The role of oxidative stress in influenza virus infection

A mitochondria targeted hydrogen peroxide fluorescent probe for monitoring oxidative stress during influenza virus infection

Hydrogen peroxide (H2O2), an important marker of oxidative stress, plays a significant role in infectious diseases. Oxidative stress induced by influenza virus infection is intricately linked to the pathological processes of host cells. In this work, a fluorescent probe QLC1 based on the coumarin was developed for fluorescence imaging of mitochondrial H2O2 level in host cells during influenza virus infection. The self-immolative reaction of QLC1 triggered by H2O2 will lead to a 250-fold fluorescence enhance and the limit of detection was determined to be 0.176 μM. Using this probe, we monitored oxidative stress during influenza infection and identified a link between redox status and influenza virus replication.

Strategy-Level Prodrug Synthesis

Organic synthesis uniquely provides opportunities to access molecules that serve defined purposes. Medicinal chemistry illustrates this attribute well with prodrug design, whereby a drug undergoes a late-stage conversion to a conditionally responsive active medicinal agent (AMA), being a notable example. Prodrugs are becoming increasingly important in medicinal chemistry but common approaches to introduce biologically responsive groups are limited in the chemoselectivity and scope of available functionalization reactions. This Concept article describes strategy-level prodrug synthesis, which is a powerful extension of classical prodrug formation that initiates sequences with the objective of introducing functionality early in a sequence to achieve greater scope, site-selectivity, and chemoselectivity for the incorporation of the biologically responsive group. Examples of functionalization using alkyne hydroamination, Curtius reaction, and alkene metathesis are highlighted along with the use of the prodrugs for biological applications.

Shrimp Virus Regulates ROS Dynamics via the Nrf2 Pathway to Facilitate Viral Replication

Reactive oxygen species (ROS) of hosts are widely involved in intracellular signaling and against pathogens. Viruses manipulate ROS homeostasis of hosts as a strategy to evade ROS-mediated negative effects of their infection, but the mechanisms remain unclear. The economically important aquaculture shrimp, Litopenaeus vannamei, is selected to investigate the molecular mechanism of how white spot syndrome virus (WSSV) regulates ROS dynamics and enhances viral replication. WSSV protein wsv220 binds to the repressor of shrimp nuclear factor erythroid 2-related factor 2 (LvNrf2), called Kelch-like ECH-associated protein 1 (LvKeap1), disrupting LvNrf2/LvKeap1 complex and facilitating LvNrf2 nuclear translocation. This activation of LvNrf2 causes up-regulation of antioxidant genes, including glucose-6-phosphate dehydrogenase (LvG6PDH), which increases nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH) production, effectively eliminating excessive ROS. Moreover, WSSV exploits LvNrf2 to establish a positive feedback loop by up-regulating viral immediate early gene wsv051, which further enhances wsv220 expression. Knockdown of LvNrf2 or LvG6PDH reduces WSSV replication and increases host ROS levels. Therefore, WSSV hijacks LvNrf2 pathway to maintain ROS homeostasis and establishes a positive feedback loop to facilitate WSSV replication. These findings reveal a novel molecular mechanism of viral manipulation of host ROS dynamics and suggest potential antiviral strategies targeting LvNrf2 pathway.

Effects of oxidative stress on viral infections: an overview

Viral infections can trigger increased reactive oxygen species (ROS) production and a reduced antioxidant response in the host, leading to redox stress, inflammation, apoptosis, and ultimately, cell and tissue damage, which contribute to disease development. A better understanding of how ROS contributes to viral pathogenesis is critical for the development of novel therapeutic interventions. In this review, we discuss the current knowledge on ROS production and its effects across various viral infections, including severe acute respiratory syndrome-coronavirus-2, influenza A virus, dengue virus, Zika virus, hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infections, to improve future therapeutic and preventive strategies for these infections.

The virucidal potential effects of violet-blue light on influenza D virus

Influenza D virus (IDV) is a novel influenza virus, first isolated from swine with influenza-like symptoms in the USA in 2011. To date, IDV circulation has been reported in various animal species such as cattle, pigs, horses with the ability to expand its range of hosts. UV radiation has been widely used for the disinfection of various sources such as water, air, and surfaces, especially in places at greater risk of contamination by viruses and bacteria, such as hospitals and health facilities. The aim of this study was to evaluate the potential virucidal effect of a violet-blue light against IDV. Viral suspension of IDV was exposed to a violet-blue light (405 nm) for different times (radiant exposures): 22 min and 30 s (5.4 J/cm2), 45 min (10.8 J/cm2), 90 min (21.6 J/cm2), 180 min (43.2 J/cm2), and 360 min (86.4 J/cm2), and different temperatures (room temperature, 4 and 37 °C). At the end of exposure, virus titration was performed on MDCK cells. After violet-blue light exposure, a viral titre reduction proportional to exposure time was observed: 0.228 log10 after 22 min and 30 s, 0.668 log10 after 45 min, 0.940 log10 after 90 min, 1.375 log10 after 180 min and 2.293 log10 after 360 min. Differences were observed among temperatures of exposure, with the greatest virucidal effect observed at room temperature. As reported for other respiratory viruses, this violet-blue light can potentially be used to reduce IDV spread in potentially hotspot areas for animals and humans.

Big data analysis of influenza vaccination and liver cancer risk in hypertensive patients: insights from a nationwide population-based cohort study

BACKGROUND

previous studies have indicated that influenza vaccination may be associated with reduced risks of certain types of cancer. However, the protective effect of influenza vaccination against primary liver cancer in individuals with hypertension remains unclear.

METHODS

In this cohort study, 37,022 patients over 55 years of age who received a diagnosis of hypertension at any time between January 1, 2001, and December 31, 2012, were enrolled from the National Health Insurance Research Database. The patients were divided into a vaccinated and an unvaccinated group. Categorical and continuous variables were analyzed using the chi-square test and t test, respectively, and the correlation between influenza vaccination and liver cancer in patients with hypertension was analyzed using time-varying COX model. Propensity score method was performed to reduce selection bias.

RESULTS

Compared with the unvaccinated group, the vaccinated group had a significantly lower incidence of liver cancer (hazard ratio = 0.56, 95% confidence interval = 0.46-0.64; p < .001). In addition, a protective effect was observed regardless of sex, age, or comorbidities. Besides, the association was dose-dependent which could be noted when patients were stratified based on the total number of vaccinations. The adjusted HRs for patients receiving 1, 2 to 3, and ≥ 4 vaccinations during the follow-up period were 0.60 (0.51-0.78), 0.48 (0.38-0.65), and 0.39(0.30-0.51), respectively.

CONCLUSIONS

In summary, influenza vaccination is linked to a decreased risk of liver cancer in individuals with hypertension. However, unmeasurable confounders may have been present in the analysis.

Difunctional oxidatively cleavable alkenyl boronates: application to cellular peroxide sensing from a fluorophore-quencher pair

This manuscript describes the development of difunctional alkenyl boronates that contain an oxidatively releasable cargo and an amine for attaching to groups that can improve physical properties or enhance cellular targeting. The design is applied to a FRET-based system that delivers a selective fluorescence response in oxidatively stressed cells.

Fullerenol C60(OH)36: Antioxidant, Cytoprotective, Anti-Influenza Virus Activity, and Self-Assembly in Aqueous Solutions and Cell Culture Media

Viral infections and many other dangerous diseases are accompanied by the development of oxidative stress, which is a consequence of an increase in the level of the reactive oxygen species (ROS). In this regard, the search for effective antioxidants remains highly relevant. We tested fullerenol C60(OH)36 in the context of the connection between its self-assembly in aqueous solutions and cell culture media, antiradical activity, UV cytoprotective action, and antiviral activity against international reference strains of influenza virus A(H1N1)pdm09, A(H3N2), and B subtypes in vitro on the MDCK cell line. Various characterization techniques, including Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, NMR and ESR spectrometry, MALDI-TOF mass spectrometry, thermal analysis (TGA and DSC), dynamic light-scattering (DLS), and ζ-potential measurements, were used to confirm the production of fullerenol and study its self-assembly in aqueous solutions and cell culture media. Fullerenol C60(OH)36 demonstrated the ability to scavenge •DPPH, •OH, O2•- radicals and 1O2 and was non-toxic in the range of the studied concentrations (up to 200 μg/mL) when incubated with MDCK cells for 24 h. In addition, fullerenol exhibited a cytoprotective effect under UV irradiation (EC50 = 29.7 ± 1.0 μM) and showed moderate activity against human influenza viruses of subtypes A(H1N1)pdm09 (SI = 9.9 ± 4.6) and A(H3N2) (SI = 12.5 ± 1.3) when determined by the hemagglutination assay (HA-test) and the MTT assay. At the same time, C60(OH)36 was ineffective in vitro against the actual strain of influenza B virus (Victoria lineage). The high bioavailability of fullerenol in combination with its cytoprotective effect, as well as its antiradical and antiviral activity combined with a relatively low toxicity, allows to consider it a promising compound for biomedical applications.

Oxidative Stress Induced by Antivirals: Implications for Adverse Outcomes During Pregnancy and in Newborns

Oxidative stress plays a critical role in various physiological and pathological processes, particularly during pregnancy, where it can significantly affect maternal and fetal health. In the context of viral infections, such as those caused by Human Immunodeficiency Virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), oxidative stress may exacerbate complications by disrupting cellular function and immune responses. Antiviral drugs, while essential in managing these infections, can also contribute to oxidative stress, potentially impacting both the mother and the developing fetus. Understanding the mechanisms by which antivirals can contribute to oxidative stress and examination of pharmacokinetic changes during pregnancy that influence drug metabolism is essential. Some research indicates that antiretroviral drugs can induce oxidative stress and mitochondrial dysfunction during pregnancy, while other studies suggest that their use is generally safe. Therefore, concerns about long-term health effects persist. This review delves into the complex interplay between oxidative stress, antioxidant defenses, and antiviral therapies, focusing on strategies to mitigate potential oxidative damage. By addressing gaps in our understanding, we highlight the importance of balancing antiviral efficacy with the risks of oxidative stress. Moreover, we advocate for further research to develop safer, more effective therapeutic approaches during pregnancy. Understanding these dynamics is essential for optimizing health outcomes for both mother and fetus in the context of viral infections during pregnancy.

A Closer Look at the Avian Influenza Virus H7N9: A Calm before the Storm?

The avian influenza A (H7N9) virus, which circulates in wild birds and poultry, has been a major concern for public health since it was first discovered in China in 2013 due to its demonstrated ability to infect humans, causing severe respiratory illness with high mortality rates. According to the World Health Organization (WHO), a total of 1568 human infections with 616 fatal cases caused by novel H7N9 viruses have been reported in China from early 2013 to January 2024. This manuscript provides a comprehensive review of the virology, evolutionary patterns, and pandemic potential of H7N9. The H7N9 virus exhibits a complex reassortment history, receiving genes from H9N2 and other avian influenza viruses. The presence of certain molecular markers, such as mutations in the hemagglutinin and polymerase basic protein 2, enhances the virus's adaptability to human hosts. The virus activates innate immune responses through pattern recognition receptors, leading to cytokine production and inflammation. Clinical manifestations range from mild to severe, with complications including pneumonia, acute respiratory distress syndrome, and multiorgan failure. Diagnosis relies on molecular assays such as reverse transcription-polymerase chain reaction. The increasing frequency of human infections, along with the virus's ability to bind to human receptors and cause severe disease, highlights its pandemic potential. Continued surveillance, vaccine development, and public health measures are crucial to limit the risk posed by H7N9. Understanding the virus's ecology, transmission dynamics, and pathogenesis is essential for developing effective prevention and control strategies.

Pharmacological Potential and Electrochemical Characteristics of Typha angustifolia Pollen

Typha angustifolia L. (TA) pollen has been utilized as a traditional Chinese medicine for treating various internal and external traumas. Moreover, bioactive compounds possess diverse pharmacological activities. This study aims to evaluate the antiviral properties of TA based on its ability to generate bioenergy, capable of inhibiting viruses. TA pollens were extracted using water and ethanol solvents. These extracts were utilized to identify the phytochemical contents and correlate with the antioxidant activity via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. HPLC analysis was conducted to identify its electron-shuttling compositions. The bioenergy-generating characteristics were determined via microbial fuel cells. The water extract (TA-W) showed higher antioxidant activity due to a higher phenolic and flavonoid content compared to the ethanol extract (TA-E). Quercetin-3-O-(2G-α-L-rhamnosyl)-rutinoside, quercetin-3-O-neohesperidoside, and quercetin are the electron shuttles (ES) identified out of the 11 compounds. TA obtained a 1.39 ± 0.10 amplification factor of power generation that indicates potential bioenergy-generating and associated antiviral characteristic properties. The findings may provide a foundation for developing antiviral medications specifically designed to target virus-related diseases, while minimizing the risk of drug toxicity and reducing the costs of drug development.

Potent and Selective Oxidatively Labile Ether-Based Prodrugs through Late-Stage Boronate Incorporation

This manuscript describes a new strategy for prodrug synthesis in which a relatively inert ether group is introduced at an early stage in a synthetic sequence and functionalized in the final step to introduce a prodrug-activating group through a chemoselective process. Boryl allyloxy (BAO) ether groups are synthesized through several metal-mediated processes to form entities that are readily cleaved under oxidative conditions commonly found in cancer cells. The high cleavage propensity of the BAO group allows for ether cleavage, making these compounds substantially more hydrolytically stable in comparison to acyl-linked prodrugs while retaining the ability to release alcohols. We report the preparation of prodrug analogues of the natural products camptothecin and pederin from acetal precursors that serve as protecting groups in their synthetic sequences. The BAO acetal groups cleave in the presence of hydrogen peroxide to release the cytotoxic agents. The pederin-based prodrug shows dramatically greater cytotoxicity than negative controls and outstanding selectivity and potency toward cancer cell lines in comparison to non-cancerous cell lines. This late-stage functionalization approach to prodrug synthesis should be applicable to numerous systems that can be accessed through chemoselective processes.

Modular Polymerase Synthesis and Internal Protein Domain Swapping via Dual Opposed Frameshifts in the Ebola Virus L Gene

Sequence analysis of the Zaire ebolavirus (EBOV) polymerase (L gene) mRNA, using online tools, identified a highly ranked -1 programmed ribosomal frameshift (FS) signal including an ideal slippery sequence heptamer (UUUAAAA), with an overlapping coding region featuring two tandem UGA codons, immediately followed by an RNA region that is the inverse complement (antisense) to a region of the mRNA of the selenoprotein iodothyronine deiodinase II (DIO2). This antisense interaction was confirmed in vitro via electrophoretic gel shift assay, using cDNAs at the EBOV and DIO2 segments. The formation of a duplex between the two mRNAs could trigger the ribosomal frameshift, by mimicking the enhancing role of a pseudoknot structure, while providing access to the selenocysteine insertion sequence (SECIS) element contained in the DIO2 mRNA. This process would allow the -1 frame UGA codons to be recoded as selenocysteine, forming part of a C-terminal module in a low abundance truncated isoform of the viral polymerase, potentially functioning in a redox role. Remarkably, 90 bases downstream of the -1 FS site, an active +1 FS site can be demonstrated, which, via a return to the zero frame, would enable the attachment of the entire C-terminal of the polymerase protein. Using a construct with upstream and downstream reporter genes, spanning a wildtype or mutated viral insert, we show significant +1 ribosomal frameshifting at this site. Acting singly or together, frameshifting at these sites (both of which are highly conserved in EBOV strains) could enable the expression of several modified isoforms of the polymerase. The 3D modeling of the predicted EBOV polymerase FS variants using the AI tool, AlphaFold, reveals a peroxiredoxin-like active site with arginine and threonine residues adjacent to a putative UGA-encoded selenocysteine, located on the back of the polymerase "hand". This module could serve to protect the viral RNA from peroxidative damage.

Persistent Post COVID-19 Endothelial Dysfunction and Oxidative Stress in Women

The assessment of endothelial dysfunction and free radical homeostasis parameters were performed in 92 women, aged 45 to 69 years, divided into the following groups: women without COVID-19 (unvaccinated, no antibodies, control); women with acute phase of COVID-19 infection (main group, COVID-19+); 12 months post COVID-19+; women with anti-SARS-CoV-2 IgG with no symptoms of COVID-19 in the last 12 months (asymptomatic COVID-19). Compared to the control, patients of the main group had lower glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities, decreased advanced glycation end products (AGEs) level, higher glutathione reductase (GR) activity, and higher glutathione S transferases pi (GSTpi), thiobarbituric acid reactants (TBARs), endothelin (END)-1, and END-2 concentrations (all p ≤ 0.05). The group with asymptomatic COVID-19 had lower 8-OHdG and oxidized glutathione (GSSG) levels, decreased total antioxidant status (TAS), and higher reduced glutathione (GSH) and GSH/GSSG levels (all p ≤ 0.05). In the group COVID-19+, as compared to the group without clinical symptoms, we detected lower GPx and SOD activities, decreased AGEs concentration, a higher TAS, and greater GR activity and GSTpi and TBARs concentrations (all p ≤ 0.05). The high content of lipid peroxidation products 12 months post COVID-19+, despite decrease in ENDs, indicates long-term changes in free radical homeostasis. These data indicate increased levels of lipid peroxidation production contribute, in part, to the development of free radical related pathologies including long-term post COVID syndrome.

Do prescription stimulants increase risk of Parkinson's disease among adults with attention-deficit hyperactivity disorder? A retrospective cohort study

BACKGROUND

Parkinson's disease (PD) is a common neurodegenerative disorder in older adults that is associated with neuroinflammation, oxidative stress, and characterized by loss of dopaminergic cells. Illicit stimulants increase oxidative stress and are associated with increased risk of PD. Prescription stimulants are similar in mechanism to illicit stimulants, yet their influence on PD is not well described. This study aims to determine if prescription stimulants influence risk of PD among older adults with attention-deficit and hyperactivity disorder (ADHD).

METHODS

We implemented a retrospective observational cohort design utilizing the TriNetX database which sources from the electronic health records of 57 healthcare organizations. Inclusion criteria were ADHD diagnosis and age ≥50. Those exposed to stimulants and the unexposed controls were matched based on demographics and known risk factors for PD. The outcome of interest was the incidence of PD over a 30-year follow-up period. We utilized TriNetX software for hazard ratio (HR) analysis.

RESULTS

Among the 59,471 individuals treated with prescription stimulants 131 of them developed PD, and there were 272 individuals who developed PD that were not prescribed stimulants. This analysis yielded a HR of 0.419 (HR = 0.419 [95% CI 0.34, 0.516], P = 0.0013).

CONCLUSION

Illicit stimulants are associated with increased risk of PD, but this study suggests prescribed stimulants may not impart that same risk. The reduced risk in this cohort may be due to protection from illicit substance use and oxidative stress, however additional study exploring the relationship between prescription stimulants and PD is warranted.

Unveiling the intersection: ferroptosis in influenza virus infection

The influenza virus (IFV) imposes a considerable health and economic burden globally, requiring a comprehensive understanding of its pathogenic mechanisms. Ferroptosis, an iron-dependent lipid peroxidation cell death pathway, holds unique implications for the antioxidant defense system, with possible contributions to inflammation. This exploration focuses on the dynamic interplay between ferroptosis and the host defense against viruses, emphasizing the influence of IFV infections on the activation of the ferroptosis pathway. IFV causes different types of cell death, including apoptosis, necrosis, and ferroptosis. IFV-induced ferroptotic cell death is mediated by alterations in iron homeostasis, intensifying the accumulation of reactive oxygen species and promoting lipid peroxidation. A comprehensive investigation into the mechanism of ferroptosis in viral infections, specifically IFV, has great potential to identify therapeutic strategies. This understanding may pave the way for the development of drugs using ferroptosis inhibitors, presenting an effective approach to suppress viral infections.

Anti-Influenza A Potential of Tagetes erecta Linn. Extract Based on Bioinformatics Analysis and In Vitro Assays

Tagetes erecta Linn. (TE) is traditionally used to treat cardiovascular, renal, and gastrointestinal diseases. In this study, we investigated the active compounds and targets of TE extract that may exert antiviral effects against influenza A. Active compounds and targets of TE extract were identified using the Traditional Chinese Medicine Systems Pharmacology database (TCSMP). The influenza A-related gene set was screened using GeneCards and the Kyoto Encyclopedia of Genes and Genomes (KEGG). A protein-protein interaction (PPI) network was built to establish the hub targets. Pathway and target studies were conducted using Gene Expression Omnibus (GEO). The interactions between active compounds and potential targets were assessed by molecular docking. An in vitro study was performed using antiviral and plaque reduction assays. From the compound and target search, we identified 6 active compounds and 95 potential targets. We retrieved 887 influenza-associated target genes and determined 14 intersecting core targets between TE and influenza. After constructing a compound-target network, we discovered lutein and beta-carotene to be the key compounds. Next, PPI network analysis identified the top three hub genes associated with influenza (IL-6, HIF1A, and IL-1β). Similarly, GEO analysis revealed IL-6, TGFB1, and CXCL8 to be the top three target genes. In our docking study, we identified that lutein and IL-6 had the strongest bindings. Our in vitro experimental results revealed that the TE extract exhibited therapeutic rather than prophylactic effects on influenza disease. We identified lutein as a main active compound in TE extract, and IL-6 as an important target associated with influenza, by using data mining and bioinformatics. Our in vitro findings indicated that TE extract exerted protective properties against the influenza A virus. We speculated that lutein, as a key active component in TE extract, is largely responsible for its antiviral effects. Therefore, we suggest TE extract as an alternative in the treatment of influenza.

Astragaloside IV inhibits inflammation caused by influenza virus via reactive oxygen species/NOD-like receptor thermal protein domain associated protein 3/Caspase-1 signaling pathway

BACKGROUND

Astragaloside IV (AS-IV) is the most active monomer in the traditional Chinese herbal medicine Radix Astragali, which has a wide range of antiviral, anti-inflammatory, and antifibrosis pharmacological effects, and shows protective effects in acute lung injury.

METHODS

This study utilized the immunofluorescence, flow cytometry, enzyme-linked immunosorbent assay, quantitative reverse transcription-polymerase chain reaction, western blot, and hematoxylin and eosin staining methods to investigate the mechanism of AS-IV in reducing viral pneumonia caused by influenza A virus in A549 cells and BALB/c mice.

RESULTS

The results showed that AS-IV suppressed reactive oxygen species production in influenza virus-infected A549 cells in a dose-dependent manner, and subsequently inhibited the activation of nucleotide-binding oligomerization domain-like receptor thermal protein domain associated protein 3 inflammasome and Caspase-1, decreased interleukin (IL) -1β and IL-18 secretion. In BALB/c mice infected with Poly (I:C), oral administration of AS-IV can significantly reduce Poly (I:C)-induced acute pneumonia and lung pathological injury.

CONCLUSIONS

AS-IV alleviates the inflammatory response induced by influenza virus in vitro and lung flammation and structural damage caused by poly (I:C) in vivo.

Emerging mechanisms in the redox regulation of mitochondrial cytochrome c oxidase assembly and function

In eukaryotic cells, mitochondria perform cellular respiration through a series of redox reactions ultimately reducing molecular oxygen to water. The system responsible for this process is the respiratory chain or electron transport system (ETS) composed of complexes I-IV. Due to its function, the ETS is the main source of reactive oxygen species (ROS), generating them on both sides of the mitochondrial inner membrane, i.e. the intermembrane space (IMS) and the matrix. A correct balance between ROS generation and scavenging is important for keeping the cellular redox homeostasis and other important aspects of cellular physiology. However, ROS generated in the mitochondria are important signaling molecules regulating mitochondrial biogenesis and function. The IMS contains a large number of redox sensing proteins, containing specific Cys-rich domains, that are involved in ETS complex biogenesis. The large majority of these proteins function as cytochrome c oxidase (COX) assembly factors, mainly for the handling of copper ions necessary for the formation of the redox reactive catalytic centers. A particular case of ROS-regulated COX assembly factor is COA8, whose intramitochondrial levels are increased by oxidative stress, promoting COX assembly and/or protecting the enzyme from oxidative damage. In this review, we will discuss the current knowledge concerning the role played by ROS in regulating mitochondrial activity and biogenesis, focusing on the COX enzyme and with a special emphasis on the functional role exerted by the redox sensitive Cys residues contained in the COX assembly factors.

The effects of urolithin A on poly I:C-induced microglial activation

Neuroinflammation can be triggered by various stimuli, including viral infections. Viruses can directly invade the brain and infect neuronal cells or indirectly trigger a "cytokine storm" in the periphery that eventually leads to microglial activation in the brain. While this initial activation of microglial cells is important for viral clearance, chronic activation leads to excessive inflammation and oxidative stress, which can be neurotoxic. Remarkebly, recent studies have shown that certain viruses such as influenza A virus, coronavirus, herpes virus and Epstein-Barr virus may be involved in the development of neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and multiple sclerosis. Therefore, it is important to find therapeutic strategies against chronic neuroinflammation triggered by viral infections. Here, we investigated the effects of urolithin A (UA) on microglial activation in vitro induced by a viral mimetic, poly I:C, in a triple co-culture system of neurons, astrocytes and microglial cells. Immunocytochemistry was used to perform a comprehensive single-cell analysis of the morphological changes of microglia as an indicator of their reactive state. Treatment with UA significantly prevented the poly I:C-induced reactive state of microglia, which was characterized by increased expression of the microglial activation markers CD68 and IBA-1. UA restored the poly I:C-induced morphology by restoring microglial ramification. In addition, UA was able to reduce the release of the pro-inflammatory mediators CCL2, TNF-α, and IL-1β and showed a trend toward attenuation of cellular ROS production in poly I:C-treated cultures. Overall, this study suggests that UA as a component of a healthy diet may help prevent virus-induced neuroinflammation and may have therapeutic potential for future studies to prevent or treat neurodegenerative diseases by targeting the associated neuroinflammatory processes.

Grass carp peroxiredoxin 5 and 6-mediated autophagy inhibit grass carp reovirus replication and mitigate oxidative stress

Peroxiredoxins (Prxs) are a family of antioxidant enzymes crucial for shielding cells against oxidative damage from reactive oxygen species (ROS). In this study, we cloned and analyzed two grass carp peroxiredoxin genes, CiPrx5 and CiPrx6. These genes exhibited ubiquitous expression across all sampled tissues, with their expression levels significantly modulated upon exposure to grass carp reovirus (GCRV). CiPrx5 was localized in the mitochondria, while CiPrx6 was uniformly distributed in the whole cells. Transfection or transformation of CiPrx5 and CiPrx6 into fish cells or E. coli significantly enhanced host resistance to H2O2 and heavy metals, leading to increased cell viability and reduced cell apoptosis rates. Furthermore, purified recombinant CiPrx5 and CiPrx6 proteins effectively protected DNA against oxidative damage. Notably, overexpression of both peroxiredoxins in fish cells effectively inhibited GCRV replication, reduced intracellular ROS levels induced by GCRV infection and H2O2 treatment, and induced autophagy. Significantly, these functions of CiPrx5 and CiPrx6 in GCRV replication and ROS mitigation were abolished upon treatment with an autophagy inhibitor. In summation, our findings suggest that grass carp Prx5 and Prx6 promote autophagy to inhibit GCRV replication, decrease intracellular ROS, and provide protection against oxidative stress.

Effects of DHAV-3 infection on innate immunity, antioxidant capacity, and lipid metabolism in ducks with different DHAV-3 susceptibilities

The aim of the experiment was to evaluate the status of innate immunity, oxidative status and lipid accumulation in ducklings exhibiting varying susceptibilities to DHAV-3 infection. In the experiment, ducklings with different DHAV-3 susceptibilities were used. Samples were collected at 6, 12, 15, and 24 h post infection (hpi), with 5 samples per time point. Plasma biochemistry, antioxidant enzyme activities, lipid content of liver and kidney were detected in the experiment. Elevated plasma level of total bilirubin, direct bilirubin, and creatinine indicated the injury of liver and kidney in susceptible ducklings (P < 0.05). The histopathological sections showed the injury in kidney. During the infection time, there was an increase in the concentrations of reactive oxygen species and oxidative damage markers (malondialdehyde and nitric oxide) in plasma of susceptible ducklings, particularly at 24 hpi (P < 0.05). Compared with the resistant ducklings, DHAV-3 infection resulted in a significant increase in the plasma total triglyceride (TG) level and a decrease in glucose level in susceptible ducklings. Gene expression of the innate immune response was both investigated in liver and kidney. In resistant ducklings, the expressions levels of pattern recognition receptors RIG-I, MDA5 remained constant. In contrast, the gene expressions peaked at 24 hpi in the susceptible ducklings. DHAV-3 infection promoted the expression of IFN, IL6, IL12β, caspase-8 or caspase-9 in both liver and kidney of susceptible ducklings. In conclusion, DHAV-3 infection led to the mobilization of antioxidant defenses, alterations in lipid metabolism, and oxidative stress in susceptible ducklings during DHAV-3 infection.

Post-Viral Pain, Fatigue, and Sleep Disturbance Syndromes: Current Knowledge and Future Directions

Background

Post-viral pain syndrome, also known as post-viral syndrome, is a complex condition characterized by persistent pain, fatigue, musculoskeletal pain, neuropathic pain, neurocognitive difficulties, and sleep disturbances that can occur after an individual has recovered from a viral infection.

Aims

This narrative review provides a summary of the sequelae of post-viral syndromes, viral agents that cause it, and the pathophysiology, treatment, and future considerations for research and targeted therapies.

Methods

Medline, PubMed, and Embase databases were used to search for studies on viruses associated with post-viral syndrome.

Conclusion

Much remains unknown regarding the pathophysiology of post-viral syndromes, and few studies have provided a comprehensive summary of the condition, agents that cause it, and successful treatment modalities. With the COVID-19 pandemic continuing to affect millions of people worldwide, the need for an understanding of the etiology of post-viral illness and how to help individuals cope with the sequalae is paramount.

The Role of the NRF2 Pathway in the Pathogenesis of Viral Respiratory Infections

In humans, acute and chronic respiratory infections caused by viruses are associated with considerable morbidity and mortality. Respiratory viruses infect airway epithelial cells and induce oxidative stress, yet the exact pathogenesis remains unclear. Oxidative stress activates the transcription factor NRF2, which plays a key role in alleviating redox-induced cellular injury. The transcriptional activation of NRF2 has been reported to affect both viral replication and associated inflammation pathways. There is complex bidirectional crosstalk between virus replication and the NRF2 pathway because virus replication directly or indirectly regulates NRF2 expression, and NRF2 activation can reversely hamper viral replication and viral spread across cells and tissues. In this review, we discuss the complex role of the NRF2 pathway in the regulation of the pathogenesis of the main respiratory viruses, including coronaviruses, influenza viruses, respiratory syncytial virus (RSV), and rhinoviruses. We also summarize the scientific evidence regarding the effects of the known NRF2 agonists that can be utilized to alter the NRF2 pathway.

Association between serum copper-zinc ratio and respiratory tract infection in children and adolescents

BACKGROUND

The aim of this study was to explore the association between serum copper-zinc (Cu-Zn) ratio and the risk of respiratory tract infection in children and adolescents.

METHODS

This cross-sectional study collected the data of 1695 participants who aged 6-17 years with follow-up data on respiratory tract infection in 2011-2012, 2013-2014 and 2015-2016 cycles from the National Health and Nutrition Examination Survey (NHANES) database. Univariate logistic regression analysis was applied to explore the covariates. Each covariate was adjusted in multivariate logistic regression analysis to explore the correlation between serum Cu-Zn ratio and respiratory tract infection. Subgroup analysis was performed to stratify the data according to age, gender and BMI. Restricted cubic spline (RCS) curve was plotted to identify the association between serum Cu-Zn ratio and respiratory tract infection.

RESULTS

The results of RCS curve depicted that the risk of respiratory tract infection was increased as the elevation of the serum Cu-Zn ratio. After adjusting for confounders, risk of respiratory tract infection in children and adolescents was elevated with the increase of serum copper-zinc ratio (OR = 1.38, 95%CI: 1.19-1.60). Compared with people with serum copper-zinc ratio <1.25, subjects who had serum copper-zinc ratio >1.52 was associated with increased risk of respiratory tract infection in children and adolescents (OR = 1.88, 95%CI: 1.19-2.98). Subgroup analysis demonstrated that the risk of respiratory tract infection was elevated as the increase of serum copper-zinc ratio in participants <12 years (OR = 1.65, 95%CI: 1.28-2.12), ≥12 years (OR = 1.27, 95%CI: 1.03-1.57), males (OR = 1.63, 95%CI: 1.29-2.06), females (OR = 1.26, 95%CI: 1.01-1.57), underweight and normal (OR = 1.35, 95%CI: 1.11-1.65), and overweight and obese participants (OR = 1.44, 95%CI: 1.15-1.80).

CONCLUSION

Higher serum Cu-Zn ratio was associated with increased risk of respiratory tract infection in children and adolescents, which suggests the importance of Zn supplement and the balance of serum Cu-Zn ratio in children and adolescents.

The oxidative stress response of Streptococcus pneumoniae: its contribution to both extracellular and intracellular survival

Streptococcus pneumoniae is a gram-positive, aerotolerant bacterium that naturally colonizes the human nasopharynx, but also causes invasive infections and is a major cause of morbidity and mortality worldwide. This pathogen produces high levels of H2O2 to eliminate other microorganisms that belong to the microbiota of the respiratory tract. However, it also induces an oxidative stress response to survive under this stressful condition. Furthermore, this self-defense mechanism is advantageous in tolerating oxidative stress imposed by the host's immune response. This review provides a comprehensive overview of the strategies employed by the pneumococcus to survive oxidative stress. These strategies encompass the utilization of H2O2 scavengers and thioredoxins, the adaptive response to antimicrobial host oxidants, the regulation of manganese and iron homeostasis, and the intricate regulatory networks that control the stress response. Here, we have also summarized less explored aspects such as the involvement of reparation systems and polyamine metabolism. A particular emphasis is put on the role of the oxidative stress response during the transient intracellular life of Streptococcus pneumoniae, including coinfection with influenza A and the induction of antibiotic persistence in host cells.

Peroxide-Mediated Release of Organophosphates from Boron-Containing Phosphotriesters: A New Class of Organophosphate Prodrugs

Phosphate mono- and diesters can be liberated efficiently from boryl allyloxy (BAO) and related phosphotriesters by H2O2. This protocol was applied to the release of a phosphorylated serine derivative and the nucleotide analogue AZT monophosphate. Nucleotide release in the presence of ATP and a kinase provides a diphosphate, demonstrating that this method can be applied to biological processes.

SARS-CoV-2 Inhibits NRF2-Mediated Antioxidant Responses in Airway Epithelial Cells and in the Lung of a Murine Model of Infection

Several viruses have been shown to modulate the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2), the master regulator of redox homeostasis. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, also seems to disrupt the balance between oxidants and antioxidants, which likely contributes to lung damage. Using in vitro and in vivo models of infection, we investigated how SARS-CoV-2 modulates the transcription factor NRF2 and its dependent genes, as well as the role of NRF2 during SARS-CoV-2 infection. We found that SARS-CoV-2 infection downregulates NRF2 protein levels and NRF2-dependent gene expression in human airway epithelial cells and in lungs of BALB/c mice. Reductions in cellular levels of NRF2 seem to be independent of proteasomal degradation and the interferon/promyelocytic leukemia (IFN/PML) pathway. Furthermore, lack of the Nrf2 gene in SARS-CoV-2-infected mice exacerbates clinical disease, increases lung inflammation, and is associated with a trend toward increased lung viral titers, indicating that NRF2 has a protective role during this viral infection. In summary, our results suggest that SARS-CoV-2 infection alters the cellular redox balance by downregulating NRF2 and its dependent genes, which exacerbates lung inflammation and disease, therefore, suggesting that the activation of NRF2 could be explored as therapeutic approach during SARS-CoV-2 infection. IMPORTANCE The antioxidant defense system plays a major function in protecting the organism against oxidative damage caused by free radicals. COVID-19 patients often present with biochemical characteristics of uncontrolled pro-oxidative responses in the respiratory tract. We show herein that SARS-CoV-2 variants, including Omicron, are potent inhibitors of cellular and lung nuclear factor erythroid 2-related factor 2 (NRF2), the master transcription factor that controls the expression of antioxidant and cytoprotective enzymes. Moreover, we show that mice lacking the Nrf2 gene show increased clinical signs of disease and lung pathology when infected with a mouse-adapted strain of SARS-CoV-2. Overall, this study provides a mechanistic explanation for the observed unbalanced pro-oxidative response in SARS-CoV-2 infections and suggests that therapeutic strategies for COVID-19 may consider the use of pharmacologic agents that are known to boost the expression levels of cellular NRF2.

Bidirectionally Regulating Viral and Cellular Ferroptosis with Metastable Iron Sulfide Against Influenza Virus

Influenza virus with numerous subtypes and frequent variation limits the development of high-efficacy and broad-spectrum antiviral strategy. Here, a novel multi-antiviral metastable iron sulfides (mFeS) against various influenza A/B subtype viruses is developed. This work finds that mFeS induces high levels of lipid peroxidation and •OH free radicals in the conservative viral envelope, which depends on Fe2+ . This phenomenon, termed as a viral ferroptosis, results in the loss of viral infectibility and pathogenicity in vitro and in vivo, respectively. Furthermore, the decoction of mFeS (Dc(mFeS)) inhibits cellular ferroptosis-dependent intracellular viral replication by correcting the virus-induced reprogrammed sulfur metabolism, a conserved cellular metabolism. Notably, personal protective equipment (PPE) that is loaded with mFeS provides good antiviral protection. Aerosol administration of mFeS combined with the decoction (mFeS&Dc) has a potential therapeutic effect against H1N1 lethal infection in mice. Collectively, mFeS represents an antiviral alternative with broad-spectrum activity against intracellular and extracellular influenza virus.

Novel neuroendocrine role of γ-aminobutyric acid and gastrin-releasing peptide in the host response to influenza infection

Gastrin-releasing peptide (GRP), an evolutionarily conserved neuropeptide, significantly contributes to influenza-induced lethality and inflammation in rodent models. Because GRP is produced by pulmonary neuroendocrine cells (PNECs) in response to γ-aminobutyric acid (GABA), we hypothesized that influenza infection promotes GABA release from PNECs that activate GABAB receptors on PNECs to secrete GRP. Oxidative stress was increased in the lungs of influenza A/PR/8/34 (PR8)-infected mice, as well as serum glutamate decarboxylase 1, the enzyme that converts L-glutamic acid into GABA. The therapeutic administration of saclofen, a GABAB receptor antagonist, protected PR8-infected mice, reduced lung proinflammatory gene expression of C-C chemokine receptor type 2 (Ccr2), cluster of differentiation 68 (Cd68), and Toll like receptor 4 (Tlr4) and decreased the levels of GRP and high-mobility group box 1 (HMGB1) in sera. Conversely, baclofen, a GABAB receptor agonist, significantly increased the lethality and inflammatory responses. The GRP antagonist, NSC77427, as well as the GABAB antagonist, saclofen, blunted the PR8-induced monocyte infiltration into the lung. Together, these data provide the first report of neuroregulatory control of influenza-induced disease.

Phenolic compound SG-1 from Balanophora harlandii and its derivatives exert anti-influenza A virus activity via activation of the Nrf2/HO-1 pathway

Influenza A virus (IAV) is one of the leading causes of respiratory illness and continues to cause pandemics around the world. Against this backdrop, drug resistance poses a challenge to existing antiviral drugs, and hence, there is an urgent need for developing new antiviral drugs. In this study, we obtained a phenolic compound SG-7, a derivative of natural compound 2-hydroxymethyl-1,4-hydroquinone, which exhibits inhibitory activity toward a panel of influenza viruses and has low cellular toxicity. Mechanistic studies have shown that SG-7 exerts its anti-IAV properties by acting on the virus itself and modulating host signaling pathways. Namely, SG-7 targets the HA2 subunit of hemagglutinin (HA) to block the fusion of viral-cellular membranes and inhibits IAV-induced oxidative stress and overexpression of pro-inflammatory factors by activating the Nrf2/HO-1 pathway and reducing NF-κB activation. In addition, SG-7 can enhance type I IFN antiviral response by inducing Nrf2 expression. Importantly, SG-7 showed the ability to inhibit viral replication in the lungs of IAV-infected mice and reduce their mortality. Therefore, SG-7 may be a promising lead compound for anti-influenza drug development.

Photobiomodulation Reduces the Cytokine Storm Syndrome Associated with COVID-19 in the Zebrafish Model

Although the exact mechanism of the pathogenesis of coronavirus SARS-CoV-2 (COVID-19) is not fully understood, oxidative stress and the release of pro-inflammatory cytokines have been highlighted as playing a vital role in the pathogenesis of the disease. In this sense, alternative treatments are needed to reduce the level of inflammation caused by COVID-19. Therefore, this study aimed to investigate the potential effect of red photobiomodulation (PBM) as an attractive therapy to downregulate the cytokine storm caused by COVID-19 in a zebrafish model. RT-qPCR analyses and protein-protein interaction prediction among SARS-CoV-2 and Danio rerio proteins showed that recombinant Spike protein (rSpike) was responsible for generating systemic inflammatory processes with significantly increased levels of pro-inflammatory (il1b, il6, tnfa, and nfkbiab), oxidative stress (romo1) and energy metabolism (slc2a1a and coa1) mRNA markers, with a pattern similar to those observed in COVID-19 cases in humans. On the other hand, PBM treatment was able to decrease the mRNA levels of these pro-inflammatory and oxidative stress markers compared with rSpike in various tissues, promoting an anti-inflammatory response. Conversely, PBM promotes cellular and tissue repair of injured tissues and significantly increases the survival rate of rSpike-inoculated individuals. Additionally, metabolomics analysis showed that the most-impacted metabolic pathways between PBM and the rSpike treated groups were related to steroid metabolism, immune system, and lipid metabolism. Together, our findings suggest that the inflammatory process is an incisive feature of COVID-19 and red PBM can be used as a novel therapeutic agent for COVID-19 by regulating the inflammatory response. Nevertheless, the need for more clinical trials remains, and there is a significant gap to overcome before clinical trials can commence.

Utility of mouth rinses with povidone-iodine and hydrogen peroxide in patients with COVID-19

INTRODUCTION

Povidone-iodine and hydrogen peroxide could be effective in against SARS-CoV-2.

METHODS

A "non-interventional trial" in 88 patients (43±17 yrs., 55% men) with SARS-CoV-2 in nasopharyngeal swabs (RT-PCR). 31 received mouth rinses/gargling with povidone-iodine (every 8h, two consecutive days), 17 with mouth rinses/gargling of hydrogen peroxide, and 40 controls. Were repeated PCR in 3, 11 and 17 days.

RESULTS

After intervention the viral load (Log10 copies/ml) remained similar in povidone-iodine (4.3±2.7 copies/ml), hydrogen peroxide (4.6±2.9 copies/ml; p=0.40) and controls (4.4±3.0 copies/ml). The percentage of patients with a negative result in the second PCR was 27% in povidone-iodine group, 23% in hydrogen peroxide and 32% in controls; in the third PCR, 62%, 54% y 58% respectively; and in the fourth PCR, 81%, 75% y 81%.

CONCLUSION

Our results do not support the clinical usefulness of mouth rinses/gargling with povidone-iodine or hydrogen peroxide in patients with COVID-19.

[Utility of mouth rinses with povidone-iodine and hydrogen peroxide in patients with COVID-19]

Introduction

Povidone-iodine and hydrogen peroxide could be effective in against SARS-CoV-2.

Methods

A "non-interventional trial" in 88 patients (43 ± 17 yrs, 55% men) with SARS-CoV-2 in nasopharyngeal swabs (RT-PCR). 31 received mouth rinses/gargling with povidone-iodine (every 8 h, two consecutive days), 17 with mouth rinses/gargling of hydrogen peroxide, and 40 controls. PCR were repeated at 3, 11 and 17 days.

Results

After intervention the viral load (Log 10 copies/ml) remained similar in povidone-iodine (4.3 ± 2.7 copies/ml), hydrogen peroxide (4.6 ± 2.9 copies/ml; p = 0.40) and controls (4.4 ± 3.0 copies/ml). The percentage of patients with a negative result in the second PCR was 27% in povidone-iodine group, 23% in hydrogen peroxide and 32% in controls; in the third PCR, 62%, 54% and 58% respectively; and in the fourth PCR, 81%, 75% and 81%.

Conclusion

Our results do not support the clinical usefulness of mouth rinses/gargling with povidone-iodine or hydrogen peroxide in patients with COVID-19.

Potential Role of Superoxide Dismutase 3 (SOD3) in Resistance to Influenza A Virus Infection

Influenza A virus infection induces the production of excessive reactive oxygen species (ROS). Overproduction of ROS can overwhelm the antioxidant defense system, leading to increasing intensive oxidative stress. However, antioxidant defense against oxidative damage induced by influenza A virus infection, and in particular the significance of the SOD3 response in the pathogenesis of influenza virus infection, has not been well characterized. Here, we investigated the potential role of SOD3 in resistance to influenza A virus infection. In this study, SOD3, as an important antioxidant enzyme, was shown to be highly elevated in A549 cells following influenza A virus infection. Furthermore, inhibition of SOD3 impacted viral replication and virulence. We found that SOD3 disrupts IAV replication by impairing the synthesis of vRNA, whereas it did not affect viral ribonucleoprotein nuclear export. In addition, overexpression of SOD3 greatly reduced the levels of ROS caused by influenza A virus infection, regulated the inflammatory response to virus infection by inhibiting the phosphorylation of p65 of the NF-κB signaling pathway, and inhibited virus-induced apoptosis to a certain extent. Taken together, these findings indicate that SOD3 is actively involved in influenza A virus replication. Pharmacological modulation or targeting of SOD3 may pave the way for a novel therapeutic approach to combating influenza A virus infection.

Oxidative profile, inflammatory responses and δ-aminolevulinate dehydratase enzyme activity in influenza B virus infection

The aim of the current study was to determine the activity of the delta-aminolevulinate dehydratase (δ-ALA-D) enzyme, oxidative stress biomarkers and the expression of cytokines in those infected with influenza B virus (IBV). To evaluate the activity of the δ-ALA-D enzyme, lipid peroxidation was estimated as levels of thiobarbituric acid reactive substances, protein and non-protein thiol groups, ferric-reducing antioxidant power (FRAP), vitamin C concentration and cytokine levels in IBV-infected individuals (n  = 50) and a control group (n = 30). δ-ALA-D activity was significantly lower in IBV-infected individuals compared with controls, as well as levels of thiols, vitamin C and FRAP. Lipid peroxidation and cytokine levels of IL-6, IL-10, IL-17A and IFN-y were statistically higher in the IBV group. In conclusion, we found evidence of the generation of oxidants, the depletion of the antioxidant system, decrease in the activity of the δ-ALA-D enzyme and an increase in the synthesis of cytokines, thus contributing to a better understanding of oxidative and inflammatory pathways during IBV infection.

Antiviral Potential of Melissa officinalis L.: A Literature Review

The use of synthetic drugs has increased in recent years; however, herbal medicine is yet more trusted among a huge population worldwide; This could be due to minimal side effects, affordable prices, and traditional beliefs. Lemongrass (Melissa officinalis) has been widely used for reducing stress and anxiety, increasing appetite and sleep, reducing pain, healing wounds, and treating poisonous insect bites and bee stings for a long time. Today, research has shown that this plant can also fight viruses including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), Herpes Simplex Virus (HSV), and Human Immunodeficiency Virus (HIV) through various mechanisms such as inhibiting HSV-1 from binding to host cell, inhibiting HSV-1 replication during the post-adsorption or inhibiting main protease and spike protein of SARS-CoV-2, furthermore, be effective in treating related diseases. This Review investigated the antiviral properties of Melissa officinalis and its effect on viral diseases. More in vitro and in vivo studies are needed to determine Melissa officinaliss underlying mechanism, and more randomized controlled trials should be done to identify its effect in humans. Also, due to the usefulness and lack of side effects, it can be used more as a complementary medicine.

Identifying and validating molecular subtypes of biliary atresia using multiple high-throughput data integration analysis

Background

Biliary atresia (BA) is the most common form of severe neonatal obstructive jaundice. The etiology and pathogenesis of BA are multifactorial, and different factors may interact to produce heterogeneous pathological features and clinical outcomes. Despite different pathological features, all patients received the same treatment strategy. This study performed integrative clustering analysis based on multiple high-throughput datasets to identify the molecular subtypes of BA and provide a new treatment strategy for personalized treatment of the different subtypes of BA.

Methods

The RNA sequence dataset GSE122340 in the Gene Expression Omnibus (GEO) database was downloaded; 31 BA and 20 control normal liver tissues were collected at our center for transcriptome sequencing, and clinical and follow-up data of BA patients were available. Molecular subtypes were identified using integrated unsupervised cluster analysis involving gene expression, biliary fibrosis, and immune enrichment scores based on the transcriptome dataset, and the results were validated using independent datasets.

Results

Based on the results of the integrated unsupervised clustering analysis, four molecular subtypes were identified: autoimmune, inflammatory, virus infection-related, and oxidative stress. The autoimmune subtype with a moderate prognosis was dominated by autoimmune responses and morphogenesis, such as the Fc-gamma receptor and Wnt signaling pathway. The biological process of the inflammatory subtype was mainly the inflammatory response, with the best prognosis, youngest age at surgery, and lowest liver stiffness. The virus infection-related subtype had the worst prognosis and was enriched for a variety of biological processes such as viral infection, immunity, anatomical morphogenesis, and epithelial mesenchymal transition. The oxidative stress subtype was characterized by the activation of oxidative stress and various metabolic pathways and had a poor prognosis. The above results were verified independently in the validation sets.

Conclusions

This study identified four molecular subtypes of BA with distinct prognosis and biological processes. According to the pathological characteristics of the different subtypes, individualized perioperative and preoperative treatment may be a new strategy to improve the prognosis of BA.

Vitisin B inhibits influenza A virus replication by multi-targeting neuraminidase and virus-induced oxidative stress

The development of drug-resistant influenza and new pathogenic virus strains underscores the need for antiviral therapeutics. Currently, neuraminidase (NA) inhibitors are commonly used antiviral drugs approved by the US Food and Drug Administration (FDA) for the prevention and treatment of influenza. Here, we show that vitisin B (VB) inhibits NA activity and suppresses H1N1 viral replication in MDCK and A549 cells. Reactive oxygen species (ROS), which frequently occur during viral infection, increase virus replication by activating the NF-κB signaling pathway, downmodulating glucose-6-phosphate dehydrogenase (G6PD) expression, and decreasing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant response activity. VB decreased virus-induced ROS generation by increasing G6PD expression and Nrf2 activity, and inhibiting NF-κB translocation to the nucleus through IKK dephosphorylation. In addition, VB reduced body weight loss, increased survival, decreased viral replication and the inflammatory response in the lungs of influenza A virus (IAV)-infected mice. Taken together, our results indicate that VB is a promising therapeutic candidate against IAV infection, complements existing drug limitations targeting viral NA. It modulated the intracellular ROS by G6PD, Nrf2 antioxidant response pathway, and NF-κB signaling pathway. These results demonstrate the feasibility of a multi-targeting drug strategy, providing new approaches for drug discovery against IAV infection.

Intake of Lactobacillus paragasseri SBT2055 improves subjective symptoms of common cold during winter season in healthy adults: A randomized, double-blind, placebo-controlled parallel-group comparative study

Objective

Lactobacillus paragasseri SBT2055 (LG2055) has been reported to show immunostimulating effects. This study aimed to investigate the effects of LG2055 on the subjective symptoms of the physical condition in healthy adults.

Materials and methods

In this randomized, double-blind, placebo-controlled, parallel-group comparative study, Japanese individuals aged 20-64 years were recruited. A total of 200 participants were randomly divided into two groups by an independent controller (LG2055 and placebo groups; 100 participants per group). Drinkable yogurts containing LG2055 or lacking LG2055 (placebo) were used as test samples. The participants ingested one bottle of the test sample once a day for 12 weeks. A daily physical health questionnaire survey (about common cold symptoms) was performed as the primary outcome, and immunological and oxidative stress markers in saliva and serum were evaluated as secondary outcomes.

Results

In total, 198 participants completed the scheduled intake of the test samples, and five participants were excluded from the final analysis. Consequently, 193 participants (LG2055 group, n = 97; placebo group, n = 96) in the Per-Protocol Set were included in the efficacy analysis. The cumulative days of each symptom were evaluated, and the LG2055 group showed a significantly higher ratio of "without symptom" in runny nose, plugged nose, sneezing, sore throat, hoarseness, cough, headache, feeling tired, and fever than the placebo group, indicating that the incidence rates of common cold symptoms were lower in the LG2055 group. Additionally, changes in the salivary secretory IgA levels were significantly higher, and the serum derivatives of reactive oxygen metabolites levels were significantly lower in the LG2055 group.

Conclusion

Our study revealed that intake of LG2055 decreased common cold symptoms and improved immune parameters in healthy adults. This suggests that LG2055 contributes to the maintenance of physical conditions by improving the host immune system.

Clinical trial registration

[https://www.umin.ac.jp/ctr/index.htm], identifier [UMIN000045901].

Computer simulations on oxidative stress-induced reactions in SARS-CoV-2 spike glycoprotein: a multi-scale approach

Oxidative stress, which occurs when an organism is exposed to an adverse stimulus that results in a misbalance of antioxidant and pro-oxidants species, is the common denominator of diseases considered as a risk factor for SARS-CoV-2 lethality. Indeed, reactive oxygen species caused by oxidative stress have been related to many virus pathogenicity. In this work, simulations have been performed on the receptor binding domain of SARS-CoV-2 spike glycoprotein to study what residues are more susceptible to be attacked by ·OH, which is one of the most reactive radicals associated to oxidative stress. The results indicate that isoleucine (ILE) probably plays a crucial role in modification processes driven by radicals. Accordingly, QM/MM-MD simulations have been conducted to study both the ·OH-mediated hydrogen abstraction of ILE residues and the induced modification of the resulting ILE radical through hydroxylation or nitrosylation reactions. All in all, in silico studies show the importance of the chemical environment triggered by oxidative stress on the modifications of the virus, which is expected to help for foreseeing the identification or development of antioxidants as therapeutic drugs.

Redox imbalance in COVID-19 pathophysiology

Background

The pathophysiologic significance of redox imbalance is unquestionable as numerous reports and topic reviews indicate alterations in redox parameters during corona virus disease 2019 (COVID-19). However, a more comprehensive understanding of redox-related parameters in the context of COVID-19-mediated inflammation and pathophysiology is required.

Methods

COVID-19 subjects (n = 64) and control subjects (n = 19) were enrolled, and blood was drawn within 72 h of diagnosis. Serum multiplex assays and peripheral blood mRNA sequencing was performed. Oxidant/free radical (electron paramagnetic resonance (EPR) spectroscopy, nitrite-nitrate assay) and antioxidant (ferrous reducing ability of serum assay and high-performance liquid chromatography) were performed. Multivariate analyses were performed to evaluate potential of indicated parameters to predict clinical outcome.

Results

Significantly greater levels of multiple inflammatory and vascular markers were quantified in the subjects admitted to the ICU compared to non-ICU subjects. Gene set enrichment analyses indicated significant enhancement of oxidant related pathways and biochemical assays confirmed a significant increase in free radical production and uric acid reduction in COVID-19 subjects. Multivariate analyses confirmed a positive association between serum levels of VCAM-1, ICAM-1 and a negative association between the abundance of one electron oxidants (detected by ascorbate radical formation) and mortality in COVID subjects while IL-17c and TSLP levels predicted need for intensive care in COVID-19 subjects.

Conclusion

Herein we demonstrate a significant redox imbalance during COVID-19 infection affirming the potential for manipulation of oxidative stress pathways as a new therapeutic strategy COVID-19. However, further work is requisite for detailed identification of oxidants (O₂^•-, H₂O₂ and/or circulating transition metals such as Fe or Cu) contributing to this imbalance to avoid the repetition of failures using non-specific antioxidant supplementation.

Ursolic acid represses influenza A virus-triggered inflammation and oxidative stress in A549 cells by modulating the miR-34c-5p/TLR5 axis

BACKGROUND

Ursolic acid (UA) is a pentacyclic triterpenoid compound with a wide range of anti-tumor, anti-inflammatory, hypotensive and other pharmacological effects. Here, the biological roles and regulatory mechanisms of UA in influenza A virus (IAV)-treated A549 cells were investigated.

METHOD

The cytotoxic impacts of UA on A549 cells with or without IAV treatment were determined using MTT and LDH assays. The inflammatory responses and oxidative stress of IAV-treated A549 cells were measured by RT-qPCR, ELISA, DCFH-DA probe, and colorimetric assays. A dual luciferase assay was carried out to validate the molecular interaction between miR-34c-5p and TLR5. Promoter methylation was detected by MSP experiment. Methylation-related proteins were quantified by western blot. Virus replication was assessed by TCID50 and western blot assays.

RESULTS

UA significantly ameliorated IAV-triggered cell injury and inflammatory response, virus replication and oxidative stress by elevating cell viability, ROS level and the activities of SOD and GSH-Px but reducing the LDH, MDA, and TCID50 values and the expression of virus-related proteins (NP) and cytokines (TNF-α, IL-1β, IL-6, and IL-18). Moreover, UA promoted miR-34c-5p expression by repressing DNMTs-mediated methylation. TLR5 was verified to be a direct target of miR-34c-5p and could be downregulated by UA. Rescue experiments revealed that silencing miR-34c-5p diminished the regulatory roles of UA in IAV-treated A549 cells.

CONCLUSION

Our data elucidated that UA attenuated IAV-triggered inflammatory responses and oxidative stress in A549 cells by regulating the miR-34c-5p/TLR5 axis, suggesting that UA plays a protective role in IAV-induced pneumonia.

Reactive oxygen species associated immunoregulation post influenza virus infection

An appropriate level of reactive oxygen species (ROS) is necessary for cell proliferation, signaling transduction, and apoptosis due to their highly reactive character. ROS are generated through multiple metabolic pathways under a fine-tuned control between oxidant and antioxidant signaling. A growing number of evidence has proved their highly relevant role in modulating inflammation during influenza virus infection. As a network of biological process for protecting organism from invasion of pathogens, immune system can react and fight back through either innate immune system or adaptive immune system, or both. Herein, we provide a review about the mechanisms of ROS generation when encounter influenza virus infection, and how the imbalanced level of ROS influences the replication of virus. We also summarize the pathways used by both the innate and adaptive immune system to sense and attack the invaded virus and abnormal levels of ROS. We further review the limitation of current strategies and discuss the direction of future work.

Recombinant Muscovy Duck Parvovirus Led to Ileac Damage in Muscovy Ducklings

Waterfowl parvovirus (WPFs) has multiple effects on the intestinal tract, but the effects of recombinant Muscovy duck parvovirus (rMDPV) have not been elucidated. In this study, 48 one-day-old Muscovy ducklings were divided into an infected group and a control group. Plasma and ileal samples were collected from both groups at 2, 4, 6, and 8 days post-infection (dpi), both six ducklings at a time. Next, we analyzed the genomic sequence of the rMDPV strain. Results showed that the ileal villus structure was destroyed seriously at 4, 6, 8 dpi, and the expression of ZO-1, Occludin, and Claudin-1 decreased at 4, 6 dpi; 4, 6, 8 dpi; and 2, 6 dpi, respectively. Intestinal cytokines IFN-α, IL-1β and IL-6 increased at 6 dpi; 8 dpi; and 6, 8 dpi, respectively, whereas IL-2 decreased at 6, 8 dpi. The diversity of ileal flora increased significantly at 4 dpi and decreased at 8 dpi. The bacteria Ochrobactrum and Enterococcus increased and decreased at 4, 8 dpi; 2, 4 dpi, respectively. Plasma MDA increased at 2 dpi, SOD, CAT, and T-AOC decreased at 2, 4, 8 dpi; 4, 8 dpi; and 4, 6, 8 dpi, respectively. These results suggest that rMDPV infection led to early intestinal barrier dysfunction, inflammation, ileac microbiota disruption, and oxidative stress.

Serum antioxidant vitamins and respiratory morbidity and mortality: a pooled analysis

BACKGROUND

Oxidative stress plays a key role in the pathogenesis of respiratory diseases; however, studies on antioxidant vitamins and respiratory outcomes have been conflicting. We evaluated whether lower serum levels of vitamins A, C, D, and E are associated with respiratory morbidity and mortality in the U.S. adult population.

METHODS

We conducted a pooled analysis of data from the 1988-1994 and 1999-2006 National Health and Nutrition Examination Survey (participants aged ≥ 20 years). We estimated covariate-adjusted odds ratios (aOR) per interquartile decrease in each serum vitamin level to quantify associations with respiratory morbidity, and covariate-adjusted hazard ratios (aHR) to quantify associations with respiratory mortality assessed prospectively through 2015. Vitamin supplementation and smoking were evaluated as potential effect modifiers.

RESULTS

Lower serum vitamin C increased the odds of wheeze among all participants (overall aOR: 1.08, 95% CI: 1.01-1.16). Among smokers, lower serum α-tocopherol vitamin E increased the odds of wheeze (aOR: 1.11, 95% CI: 1.04-1.19) and chronic bronchitis/emphysema (aOR: 1.13, 95% CI: 1.03-1.24). Conversely, lower serum γ-tocopherol vitamin E was associated with lower odds of wheeze and chronic bronchitis/emphysema (overall aORs: 0.85, 95% CI: 0.79-0.92 and 0.85, 95% CI: 0.76-0.95, respectively). Lower serum vitamin C was associated with increased chronic lower respiratory disease (CLRD) mortality in all participants (overall aHR: 1.27, 95% CI: 1.07-1.51), whereas lower serum 25-hydroxyvitamin D (25-OHD) tended to increase mortality from CLRD and influenza/pneumonia among smokers (aHR range: 1.33-1.75). Mortality from influenza/ pneumonia increased with decreasing serum vitamin A levels in all participants (overall aHR: 1.21, 95% CI: 0.99-1.48). In pooled analysis, vitamin C deficiency and 25-OHD insufficiency were associated with mortality from influenza/pneumonia, increasing mortality risk up to twofold.

CONCLUSIONS

Our analysis of nationally representative data on over 34,000 participants showed that lower serum levels of vitamins A, C, D, and α-tocopherol vitamin E are associated with increased respiratory morbidity and/or mortality in U.S. adults. The results underscore the importance of antioxidant vitamins in respiratory health.

Superoxide Dismutase Activity in Male and Female Patients of Different Age with Moderate COVID-19

The study involved 271 patients (132 men and 139 women) with moderate COVID-19. Superoxide dismutase (SOD) activity in erythrocytes was measured spectrophotometrically. In total group of patients (divided into age groups of 18-35, 36-45, 46-60, and 61-90 years), higher SOD activity was found in the 18-35 age group in comparison with the groups 46-60 years (p<0.01) and 61-90 years (p<0.05). Then, the groups were additionally divided by sex. In men, no differences in enzyme activity were found between the age groups. In women of early reproductive age, SOD activity was higher than in groups 36-45, 46-60, and 61-90 years. The sex differences consisted in higher SOD activity in women aged 18-35 years in comparison with men of this age. These data should be taken into account when choosing the tactics of therapy for patients with moderate COVID-19 course.

Modulating the Antioxidant Response for Better Oxidative Stress-Inducing Therapies: How to Take Advantage of Two Sides of the Same Medal?

Oxidative stress-inducing therapies are characterized as a specific treatment that involves the production of reactive oxygen and nitrogen species (RONS) by external or internal sources. To protect cells against oxidative stress, cells have evolved a strong antioxidant defense system to either prevent RONS formation or scavenge them. The maintenance of the redox balance ensures signal transduction, development, cell proliferation, regulation of the mechanisms of cell death, among others. Oxidative stress can beneficially be used to treat several diseases such as neurodegenerative disorders, heart disease, cancer, and other diseases by regulating the antioxidant system. Understanding the mechanisms of various endogenous antioxidant systems can increase the therapeutic efficacy of oxidative stress-based therapies, leading to clinical success in medical treatment. This review deals with the recent novel findings of various cellular endogenous antioxidant responses behind oxidative stress, highlighting their implication in various human diseases, such as ulcers, skin pathologies, oncology, and viral infections such as SARS-CoV-2.

Effects of Quercitrin on PRV-Induced Secretion of Reactive Oxygen Species and Prediction of lncRNA Regulatory Targets in 3D4/2 Cells

Quercitrin is a kind of flavonoid that is found in many plants; it has good antioxidant activity, and can regulate oxidative stress induced by Pseudorabies virus (PRV)-infected cells. In this study, the secretion of reactive oxygen species (ROS) induced by PRV infection was detected by flow cytometry, and RNA expression profiles of the 3D4/2 cells were produced and analyzed by sequenced GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes); the sequencing results were verified by RT-qCR. The results showed that the secretion of ROS induced by PRV infection in 3D4/2 cells could be significantly decreased by quercitrin. The differentially expressed 1055 mRNA, 867 lncRNA, 99 miRNA, and 69 circRNA were detected between the control group and the PRV infection group. The differentially expressed 1202 mRNA, 785 lncRNA, 115 miRNA, and 79 circRNA were found between the PRV+ quercitrin group and the control group. The differentially expressed 357 mRNA, 69 lncRNA, 111 miRNA, and 81 circRNA were obtained between the PRV+ quercitrin group and the PRV group. The significantly differentially expressed mRNAs were mainly involved in cell metabolism, regulatory protein phosphorylation, protein phosphorylation, antioxidation, regulatory phosphorylation, and so on. Among them, the mRNAs related to antioxidant response and oxidative stress were thioredoxin-interacting protein (TXNIP) and nitric oxide synthase 2 (NOS2). According to the network diagram of lncRNA–miRNA–mRNA, two targeted miRNA (ssc-miR-450c-3p and novel-m0400-3p) relationships with TXNIP and NOS2 were screened. This study provides a scientific foundation for further research for the function of quercitrin in anti-virus-induced oxidative stress.