ABSTRACT
Neutrophilic granulocytes (NG) are the main drivers of pathological inflammation in COVID-19. Objective. To specify the mechanisms of immunopathogenesis of COVID-19 based on a comparative immunological study of the number and phenotype of CD16+SD62L+CD11b+CD63- and CD16+SD62L+CD11b+CD63+ subsets with an assessment of their effector functions against changing profile of NG-associated cytokines IL-8, IL-18, IL-17A, VEGF-A, IFNalpha, and IFNgamma. Patients and methods. In patients with moderate-to-severe and severe COVID-19, we determined IL-1beta, TNFalpha, IL-6, IL-8, IL-18, IL-17A, VEGF-A, IFNalpha, and IFNgamma (ELISA), the phenotype of CD16+SD62L+CD11b+CD63- and CD16+SD62L+CD11b+CD63+ subsets, NF-kappaB-NG (CYTOMICS FC500), phagocytically active NG (%), neutrophil extracellular traps (NETs), NG in apoptosis, and the activity of NADPH oxidase. Results. In COVID-19 against the background of IFNalpha and IFNgamma production blockade and high levels of NG-associated IL-8, IL-18, IL-17A, VEGF-A, a reduction in the number of mature and functionally active CD16brightSD62LbrightCD11bbrightCD63-NG subsets was revealed, as well as an increase in the number of CD16dimSD62LdimSD11bbrightCD63-NG subsets with an immunosuppressive phenotype and CD16brightSD62LbrightSD11bbrightCD63bright-NG subsets with high cytotoxic activity and ability to form NETs, a decrease in the percentage of phagocytically active NG and an increase in the activity of NADPH oxidase, NETs, and NG in apoptosis. Conclusion. IFNalpha deficiency provokes a hyperergic response of NG-associated cytokines, which leads to the formation of uncontrolled immune inflammation involving NG subsets with an immunosuppressive and cytotoxic phenotype, exacerbating the course of COVID-19. The use of recombinant IFNalpha-2b with antioxidants (Viferon) in the early stages of the disease can help to restore immune homeostasis, normalize the level of NG-associated cytokines, reduce NERTs, and achieve good clinical efficacy.Copyright © 2022, Dynasty Publishing House. All rights reserved.
ABSTRACT
Objective To explore the core targets and important pathways of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) induced atherosclerosis (AS) progression from the perspective of immune inflammation, so as to predict the potential prevention and treatment of traditional Chinese medicine (TCM). Methods Microarray data were obtained from the Gene Expression Omnibus (GEO) database for coronavirus disease 2019 (COVID-19) patients and AS patients, and the "limmar" and "Venn" packages were used to screen out the common differentially expressed genes (DEGs) genes in both diseases. The gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analyses were performed on the common DEGs to annotate their functions and important pathways. The two gene sets were scored for immune cells and immune function to assess the level of immune cell infiltration. The protein-protein interaction (PPI) network was constructed by STRING database, and the CytoHubba plug-in of Cytoscape was used to identify the hub genes. Two external validation datasets were introduced to validate the hub genes and obtain the core genes. Immuno-infiltration analysis and gene set enrichment analysis (GSEA) were performed on the core genes respectively. Finally the potential TCM regulating the core genes were predicted by Coremine Medical database. Results A total of 7898 genes related to COVID-19, 471 genes related to AS progression;And 51 common DEGs, including 32 highly expressed genes and 19 low expressed genes were obtained. GO and KEGG analysis showed that common DEGs, which were mainly localized in cypermethrin-encapsulated vesicles, platelet alpha particles, phagocytic vesicle membranes and vesicles, were involved in many biological processes such as myeloid differentiation factor 88 (MyD88)-dependent Toll-like receptor signaling pathway transduction, interleukin-8 (IL-8) production and positive regulation, IL-6 production and positive regulation to play a role in regulating nicotinamide adenine dinucleotide phosphate oxidase activity, Toll-like receptor binding and lipopeptide and glycosaminoglycan binding through many biological pathways, including Toll-like receptor signaling pathways, neutrophil extracellular trap formation, complement and coagulation cascade reactions. The results of immune infiltration analysis demonstrated the state of immune microenvironment of COVID-19 and AS. A total of 5 hub genes were obtained after screening, among which Toll-like receptor 2 (TLR2), cluster of differentiation 163 (CD163) and complement C1q subcomponent subunit B (C1QB) genes passed external validation as core genes. The core genes showed strong correlation with immune process and inflammatory response in both immune infiltration analysis and GSEA enrichment analysis. A total of 35 TCMs, including Chuanxiong (Chuanxiong Rhizoma), Taoren (Persicae Semen), Danggui (Angelicae Sinensis Radix), Huangqin (Scutellariae Radix), Pugongying (Taraxaci Herba), Taizishen (Pseudostellariae Radix), Huangjing (Polygonati Rhizoma), could be used as potential therapeutic agents. Conclusion TLR2, CD163 and C1QB were the core molecules of SARS-CoV-2-mediated immune inflammatory response promoting AS progression, and targeting predicted herbs were potential drugs to slow down AS progression in COVID-19 patients.Copyright © 2023 Editorial Office of Chinese Traditional and Herbal Drugs. All rights reserved.
ABSTRACT
Neutrophilic granulocytes (NG) are the main drivers of pathological inflammation in COVID-19. Objective. To specify the mechanisms of immunopathogenesis of COVID-19 based on a comparative immunological study of the number and phenotype of CD16+SD62L+CD11b+CD63- and CD16+SD62L+CD11b+CD63+ subsets with an assessment of their effector functions against changing profile of NG-associated cytokines IL-8, IL-18, IL-17A, VEGF-A, IFNalpha, and IFNgamma. Patients and methods. In patients with moderate-to-severe and severe COVID-19, we determined IL-1beta, TNFalpha, IL-6, IL-8, IL-18, IL-17A, VEGF-A, IFNalpha, and IFNgamma (ELISA), the phenotype of CD16+SD62L+CD11b+CD63- and CD16+SD62L+CD11b+CD63+ subsets, NF-kappaB-NG (CYTOMICS FC500), phagocytically active NG (%), neutrophil extracellular traps (NETs), NG in apoptosis, and the activity of NADPH oxidase. Results. In COVID-19 against the background of IFNalpha and IFNgamma production blockade and high levels of NG-associated IL-8, IL-18, IL-17A, VEGF-A, a reduction in the number of mature and functionally active CD16brightSD62LbrightCD11bbrightCD63-NG subsets was revealed, as well as an increase in the number of CD16dimSD62LdimSD11bbrightCD63-NG subsets with an immunosuppressive phenotype and CD16brightSD62LbrightSD11bbrightCD63bright-NG subsets with high cytotoxic activity and ability to form NETs, a decrease in the percentage of phagocytically active NG and an increase in the activity of NADPH oxidase, NETs, and NG in apoptosis. Conclusion. IFNalpha deficiency provokes a hyperergic response of NG-associated cytokines, which leads to the formation of uncontrolled immune inflammation involving NG subsets with an immunosuppressive and cytotoxic phenotype, exacerbating the course of COVID-19. The use of recombinant IFNalpha-2b with antioxidants (Viferon) in the early stages of the disease can help to restore immune homeostasis, normalize the level of NG-associated cytokines, reduce NERTs, and achieve good clinical efficacy.Copyright © 2022, Dynasty Publishing House. All rights reserved.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a pathogenic coronavirus that emerged in late 2019, resulting in coronavirus disease (COVID-19). COVID-19 can be potentially fatal among a certain group of patients. Older age and underlying medical illness are the major risk factors for COVID-19-related fatal respiratory dysfunction. The reason for the pathogenicity of COVID-19 in the older age group remains unclear. Factors, such as coagulopathy, cytokine storm, metabolic disrup-tion, and impaired T cell function, may worsen the symptoms of the disease. Recent literature has indicat-ed that viral infections are particularly associated with a high degree of oxidative stress and an imbalance of antioxidant response. Although pharmacological management has taken its place in reducing the severity of COVID-19, the antioxidants can serve as an adjunct therapy to protect an individual from oxidative damage triggered by SARS-CoV-2 infection. In general, antioxidant enzymes counteract free radicals and prevent their formation. The exact functional role of antioxidant supplements in reducing disease symptoms of SARS-CoV-2 infection remains mostly unknown. In this review, the functional role of natural antioxidants in SARS-CoV-2 infection management is discussed in brief.Copyright © 2022 Bentham Science Publishers.
ABSTRACT
Objective: Severe acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) seen in SARs-CoV-2 infection has been attributed to the disruption of the immune response in COVID-19 patients. Neutrophilia and marked lymphocyte reductions are associated with disease severity and seem predictive of disease outcome in moderate and severe COVID-19 patients. Herein, we aim to decipher possible mechanisms involved in extensive tissue injury observed in COVID-19 patients, accompanied by vasculopathy, coagulopathy, and a high incidence of thrombotic complications in severe patients. Method(s): We searched PubMED for keywords including COVID-19 pathogenesis, thrombosis, and vasculities. Result(s): Neutrophils can undergo a specialized form of apoptosis to yield thread-like extracellular structures termed neutrophil extracellular traps (NETs), termed NETosis, which form web-like scaffolds of DNA, histones, and toxic protein granules and enzymes, whose primary function is to trap and eliminate microbes. However, uncontrolled NET production can lead to ALI and ARDS, coagulopathy, multiple organ failure, and autoimmune disease. Dysregulation of NETs promotes production of anti-neutrophil cytoplasmic antibodies (ANCA) which affects small vessels through ANCA-associated vasculitis (AAV). Furthermore, NETs can also induce thrombosis via formation of scaffolds that trap platelets, RBCs, fibronectin, and other proteins, which can also induce coagulation. Conclusion(s): We suggest that NET production is central during SARS-CoV-2 infection and COVID-19 pathogenesis, associated with alveolar damage accumulation of edema, endothelial injury and coagulopathy, elevated platelet activation and thrombogenesis forming a NET production feed-forward loop, causing diffuse small vessel vasculitis in the lungs and other organs. Copyright © 2020 FSG Communications Ltd. All rights reserved.
ABSTRACT
Purpose : Background: Despite being primarily a respiratory disease, COVID-19 can lead to non-respiratory complications, including myocardial infarction and acute ischemic stroke. Moreover, COVID-19 spike protein (SP) was reported in the retina of deceased patients with COVID-19. Retinal microvascular abnormalities as loss of microvasculature and distinct thinning of the microcapillaries were reported in patients who recovered from COVID-19. We are still in the midst of the COVID-19 pandemic, with more deaths and cases every day. Therefore investigating the impact of COVID-19 on the retinal neurovascular environment and the long-term effect of this virus on vision is of great interest. Purpose: To study the contribution of COVID-19 SP to retinal inflammation and vascular death. Methods : Methods: COVID-19 SP, a highly glycosylated protein that allows the virus to penetrate the cell and cause infection, was injected intravitreally in 6-8 weeks global h-ACE2 knock-in mice and wild-type mice. Mice were sacrificed after 14 days, then vascular cell death and inflammation were evaluated by the presence of acellular capillaries and the expression of inflammatory and apoptotic markers. To complement our in-vivo studies, Human Microvascular Endothelial Cells (HMEC) were treated with 100 nM COVID-19 SP for 48 hours. The expression of inflammatory and apoptotic markers was assessed by PCR western blot. Results : Results: Our results showed that HMEC exposed to COVID-19 SP for 48 hours displayed an increase in inflammatory and apoptotic markers expression including TNF-α, IL-1β, IL-6, and cleaved caspase-3 compared to control conditions. Additionally, COVID-19 SP enhanced the oxidative stress in HMEC, evident by the increase in nitro-tyrosine formation, superoxide dismutase, and NADPH oxidase complex 1 (NOX1 and NOX5) expression. The in-vivo findings came in agreement with our in-vitro studies. We found that intravitreal injection of the COVID-19 SP-induced 1) strong activation of the retinal glial cells, assessed by GFAP radial staining, and 2) increased vascular death, assessed by acellular capillaries formation 14 days after the injection. Conclusions : Conclusions: Our findings highlight the possible role of COVID-19 SP in inducing retinal inflammation and vascular death. Further studies are required to reveal the impact of COVID-19 SP on visual acuity and the possibility of causing visual impairment using various animal models.
ABSTRACT
Introduction: Management of acute respiratory distress including COVID-19 pneumonia involves O2 supplementation, which is lifesaving, but causes severe hyperoxic acute lung injury (HALI). AT2 cells are the most affected cell type in hyperoxia (HO). NADPH oxidase (NOX) is a major source of reactive oxygen species (ROS) in HO. NOX4, the only functionally active NOX present in mitochondria, and primarily produces H2O2 as well as mtROS has been shown to be involved in several human pathologies. Not much is known about NOX4-induced mitochondrial injury in HALI. The current study aims to determine the role of AT2 epithelial cell NOX4 in HALI and the impact of HO on the modulation of mtROS and mitochondrial dynamics in HALI. Methods: Nox4-/-Spc-Cre animals were generated using tamoxifen induction and the knockdown was validated. The Nox4- /-Spc-Cre knockout (KO) and wild type (WT) mice were exposed to room air (NO) or 95% O2 (HO) for 66h to study the structural and functional changes in the lung. Transmission Electron Microscopy (TEM) was used to study the HO-induced changes in mitochondria. Isolated primary AT2 and/ mouse lung epithelial (MLE) cell line was investigated for mtROS, mt dynamics and apoptosis. Mitochondrial injury was assessed in Nox4 WT and Nox4 silenced cells. Results: C57BL/6J WT animals subjected to HO for 66h showed increased expression of NOX4, determining the role of NOX4 in HALI. The H&E staining demonstrated significant HALI in Nox4 WT animals exposed to HO compared to Nox4 KO as determined by increased infiltration of neutrophils, alveolar wall thickening and presence of proteinaceous debris in the alveolar space. Further, increased BAL cell count and protein levels, increased AT2 cell death and elevation of the proinflammatory cytokine IL- 6 and the chemokine KC was seen in WT animals compared to Nox4 KO. Analysis of lung tissues by TEM showed mitochondrial swelling, cristae damage and mitophagy in AT2 cells due to HO. Changes in mt injury markers were also observed. HO-induced NOX4 increase in primary AT2/ MLE-12 cells resulted in increased mtROS production and apoptosis, which was reduced with Nox4 siRNA silencing. Conclusion: This study suggests that the HO induced NOX4 expression in mouse lung, and deletion of Nox4 gene in AT2 cells reduced mtROS production and apoptosis and protected the lungs from severe hyperoxic lung injury. These results suggest NOX4 as a potential target for the treatment of HALI.