Respiratory Syncytial Virus-Induced Oxidative Stress Leads to an Increase in Labile Zinc Pools in Lung Epithelial Cells

Oxidative stress and ROS-mediated cellular events in RSV infection: potential protective roles of antioxidants

Respiratory syncytial virus (RSV), a member of the Pneumoviridae family, can cause severe acute lower respiratory tract infection in infants, young children, immunocompromised individuals and elderly people. RSV is associated with an augmented innate immune response, enhanced secretion of inflammatory cytokines, and necrosis of infected cells. Oxidative stress, which is mainly characterized as an imbalance in the production of reactive oxygen species (ROS) and antioxidant responses, interacts with all the pathophysiologic processes above and is receiving increasing attention in RSV infection. A gradual accumulation of evidence indicates that ROS overproduction plays an important role in the pathogenesis of severe RSV infection and serves as a major factor in pulmonary inflammation and tissue damage. Thus, antioxidants seem to be an effective treatment for severe RSV infection. This article mainly reviews the information on oxidative stress and ROS-mediated cellular events during RSV infection for the first time.

COVID-19 Complications: Oxidative Stress, Inflammation, and Mitochondrial and Endothelial Dysfunction

SARS-CoV-2 infection, discovered and isolated in Wuhan City, Hubei Province, China, causes acute atypical respiratory symptoms and has led to profound changes in our lives. COVID-19 is characterized by a wide range of complications, which include pulmonary embolism, thromboembolism and arterial clot formation, arrhythmias, cardiomyopathy, multiorgan failure, and more. The disease has caused a worldwide pandemic, and despite various measures such as social distancing, various preventive strategies, and therapeutic approaches, and the creation of vaccines, the novel coronavirus infection (COVID-19) still hides many mysteries for the scientific community. Oxidative stress has been suggested to play an essential role in the pathogenesis of COVID-19, and determining free radical levels in patients with coronavirus infection may provide an insight into disease severity. The generation of abnormal levels of oxidants under a COVID-19-induced cytokine storm causes the irreversible oxidation of a wide range of macromolecules and subsequent damage to cells, tissues, and organs. Clinical studies have shown that oxidative stress initiates endothelial damage, which increases the risk of complications in COVID-19 and post-COVID-19 or long-COVID-19 cases. This review describes the role of oxidative stress and free radicals in the mediation of COVID-19-induced mitochondrial and endothelial dysfunction.

Antenatal and Postnatal Sequelae of Oxidative Stress in Preterm Infants: A Narrative Review Targeting Pathophysiological Mechanisms

The detrimental effects of oxidative stress (OS) can start as early as after conception. A growing body of evidence has shown the pivotal role of OS in the development of several pathological conditions during the neonatal period, which have been therefore defined as OS-related neonatal diseases. Due to the physiological immaturity of their antioxidant defenses and to the enhanced antenatal and postnatal exposure to free radicals, preterm infants are particularly susceptible to oxidative damage, and several pathophysiological cascades involved in the development of prematurity-related complications are tightly related to OS. This narrative review aims to provide a detailed overview of the OS-related pathophysiological mechanisms that contribute to the main OS-related diseases during pregnancy and in the early postnatal period in the preterm population. Particularly, focus has been placed on pregnancy disorders typically associated with iatrogenic or spontaneous preterm birth, such as intrauterine growth restriction, pre-eclampsia, gestational diabetes, chorioamnionitis, and on specific postnatal complications for which the role of OS has been largely ascertained (e.g., respiratory distress, bronchopulmonary dysplasia, retinopathy of prematurity, periventricular leukomalacia, necrotizing enterocolitis, neonatal sepsis). Knowledge of the underlying pathophysiological mechanisms may increase awareness on potential strategies aimed at preventing the development of these conditions or at reducing the ensuing clinical burden.

Upper Airways Spray for Viral Infections Prevention

Aim

Several studies emphasized the antiviral properties of many natural compounds enclosed in nutraceuticals formulas and quite effective to prevent the respiratory infections. The rationale of our investigation has been to achieve protection from common cold viruses' infection of the upper airways pooling together and dispensing different active principles on a multistep defense basis. Material and Methods. 30 patients affected by sudden aspecific viral-induced sore throat rhinitis were divided in two groups: (1) the first group included 15 patients which were administered with our spray formula and (2) the second group included 15 patients with the commercial nasal lavage kit. The mucous smear was stained with May Grunwald-Giemsa to exclude eosinophilic infiltrate and confirm the prevalence of granulocytes and lympho-monocytes typical of viral seasonal inflammatory upper airways conditions.

Results

The symptomatic relieve is remarkedly evident in the treated group with our spray compared to the second group treated with commercial nasal lavage kit.

Conclusions

The open case-control retrospective observational study showed a definite benefit of the spray based on natural herbal extracts to take control of the upper airways respiratory distress due to viral infections.

Exploring the Role of Heavy Metals and Their Derivatives on the Pathophysiology of COVID-19

Many aspects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its disease, COVID-19, have been studied to determine its properties, transmission mechanisms, and pathology. These efforts are aimed at identifying potential approaches to control or treat the disease. Early treatment of novel SARS-CoV-2 infection to minimize symptom progression has minimal evidence; however, many researchers and firms are working on vaccines, and only a few vaccines exist. COVID-19 is affected by several heavy metals and their nanoparticles. We investigated the effects of heavy metals and heavy metal nanoparticles on SARS-CoV-2 and their roles in COVID-19 pathogenesis. AgNPs, AuNPs, gold-silver hybrid NPs, copper nanoparticles, zinc oxide, vanadium, gallium, bismuth, titanium, palladium, silver grafted graphene oxide, and some quantum dots were tested to see if they could minimize the severity or duration of symptoms in patients with SARS-CoV-2 infection when compared to standard therapy.

Dengue virus replication enhances labile zinc pools by modulation of ZIP8

Zinc‐dependent viral proteins rely on intracellular zinc homeostasis for successful completion of infectious life‐cycle. Here, we report that the intracellular labile zinc levels were elevated at early stages of dengue virus (DENV) infection in hepatic cells and this increase in free zinc was abolished in cells infected with UV‐inactivated virus or with a DENV replication inhibitor implicating a role for zinc homeostasis in viral RNA replication. This change in free zinc was mediated by zinc transporter, ZIP8, as siRNA‐mediated knockdown of ZIP8 resulted in abrogation of increase in free zinc levels leading to significant reduction in DENV titers suggesting a crucial role for ZIP8 in early stages of DENV replication. Furthermore, elevated free zinc levels correlated with high copy numbers of dengue genome in peripheral blood leukocytes obtained from dengue patients compared to healthy controls suggesting a critical role for zinc homeostasis in dengue infection.

Oxidative stress specifically inhibits replication of dengue virus

Reactive oxygen species (ROS) are chemically active species which are involved in maintaining cellular and signalling processes at physiological concentrations. Therefore, cellular components that regulate redox balance are likely to play a crucial role in viral life-cycle either as promoters of viral replication or with antiviral functions. Zinc is an essential micronutrient associated with anti-oxidative systems and helps in maintaining a balanced cellular redox state. Here, we show that zinc chelation leads to induction of reactive oxygen species (ROS) in epithelial cells and addition of zinc restores ROS levels to basal state. Addition of ROS (H₂O₂) inhibited dengue virus (DENV) infection in a dose-dependent manner indicating that oxidative stress has adverse effects on DENV infection. ROS affects early stages of DENV replication as observed by quantitation of positive and negative strand viral RNA. We observed that addition of ROS specifically affected viral titres of positive strand RNA viruses. We further demonstrate that ROS specifically altered SEC31A expression at the ER suggesting a role for SEC31A-mediated pathways in the life-cycle of positive strand RNA viruses and provides an opportunity to identify drug targets regulating oxidative stress responses for antiviral development.

Potential molecular mechanisms of zinc- and copper-mediated antiviral activity on COVID-19

Novel coronavirus disease 2019 (COVID-19) has spread across the globe; and surprisingly, no potentially protective or therapeutic antiviral molecules are available to treat severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, zinc (Zn) and copper (Cu) have been shown to exert protective effects due to their antioxidant, anti-inflammatory, and antiviral properties. Therefore, it is hypothesized that supplementation with Zn and Cu alone or as an adjuvant may be beneficial with promising efficacy and a favorable safety profile to mitigate symptoms, as well as halt progression of the severe form of SARS-CoV-2 infection. The objective of this review is to discuss the proposed underlying molecular mechanisms and their implications for combating SARS-CoV-2 infection in response to Zn and Cu administration. Several clinical trials have also included the use of Zn as an adjuvant therapy with dietary regimens/antiviral drugs against COVID-19 infection. Overall, this review summarizes that nutritional intervention with Zn and Cu may offer an alternative treatment strategy by eliciting their virucidal effects through several fundamental molecular cascades, such as, modulation of immune responses, redox signaling, autophagy, and obstruction of viral entry and genome replication during SARS-CoV-2 infection.

SARS-CoV-2 and Other Respiratory Viruses: What Does Oxidative Stress Have to Do with It?

The phenomenon of oxidative stress, characterized as an imbalance in the production of reactive oxygen species and antioxidant responses, is a well-known inflammatory mechanism and constitutes an important cellular process. The relationship of viral infections, reactive species production, oxidative stress, and the antiviral response is relevant. Therefore, the aim of this review is to report studies showing how reactive oxygen species may positively or negatively affect the pathophysiology of viral infection. We focus on known respiratory viral infections, especially severe acute respiratory syndrome coronaviruses (SARS-CoVs), in an attempt to provide important information on the challenges posed by the current COVID-19 pandemic. Because antiviral therapies for severe acute respiratory syndrome coronaviruses (e.g., SARS-CoV-2) are rare, knowledge about relevant antioxidant compounds and oxidative pathways may be important for understanding viral pathogenesis and identifying possible therapeutic targets.