CD‐sACE2 inclusion compounds: An effective treatment for coronavirus disease 2019 (COVID‐19)

Role of renin-angiotensin system/angiotensin converting enzyme-2 mechanism and enhanced COVID-19 susceptibility in type 2 diabetes mellitus

Coronavirus disease 2019 (COVID-19) is a disease that caused a global pandemic and is caused by infection of severe acute respiratory syndrome coronavirus 2 virus. It has affected over 768 million people worldwide, resulting in approximately 6900000 deaths. High-risk groups, identified by the Centers for Disease Control and Prevention, include individuals with conditions like type 2 diabetes mellitus (T2DM), obesity, chronic lung disease, serious heart conditions, and chronic kidney disease. Research indicates that those with T2DM face a heightened susceptibility to COVID-19 and increased mortality compared to non-diabetic individuals. Examining the renin-angiotensin system (RAS), a vital regulator of blood pressure and pulmonary stability, reveals the significance of the angiotensin-converting enzyme (ACE) and ACE2 enzymes. ACE converts angiotensin-I to the vasoconstrictor angiotensin-II, while ACE2 counters this by converting angiotensin-II to angiotensin 1-7, a vasodilator. Reduced ACE2 expression, common in diabetes, intensifies RAS activity, contributing to conditions like inflammation and fibrosis. Although ACE inhibitors and angiotensin receptor blockers can be therapeutically beneficial by increasing ACE2 levels, concerns arise regarding the potential elevation of ACE2 receptors on cell membranes, potentially facilitating COVID-19 entry. This review explored the role of the RAS/ACE2 mechanism in amplifying severe acute respiratory syndrome coronavirus 2 infection and associated complications in T2DM. Potential treatment strategies, including recombinant human ACE2 therapy, broad-spectrum antiviral drugs, and epigenetic signature detection, are discussed as promising avenues in the battle against this pandemic.

Progress in Treatment and Diagnostics of Infectious Disease with Polymers

In this era of advanced technology and innovation, infectious diseases still cause significant morbidity and mortality, which need to be addressed. Despite overwhelming success in the development of vaccines, transmittable diseases such as tuberculosis and AIDS remain unprotected, and the treatment is challenging due to frequent mutations of the pathogens. Formulations of new or existing drugs with polymeric materials have been explored as a promising new approach. Variations in shape, size, surface charge, internal morphology, and functionalization position polymer particles as a revolutionary material in healthcare. Here, an overview is provided of major diseases along with statistics on infection and death rates, focusing on polymer-based treatments and modes of action. Key issues are discussed in this review pertaining to current challenges and future perspectives.

Cyclodextrins as eminent constituents in nanoarchitectonics for drug delivery systems

Cyclodextrins have been widely employed for drug delivery systems (DDSs) in which drugs are selectively delivered to a target site in the body. Recent interest has been focused on the construction of cyclodextrin-based nanoarchitectures that show sophisticated DDS functions. These nanoarchitectures are precisely fabricated based on three important features of cyclodextrins, namely (1) the preorganized three-dimensional molecular structure of nanometer size, (2) the easy chemical modification to introduce functional groups, and (3) the formation of dynamic inclusion complexes with various guests in water. With the use of photoirradiation, drugs are released from cyclodextrin-based nanoarchitectures at designated timing. Alternatively, therapeutic nucleic acids are stably protected in the nanoarchitectures and delivered to the target site. The efficient delivery of the CRISPR-Cas9 system for gene editing was also successful. Even more complicated nanoarchitectures can be designed for sophisticated DDSs. Cyclodextrin-based nanoarchitectures are highly promising for future applications in medicine, pharmaceutics, and other relevant fields.

COVID-19 and renin angiotensin aldosterone system: Pathogenesis and therapy

AIMS

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to the ACE2 component of the renin-angiotensin aldosterone system (RAAS) and infects the human cells. The aims of the present review were to look at the role and alteration of the RAAS components in SARS-CoV-2 infection, therapeutic approaches, and clinical trials in this field.

METHODS

We surveyed the literature (PubMed, Web of Science, and Scopus) till August 18, 2021, and 59 published papers regarding the components of the RAAS and their role and alterations in SARS-CoV-2 infection along with various COVID-19 therapies based on the RASS components were included in the study.

RESULTS

ACE inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor inhibitors are agents that significantly enhance the ACE2 and Ang-(1-7) levels, which can be suggestive for their role as therapeutics against SARS-CoV-2 infection. Beta-adrenergic blockers, which negatively regulate renin release from juxtaglomerular cells, and vitamin D, as a regulator of the RAAS and renin expression, are proposed therapeutics in the treatment of COVID-19. Some antihyperglycemic agents could be potentially protective against COVID-19-induced lung injury. Also, the inhibition of the Janus kinase/signal transducer and activator of the transcription pathway as a potential treatment for COVID-19 has been suggested. Finally, resveratrol, an antioxidant that can suppress Ang II, has been suggested as an adjunct to other therapies.

CONCLUSION

Regarding the suggested potential therapies for COVID-19, there are many clinical trials whose results might change the treatment strategies of SARS-CoV-2 infection. So, the results of well-organized clinical trials on the efficacy and safety of the mentioned agents in the treatment of COVID-19 will be useful in the management and therapy of the disease.

Lipids in Pathophysiology and Development of the Membrane Lipid Therapy: New Bioactive Lipids

Membranes are mainly composed of a lipid bilayer and proteins, constituting a checkpoint for the entry and passage of signals and other molecules. Their composition can be modulated by diet, pathophysiological processes, and nutritional/pharmaceutical interventions. In addition to their use as an energy source, lipids have important structural and functional roles, e.g., fatty acyl moieties in phospholipids have distinct impacts on human health depending on their saturation, carbon length, and isometry. These and other membrane lipids have quite specific effects on the lipid bilayer structure, which regulates the interaction with signaling proteins. Alterations to lipids have been associated with important diseases, and, consequently, normalization of these alterations or regulatory interventions that control membrane lipid composition have therapeutic potential. This approach, termed membrane lipid therapy or membrane lipid replacement, has emerged as a novel technology platform for nutraceutical interventions and drug discovery. Several clinical trials and therapeutic products have validated this technology based on the understanding of membrane structure and function. The present review analyzes the molecular basis of this innovative approach, describing how membrane lipid composition and structure affects protein-lipid interactions, cell signaling, disease, and therapy (e.g., fatigue and cardiovascular, neurodegenerative, tumor, infectious diseases).

Killing Two Birds with One Stone by Administration of Soluble ACE2: A Promising Strategy to Treat Both Cardiovascular Diseases and SARS-CoV-2 Infection

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters host cells mainly by the angiotensin converting enzyme 2 (ACE2) receptor, which can recognize the spike (S) protein by its extracellular domain. Previously, recombinant soluble ACE2 (sACE2) has been clinically used as a therapeutic treatment for cardiovascular diseases. Recent data demonstrated that sACE2 can also be exploited as a decoy to effectively inhibit the cell entry of SARS-CoV-2, through blocking SARS-CoV-2 binding to membrane-anchored ACE2. In this study, we summarized the current findings on the optimized sACE2-based strategies as a therapeutic agent, including Fc fusion to prolong the half-life of sACE2, deep mutagenesis to create high-affinity decoys for SARS-CoV-2, or designing the truncated functional fragments to enhance its safety, among others. Considering that COVID-19 patients are often accompanied by manifestations of cardiovascular complications, we think that administration of sACE2 in COVID-19 patients may be a promising therapeutic strategy to simultaneously treat both cardiovascular diseases and SARS-CoV-2 infection. This review would provide insights for the development of novel therapeutic agents against the COVID-19 pandemic.

A hitchhiker's guide through the COVID-19 galaxy

Numerous reviews have summarized the epidemiology, pathophysiology and the various therapeutic aspects of Coronavirus disease 2019 (COVID-19), but a practical guide on "how to treat whom with what and when" based on an understanding of the immunological background of the disease stages remains missing. This review attempts to combine the current knowledge about the immunopathology of COVID-19 with published evidence of available and emerging treatment options. We recognize that the information about COVID-19 and its treatment is rapidly changing, but hope that this guide offers those on the frontline of this pandemic an understanding of the host response in COVID-19 patients and supports their ongoing efforts to select the best treatments tailored to their patient's clinical status.

Polymeric Materials as Potential Inhibitors Against SARS-CoV-2

Recently discovered SARS-CoV-2 caused a pandemic that triggered researchers worldwide to focus their research on all aspects of this new peril to humanity. However, in the absence of specific therapeutic intervention, some preventive strategies and supportive treatment minimize the viral transmission as studied by some factors such as basic reproduction number, case fatality rate, and incubation period in the epidemiology of viral diseases. This review briefly discusses coronaviruses' life cycle of SARS-CoV-2 in a human host cell and preventive strategies at some selected source of infection. The antiviral activities of synthetic and natural polymers such as chitosan, hydrophobically modified chitosan, galactosylated chitosan, amine-based dendrimers, cyclodextrin, carrageenans, polyethyleneimine, nanoparticles are highlighted in this article. Mechanism of virus inhibition, detection and diagnosis are also presented. It also suggests that polymeric materials and nanoparticles can be effective as potential inhibitors and immunization against coronaviruses which would further develop new technologies in the field of polymer and nanoscience.

SARS-CoV-2: is there neuroinvasion?

BACKGROUND

SARS-CoV-2, a coronavirus (CoV), is known to cause acute respiratory distress syndrome, and a number of non-respiratory complications, particularly in older male patients with prior health conditions, such as obesity, diabetes and hypertension. These prior health conditions are associated with vascular dysfunction, and the CoV disease 2019 (COVID-19) complications include multiorgan failure and neurological problems. While the main route of entry into the body is inhalation, this virus has been found in many tissues, including the choroid plexus and meningeal vessels, and in neurons and CSF.

MAIN BODY

We reviewed SARS-CoV-2/COVID-19, ACE2 distribution and beneficial effects, the CNS vascular barriers, possible mechanisms by which the virus enters the brain, outlined prior health conditions (obesity, hypertension and diabetes), neurological COVID-19 manifestation and the aging cerebrovascualture. The overall aim is to provide the general reader with a breadth of information on this type of virus and the wide distribution of its main receptor so as to better understand the significance of neurological complications, uniqueness of the brain, and the pre-existing medical conditions that affect brain. The main issue is that there is no sound evidence for large flux of SARS-CoV-2 into brain, at present, compared to its invasion of the inhalation pathways.

CONCLUSIONS

While SARS-CoV-2 is detected in brains from severely infected patients, it is unclear on how it gets there. There is no sound evidence of SARS-CoV-2 flux into brain to significantly contribute to the overall outcomes once the respiratory system is invaded by the virus. The consensus, based on the normal route of infection and presence of SARS-CoV-2 in severely infected patients, is that the olfactory mucosa is a possible route into brain. Studies are needed to demonstrate flux of SARS-CoV-2 into brain, and its replication in the parenchyma to demonstrate neuroinvasion. It is possible that the neurological manifestations of COVID-19 are a consequence of mainly cardio-respiratory distress and multiorgan failure. Understanding potential SARS-CoV-2 neuroinvasion pathways could help to better define the non-respiratory neurological manifestation of COVID-19.

The Use of Cyclodextrin or its Complexes as a Potential Treatment Against the 2019 Novel Coronavirus: A Mini-Review

Severe Acute Respiratory Syndrome Coronavirus 2 has spread rapidly since its discovery in December 2019 in the Chinese province of Hubei, reaching this day all the continents. This scourge is, unfortunately, in lineage with various dangerous outbreaks such as Ebola, Cholera, Spanish flu, American seasonal flu. Until today, the best solution for the moment remains prevention (Social distancing, hand disinfection, use of masks, partial or total sanitary containment, etc.); there is also the emergence of drug treatment (research and development, clinical trials, use on patients). Recent reviews emphasized the role of membrane lipids in the infectivity mechanism of SARS-COV-2. Cholesterol-rich parts of cell membranes serve as docking places of host cells for the viruses. Coronavirus 2 is a member of a virus family with lipid envelope that fuses with host cell through endocytosis, internalizing its components in the cell. In vitro cell models have shown that depletion of cholesterol by cyclodextrin, and particularly methyl beta cyclodextrin disturb the host cell membrane lipid composition this way, reducing the attachment of the virus to the protein receptors. This review aims to summarize the state of the art of research concerning the use of cyclodextrin or its complexes as a potential treatment against this new virus and update work already published.

Safety of ACE-I and ARB medications in COVID-19: A retrospective cohort study of inpatients and outpatients in California

INTRODUCTION

There is significant interest in the use of angiotensin converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARB) in coronavirus disease 2019 (COVID-19) and concern over potential adverse effects since these medications upregulate the severe acute respiratory syndrome coronavirus 2 host cell entry receptor ACE2. Recent studies on ACE-I and ARB in COVID-19 were limited by excluding outpatients, excluding patients by age, analyzing ACE-I and ARB together, imputing missing data, and/or diagnosing COVID-19 by chest computed tomography without definitive reverse transcription polymerase chain reaction (RT-PCR), all of which are addressed here.

METHODS

We performed a retrospective cohort study of 1023 COVID-19 patients diagnosed by RT-PCR at Stanford Hospital through April 8, 2020 with a minimum follow-up time of 14 days to investigate the association between ACE-I or ARB use with outcomes.

RESULTS

Use of ACE-I or ARB medications was not associated with increased risk of hospitalization, intensive care unit admission, or death. Compared to patients with charted past medical history, there was a lower risk of hospitalization for patients on ACE-I (odds ratio (OR) 0.43; 95% confidence interval (CI) 0.19-0.97; P = 0.0426) and ARB (OR 0.39; 95% CI 0.17-0.90; P = 0.0270). Compared to patients with hypertension not on ACE-I or ARB, patients on ARB medications had a lower risk of hospitalization (OR 0.09; 95% CI 0.01-0.88; P = 0.0381).

CONCLUSIONS

These findings suggest that the use of ACE-I and ARB is not associated with adverse outcomes and may be associated with improved outcomes in COVID-19, which is immediately relevant to care of the many patients on these medications.

Human cell receptors: potential drug targets to combat COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the coronavirus disease 2019 (COVID-19). The World Health Organization (WHO) has announced that COVID-19 is a pandemic having a higher spread rate rather than the mortality. Identification of a potential approach or therapy against COVID-19 is still under consideration. Therefore, it is essential to have an insight into SARS-CoV-2, its interacting partner, and domains for an effective treatment. The present study is divided into three main categories, including SARS-CoV-2 prominent receptor and its expression levels, other interacting partners, and their binding domains. The first section focuses primarily on coronaviruses' general aspects (SARS-CoV-2, SARS-CoV, and the Middle East Respiratory Syndrome Coronaviruses (MERS-CoV)) their structures, similarities, and mode of infections. The second section discusses the host receptors which includes the human targets of coronaviruses like dipeptidyl peptidase 4 (DPP4), CD147, CD209L, Angiotensin-Converting Enzyme 2 (ACE2), and other miscellaneous targets (type-II transmembrane serine proteases (TTSPs), furin, trypsin, cathepsins, thermolysin, elastase, phosphatidylinositol 3-phosphate 5-kinase, two-pore segment channel, and epithelium sodium channel C-α subunit). The human cell receptor, ACE2 plays an essential role in the Renin-Angiotensin system (RAS) pathway and COVID-19. Thus, this section also discusses the ACE2 expression and risk of COVID-19 infectivity in various organs and tissues such as the liver, lungs, intestine, heart, and reproductive system in the human body. Absence of ACE2 protein expression in immune cells could be used for limiting the SARS-CoV-2 infection. The third section covers the current available approaches for COVID-19 treatment. Overall, this review focuses on the critical role of human cell receptors involved in coronavirus pathogenesis, which would likely be used in designing target-specific drugs to combat COVID-19.

Differences in clinical characteristics and liver injury between suspected and confirmed COVID-19 patients in Jingzhou, Hubei Province of China

ABSTRACT

To evaluate the clinical characteristics and liver injury in coronavirus disease 2019 (COVID-19) patients, and analyze the differences between suspected and confirmed COVID-19 patients, this retrospective study was performed on 157 COVID-19 patients and 93 suspected patients who were ultimately excluded from COVID-19 (control patients). Differences in clinical characteristics and liver injury between suspected and confirmed COVID-19 patients were analyzed. Age, male sex, fever, chest tightness and dyspnea were related to the severity of COVID-19. C-reactive protein (CRP) and D-dimer may be predictors of the severity of COVID-19. Computed tomography (CT) played an important role in the screening of COVID-19 and the evaluation of disease severity. Multiple factors may cause liver injury in COVID-19 patients. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be more likely to cause liver injury than common respiratory infectious diseases. Age, temperature (T), white blood cell (WBC), lymphocytes (LY), hematocrit (HCT), CRP, and finger pulse oxygen saturation (SpO2) may correlate with liver function impairment and may predict the occurrence and severity of liver function impairment. Some therapeutic drugs (like glucocorticoid) may be involved in the liver function impairment of COVID-19 patients. Most liver function indices improved significantly after active treatment. Although COVID-19 and other common respiratory infectious diseases share some clinical characteristics, COVID-19 has its own characteristics.

Potential role of IFN-α in COVID-19 patients and its underlying treatment options

The coronavirus disease (COVID-19) caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly worldwide. Given that this contagious viral outbreak is still unfolding, it is urgent to understand the pathogenesis of SARS-CoV-2 infection and explore effective treatments to protect patients from developing a severe illness related to COVID-19. Recently, IFN-α has been considered a potential therapeutic strategy to treat COVID-19 disease, mainly because the innate immune system rapidly produces IFN-α as the first line of defense to combat viral infections. However, IFN-α can also play a role in immunoregulatory effects, causing pathogenic damage and uncontrolled inflammatory responses. There are 13 human IFN-α subtypes that bind to the same receptor and induce different interferon-stimulated gene (ISG) expression, regulating various antiviral and immunoregulatory effects. The varying degrees of inflammatory regulations may raise concerns about the possible side effects to enlarge the inflammatory responses, exacerbating the severity of infection. Thus, the analysis of various IFN-α subtype induction during SARS-CoV-2 infection is necessary in exploring the mechanism of COVID-19 pathogenesis. This review summarizes the current understanding of IFN-α in the pathogenesis of respiratory virus diseases and IFN-α based clinical intervention used in SARS-CoV-2 infection and other respiratory virus diseases. Besides, new ideas in selecting suitable IFN-α subtypes or combinations as drug candidates for viral infection treatment will also be discussed.Key Points• IFN-α plays an important role in anti-viral and immunoregulatory effects in COVID-19 patients caused by SARS-CoV-2.• The uncontrolled inflammation and disease severity correlated to the diversity of IFN-α subtype induction.• Selecting suitable IFN-α subtypes or combinations as drug candidates will be beneficial for the treatment of patients with COVID-19.

Antiviral Abidol is Associated with the Reduction of In-Hospital Mortality in COVID-19 Patients

Objective:

Coronavirus disease 2019 (COVID-19) is a global public health crisis. There are no specific antiviral agents for the treatment of SARS-CoV-2. Information regarding the effect of Abidol on in-hospital mortality is scarce. The present study aimed to evaluate the treatment effect of Abidol for patients with COVID-19 before and after propensity score matching (PSM).

Methods:

This retrospective cohort study analyzed 1019 patients with confirmed COVID-19 in China from December 22, 2019 to March 13, 2020. Patients were divided to Abidol (200 mg, tid, 5–7 days, n = 788, 77.3%) and No-Abidol (n = 231, 22.7%) groups. The primary outcome was the mortality during hospitalization.

Results:

Among 1019 COVID-19 patients, the age was (60.4 ± 14.5) years. Abidol-treated patients, compared with No-Abidol-treated patients, had a shorter duration from onset of symptoms to admission, less frequent renal dysfunction, lower white blood cell counts (lymphocytes <0.8) and erythrocyte sending rate, lower interleukin-6, higher platelet counts and plasma IgG and oxygen saturation, and less frequent myocardial injury. The mortality during hospitalization before PSM was 17.9% in Abidol group and 34.6% in No-Abidol (hazard ratio (HR) = 2.610, 95% confident interval (CI): 1.980–3.440), all seen in severe and critical patients. After PSM, the in-hospital death was 13.6% in Abidol and 28.6% in No-Abidol group (HR = 2.728, 95% CI: 1.598–4.659).

Conclusions:

Abidol-treatment results in less in-hospital death for severe and critical patients with COVID-19. Further randomized study is warranted to confirm the findings from this study.

Severe Acute Respiratory Syndrome-Associated Coronavirus 2 Infection and Organ Dysfunction in the ICU: Opportunities for Translational Research

OBJECTIVES

Since the beginning of the coronavirus disease 2019 pandemic, hundreds of thousands of patients have been treated in ICUs across the globe. The severe acute respiratory syndrome-associated coronavirus 2 virus enters cells via the angiotensin-converting enzyme 2 receptor and activates several distinct inflammatory pathways, resulting in hematologic abnormalities and dysfunction in respiratory, cardiac, gastrointestinal renal, endocrine, dermatologic, and neurologic systems. This review summarizes the current state of research in coronavirus disease 2019 pathophysiology within the context of potential organ-based disease mechanisms and opportunities for translational research.

DATA SOURCES

Investigators from the Research Section of the Society of Critical Care Medicine were selected based on expertise in specific organ systems and research focus. Data were obtained from searches conducted in Medline via the PubMed portal, Directory of Open Access Journals, Excerpta Medica database, Latin American and Caribbean Health Sciences Literature, and Web of Science from an initial search from December 2019 to October 15, 2020, with a revised search to February 3, 2021. The medRxiv, Research Square, and clinical trial registries preprint servers also were searched to limit publication bias.

STUDY SELECTION

Content experts selected studies that included mechanism-based relevance to the severe acute respiratory syndrome-associated coronavirus 2 virus or coronavirus disease 2019 disease.

DATA EXTRACTION

Not applicable.

DATA SYNTHESIS

Not applicable.

CONCLUSIONS

Efforts to improve the care of critically ill coronavirus disease 2019 patients should be centered on understanding how severe acute respiratory syndrome-associated coronavirus 2 infection affects organ function. This review articulates specific targets for further research.

Natural compounds as inhibitors of SARS-CoV-2 endocytosis: A promising approach against COVID-19

BACKGROUND AND AIM

The recent COVID-19 pandemic caused by SARS-CoV-2 affected more than six million people and caused thousands of deaths. The lack of effective drugs or vaccines against SARS-CoV-2 further worsened the situation. This review is focused on the identification of molecules that may inhibit viral entry into host cells by endocytosis.

METHODS

We performed the literature search for these natural compounds in the articles indexed in PubMed.

RESULTS

Natural products against viral infections have been gaining importance in recent years. Specific natural compounds like phytosterols, polyphenols, flavonoids, citrus, galangal, curcuma and hydroxytyrosol are being analyzed to understand whether they could inhibit SARS-CoV-2.

CONCLUSIONS

We reviewed natural compounds with potential antiviral activity against SARS-CoV-2 that could be used as a treatment for COVID-19.

Pirfenidone: A novel hypothetical treatment for COVID-19

Cytokine storm, multiorgan failure, and particularly acute respiratory distress syndrome (ARDS) is the leading cause of mortality and morbidity in patients with COVID-19. A fulminant ARDS kills the majority of COVID-19 victims. Pirfenidone (5-methyl-1-phenyl-2-[1H]-pyridone), is a novel anti-fibrotic agent with trivial adverse effects. Pirfenidone is approved for the treatment of Idiopathic Pulmonary Fibrosis (IPF) for patients with mild to moderate disease. Pirfenidone could inhibit apoptosis, downregulate ACE receptors expression, decrease inflammation by several mechanisms and ameliorate oxidative stress and hence protect pneumocytes and other cells from COVID-19 invasion and cytokine storm simultaneously. Based on the pirfenidone mechanism of action and the known pathophysiology of COVID-19, I believe that pirfenidone has the potential for the treatment of COVID-19 patients.

Angiotensin-converting enzyme 2 (ACE2) receptor and SARS-CoV-2: Potential therapeutic targeting

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a beta coronavirus that uses the human angiotensin-converting enzyme 2 (ACE2) receptor as a point of entry. The present review discusses the origin and structure of the virus and its mechanism of cell entry followed by the therapeutic potentials of strategies directed towards SARS-CoV2-ACE2 binding, the renin-angiotensin system, and the kinin-kallikrein system. SARS-CoV2-ACE2 binding-directed approaches mainly consist of targeting receptor binding domain, ACE2 blockers, soluble ACE2, and host protease inhibitors. In conclusion, blocking or manipulating the SARS-CoV2-ACE2 binding interface perhaps offers the best tactic against the virus that should be treated as a fundamental subject of future research.

The Pathophysiology, Diagnosis and Treatment of Corona Virus Disease 2019 (COVID-19)

Since the beginning of this century, beta coronaviruses (CoV) have caused three zoonotic outbreaks. However, little is currently known about the biology of the newly emerged SARS-CoV-2 in late 2019. There is a spectrum of clinical features from mild to severe life threatening disease with major complications like severe pneumonia, acute respiratory distress syndrome, acute cardiac injury and septic shock. The genome of SARS-CoV-2 encodes polyproteins, four structural proteins and six accessory proteins. SARS-CoV-2 tends to utilize Angiotensin-converting enzyme 2 (ACE2) of various mammals. The imbalance between ACE/Ang II/AT1R pathway and ACE2/Ang(1-7)/Mas receptor pathway in the renin-angiotensin system leads to multi-system inflammation. The early symptoms of COVID-19 pneumonia are low to midgrade fever, dry cough and fatigue. Vigilant screening is important. The diagnosis of COVID-19 should be based on imaging findings along with epidemiological history and nucleic acid detection. Isolation and quarantine of suspected cases is recommended. Management is primarily supportive, with newer antiviral drugs/vaccines under investigation.

COVID-19 susceptibility: potential of ACE2 polymorphisms

Background

Angiotensin-converting enzyme 2 (ACE2) is a metallopeptidase that primarily functions as a negative regulator of renin angiotensin system (RAS) by converting angiotensin II (Ang II) to angiotensin 1-7. Contrary to this, another RAS component, angiotensin-converting enzyme (ACE) catalyzes synthesis of Ang II from angiotensin I (Ang I) that functions as active compound in blood pressure regulation. This indicates importance of ACE/ACE2 level in regulating blood pressure by targeting Ang II. An outbreak of severe acute respiratory syndrome (SARS) highlighted the additional role of ACE2 as a receptor for SARS coronavirus (SARS-CoV) infection.

Main body of the abstract

ACE2 is a functional receptor for SARS-CoV and SARS-CoV-2. Activation of spike (S)-protein by either type II transmembrane serine proteases (TTSPs) or cathepsin-mediated cleavage initiates receptor binding and viral entry. In addition to TTSPs, ACE2 can also be trimmed by ADAM 17 (a disintegrin and metalloproteinase 17) that competes for the same receptor. Cleavage by TTSPs activates ACE2 receptor for binding, whereas ADAM17 releases extracellular fragment called soluble ACE2 (sACE2). Structural studies of both ACE2 and S-protein have found critical sites involved in binding mechanism. In addition to studies on structural motifs, few single-nucleotide polymorphism (SNPs) studies have been done to find an association between genetic variants and SARS susceptibility. Though no association was found in those reports, but seeing the non-reproducibility of SNP studies among different ethnic groups, screening of ACE2 SNPs in individual population can be undertaken.

Short conclusion

Thus, screening for novel SNPs focussing on recently identified critical regions of ACE2 can be targeted to monitor susceptibility towards coronavirus disease 2019 (COVID-19).

The Lord of the NanoRings: Cyclodextrins and the battle against SARS-CoV-2

A handful of singular structures and laws can be observed in nature. They are not always evident but, once discovered, it seems obvious how to take advantage of them. In chemistry, the discovery of reproducible patterns stimulates the imagination to develop new functional materials and technological or medical applications. Two clear examples are helical structures at different levels in biological polymers as well as ring and spherical structures of different size and composition. Rings are intuitively observed as holes able to thread elongated structures. A large number of real and fictional stories have rings as inanimate protagonists. The design, development or just discovering of a special ring has often been taken as a symbol of power or success. Several examples are the Piscatory Ring wore by the Pope of the Catholic Church, the NBA Championship ring and the One Ring created by the Dark Lord Sauron in the epic story The Lord of the Rings. In this work, we reveal the power of another extremely powerful kind of rings to fight against the pandemic which is currently affecting the whole world. These rings are as small as ~1 nm of diameter and so versatile that they are able to participate in the attack of viruses, and specifically SARS-CoV-2, in a large range of different ways. This includes the encapsulation and transport of specific drugs, as adjuvants to stabilize proteins, vaccines or other molecules involved in the infection, as cholesterol trappers to destabilize the virus envelope, as carriers for RNA therapies, as direct antiviral drugs and even to rescue blood coagulation upon heparin treatment.

“One ring to rule them all. One ring to find them. One ring to bring them all and in the darkness bind them.” J. R. R. Tolkien.

Current coronavirus (SARS-CoV-2) epidemiological, diagnostic and therapeutic approaches: An updated review until June 2020

Coronaviruses are a group of enveloped viruses with non-segmented, single-stranded, and positive-sense RNA genomes. In December 2019, an outbreak of coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in Wuhan City, China. The World Health Organization (WHO) declared the coronavirus outbreak as a global pandemic in March 2020. Fever, dry cough and fatigue are found in the vast majority of all COVID-19 cases. Early diagnosis, treatment and future prevention are keys to COVID-19 management. Currently, the unmet need to develop cost-effective point-of-contact test kits and efficient laboratory techniques for confirmation of COVID-19 infection has powered a new frontier of diagnostic innovation. No proven effective therapies or vaccines for SARS-CoV-2 currently exist. The rapidly increasing research regarding COVID-19 virology provides a significant number of potential drug targets. Remdesivir may be the most promising therapy up till now. On May 1, 2020, Gilead Sciences, announced that the U.S. Food and Drug Administration (FDA) has granted emergency use authorization (EUA) for the investigational Remdesivir as a potential antiviral for COVID-19 treatment. On May 7, 2020, Gilead Sciences, announced that the Japanese Ministry of Health, Labour and Welfare (MHLW) has granted regulatory approval of Veklury® (Remdesivir) as a treatment for SARS-CoV-2 infection, the virus that causes COVID-19 acute respiratory syndrome, under an exceptional approval pathway. Also, Corticosteroids are recommended for severe cases only to suppress the immune response and reduce symptoms, but not for mild and moderate patients where they are associated with a high-risk side effect. Based on the currently published evidence, we tried to highlight different diagnostic approaches, side effects and therapeutic agents that could help physicians in the frontlines.

Immune Response and COVID-19: A mirror image of Sepsis

The emergence of SARS-CoV-2 virus and its associated disease COVID-19 have triggered significant threats to public health, in addition to political and social changes. An important number of studies have reported the onset of symptoms compatible with pneumonia accompanied by coagulopathy and lymphocytopenia during COVID-19. Increased cytokine levels, the emergence of acute phase reactants, platelet activation and immune checkpoint expression are some of the biomarkers postulated in this context. As previously observed in prolonged sepsis, T-cell exhaustion due to SARS-CoV-2 and even their reduction in numbers due to apoptosis hinder the response to the infection. In this review, we synthesized the immune changes observed during COVID-19, the role of immune molecules as severity markers for patient stratification and their associated therapeutic options.

COVID-19 as an Acute Inflammatory Disease

The 2019 coronavirus disease (COVID-19) pandemic caused by the virus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has created an unprecedented global crisis for the infrastructure sectors, including economic, political, healthcare, education, and research systems. Although over 90% of infected individuals are asymptomatic or manifest noncritical symptoms and will recover from the infection, those individuals presenting with critical symptoms are in urgent need of effective treatment options. Emerging data related to mechanism of severity and potential therapies for patients presenting with severe symptoms are scattered and therefore require a comprehensive analysis to focus research on developing effective therapeutics. A critical literature review suggests that the severity of SARS-CoV-2 infection is associated with dysregulation of inflammatory immune responses, which in turn inhibits the development of protective immunity to the infection. Therefore, the use of therapeutics that modulate inflammation without compromising the adaptive immune response could be the most effective therapeutic strategy.

COVID-19: the endocrine opportunity in a pandemic

The 2019 Coronavirus disease (COVID-19) pandemic has disrupted the social, economical and medical system worldwide. Although it is strictly an infectious disease, its intricate bidirectional relationship with various non-communicable metabolic diseases and endocrinological factors has been observed. While diabetes, hypertension, obesity have been found to be independent risk factors for COVID-19 disease severity and mortality, more inclination towards sedentary lifestyle, psychosocial stress at this critical time may be the harbingers of metabolic syndrome. Thus, endocrinologists have a great opportunity to play their role to combat this pandemic. This paper examines how various endocrinological disorders influence the dynamics of COVID-19 and vice versa. Moreover, it also intends to review the clinical guidelines to be adopted in practice of endocrinology in this trying time.