with COVID-19.

COVID-19 in G6PD-deficient patients, oxidative stress, and neuropathology

Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that regulates energy metabolism mainly through the pentose phosphate pathway (PPP). It is well known that this enzyme participates in the antioxidant/oxidant balance via the synthesis of energy-rich molecules: nicotinamide adenine dinucleotide phosphate reduced (NADPH), the reduced form of flavin adenine dinucleotide (FADH) and glutathione (GSH), controlling reactive oxygen species generation. Coronavirus disease 19 (COVID-19), induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is considered a public health problem which has caused approximately 4.5 million deaths since December 2019. In relation to the role of G6PD in COVID-19 development, it is known from the existing literature that G6PD-deficient patients infected with SARS-CoV-2 are more susceptible to thrombosis and hemolysis, suggesting that G6PD deficiency facilitates infection by SARS-CoV-2. In relation to G6PD and neuropathology, it has been observed that deficiency of this enzyme is also present with an increase in oxidative markers. In relation to the role of G6PD and the neurological manifestations of COVID-19, it has been reported that the enzymatic deficiency in patients infected with SARS-CoV-2 exacerbates the disease, and, in some clinical reports, an increase in hemolysis and thrombosis was observed when patients were treated with hydroxychloroquine (OH-CQ), a drug with oxidative properties. In the present work, we summarize the evidence of the role of G6PD in COVID-19 and its possible role in the generation of oxidative stress and glucose metabolism deficits and inflammation present in this respiratory disease and its progression including neurological manifestations.

The COVID-19-diabetes mellitus molecular tetrahedron

Accumulating molecular evidence suggests that insulin resistance, rather than SARS-CoV-2- provoked beta-cell impairment, plays a major role in the observed rapid metabolic deterioration in diabetes, or new-onset hyperglycemia, during the COVID-19 clinical course. In order to clarify the underlying complexity of COVID-19 and diabetes mellitus interactions, we propose the imaginary diabetes-COVID-19 molecular tetrahedron with four lateral faces consisting of SARS-CoV-2 entry via ACE2 (lateral face 1), the viral hijacking and replication (lateral face 2), acute inflammatory responses (lateral face 3), and the resulting insulin resistance (lateral face 4). The entrance of SARS-CoV-2 using ACE2 receptor triggers an array of multiple molecular signaling beyond that of the angiotensin II/ACE2-Ang-(1-7) axis, such as down-regulation of PGC-1 α/irisin, increased SREBP-1c activity, upregulation of CD36 and Sirt1 inhibition leading to insulin resistance. In another arm of the molecular cascade, the SARS-CoV-2 hijacking and replication induces a series of molecular events in the host cell metabolic machinery, including upregulation of SREBP-2, decrement in Sirt1 expression, dysregulation in PPAR-ɣ, and LPI resulting in insulin resistance. The COVID-19-diabetes molecular tetrahedron may suggest novel targets for therapeutic interventions to overcome insulin resistance that underlies the pathophysiology of worsening metabolic control in patients with diabetes mellitus or the new-onset of hyperglycemia in COVID-19.

The Renin-Angiotensin System as a Component of Biotrauma in Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a major concern in critical care medicine with a high mortality of over 30%. Injury to the lungs is caused not only by underlying pathological conditions such as pneumonia, sepsis, or trauma, but also by ventilator-induced lung injury (VILI) resulting from high positive pressure levels and a high inspiratory oxygen fraction. Apart from mechanical factors that stress the lungs with a specific physical power and cause volutrauma and barotrauma, it is increasingly recognized that lung injury is further aggravated by biological mediators. The COVID-19 pandemic has led to increased interest in the role of the renin-angiotensin system (RAS) in the context of ARDS, as the RAS enzyme angiotensin-converting enzyme 2 serves as the primary cell entry receptor for severe acute respiratory syndrome (SARS) coronavirus (CoV)-2. Even before this pandemic, studies have documented the involvement of the RAS in VILI and its dysregulation in clinical ARDS. In recent years, analytical tools for RAS investigation have made major advances based on the optimized precision and detail of mass spectrometry. Given that many clinical trials with pharmacological interventions in ARDS were negative, RAS-modifying drugs may represent an interesting starting point for novel therapeutic approaches. Results from animal models have highlighted the potential of RAS-modifying drugs to prevent VILI or treat ARDS. While these drugs have beneficial pulmonary effects, the best targets and application forms for intervention still have to be determined to avoid negative effects on the circulation in clinical settings.

A new wave of COVID-19 in 2021 with unique genetic characters -present global scenario and beholding onwards

After the first report of a coronavirus-associated pneumonia outbreak in December 2019, the virus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) that causes the infection/disease (COVID-19) has developed into a pandemic, with >100 million people infected in over 210 countries along with two million people have died from COVID-19 till today. Coronaviruses are positive-stranded RNA viruses having restricted RNA polymerase proofreading ability thus it is very genetically susceptible to mutation. The evolution of SARS-CoV-2 from a single-point zoonotic introduction in Wuhan in November or December 2019 was widely expected, and viral sequence surveillance was developed as a result. When the first sequence of SARS-CoV-2 was released, a race to develop vaccines started, and several vaccines are now used worldwide. Independent SARS-CoV-2 lineages have recently been identified in the UK (B.1.1.7), Brazil (P.1), South Africa (B.1.351), and India (B.1.617). The recent appearance of several SARS-CoV-2 variant strains has shattered faith in the modern generation of vaccines' ability to provide enduring defense against infection. The risk of escaping natural and induced immunity has encouraged an urgency to comprehend the implications of these improvements, as well as a drive to develop new approaches to combat SARS-CoV-2 variants.

Testosterone as a Biomarker of Adverse Clinical Outcomes in SARS-CoV-2 Pneumonia

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may affect testicles. Lower testosterone levels have been associated with worse clinical outcomes and higher mortality. Our objective was to evaluate the hypothalamic−pituitary−gonadal axis of men admitted with SARS-CoV-2 pneumonia and its link with the pneumonia-treatment intensification. Short-term changes in hormonal parameters were also assessed. Methods: Men admitted with SARS-CoV-2 pneumonia were recruited in two different hospitals in Piedmont, Italy. In all patients, the assessment of total testosterone (TT), calculated free testosterone (cFT), gonadotropins, inhibin B (InhB), and other biochemical evaluations were performed at admission (T0) and before discharge (T1). Through a review of medical records, clinical history was recorded, including data on pneumonia severity. Results: Thirty-five men (median age 64 [58−74] years) were recruited. Lower TT and cFT levels at T0 were associated with CPAP therapy (p = 0.045 and 0.028, respectively), even after adjusting for age and PaO2/FIO2 ratio in a multivariable analysis. In those discharged alive, lower TT and cFT levels were associated with longer hospital stay (p < 0.01). TT, cFT, and InhB were below the normal range at T0 and significantly increased at T1 (TT 1.98 [1.30−2.72] vs. 2.53 [1.28−3.37] ng/mL, p = 0.038; cFT (0.0441 [0.0256−0.0742] vs. 0.0702 [0.0314−0.0778] ng/mL, p = 0.046; InhB 60.75 [25.35−88.02] vs. 77.05 [51.15−134.50], p < 0.01). Conclusions: Both TT and cFT levels are associated with adverse clinical outcomes in men admitted with SARS-CoV-2 pneumonia. As TT, cFT and InhB levels increase before discharge, short-term functional recovery of steroidogenesis and an indirect improvement of spermatozoa functional status could be hypothesized.

Angiotensin II Type I Receptor (AT1R): The Gate towards COVID-19-Associated Diseases

The binding of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein to its cellular receptor, the angiotensin-converting enzyme 2 (ACE2), causes its downregulation, which subsequently leads to the dysregulation of the renin-angiotensin system (RAS) in favor of the ACE-angiotensin II (Ang II)-angiotensin II type I receptor (AT1R) axis. AT1R has a major role in RAS by being involved in several physiological events including blood pressure control and electrolyte balance. Following SARS-CoV-2 infection, pathogenic episodes generated by the vasoconstriction, proinflammatory, profibrotic, and prooxidative consequences of the Ang II-AT1R axis activation are accompanied by a hyperinflammatory state (cytokine storm) and an acute respiratory distress syndrome (ARDS). AT1R, a member of the G protein-coupled receptor (GPCR) family, modulates Ang II deleterious effects through the activation of multiple downstream signaling pathways, among which are MAP kinases (ERK 1/2, JNK, p38MAPK), receptor tyrosine kinases (PDGF, EGFR, insulin receptor), and nonreceptor tyrosine kinases (Src, JAK/STAT, focal adhesion kinase (FAK)), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. COVID-19 is well known for generating respiratory symptoms, but because ACE2 is expressed in various body tissues, several extrapulmonary pathologies are also manifested, including neurologic disorders, vasculature and myocardial complications, kidney injury, gastrointestinal symptoms, hepatic injury, hyperglycemia, and dermatologic complications. Therefore, the development of drugs based on RAS blockers, such as angiotensin II receptor blockers (ARBs), that inhibit the damaging axis of the RAS cascade may become one of the most promising approaches for the treatment of COVID-19 in the near future. We herein review the general features of AT1R, with a special focus on the receptor-mediated activation of the different downstream signaling pathways leading to specific cellular responses. In addition, we provide the latest insights into the roles of AT1R in COVID-19 outcomes in different systems of the human body, as well as the role of ARBs as tentative pharmacological agents to treat COVID-19.

Prognosis and antibody profiles in survivors of critical illness from COVID-19: a prospective multicentre cohort study

BACKGROUND

There is a need to assess the long-term outcomes of survivors of critical illness from COVID-19.

METHODS

Ninety-two survivors of critical illness from COVID-19 from four hospitals in Hubei Province, China participated in this prospective cohort study. Multiple characteristics, including lung function (lung volumes, diffusing capacity for carbon monoxide, chest computed tomography scores, and walking capacity); immune status (SARS-CoV-2-neutralising antibody and all subtypes of immunoglobulin (Ig) G against SARS-CoV-2, immune cells in response to ex vivo antigen peptide stimuli, and lymphocyte count and its subtypes); liver, coagulation, and kidney functions; quality of life; cognitive function; and mental status, were assessed after 3, 6, and 12 months of follow-up.

RESULTS

Amongst the 92 enrolled survivors, 72 (78%) patients required mechanical ventilation. At 12 months, the predicted percentage diffusing capacity of lung for carbon monoxide was 82% (inter-quartile range [IQR]: 76-97%) with a residual volume of 77 (64-88)%. Other lung function parameters and the 6-min walk test improved gradually over time and were almost back to normal by 12 months. The titres of IgG and neutralising antibody to COVID-19 remained high at 12 months compared with those of controls who were not infected with COVID-19, although IgG titres decreased significantly from 34.0 (IQR: 23.8-74.3) to 15.0 (5.8-24.3) AU ml-1 (P<0.001), whereas neutralising antibodies decreased from 29.99 (IQR: 19.43-53.93) AU ml-1 at 6 months to 19.75 (13.1-29.8) AU ml-1 (P<0.001) at 12 months. In general, liver, kidney, physical, and mental functions also improved over time.

CONCLUSIONS

Survivors of critical illness from COVID-19 show some persistent long-term impairments in lung function. However, a majority of these tests were normal by 12 months. These patients still had detectable levels of neutralising antibodies against SARS-CoV-2 and all types of IgG at 12 months, but the levels had declined over this time period.

CLINICAL TRIAL REGISTRATION

None.

Potential mechanisms underlying lithium treatment for Alzheimer's disease and COVID-19

Disruption of intracellular Ca2+ homeostasis plays an important role as an upstream pathology in Alzheimer's disease (AD), and correction of Ca2+ dysregulation has been increasingly proposed as a target of future effective disease-modified drugs for treating AD. Calcium dysregulation is also an upstream pathology for the COVID-19 virus SARS-CoV-2 infection and replication, leading to host cell damage. Clinically available drugs that can inhibit the disturbed intracellular Ca2+ homeostasis have been repurposed to treat COVID-19 patients. This narrative review aims at exploring the underlying mechanism by which lithium, a first line drug for the treatment of bipolar disorder, inhibits Ca2+ dysregulation and associated downstream pathology in both AD and COVID-19. It is suggested that lithium can be repurposed to treat AD patients, especially those afflicted with COVID-19.

Bradykinin-target therapies in SARS-CoV-2 infection: current evidence and perspectives

Coronavirus disease 2019 (COVID-19) is a potentially fatal disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that preferentially infects the respiratory tract. Bradykinin (BK) is a hypotensive substance that recently emerged as one of the mechanisms to explain COVID-19-related complications. Concerning this, in this review, we try to address the complex link between BK and pathophysiology of COVID-19, investigating the role of this peptide as a potential target for pharmacological modulation in the management of SARS-CoV-2. The pathology of COVID-19 may be more a result of the BK storm than the cytokine storm, and which BK imbalance is a relevant factor in the respiratory disorders caused by SARS-CoV-2 infection. Regarding this, an interesting point of intervention for this disease is to modulate BK signaling. Some drugs, such as icatibant, ecallantide, and noscapine, and even a human monoclonal antibody, lanadelumab, have been studied for their potential utility in COVID-19 by modulating BK signaling. The interaction of the BK pathway and the involvement of cytokines such as IL-6 and IL1 may be key to the use of blockers, even if only as adjuvants. In fact, reduction of BK, mainly DABK, is considered a relevant strategy to improve clinical conditions of COVID-19 patients. In this context, despite the current unproven clinical efficacy, drugs repurposing that block B1 or B2 receptor activation have gained prominence for the treatment of COVID-19 in the world.

Clinical and Molecular Relationships between COVID-19 and Feline Infectious Peritonitis (FIP)

The emergence of severe acute respiratory syndrome 2 (SARS-CoV-2) has led the medical and scientific community to address questions surrounding the pathogenesis and clinical presentation of COVID-19; however, relevant clinical models outside of humans are still lacking. In felines, a ubiquitous coronavirus, described as feline coronavirus (FCoV), can present as feline infectious peritonitis (FIP)-a leading cause of mortality in young cats that is characterized as a severe, systemic inflammation. The diverse extrapulmonary signs of FIP and rapidly progressive disease course, coupled with a closely related etiologic agent, present a degree of overlap with COVID-19. This paper will explore the molecular and clinical relationships between FIP and COVID-19. While key differences between the two syndromes exist, these similarities support further examination of feline coronaviruses as a naturally occurring clinical model for coronavirus disease in humans.

The mechanism underlying extrapulmonary complications of the coronavirus disease 2019 and its therapeutic implication

The coronavirus disease 2019 (COVID-19) is a highly transmissible disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that poses a major threat to global public health. Although COVID-19 primarily affects the respiratory system, causing severe pneumonia and acute respiratory distress syndrome in severe cases, it can also result in multiple extrapulmonary complications. The pathogenesis of extrapulmonary damage in patients with COVID-19 is probably multifactorial, involving both the direct effects of SARS-CoV-2 and the indirect mechanisms associated with the host inflammatory response. Recognition of features and pathogenesis of extrapulmonary complications has clinical implications for identifying disease progression and designing therapeutic strategies. This review provides an overview of the extrapulmonary complications of COVID-19 from immunological and pathophysiologic perspectives and focuses on the pathogenesis and potential therapeutic targets for the management of COVID-19.

Decreased serum levels of angiotensin converting enzyme (ACE)2 and enhanced cytokine levels with severity of COVID-19: normalisation upon disease recovery

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). Circulating soluble angiotensin-converting enzyme (sACE2)2, the main receptor for SARS-CoV-2, together with components of the renin-angiotensin system promote infection and disease severity.

Objective

This pilot study followed the time-course of sACE2 levels in relation to systemic cytokines in severe and moderate COVID-19 patients treated with remdesivir/dexamethasone in combination.

Methods

Peripheral blood was obtained upon admission from 30 patients (12 with moderate disease and 18 with severe disease) and 14 patients with PCR-confirmed mild COVID-19. Severe and moderate patients were treated with remdesivir (200mg/first day and 100mg/day for the remaining days) and dexamethasone (100mg/day). 6 healthy control subjects (HC) were also enrolled. Serum interleukin (IL)-6 and IL-8 and sACE2 levels were measured by ELISA at baseline and during treatment in severe and moderate patients and at baseline in mild and HCs.

Results

Baseline sACE2 levels were lower in severe (p = 0.0005) and moderate (p = 0.0022) patients than in patients with mild COVID-19 and in HC (p = 0.0023 and p = 0.0012 respectively). Treatment significantly increased sACE2 levels in patients with moderate disease (p = 0.0156) but only 50% of patients with severe disease showed enhanced levels compared to baseline. Systemic IL-6 and IL-8 levels were higher in all patient groups compared with HC and were not significantly affected over time or by remdesivir/dexamethasone treatment for 5 days.

Conclusion

Serum sACE2 levels increase in severe COVID-19 patients as they recover over time whilst circulating cytokines are unaffected. Future studies should link these results to clinical outcomes.