Angiotensin-Converting Enzyme 2 (ACE2) Is a Key Modulator of the Renin Angiotensin System in Health and Disease. Int J Pept. 2012;2012:256294. [PMID: 22536270 PMCID: PMC3321295 DOI: 10.1155/2012/256294]

Target SARS-CoV-2: computation of binding energies with drugs of dexamethasone/umifenovir by molecular dynamics using OPLS-AA force field

Introduction

In recent times, myriads of public have been infected with a novel SARS-CoV-2, and the fatality toll has reached thousands and been mounting step by step, which is a major crisis in the world. The challenge for this burning issue pertinent to repurposed medicines which prevent novel coronavirus is of immense concern for all scientists around the globe until the arrival of the vaccine.

Methods

Because of the global high priority rating on the search for the repurposed drugs which outfits clinical suitability to SARS-CoV-2, a unique theoretical methodology is proposed. The approach is based on explorations of biothermodynamics computed via molecular dynamics, root-mean-square deviation (RMSD), radius of gyration (Rg) and interactions. This unique methodology is tested for umifenovir/dexamethasone drugs on (SARS-CoV-2) main protease.

Results

This theoretical exploration not only suggested the presence of strong interactions between (SARS-CoV-2 + umifenovir/dexamethasone) but also emphasized the clinical suitability of dexamethasone over umifenovir to treat SARS-CoV-2. This supremacy of dexamethasone is well supported by the results of global clinical trials and COVID-19 therapeutic approved management guidelines of countries.

Conclusions

Thus, this work will pave a way for incremental advancement towards future design and development of more specific inhibitors for the treatment of SARS-CoV-2 infection in humans.

Translating bioactive peptides for COVID-19 therapy

COVID-19 (Coronavirus disease 2019) is a global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a positive-sense RNA virus. This virus has emerged as a threat to global health, social stability, and the global economy. This pandemic continues to cause rampant mortality worldwide with the dire urgency to develop novel therapeutic agents. To meet this task, this article discusses advances in the research and potential application of bioactive peptides for possible mitigation of infection by SARS-CoV-2. Growing insight into the molecular biology of SARS-CoV-2 has revealed potential druggable targets for bioactive peptides. Bioactive peptides with unique amino acid sequences can mitigate such targets including, type II transmembrane serine proteases (TMPRSS2) inhibition, furin cleavage, and renin-angiotensin-aldosterone system (RAAS) members. Based on current evidence and structure-function analysis, multiple bioactive peptides present potency to neutralize the virus. To date, no SARS-CoV-2-explicit drug has been reported, but we here introduce bioactive peptides in the perspective of their potential activity against SARS-CoV-2 infection.

Promising phytochemicals of traditional Indian herbal steam inhalation therapy to combat COVID-19 - An in silico study

Background

COVID-19, the presently prevailing global public health emergency has culminated in international instability in economy. This unprecedented pandemic outbreak pressingly necessitated the trans-disciplinary approach in developing novel/new anti-COVID-19 drugs especially, small molecule inhibitors targeting the seminal proteins of viral etiological agent, SARS-CoV-2.

Methods

Based on the traditional medicinal knowledge, we made an attempt through molecular docking analysis to explore the phytochemical constituents of three most commonly used Indian herbs in ‘steam inhalation therapy’ against well recognized viral receptor proteins.

Results

A total of 57 phytochemicals were scrutinized virtually against four structural protein targets of SARS-CoV-2 viz. 3CL^pro, ACE-2, spike glycoprotein and RdRp. Providentially, two bioactives from each of the three plants i.e. apigenin-o-7-glucuronide and ellagic acid from Eucalyptus globulus; eudesmol and viridiflorene from Vitex negundo and; vasicolinone and anisotine from Justicia adhatoda were identified to be the best hit lead molecules based on interaction energies, conventional hydrogen bonding numbers and other non-covalent interactions. On comparison with the known SARS-CoV-2 protease inhibitor –lopinavir and RdRp inhibitor –remdesivir, apigenin-o-7-glucuronide was found to be a phenomenal inhibitor of both protease and polymerase, as it strongly interacts with their active sites and exhibited remarkably high binding affinity. Furthermore, in silico drug-likeness and ADMET prediction analyses clearly evidenced the usability of the identified bioactives to develop as drug against COVID-19.

Conclusion

Overall, the data of the present study exemplifies that the phytochemicals from selected traditional herbs having significance in steam inhalation therapy would be promising in combating COVID-19.

Neurological and Neuropsychological Changes Associated with SARS-CoV-2 Infection: New Observations, New Mechanisms

SARS-CoV-2 infects cells through angiotensin-converting enzyme 2 (ACE2), a ubiquitous receptor that interacts with the virus' surface S glycoprotein. Recent reports show that the virus affects the central nervous system (CNS) with symptoms and complications that include dizziness, altered consciousness, encephalitis, and even stroke. These can immerge as indirect immune effects due to increased cytokine production or via direct viral entry into brain tissue. The latter is possible through neuronal access via the olfactory bulb, hematogenous access through immune cells or directly across the blood-brain barrier (BBB), and through the brain's circumventricular organs characterized by their extensive and highly permeable capillaries. Last, the COVID-19 pandemic increases stress, depression, and anxiety within infected individuals, those in isolation, and high-risk populations like children, the elderly, and health workers. This review surveys the recent updates of CNS manifestations post SARS-CoV-2 infection along with possible mechanisms that lead to them.

Anti-inflammatory drugs and the renin-angiotensin-aldosterone system: Current knowledge and potential effects on early SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of coronavirus disease 19 (COVID-19), and is genetically related to the 2003 SARS and Middle East respiratory syndrome (MERS-CoV) coronaviruses. Recent studies have reported that similar to SARS-CoV, this strain expresses a spike protein (S) with a receptor binding domain (RBD) that binds to angiotensin-converting enzyme 2 (ACE2) - an enzyme expressed mostly in the endothelium, kidneys, heart, gastrointestinal tract and lungs - to facilitate viral entry and intracellular replication. Incidentally, the renin-angiotensin-aldosterone system (RAAS) is integral to physiologic control of both ACE and ACE2 expression, and is an essential system utilized by SARS-CoV-2, albeit with varying schools of thought on how it can affect viral entry. In this paper, we will review current knowledge on the RAAS and how it can be affected by non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroid use at the organ and cellular levels. We will then discuss the relevance of these interactions on organ-specific ACE2 expression, and provide scientific insights on how this mechanism can potentially affect SARS-CoV-2 infection in the early phases of disease. From the standpoint of other known viruses, we will then aim to discuss the potential uses or restrictions of these drugs in viral infection, and provide an update on relevant studies about COVID-19.

Interaction of Severe Acute Respiratory Syndrome Coronavirus 2 and Diabetes

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing a worldwide epidemic. It spreads very fast and hits people of all ages, especially patients with underlying diseases such as diabetes. In this review, we focus on the influences of diabetes on the outcome of SARS-CoV-2 infection and the involved mechanisms including lung dysfunction, immune disorder, abnormal expression of angiotensin-converting enzyme 2 (ACE2), overactivation of mechanistic target of rapamycin (mTOR) signaling pathway, and increased furin level. On the other hand, SARS-CoV-2 may trigger the development of diabetes. It causes the damage of pancreatic β cells, which is probably mediated by ACE2 protein in the islets. Furthermore, SARS-CoV-2 may aggravate insulin resistance through attacking other metabolic organs. Of note, certain anti-diabetic drugs (OADs), such as peroxisome proliferator-activated receptor γ (PPARγ) activator and glucagon-like peptide 1 receptor (GLP-1R) agonist, have been shown to upregulate ACE2 in animal models, which may increase the risk of SARS-CoV-2 infection. However, Metformin, as a first-line medicine for the treatment of type 2 diabetes mellitus (T2DM), may be a potential drug benefiting diabetic patients with SARS-CoV-2 infection, probably via a suppression of mTOR signaling together with its anti-inflammatory and anti-fibrosis function in lung. Remarkably, another kind of OADs, dipeptidyl Peptidase 4 (DPP4) inhibitor, may also exert beneficial effects in this respect, probably via a prevention of SARS-CoV-2 binding to cells. Thus, it is of significant to identify appropriate OADs for the treatment of diabetes in the context of SARS-CoV-2 infections.

Smoking and COVID-19: What we know so far

The ongoing COVID-19 pandemic has placed a spotlight on infectious diseases and their associations with host factors and underlying conditions. New data on the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus are entering the public domain at a rapid rate such that their distillation often lags behind. To minimise weak associations becoming perceived as established paradigms, it is imperative that methodologies and outputs from different studies are appropriately critiqued and compared. In this review, we examine recent data on a potential relationship between smoking and COVID-19. While the causal role of smoking has been firmly demonstrated in regard to lung cancer and chronic obstructive pulmonary disease, such associations have the benefit of decades' worth of multi-centre epidemiological and mechanistic data. From our analysis of the available studies to date, it appears that a relationship is emerging in regard to patients with a smoking history having a higher likelihood of developing more severe symptoms of COVID-19 disease than non-smokers. Data on whether COVID-19 has a greater incidence in smokers than non-smokers is thus far, contradictory and inconclusive. There is therefore a need for some caution to be exercised until further research has been conducted in a wider range of geographical settings with sufficient numbers of patients that have been carefully phenotyped in respect of smoking status and adequate statistical control for confounding factors.

Contribution of gut microbiota and multiple organ failure in the pathogenesis of COVID-19 infection

COVID-19, which originated in Wuhan, China, has spread rapidly all over the world. An increasing number of COVID-19 cases are caused by human-to-human transmission via respiratory droplets, coughs, and sneezes. The symptoms of COVID-19 patients are heterogeneous, ranging from mild upper respiratory symptoms (fever, languidness, unstable walking, dry cough, fatigue, and respiratory symptoms) to severe pneumonitis and even acute respiratory distress syndrome (ARDS) or death. COVID-19 invades human respiratory epithelial cells by binding with angiotensin-converting enzyme 2 (ACE2) receptors on human cell surfaces. Death in COVID-19 patients is caused by multiorgan function failure. In addition, systemic immune overactivation due to COVID-19 infection produces elevated expression of proinflammatory cytokines and chemokines, resulting in a so-called cytokine storm, a process that is an important factor in COVID-19 disease progression and multiple organ failure leading to death.

Cardiovascular Pathophysiology, Epidemiology, and Treatment Considerations of Coronavirus Disease 2019 (COVID-19): A Review

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is rapidly evolving, with important cardiovascular considerations. The presence of underlying cardiovascular risk factors and established cardiovascular disease (CVD) may affect the severity and clinical management of patients with COVID-19. We conducted a review of the literature to summarize the cardiovascular pathophysiology, risk factors, clinical presentations, and treatment considerations of COVID-19 patients with underlying CVD. Angiotensin-converting enzyme 2 (ACE2) has been identified as a functional receptor for the SARS-CoV-2 virus, and it is associated with the cardiovascular system. Hypertension, diabetes, and CVD are the most common comorbidities in COVID-19 patients, and these factors have been associated with the progression and severity of COVID-19. However, elderly populations, who develop more-severe COVID-19 complications, are naturally exposed to these comorbidities, underscoring the possible confounding of age. Observational data support international cardiovascular societies' recommendations to not discontinue ACE inhibitor/angiotensin-receptor blocker therapy in patients with guideline indications for fear of the increased risk of SARS-CoV-2 infection, severe disease, or death. In addition to the cardiotoxicity of experimental antivirals and potential interactions of experimental therapies with cardiovascular drugs, several strategies for cardiovascular protection have been recommended in COVID-19 patients with underlying CVD. Troponin elevation is associated with increased risk of in-hospital mortality and adverse outcomes in patients with COVID-19. Cardiovascular care teams should have a high index of suspicion for fulminant myocarditis-like presentations being SARS-CoV-2 positive, and remain vigilant for cardiovascular complications in COVID-19 patients.

Alveolar epithelial cell type II as main target of SARS-CoV-2 virus and COVID-19 development via NF-Kb pathway deregulation: A physio-pathological theory

The Corona Virus Disease (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) requires a rapid solution and global collaborative efforts in order to define preventive and treatment strategies. One of the major challenges of this disease is the high number of patients needing advanced respiratory support due to the Acute Respiratory Distress Syndrome (ARDS) as the lung is the major - although not exclusive - target of the virus. The molecular mechanisms, pathogenic drivers and the target cell type(s) in SARS-CoV-2 infection are still poorly understood, but the development of a "hyperactive" immune response is proposed to play a role in the evolution of the disease and it is envisioned as a major cause of morbidity and mortality. Here we propose a theory by which the main targets for SARS-CoV-2 are the Type II Alveolar Epithelial Cells and the clinical manifestations of the syndrome are a direct consequence of their involvement. We propose the existence of a vicious cycle by which once alveolar damage starts in AEC II cells, the inflammatory state is supported by macrophage pro-inflammatory polarization (M1), cytokines release and by the activation of the NF-κB pathway. If this theory is confirmed, future therapeutic efforts can be directed to target Type 2 alveolar cells and the molecular pathogenic drivers associated with their dysfunction with currently available therapeutic strategies.

Review on COVID-19 Etiopathogenesis, Clinical Presentation and Treatment Available with Emphasis on ACE2

In December 2019, Wuhan city in the Hubei province of China reported for the first time a cluster of patients infected with a novel coronavirus, since then there has been an outburst of this disease across the globe affecting millions of human inhabitants. Severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2), is a member of beta coronavirus family which upon exposure caused a highly infectious disease called novel coronavirus disease-2019 (COVID-19). COVID-19, a probably bat originated disease was declared by World Health Organization (WHO) as a global pandemic in March 2020. Since then, despite rigorous global containment and quarantine efforts, the disease has affected nearly 56,261,952 laboratory confirmed human population and caused deaths of over 1,349,506 lives worldwide. Virus passes in majority through respiratory droplets and then enters lung epithelial cells by binding to angiotensin converting enzyme 2 (ACE2) receptor and there it undergoes replication and targeting host cells causing severe pathogenesis. Majority of human population exposed to SARS-CoV-2 having fully functional immune system undergo asymptomatic infection while 5-10% are symptomatic and only 1-2% are critically affected and requires ventilation support. Older people or people with co-morbidities are severely affected by COVID-19. These categories of patients also display cytokine storm due to dysfunctional immune response which brutally destroys the affected organs and may lead to death in some. Real time PCR is still considered as standard method of diagnosis along with other serology, radiological and biochemical investigations. Till date, no specific validated medication is available for the treatment of COVID-19 patients. Thus, this review provides detailed knowledge about the different landscapes of disease incidence, etiopathogenesis, involvement of various organs, diagnostic criteria's and treatment guidelines followed for management of COVID-19 infection since its inception. In conclusion, extensive research to recognize novel pathways and their cross talk to combat this virus in precarious settings is our future positive hope.

SARS-CoV-2 (COVID-19): Beginning to Understand a New Virus

Within the last two decades, several members of the Coronaviridae family demonstrated epidemic potential. In late 2019, an unnamed genetic relative, later named SARS-CoV-2 (COVID-19), erupted in the highly populous neighborhoods of Wuhan, China. Unchecked, COVID-19 spread rapidly among interconnected communities and related households before containment measures could be enacted. At present, the mortality rate of COVID-19 infection worldwide is 6.6%. In order to mitigate the number of infections, restrictions or recommendations on the number of people that can gather in a given area have been employed by governments worldwide. For governments to confidently lift these restrictions as well as counter a potential secondary wave of infections, alternative medications and diagnostic strategies against COVID-19 are urgently required. This review has focused on these issues.

Mega doses of retinol: A possible immunomodulation in Covid-19 illness in resource-limited settings

Of all the nutrients, vitamin A has been the most extensively evaluated for its impact on immunity. There are three main forms of vitamin A, retinol, retinal and retinoic acid (RA) with the latter being most biologically active and all‐trans‐RA (ATRA) its main derivative. Vitamin A is a key regulator of the functions of various innate and adaptive immune cells and promotes immune‐homeostasis. Importantly, it augments the interferon‐based innate immune response to RNA viruses decreasing RNA virus replication. Several clinical trials report decreased mortality in measles and Ebola with vitamin A supplementation.During the Covid‐19 pandemic interventions such as convalescent plasma, antivirals, monoclonal antibodies and immunomodulator drugs have been tried but most of them are difficult to implement in resource‐limited settings. The current review explores the possibility of mega dose vitamin A as an affordable adjunct therapy for Covid‐19 illness with minimal reversible side effects. Insight is provided into the effect of vitamin A on ACE‐2 expression in the respiratory tract and its association with the prognosis of Covid‐19 patients. Vitamin A supplementation may aid the generation of protective immune response to Covid‐19 vaccines. An overview of the dosage and safety profile of vitamin A is presented along with recommended doses for prophylactic/therapeutic use in randomised controlled trials in Covid‐19 patients.

Classical and alternative receptors for SARS-CoV-2 therapeutic strategy

Understanding the molecules that are essential for severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) entry can provide insights into viral infection and dissemination. Recently, it has been identified from several studies that angiotensin‐converting enzyme 2 receptor and transmembrane serine protease 2 are the main entry molecules for the SARS‐CoV‐2, which produced the pandemic of Covid‐19. However, additional evidence showed several other viral receptors and cellular proteases that are also important in facilitating viral entry and transmission in the target cells. In this review, we summarized the types of SARS‐CoV‐2 entry molecules and discussed their crucial roles for virus binding, protein priming and fusion to the cellular membrane important for SARS‐CoV‐2 infection.

Liver dysfunction in COVID-19: a useful prognostic marker of severe disease?

BACKGROUND

COVID-19 is a global pandemic caused by the novel coronavirus SARS-CoV-2. Risk factors and prognostic markers of severe disease remain to be fully determined, although some studies have suggested a correlation between abnormal liver function and adverse outcomes. Further studies are needed to investigate this further.

METHODS

This retrospective study enrolled patients with a confirmed diagnosis of COVID-19 who were admitted to Kingston Hospital in the UK. Data collected included age, sex, ethnicity, comorbidity profile, biochemical markers of liver function and the acute phase response, and overall outcome.

RESULTS

Between 16 March 2020 and 30 April 2020, a total of 343 patients were admitted to the acute medical team at Kingston Hospital. Excluding those with a history of liver disease, 299 patients had liver function tests performed with abnormalities demonstrated in 44.8% of individuals. Derangement of liver function was associated with greater need for ventilatory support (p<0.001), admission to high dependency unit or intensive care (p<0.001) and increased length of hospital stay (p<0.001). Of note, liver dysfunction was more common in those of non-white ethnicity (p=0.007) and correlated with higher levels of C reactive protein (p=0.01) and ferritin (p<0.001).

CONCLUSION

Abnormal liver function is associated with a negative outcome among those hospitalised with COVID-19. The cause for this association is unclear, but correlation between abnormal liver function and higher serum levels of acute phase proteins suggest that dysregulation of the immune system in response to SARS-CoV-2 may be contributory.

An ACE2 Microbody Containing a Single Immunoglobulin Fc Domain Is a Potent Inhibitor of SARS-CoV-2

Soluble forms of angiotensin-converting enzyme 2 (ACE2) have recently been shown to inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We report on an improved soluble ACE2, termed a "microbody," in which the ACE2 ectodomain is fused to Fc domain 3 of the immunoglobulin (Ig) heavy chain. The protein is smaller than previously described ACE2-Ig Fc fusion proteins and contains an H345A mutation in the ACE2 catalytic active site that inactivates the enzyme without reducing its affinity for the SARS-CoV-2 spike. The disulfide-bonded ACE2 microbody protein inhibits entry of SARS-CoV-2 spike protein pseudotyped virus and replication of live SARS-CoV-2 in vitro and in a mouse model. Its potency is 10-fold higher than soluble ACE2, and it can act after virus bound to the cell. The microbody inhibits the entry of β coronaviruses and virus with the variant D614G spike. The ACE2 microbody may be a valuable therapeutic for coronavirus disease 2019 (COVID-19) that is active against viral variants and future coronaviruses.

Hypertension and renin-angiotensin system blockers are not associated with expression of angiotensin-converting enzyme 2 (ACE2) in the kidney

AIMS

Angiotensin-converting enzyme 2 (ACE2) is the cellular entry point for severe acute respiratory syndrome coronavirus (SARS-CoV-2)-the cause of coronavirus disease 2019 (COVID-19). However, the effect of renin-angiotensin system (RAS)-inhibition on ACE2 expression in human tissues of key relevance to blood pressure regulation and COVID-19 infection has not previously been reported.

METHODS AND RESULTS

We examined how hypertension, its major metabolic co-phenotypes, and antihypertensive medications relate to ACE2 renal expression using information from up to 436 patients whose kidney transcriptomes were characterized by RNA-sequencing. We further validated some of the key observations in other human tissues and/or a controlled experimental model. Our data reveal increasing expression of ACE2 with age in both human lungs and the kidney. We show no association between renal expression of ACE2 and either hypertension or common types of RAS inhibiting drugs. We demonstrate that renal abundance of ACE2 is positively associated with a biochemical index of kidney function and show a strong enrichment for genes responsible for kidney health and disease in ACE2 co-expression analysis.

CONCLUSION

Our results indicate that neither hypertension nor antihypertensive treatment is likely to alter the expression of the key entry receptor for SARS-CoV-2 in the human kidney. Our data further suggest that in the absence of SARS-CoV-2 infection, kidney ACE2 is most likely nephro-protective but the age-related increase in its expression within lungs and kidneys may be relevant to the risk of SARS-CoV-2 infection.

Management of Coronavirus Disease 2019 (COVID-19) Pandemic: From Diagnosis to Treatment Strategies

Following the emergence of severe acute respiratory syndrome (SARS) in 2002 and the Middle East respiratory syndrome (MERS) in 2012, the world is now combating a third large‐scale outbreak caused by a coronavirus, the coronavirus disease 2019 (COVID‐19). After the rapid spread of SARS‐coronavirus (CoV)‐2 (the virus causing COVID‐19) from its origin in China, the World Health Organization (WHO) declared a Public Health Emergency of International Concern (PHEIC) on January 30, 2020. From the beginning of the COVID‐19 pandemic, a significant number of studies have been conducted to better understand the biology and pathogenesis of the novel coronavirus, and to aid in developing effective treatment regimens, therapeutics, and vaccines. This review focuses on the recent advancements in the rapidly evolving areas of clinical care and management of COVID‐19. The emerging strategies for the diagnosis and treatment of this disease are explored, and the development of effective vaccines is reviewed.

COVID-19-Associated Hyper-Fibrinolysis: Mechanism and Implementations

The emerging novel coronavirus disease (COVID-19), which is caused by the SARS-CoV-2 presents with high infectivity, morbidity and mortality. It presenting a need for immediate understanding of its pathogenicity. Inflammation and coagulation systems are over-activated in COVID-19. SARS-CoV-2 damages endothelial cell and pneumocyte, resulting in hemostatic disorder and ARDS. An influential biomarkers of poor outcome in COVID-19 are high circulating cytokines and D-dimer level. This latter is due to hyper-fibrinolysis and hyper-coagulation. Plasmin is a key player in fibrinolysis and is involved in the cleavage of many viruses envelop proteins, including SARS-CoV. This function is similar to that of TMPRSS2, which underpins the entry of viruses into the host cell. In addition, plasmin is involved in the pathophysiology of ARDS in SARS and promotes secretion of cytokine, such as IL-6 and TNF, from activated macrophages. Here, we suggest an out-of-the-box treatment for alleviating fibrinolysis and the ARDS of COVID-19 patients. This proposed treatment is concomitant administration of an anti-fibrinolytic drug and the anticoagulant.

Possible Transmission Flow of SARS-CoV-2 Based on ACE2 Features

Angiotensin-converting enzyme 2 (ACE2) is the cellular receptor for the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that is engendering the severe coronavirus disease 2019 (COVID-19) pandemic. The spike (S) protein receptor-binding domain (RBD) of SARS-CoV-2 binds to the three sub-domains viz. amino acids (aa) 22–42, aa 79–84, and aa 330–393 of ACE2 on human cells to initiate entry. It was reported earlier that the receptor utilization capacity of ACE2 proteins from different species, such as cats, chimpanzees, dogs, and cattle, are different. A comprehensive analysis of ACE2 receptors of nineteen species was carried out in this study, and the findings propose a possible SARS-CoV-2 transmission flow across these nineteen species.

Pathophysiology of SARS-CoV-2 in Lung of Diabetic Patients

Novel coronavirus disease (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Its impact on patients with comorbidities is clearly related to fatality cases, and diabetes has been linked to one of the most important causes of severity and mortality in SARS-CoV-2 infected patients. Substantial research progress has been made on COVID-19 therapeutics; however, effective treatments remain unsatisfactory. This unmet clinical need is robustly associated with the complexity of pathophysiological mechanisms described for COVID-19. Several key lung pathophysiological mechanisms promoted by SARS-CoV-2 have driven the response in normoglycemic and hyperglycemic subjects. There is sufficient evidence that glucose metabolism pathways in the lung are closely tied to bacterial proliferation, inflammation, oxidative stress, and pro-thrombotic responses, which lead to severe clinical outcomes. It is also likely that SARS-CoV-2 proliferation is affected by glucose metabolism of type I and type II cells. This review summarizes the current understanding of pathophysiology of SARS-CoV-2 in the lung of diabetic patients and highlights the changes in clinical outcomes of COVID-19 in normoglycemic and hyperglycemic conditions.

Arterial Hypertension as a Risk Comorbidity Associated with COVID-19 Pathology

Coronavirus disease 2019 (COVID-19), caused by the novel coronavirus severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), is an ongoing global public health challenge. Current clinical data suggest that, in COVID-19 patients, arterial hypertension (AH) is one of the most common cardiovascular comorbidities; it can worsen outcomes and increase the risk of admission to intensive care unit (ICU). The exact mechanisms through which AH contributes to the poor prognosis in COVID-19 are not yet clear. The putative relationship between AH and COVID-19 may be linked to the role of angiotensin-converting enzyme 2 (ACE2), a key element of the AH pathophysiology. Another mechanism connecting AH and COVID-19 is the dysregulation of the immune system resulting in a cytokine storm, mediated by an imbalanced response of T helper cells subtypes. Therefore, it is essential to optimize blood pressure control in hypertensive patients and monitor them carefully for cardiovascular and other complications for the duration of COVID-19 infection. The question whether AH-linked ACE2 gene polymorphisms increase the risk and/or worsen the course of SARS-CoV-2 infection should also receive further consideration.

SARS-CoV-2, ACE2 expression, and systemic organ invasion

A novel coronavirus disease, COVID-19, has created a global pandemic in 2020, posing an enormous challenge to healthcare systems and affected communities. COVID-19 is caused by severe acute respiratory syndrome (SARS)-coronavirus-2 (CoV-2) that manifests as bronchitis, pneumonia, or a severe respiratory illness. SARS-CoV-2 infects human cells via binding a "spike" protein on its surface to angiotensin-converting enzyme 2 (ACE2) within the host. ACE2 is crucial for maintaining tissue homeostasis and negatively regulates the renin-angiotensin-aldosterone system (RAAS) in humans. The RAAS is paramount for normal function in multiple organ systems including the lungs, heart, kidney, and vasculature. Given that SARS-CoV-2 internalizes via ACE2, the resultant disruption in ACE2 expression can lead to altered tissue function and exacerbate chronic diseases. The widespread distribution and expression of ACE2 across multiple organs is critical to our understanding of the varied clinical outcomes of COVID-19. This perspective review based on the current literature was prompted to show how disruption of ACE2 by SARS-CoV-2 can affect different organ systems.

Body Localization of ACE-2: On the Trail of the Keyhole of SARS-CoV-2

The explosion of the new coronavirus (SARS-CoV-2) pandemic has brought the role of the angiotensin converting enzyme 2 (ACE2) back into the scientific limelight. Since SARS-CoV-2 must bind the ACE2 for entering the host cells in humans, its expression and body localization are critical to track the potential target organ of this infection and to outline disease progression and clinical outcomes. Here, we mapped the physiological body distribution, expression, and activities of ACE2 and discussed its potential correlations and mutal interactions with the disparate symptoms present in SARS-CoV-2 patients at the level of different organs. We highlighted that despite during SARS-CoV-2 infection ACE2-expressing organs may become direct targets, leading to severe pathological manifestations, and subsequent multiple organ failures, the exact mechanism and the potential interactions through which ACE2 acts in these organs is still heavily debated. Further scientific efforts, also considering a personalized approach aimed to consider specific patient differences in the mutual interactions ACE2-SARS-CoV-2 and the long-term health effects associated with COVID-19 are currently mandatory.

A potential hypothesis for 2019-nCoV infection therapy through delivery of recombinant ACE2 by red blood cell-hitchhiking

A novel infectious disease, caused by 2019 Novel Coronavirus (2019-nCoV) is responsible for the recent outbreak of severe respiratory disease. The 2019-nCoV spread rapidly and reaching epidemic proportions in many countries of the world. ACE2 was identified as a key receptor for 2019-nCoV infections. Excessive form of soluble ACE2 rescues cellular ACE2 activity which has a protective role in acute lung failure and neutralizes the virus. The short half-life of ACE2 is a major limitation to its practical application. Nanoparticle-based drug delivery systems are one of the most widely investigated approaches for developing novel therapies for a variety of diseases. Nevertheless, nanoparticles suffer from the rapid removal from the bloodstream by the reticuloendothelial system (RES). A noncovalent attachment of nanoparticles to RBCs increases their half-life in blood and allows transient accumulation in the lungs, while decreases their uptake by the liver and spleen. Connecting the recombinant ACE2 into the surface of nanoparticles that were attached to RBCs can be a potential therapeutic approach for 2019-nCoV infection through increasing their lung targeting to naturalize the virus and also acting as a bioreactor in the blood circulation to decrease serum level of Angiotensin II and protects lungs from injury/ARDS.

Factors leading to high morbidity and mortality of COVID-19 in patients with type 2 diabetes

Coronavirus disease 2019 (COVID-19) is a recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus. Diabetes (mostly type 2 diabetes mellitus, T2DM) and hyperglycemia are among the major comorbidities in patients with COVID-19 leading to poor outcomes. Reports show that patients with diabetes and COVID-19 are at an increased risk for developing severe complications including acute respiratory distress syndrome, multi-organ failure, and death. Here we explore potential mechanistic links that could explain the observed higher morbidity and mortality in this patient population. Patients with T2DM have an underlying increased level of inflammation associated with obesity and insulin resistance in addition to other comorbidities including hypertension, obesity, cardiovascular disease, dyslipidemia, and being older. We review evidence that T2DM with hyperglycemia are among factors that lead to elevated expression of angiotensin-converting enzyme 2 (ACE2) in lungs and other tissues; ACE2 is the cellular "receptor" and port of viral entry. The preexisting chronic inflammation with augmented inflammatory response to the infection and the increasing viral load leads to extreme systemic immune response ("cytokine storm") that is strongly associated with increased severity of COVID-19. Based on the available evidence, it is recommended by a panel of experts that safe but stringent control of blood glucose, blood pressure, and lipids be carried out in patients with T2DM, measures that could potentially serve to decrease the severity of COVID-19 should these patients contract the viral infection. Once the infection occurs, then attention should be directed to proper glycemic control with use of insulin and frequent monitoring of blood glucose levels.

Gastrointestinal symptoms associated with COVID-19: impact on the gut microbiome

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the greatest worldwide pandemic since the 1918 flu. The consequences of the coronavirus disease 2019 (COVID-19) are devastating and represent the current major public health issue across the globe. At the onset, SARS-CoV-2 primarily attacks the respiratory system as it represents the main point of entry in the host, but it also can affect multiple organs. Although most of the patients do not present symptoms or are mildly symptomatic, some people infected with SARS-CoV-2 that experience more severe multiorgan dysfunction. The severity of COVID-19 is typically combined with a set of comorbidities such as hypertension, diabetes, obesity, and/or advanced age that seriously exacerbates the consequences of the infection. Also, SARS-CoV-2 can cause gastrointestinal symptoms, such as vomiting, diarrhea, or abdominal pain during the early phases of the disease. Intestinal dysfunction induces changes in intestinal microbes, and an increase in inflammatory cytokines. Thus, diagnosing gastrointestinal symptoms that precede respiratory problems during COVID-19 may be necessary for improved early detection and treatment. Uncovering the composition of the microbiota and its metabolic products in the context of COVID-19 can help determine novel biomarkers of the disease and help identify new therapeutic targets. Elucidating changes to the microbiome as reliable biomarkers in the context of COVID-19 represent an overlooked piece of the disease puzzle and requires further investigation.

Review of COVID-19 and male genital tract

COVID‐19 pandemic leads to health challenges globally, and its diverse aspects need to be uncovered. Multi‐organ injuries have been reported by describing potential SARS‐CoV‐2 entrance routes: ACE2 and TMPRSS2. Since these cell surface receptors’ expression has been disclosed within the male reproductive system, its susceptibility to being infected by SARS‐CoV‐2 has been summarised through this literature review. Expression of ACE2 and TMPRSS2 at RNA or protein level has been reported across various investigations indicates that the male genitalia potentially is vulnerable to SARS‐CoV‐2 infection. Presence of SARS‐CoV‐2 within semen samples and following direct viral damage, secondary inflammatory response causing orchitis or testicular discomfort and finally the amount of viral load leading testicular damage and immune response activation are among probable underlying mechanisms. Therefore, genital examination and laboratory tests should be considered to address the male reproductive tract complications and fertility issues.

Down's syndrome and COVID-19: risk or protection factor against infection? A molecular and genetic approach

Down syndrome (DS) is the most common genetic cause of learning difficulties and intellectual disabilities. DS patients often present with several congenital defects and chronic diseases, including immunity disorders. Elevated levels of pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α) have been seen, which appear to vary with age. At birth, patients present with combined immunodeficiency, with frequent infections that decrease with age. Furthermore, high levels of IL-4 and IL-10 with anti-inflammatory properties and low levels of IL-6 and TNF-α are described in children. The immune system is believed to play an essential role in SARS-CoV-2 pathogenesis, and it has been associated with elevated levels of pro-inflammatory cytokines and an exaggerated cytokine release syndrome (CRS) that may eventually trigger a severe situation called cytokine storm. On the other hand, genetic features seem to be involved in the predisposition to illness and its severity. Overexpression of DSCR1 and ZAKI-4 inhibits the translocation of activated T lymphocyte nuclear factor (NF-AT) to the nucleus, a main step in the inflammatory responsiveness. We discuss here the possible role of immunology and genetic features of DS in the infection and prognosis in COVID-19.

Should ACE2 be given a chance in COVID-19 therapeutics: A semi-systematic review of strategies enhancing ACE2

The severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) has resulted in almost 28 million cases of COVID-19 (Corona virus disease-2019) and more than 900000 deaths worldwide since December 2019. In the absence of effective antiviral therapy and vaccine, treatment of COVID-19 is largely symptomatic. By making use of its spike (S) protein, the virus binds to its primary human cell receptor, angiotensin converting enzyme 2 (ACE2) which is present in the pulmonary epithelial cells as well as other organs. SARS-CoV-2 may cause a downregulation of ACE2. ACE2 plays a protective role in the pulmonary system through its Mas-receptor and alamandine-MrgD-TGR7 pathways. Loss of this protective effect could be a major component of COVID-19 pathogenesis. An attractive strategy in SARS-CoV-2 therapeutics would be to augment ACE2 either directly by supplementation or indirectly through drugs which increase its levels or stimulate its downstream players. In this semi-systematic review, we have analysed the pathophysiological interplay between ACE and ACE2 in the cardiopulmonary system, the modulation of these two proteins by SARS-CoV-2, and potential therapeutic avenues targeting ACE-Ang II and ACE2-Ang (1-7) axes, that can be utilized against COVID-19 disease progression.

Covid 19 and its cardiovascular effects

COVID-19 pandemic is mainly related with the pulmonary problems initially but now as the pandemic is growing it is observed that almost all organ systems of the body are affected. Up to 20-30% patients who are admitted in Covid hospitals are showing cardiovascular involvement. Severity of cardiovascular disease in a COVID-19 patient depends whether a patient is having pre-existing cardiac disease or not. Patients with pre-existing cardiac disease have more severe infection and associated mortality. Severe COVID-19 infection shows close association with myocardial damage and various arrythmias. The cardiovascular involvement occurs by either engagement directly with the angiotensin converting enzyme 2 or indirectly by the effect of inflammatory mediators which are generated as a result of viral-host response to infection. The COVID-19 disease is said to produce a wide spectrum of affliction ranging between even asymptomatic patient to Cardiovascular syndrome. Even after recovering from COVID-19 patients can reappear in the hospital with cardiomyopathies and arrythmias.

SARS-CoV-2 and interferon blockade

The response to viral infection generally includes an activation of the adaptive immune response to produce cytotoxic T cells and neutralizing antibodies. We propose that SARS-CoV-2 activates the innate immune system through the renin-angiotensin and kallikrein-bradykinin pathways, blocks interferon production and reduces an effective adaptive immune response. This model has therapeutic implications.

Cancer Stem Cells in Head and Neck Metastatic Malignant Melanoma Express Components of the Renin-Angiotensin System

Components of the renin-angiotensin system (RAS) are expressed by cancer stem cells (CSCs) in many cancer types. We here investigated expression of the RAS by the CSC subpopulations in human head and neck metastatic malignant melanoma (HNmMM) tissue samples and HNmMM-derived primary cell lines. Immunohistochemical staining demonstrated expression of pro-renin receptor (PRR), angiotensin-converting enzyme (ACE), and angiotensin II receptor 2 (AT₂R) in all; renin in one; and ACE2 in none of the 20 HNmMM tissue samples. PRR was localized to cells within the tumor nests (TNs), while AT₂R was expressed by cells within the TNs and the peritumoral stroma (PTS). ACE was localized to the endothelium of the tumor microvessels within the PTS. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) detected transcripts for PRR, ACE, ACE2, and AT₁R, in all the five HNmMM tissue samples and four HNmMM-derived primary cell lines; renin in one tissue sample and one cell line, and AT₂R in none of the five HNmMM tissue samples and cell lines. Western blotting showed variable expression of ACE, PRR, and AT₂R, but not ACE2, in six HNmMM tissue samples and two HNmMM-derived primary cell lines. Immunofluorescence staining of two HNmMM tissue samples demonstrated expression of PRR and AT₂R by the SOX2+ CSCs within the TNs and the OCT4+ CSCs within the PTS, with ACE localized to the endothelium of the tumor microvessels within the PTS.

COVID-19: Case fatality and ACE2 inhibitors treatment concerns in patients with comorbidities

The Corona Virus Disease 2019 (COVID-19) outbreak is becoming pandemic with the highest mortality in patients with associated comorbidities. These RNA viruses containing 4 structural proteins usually use spike protein to enter the host cell. Angiotensin-converting enzyme 2 (ACE2) acts as a host receptor for the virus. Therefore, medications acting on renin-angiotensin-aldosterone system can lead to serious complications, especially in patients with diabetes and hypertension. To avoid this, other potential treatment modalities should be used in COVID-19 patients with associated comorbidities.

A Novel Coronavirus Disease (COVID-19): a Review of Host Cell Signaling Pathways

Coronaviruses (CoVs) are the largest group of positive-sense RNA viruses. By increasing our understanding of the interactions between CoVs and the host innate immune system, we can evaluate the development and persistence of inflammation in the lungs and reduce the risk of CoV-induced lung inflammation with a new group of genetic variants. Here, we aim to discuss some recent changes in host cell factors that may be used by CoV to promote the proliferation cycle. We also discuss different host cell signaling pathways that can be considered in the host-pathogen interactions at the molecular level. The pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has created new challenges for the cultural, economic, and health infrastructures. Therefore, it is important that healthcare systems and physicians recognize a global integrated framework for monitoring the progression of COVID-19 to develop targeted therapies that can potentially save human lives.

COVID-19, microthromboses, inflammation, and platelet activating factor

Recent articles report elevated markers of coagulation, endothelial injury, and microthromboses in lungs from deceased COVID-19 patients. However, there has been no discussion of what may induce intravascular coagulation. Platelets are critical in the formation of thrombi and their most potent trigger is platelet activating factor (PAF), first characterized by Demopoulos and colleagues in 1979. PAF is produced by cells involved in host defense and its biological actions bear similarities with COVID-19 disease manifestations. PAF can also stimulate perivascular mast cell activation, leading to inflammation implicated in severe acute respiratory syndrome (SARS). Mast cells are plentiful in the lungs and are a rich source of PAF and of inflammatory cytokines, such as IL-1β and IL-6, which may contribute to COVID-19 and especially SARS. The histamine-1 receptor antagonist rupatadine was developed to have anti-PAF activity, and also inhibits activation of human mast cells in response to PAF. Rupatadine could be repurposed for COVID-19 prophylaxis alone or together with other PAF-inhibitors of natural origin such as the flavonoids quercetin and luteolin, which have antiviral, anti-inflammatory, and anti-PAF actions.

A hypothesis for pathobiology and treatment of COVID-19: The centrality of ACE1/ACE2 imbalance

Angiotensin Converting Enzyme2 is the cell surface binding site for the coronavirus SARS-CoV-2, which causes COVID-19. We propose that an imbalance in the action of ACE1- and ACE2-derived peptides, thereby enhancing angiotensin II (Ang II) signalling is primary driver of COVID-19 pathobiology. ACE1/ACE2 imbalance occurs due to the binding of SARS-CoV-2 to ACE2, reducing ACE2-mediated conversion of Ang II to Ang peptides that counteract pathophysiological effects of ACE1-generated ANG II. This hypothesis suggests several approaches to treat COVID-19 by restoring ACE1/ACE2 balance: (a) AT receptor antagonists; (b) ACE1 inhibitors (ACEIs); (iii) agonists of receptors activated by ACE2-derived peptides (e.g. Ang (1-7), which activates MAS1); (d) recombinant human ACE2 or ACE2 peptides as decoys for the virus. Reducing ACE1/ACE2 imbalance is predicted to blunt COVID-19-associated morbidity and mortality, especially in vulnerable patients. Importantly, approved AT antagonists and ACEIs can be rapidly repurposed to test their efficacy in treating COVID-19. LINKED ARTICLES: This article is part of a themed issue on The Pharmacology of COVID-19. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.21/issuetoc.

Cardiology and COVID-19: do we have sufficient information?

Novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2, which originated in Wuhan (China), transformed into a worldwide pandemic. The short span associated with the spread of the virus and its varied manifestations presents a steep learning curve for many clinicians on the front-line of treatment. Cardiology is one such affected area. This paper details the signs and symptoms of cardiovascular disease resulting from COVID-19, including its proposed pathophysiology, signs and symptoms, treatments and outcomes under investigation. The consensus is that COVID-19 patients with cardiovascular injury have a shorter duration from symptom onset to deterioration, higher mortality and higher prevalence in older populations. Diagnosis and intervention for patients with underlying cardiovascular comorbidities is critical.

COVID-19 and Hematology-What Do We Know So Far?

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), the causative agent of the novel coronavirus disease 2019 (COVID 19), was reported to the World Health Organization in late 2019. This disease quickly evolved into a public health concern and was declared a pandemic on March 11, 2020. COVID-19's high transmission rate and potential to cause a spectrum of systemic diseases makes it imperative for researchers and clinicians worldwide to collaborate and develop a strategy to manage and contain this disease. Studies have shown a wide range of hematological abnormalities and virus-related coagulopathies in affected patients, resulting in an increased propensity to develop serious thrombotic complications or disseminated intravascular coagulation (DIC) in severe cases. The fatal implications of coagulopathy in the form of pulmonary embolism (PE), myocardial infarction (MI), and cerebral infarction compelled us to study in-depth the pathophysiology and treatment options related to COVID-19. This analysis reviews published reports on patients with confirmed SARS-COV-2 infection and associated coagulopathy, defined as abnormalities in the coagulation parameters prothrombin time (PT), activated partial thromboplastin time (aPTT), antithrombin time, fibrinogen, fibrin degradation products, and D-dimer. In this review, we present the hematological manifestations of COVID-19, focusing on virus-associated coagulopathy and relevant pathophysiology, clinical outcomes, and treatment.

Supervised molecular dynamics for exploring the druggability of the SARS-CoV-2 spike protein

The recent outbreak of the respiratory syndrome-related coronavirus (SARS-CoV-2) is stimulating an unprecedented scientific campaign to alleviate the burden of the coronavirus disease (COVID-19). One line of research has focused on targeting SARS-CoV-2 proteins fundamental for its replication by repurposing drugs approved for other diseases. The first interaction between the virus and the host cell is mediated by the spike protein on the virus surface and the human angiotensin-converting enzyme (ACE2). Small molecules able to bind the receptor-binding domain (RBD) of the spike protein and disrupt the binding to ACE2 would offer an important tool for slowing, or even preventing, the infection. Here, we screened 2421 approved small molecules in silico and validated the docking outcomes through extensive molecular dynamics simulations. Out of six drugs characterized as putative RBD binders, the cephalosporin antibiotic cefsulodin was further assessed for its effect on the binding between the RBD and ACE2, suggesting that it is important to consider the dynamic formation of the heterodimer between RBD and ACE2 when judging any potential candidate.

Herbal plants coordinate COVID-19 in multiple dimensions - An insight analysis for clinically applied remedies

The use of multipronged measures, including traditional Chinese medicine (TCM), has greatly increased in response to the COVID-19 pandemic, and we found the use of TCM and is positively correlated with the regional cure rate in China (R=0.77, P<10-5). We analyzed 185 commonly administered TCM recipes comprised of 210 herbs nationwide to reveal mechanistic insight. Eight out of the 10 most commonly used herbs showed anti-coronavirus potential by intersecting with COVID-19 targets. Intriguingly, 17 compounds from the 5 most commonly used herbs were revealed to have direct anti-SARS-CoV-2 potential by docking with the two core structures [CoV spike (S) glycoprotein (6SVB) and CoV 3CL hydrolase (6LU7)]. Seven reported COVID-19 drugs served as positive controls; among them, retionavir (-7.828 kcal/mol) and remdesivir (-8.738 kcal/mol) performed best with 6VSB and 6LU7, respectively. The top candidate was madreselvin B (6SVB: -8.588 kcal/mol and 6LU7: -9.017 kcal/mol), an appreciable component of Flos Lonicerae. Eighty-six compounds from 22 unlisted herbs were further identified among 2,042 natural compounds, completing our arsenal for TCM formulations. The mechanisms have been implicated as multifactorial, including activation of immunoregulation (Th2, PPAR and IL10), suppression of acute inflammatory responses (IL-6, IL-1α/β, TNF, COX2/1, etc.), enhancement of antioxidative activity (CAT and SOD1), and modulation of apoptosis (inhibited CASP3). It is of interest to understand the biological mechanisms of TCM recipes. We then analyzed 18 representative remedies based on molecular targets associated with 14 medical conditions over the disease course, e.g., pyrexia, coughing, asthenia, lymphopenia, cytokine storm, etc. The significant level of coherence (SLC) revealed, in part, the potential uses and properties of corresponding TCMs. Thus, herbal plants coordinate to combat COVID-19 in multiple dimensions, casting a light of hope before effective vaccines are developed.

Severe acute respiratory syndrome coronavirus 2 and renin-angiotensin system blockers: A review and pooled analysis

A novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing an international outbreak of respiratory illness described as coronavirus disease 2019 (COVID-19). SARS-CoV-2 infects human cells by binding to angiotensin-converting enzyme 2. Small studies suggest that renin-angiotensin system (RAS) blockers may upregulate the expression of angiotensin-converting enzyme 2, affecting susceptibility to SARS-CoV-2. This may be of great importance considering the large number of patients worldwide who are treated with RAS blockers, and the well-proven clinical benefit of these treatments in several cardiovascular conditions. In contrast, RAS blockers have also been associated with better outcomes in pneumonia models, and may be beneficial in COVID-19. This review sought to analyse the evidence regarding RAS blockers in the context of COVID-19 and to perform a pooled analysis of the published observational studies to guide clinical decision making. A total of 21 studies were included, comprising 11,539 patients, of whom 3417 (29.6%) were treated with RAS blockers. All-cause mortality occurred in 587/3417 (17.1%) patients with RAS blocker treatment and in 982/8122 (12.1%) patients without RAS blocker treatment (odds ratio 1.00, 95% confidence interval 0.69-1.45; P=0.49; I²=84%). As several hypotheses can be drawn from experimental analysis, we also present the ongoing randomized studies assessing the efficacy and safety of RAS blockers in patients with COVID-19. In conclusion, according to the current data and the results of the pooled analysis, there is no evidence supporting any harmful effect of RAS blockers on the course of patients with COVID-19, and it seems reasonable to recommend their continuation.

The chest CT features of coronavirus disease 2019 (COVID-19) in China: a meta-analysis of 19 retrospective studies

OBJECTIVE

Aimed to summarize the characteristics of chest CT imaging in Chinese hospitalized patients with Coronavirus Disease 2019 (COVID-19) to provide reliable evidence for further guiding clinical routine.

METHODS

PubMed, Embase and Web of Science databases were searched to identify relevant articles involving the features of chest CT imaging in Chinese patients with COVID-19. All data were analyzed utilizing R i386 4.0.0 software. Random-effects models were employed to calculate pooled mean differences.

RESULTS

19 retrospective studies (1332 cases) were included. The results demonstrated that the combined proportion of ground-glass opacities (GGO) was 0.79 (95% CI 0.68, 0.89), consolidation was 0.34 (95% CI 0.23, 0.47); mixed GGO and consolidation was 0.46 (95% CI 0.37; 0.56); air bronchogram sign was 0.41 (95% CI 0.26; 0.55); crazy paving pattern was 0.32 (95% CI 0.17, 0.47); interlobular septal thickening was 0.55 (95% CI 0.42, 0.67); reticulation was 0.30 (95% CI 0.12, 0.48); bronchial wall thickening was 0.24 (95% CI 0.11, 0.40); vascular enlargement was 0.74 (95% CI 0.64, 0.86); subpleural linear opacity was 0.28 (95% CI 0.12, 0.48); intrathoracic lymph node enlargement was 0.03 (95% CI 0.00, 0.07); pleural effusions was 0.03 (95% CI 0.02, 0.06). The distribution in lung: the combined proportion of central was 0.05 (95% CI 0.01, 0.11); peripheral was 0.74 (95% CI 0.62, 0.84); peripheral involving central was 0.38 (95% CI 0.19, 0.75); diffuse was 0.19 (95% CI 0.06, 0.32); unifocal involvement was 0.09 (95% CI 0.05, 0.14); multifocal involvement was 0.57 (95% CI 0.48, 0.68); unilateral was 0.16 (95% CI 0.10, 0.23); bilateral was 0.83 (95% CI 0.78, 0.89); The combined proportion of lobes involved (> 2) was 0.70 (95% CI 0.61, 0.78); lobes involved (≦ 2) was 0.35 (95% CI 0.26, 0.44).

CONCLUSION

GGO, vascular enlargement, interlobular septal thickening more frequently occurred in patients with COVID-19, which distribution features were peripheral, bilateral, involved lobes > 2. Therefore, based on chest CT features of COVID-19 mentioned, it might be a promising means for identifying COVID-19.

Emerging Molecular Prospective of SARS-CoV-2: Feasible Nanotechnology Based Detection and Inhibition

The rapid dissemination of SARS-CoV-2 demonstrates how vulnerable it can make communities and is why it has attained the status of global pandemic. According to the estimation from Worldometer, the SARS-CoV-2 affected cases and deaths are exponentially increasing worldwide, marking the mortality rate as ∼3.8% with no probability of its cessation till now. Despite massive attempts and races among scientific communities in search of proper therapeutic options, the termination of this breakneck outbreak of COVID-19 has still not been made possible. Therefore, this review highlights the diverse molecular events induced by a viral infection, such as autophagy, unfolded protein response (UPR), and inflammasome, illustrating the intracellular cascades regulating viral replication inside the host cell. The SARS-CoV-2-mediated endoplasmic reticulum stress and apoptosis are also emphasized in the review. Additionally, host's immune response associated with SARS-CoV-2 infection, as well as the genetic and epigenetic changes, have been demonstrated, which altogether impart a better understanding of its epidemiology. Considering the drawbacks of available diagnostics and medications, herein we have presented the most sensitive nano-based biosensors for the rapid detection of viral components. Moreover, conceptualizing the viral-induced molecular changes inside its target cells, nano-based antiviral systems have also been proposed in this review.

Infusion of HLA-matched and static magnetic field-exposed allogenic lymphocytes treating lymphocytopenia and cytokine storm syndrome: A treatment proposal for COVID-19 patients

Among haematological parameters of patients seriously ill with the coronavirus infectious disease 2019 (COVID-19), leucocytosis, lymphocytopenia, and the abnormal release of circulating cytokines, termed cytokine storm syndrome (CSS, also known as cytokine release syndrome or CRS), were found associated with disease severity. In particular, according to the serum cytokine profiling, pro-inflammatory interleukin 6 (IL-6) and anti-inflammatory interleukin 10 (IL-10) were observed to be considerably higher in patients experiencing respiratory distress, septic shock and/or multi-organ failure, namely "critical cases" requiring intensive care unit (ICU) admission, very often resulting in death. Interestingly, the production of these cytokines from human lymphocytes was found to be modulated by exposure of 24 h to a 554.2-553.8 mT inhomogeneous static magnetic field (SMF), which elicits IL-10 and suppresses IL-6. Thus, herein, with the aim of restoring lymphocyte count and physiological serum levels of IL-6 and IL-10, the infusion of human leukocyte antigen (HLA)-matched and SMF-exposed allogenic lymphocytes is proposed for the first time as an easy and affordable treatment option for COVID-19 patients. Even if the count of lymphocytes in COVID-19 patients is very low, SMF exposure may be a valuable tool for reprogramming autologous lymphocytes towards physiological conditions. Furthermore, the same procedure could be extended to include the whole autologous or allogenic white blood cells (WBCs). Time-varying/pulsed magnetic fields exerting comparable cell effects could also be employed.

Deadly Companions: COVID-19 and Diabetes in Mexico

In this commentary, I assess the adverse syndemic interactions between COVID-19 and diabetes mellitus. This syndemic is of major concern for a country like Mexico which has seen a steady rise in the percentage of its population suffering these diseases. Mexico now has one of the highest rates of diabetes in the world and a rapidly growing COVID-19 caseload.

Cardiac Injury Patterns and Inpatient Outcomes Among Patients Admitted With COVID-19

Although certain risk factors have been associated with increased morbidity and mortality in patients admitted with Coronavirus Disease 2019 (COVID-19), the impact of cardiac injury and high-sensitivity troponin-I (hs-cTnI) concentrations are not well described. In this large retrospective longitudinal cohort study, we analyzed the cases of 1,044 consecutively admitted patients with COVID-19 from March 9 until April 15. Cardiac injury was defined by hs-cTnI concentration >99th percentile. Patient characteristics, laboratory data, and outcomes were described in patients with cardiac injury and different hs-cTnI cut-offs. The primary outcome was mortality, and the secondary outcomes were length of stay, need for intensive care unit care or mechanical ventilation, and their different composites. The final analyzed cohort included 1,020 patients. The median age was 63 years, 511 (50% patients were female, and 403 (40% were white. 390 (38%) patients had cardiac injury on presentation. These patients were older (median age 70 years), had a higher cardiovascular disease burden, in addition to higher serum concentrations of inflammatory markers. They also exhibited an increased risk for our primary and secondary outcomes, with the risk increasing with higher hs-cTnI concentrations. Peak hs-cTnI concentrations continued to be significantly associated with mortality after a multivariate regression controlling for comorbid conditions, inflammatory markers, acute kidney injury, and acute respiratory distress syndrome. Within the same multivariate regression model, presenting hs-cTnI concentrations were not significantly associated with outcomes, and undetectable hs-cTnI concentrations on presentation did not completely rule out the risk for mechanical ventilation or death. In conclusion, cardiac injury was common in patients admitted with COVID-19. The extent of cardiac injury and peak hs-cTnI concentrations were associated with worse outcomes.

Cardiovascular risk in COVID-19 infection

A few months ago a new coronavirus was identified in Cina officially named by the WHO as COVID-19. The thousands of patients who died showed pneumonia and alveolar damage, but actually, according to several authors in addition to the acute respiratory distress syndrome the virus can give rise to multiorgan failure. In fact, many people died equally despite being intubated and treated for respiratory failure. In this review, we especially wanted to describe the virus effects on the cardiovascular system, probably the leading cause of death of thousands of deceased patients. Therefore, mortality is indirectly induced by the virus through vascular inflammation and cardiovascular damage and patients with severe COVID-19 infection showed significantly increased levels of cardiac troponin I and inflammatory cytokines. The main activation of the signal pathways for the production of inflammatory cytokines are the toll-like receptors that recognize the presence of viral nucleic acids and the ACE-2 receptors, that the virus uses to infect the cells. The binding to ACE-2 also allows to promote high levels of angiotensin II by promoting high levels of blood pressure. High levels of IL-6, IL-1B and IL-8 have been associated with plaque instability and increased thrombotic risk. Furthermore IL-6 is involved in the stimulation of matrix-degrading enzymes such as matrix metalloproteinases, and may contribute to the development of acute coronary syndrome. In addition, TNF-α, IL-1 and IL-6 present in patients with severe COVID-19 are associated with coagulation activation and thrombin generation resulting in disseminated intravascular coagulation or thrombotic microangiopathy. Considering these pathological effects of the virus, anti-inflammatory and anticoagulant treatments are to be considered to avoid cardiovascular events. In this regard, heparin, in addition to its anticoagulant characteristics, has been shown to have good control over inflammation and to be a good anti-viral drug.