Virus-induced Acute Lung Injury Research Articles

From bioinformatics to anti-inflammation and immune regulation

Background: ACT001 is a potent anti-inflammatory small-molecule drug. However, the single cell and spatial molecular basis of pyroptosis and whether ACT001 exerts a therapeutic effect by preventing pyroptosis on acute lung injury (ALI) remains unclear. Methods: The bioinformatics approach was employed to identify single cell and spatial landscape of nucleotide-binding domains and leucine-rich repeat protein 3 (NLRP3)-dependent pyroptosis in lipopolysaccharide (LPS) and influenza virus-induced ALI. Molecular docking was performed to elucidate the relationship between ACT001 and NLRP3. LPS-induced ALI mice model was established. Histopathological analysis and bronchoalveolar lavage fluid collection were conducted to investigate the anti-inflammatory and protective effects. In vitro experiments were also performed on bone marrow–derived macrophages to explore the effect of ACT001 on the balance of mitochondrial fusion and fission protein. Results: Single cell transcriptomic and spatial transcriptomic analysis predicted that NLRP3-dependent pyroptosis significantly correlated with the development of ALI both in single cell and spatial distribution. Molecular docking provided a stable and reliable docking between ACT001 and NLRP3. ACT001 improved the 7-day survival of mice by approximately 50% over the loading dose of LPS-induced ALI. ACT001 (5 uM) attenuated the disruption of mitochondrial integrity and reactive oxygen species. Further, ACT001 reduced the overexpression of the mitochondrial fission protein DRP1 without affecting fusion protein Mitofusin2 levels. Moreover, ACT001 exerted a similar protective effect of suppressing pyroptosis as the DRP1-inhibitor Mdivi-1. Conclusions: Our study revealed that pyroptosis genes were highly expressed in single-cell and spatial mapping along the first week of ALI occurrence. ACT001 attenuates ALI by reducing the NLRP3-dependent pyroptosis and balancing mitochondrial fission and fusion.

From bioinformatics to anti-inflammation and immune regulation: ACT001 in lipopolysaccharide-induced lung injury.

ACT001 is a potent anti-inflammatory small-molecule drug. However, the single cell and spatial molecular basis of pyroptosis and whether ACT001 exerts a therapeutic effect by preventing pyroptosis on acute lung injury (ALI) remains unclear. The bioinformatics approach was employed to identify single cell and spatial landscape of nucleotide-binding domains and leucine-rich repeat protein 3 (NLRP3)-dependent pyroptosis in lipopolysaccharide (LPS) and influenza virus-induced ALI. Molecular docking was performed to elucidate the relationship between ACT001 and NLRP3. LPS-induced ALI mice model was established. Histopathological analysis and bronchoalveolar lavage fluid collection were conducted to investigate the anti-inflammatory and protective effects. In vitro experiments were also performed on bone marrow-derived macrophages to explore the effect of ACT001 on the balance of mitochondrial fusion and fission protein. Single cell transcriptomic and spatial transcriptomic analysis predicted that NLRP3-dependent pyroptosis significantly correlated with the development of ALI both in single cell and spatial distribution. Molecular docking provided a stable and reliable docking between ACT001 and NLRP3. ACT001 improved the 7-day survival of mice by approximately 50% over the loading dose of LPS-induced ALI. ACT001 (5 uM) attenuated the disruption of mitochondrial integrity and reactive oxygen species. Further, ACT001 reduced the overexpression of the mitochondrial fission protein DRP1 without affecting fusion protein Mitofusin2 levels. Moreover, ACT001 exerted a similar protective effect of suppressing pyroptosis as the DRP1-inhibitor Mdivi-1. Our study revealed that pyroptosis genes were highly expressed in single-cell and spatial mapping along the first week of ALI occurrence. ACT001 attenuates ALI by reducing the NLRP3-dependent pyroptosis and balancing mitochondrial fission and fusion.

Monitoring the Cascade of Monocyte-Derived Macrophages to Influenza Virus Infection in Human Alveolus Chips.

Respiratory viruses ravage the world and seriously threaten people's health. Despite intense research efforts, the immune mechanism underlying respiratory virus-induced acute lung injury (ALI) and pulmonary fibrosis (PF) has not been fully elucidated. Here, the cascade of monocyte-derived macrophages to influenza A virus infection is monitored on an optimized human alveolus chip to reveal the role of macrophages in the development of ALI and PF. We find that viral infection causes damage to the alveolar air-liquid barrier and the release of inflammatory cytokines, which induce the M0 macrophages to gather and polarize to the M1 phenotype at the damaged site through recruitment, adhesion, migration, and activation, leading to ALI. Afterward, M1 macrophages polarize into the M2 phenotype, and then transform into myofibroblasts, followed by enhanced secretion of various anti-inflammatory cytokines and profibrotic cytokines, to promote PF. Our study provides an insight into the pathogenesis of virus-induced ALI and PF, which will assist in the development of therapeutic strategies and drugs for treating influenza and other respiratory virus infections.

Insights into the mechanism of action of pterostilbene against influenza A virus-induced acute lung injury

BackgroundSevere respiratory system illness caused by influenza A virus infection is associated with excessive inflammation and abnormal apoptosis in alveolar epithelial cells (AEC). However, there are limited therapeutic options for influenza-associated lung inflammation and apoptosis. Pterostilbene (PTE, trans-3,5-dimethoxy-4-hydroxystilbene) is a dimethylated analog of resveratrol that has been reported to limit influenza A virus infection by promoting antiviral innate immunity, but has not been studied for its protective effects on virus-associated inflammation and injury in AEC. PurposeOur study aimed to investigate the protective effects and underlying mechanisms of PTE in modulating inflammation and apoptosis in AEC, as well as its effects on macrophage polarization during influenza virus infection. Study design and methodsA murine model of influenza A virus-mediated acute lung injury was established by intranasal inoculation with 5LD50 of mouse-adapted H1N1 viruses. Hematoxylin and eosin staining, immunofluorescence, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, western blotting, Luminex and flow cytometry were performed. ResultsPTE effectively mitigated lung histopathological changes and injury induced by H1N1 viruses in vivo. These beneficial effects of PTE were attributed to the suppression of inflammation and apoptosis in AEC, as well as the modulation of M1 macrophage polarization. Mechanistic investigations revealed that PTE activated the phosphorylated AMP-activated protein kinase alpha (P-AMPKα)/sirtui1 (Sirt1)/PPARγ coactivator 1-alpha (PGC1α) signal axis, leading to the inhibition of nuclear factor kappa-B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) signaling induced by H1N1 viruses, thereby attenuating inflammation and apoptosis in AEC. PTE also forced activation of the P-AMPKα/Sirt1/PGC1α signal axis in RAW264.7 cells, counteracting the activation of phosphorylated signal transducer and activator of transcription 1 (P-STAT1) induced by H1N1 viruses and the augment of P-STAT1 activation in RAW264.7 cells with interferon-gamma (IFN-γ) pretreatment before viral infection, thereby reducing H1N1 virus-mediated M1 macrophage polarization as well as the enhancement of macrophages into M1 phenotypes elicited by IFN-γ pretreatment. Additionally, the promotion of the transition of macrophages towards the M2 phenotype by PTE was also related to activation of the P-AMPKα/Sirt1/PGC1α signal axis. Moreover, co-culturing non-infected AEC with H1N1 virus-infected RAW264.7 cells in the presence of PTE inhibited apoptosis and tight junction disruption, which was attributed to the suppression of pro-inflammatory mediators and pro-apoptotic factors in an AMPKα-dependent manner. ConclusionIn conclusion, our findings suggest that PTE may serve as a promising novel therapeutic option for treating influenza-associated lung injury. Its ability to suppress inflammation and apoptosis in AEC, modulate macrophage polarization, and preserve alveolar epithelial cell integrity highlights its potential as a therapeutic agent in influenza diseases.

A novel flavonol-polysaccharide from Tamarix chinensis alleviates influenza A virus-induced acute lung injury. Evidences for its mechanism of action

BackgroundTamarix chinensis Lour. is a Chinese medicine used for treating inflammation-related diseases and its crude polysaccharides (MBAP90) exhibited significant anticomplement activities in vitro. PurposeTo obtain anticomplement homogenous polysaccharides from MBAP90 and explore its therapeutic effects and potential mechanism on influenza A virus (IAV)-induced acute lung injury (ALI). MethodsAnticomplement activity-guided fractionation of the water-soluble crude polysaccharides from the leaves and twigs of T. chinensis were performed by diethylaminoethyl-52 (DEAE-52) cellulose and gel permeation columns to yield a homogeneous polysaccharide MBAP-5, which was further characterized using ultra-high-performance liquid chromatography-ion trap tandem mass spectrometry (UPLC-IT-MS) and nuclear magnetic resonance (NMR) analysis. In vitro, the anticomplement activity of MBAP-5 through classical pathway was measured using a hemolytic test. The therapeutic effects of MBAP-5 on ALI were evaluated in H1N1-infected mice. H&E staining, enzyme linked immunosorbent assay (ELISA), immunohistochemistry, and western blot were used to systematically access lung histomorphology, inflammatory cytokines, degree of complement component 3c, 5aR, and 5b-9 (C3c, C5aR, and C5b-9) deposition, and inflammasome signaling pathway protein expressions in lung tissues. ResultsMBAP-5 was a novel flavonol-polysaccharide with the molecular weight (Mw) of 153.6 kDa. Its structure was characterized to process a backbone of →4)-α-D-GlcpA-(1→, →6)-α-D-Glcp-(1→, →3,4)-α-D-Glcp-(1→, →3,4,6)-α-D-Glcp-(1→, and →4,6)-β-D-Glcp-(1→, as well as branches of α-L-Araf-(1→ and β-D-Galp-(1→. Particularly, O-3 of →3,4,6)-α-D-Glcp-(1→ was substituted by quercetin. In vitro assay showed that MBAP-5 had a potent anticomplement activity with a CH50 value of 102 ± 4 µg/ml. Oral administration of MBAP-5 (50 and 100 mg/kg) effectively attenuated the H1N1-induced pulmonary injury in vivo by reducing pulmonary edema, virus replication, and inflammatory responses. Mechanistically, MBAP-5 inhibited the striking deposition and contents of complement activation products (C3c, C5aR, and C5b-9) in the lung. Toll-like receptor 4 (TLR4) /transcription factor nuclear factor κB (NF-κB) signaling pathway was constrained by MBAP-5 treatment. In addition, MBAP-5 could suppress activation of the inflammasome pathways, including Nod‐like receptor pyrin domain 3 (NLRP3), cysteinyl aspartate specific proteinase-1/12 (caspase-1/12), apoptosis‑associated speck‑like protein (ASC), gasdermin D (GSDMD), interleukin (IL)-1β, and IL-18 expressions. ConclusionsA novel flavonol-polysaccharide MBAP-5 isolated from T. chinensis demonstrated a therapeutic effect against ALI induced by IAV attack. The mechanism might be associated with inhibition of complement system and inflammasome pathways activation.

Mesenchymal stem cells induce dynamic immunomodulation of airway and systemic immune cells in vivo but do not improve survival for mice with H1N1 virus-induced acute lung injury.

Introduction: Influenza A virus (IAV)-induced acute lung injury (ALI) is characterized by pronounced proinflammatory activation and respiratory lung dysfunction. In this study, we performed deep immune profiling on airway and circulating immune cells to examine the effect of immunomodulation and therapeutic outcomes of mesenchymal stem cells (MSCs) therapy in mice with IAV-induced ALI. Methods: Animals were inoculated intranasally with H1N1 IAV, followed by intravenous administration of vehicle, or human clinical-grade, bone marrow-derived MSCs 24-h later, and monitored for six days to evaluate the survival. In another set of animals, bronchoalveolar lavage (BAL) fluid and whole blood were collected three days after infection for flow or mass cytometry (CyTOF) immune profiling analysis. Results: Immune cell population and phenotypic shifts in blood were mapped by CyTOF. Increases were observed in granulocytes and myeloid-derived cells in blood from vehicle-treated animals. While MSC treatment accentuated changes in these populations, naïve B, antibody-secreting B cells, and T cells were decreased in MSC-treated animals at day 3. Compared to sham animals, IAV infection induced a significant 5.5-fold increase in BAL total cell counts, including CD4+ and CD8+ T cells, CD19+ B cells, CD11b+Ly6G+neutrophils, and CD11b+Ly6C+monocytes. MSC treatment significantly decreased BAL total cell counts in IAV-infected mice, specifically the number of infiltrating CD4+ T cells and CD11b+Ly6G+neutrophils. In contrast, there were increases in CD8+ T cells, B cells, and monocytes in the alveolar space in MSC-treated animals. Phenotypic immune cell profiling of blood and BAL revealed a significantly higher proportion of the monocyte population with the M2 phenotype (CD206) in MSC-treated animals; however, this failed to confer protective effects in the survival of infected mice or reduce viral titer in the lung. Further investigation revealed that MSCs were susceptible to IAV infection, leading to increased cell death and potentially affecting their efficacy. Conclusion: These findings provided in vivo evidence that MSCs promote the selective recruitment of immune cells to the site of infection during IAV infection, with reductions in proinflammatory phenotypes. However, MSCs offered no survival benefit in IAV-infected animals, possibly due to MSCs' H1N1 IAV susceptibility and subsequent cell death.

Extracellular vesicles: A promising therapy against SARS-CoV-2 infection

Extracellular vesicles: A promising therapy against SARS-CoV-2 infection

Recuperative herbal formula Jing Si maintains vasculature permeability balance, regulates inflammation and assuages concomitants of “Long-Covid”

Coronavirus disease 2019 (COVID-19) is a worldwide health threat that has long-term effects on the patients and there is currently no efficient cure prescribed for the treatment and the prolonging effects. Traditional Chinese medicines (TCMs) have been reported to exert therapeutic effect against COVID-19. In this study, the therapeutic effects of Jing Si herbal tea (JSHT) against COVID-19 infection and associated long-term effects were evaluated in different in vitro and in vivo models. The anti-inflammatory effects of JSHT were studied in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and in Omicron pseudotyped virus-induced acute lung injury model. The effect of JSHT on cellular stress was determined in HK-2 proximal tubular cells and H9c2 cardiomyoblasts. The therapeutic benefits of JSHT on anhedonia and depression symptoms associated with long COVID were evaluated in mice models for unpredictable chronic mild stress (UCMS). JSHT inhibited the NF-ƙB activities, and significantly reduced LPS-induced expression of TNFα, COX-2, NLRP3 inflammasome, and HMGB1. JSHT was also found to significantly suppress the production of NO by reducing iNOS expression in LPS-stimulated RAW 264.7 cells. Further, the protective effects of JSHT on lung tissue were confirmed based on mitigation of lung injury, repression in TMRRSS2 and HMGB-1 expression and reduction of cytokine storm in the Omicron pseudotyped virus-induced acute lung injury model. JSHT treatment in UCMS models also relieved chronic stress and combated depression symptoms. The results therefore show that JSHT attenuates the cytokine storm by repressing NF-κB cascades and provides the protective functions against symptoms associated with long COVID-19 infection.

Diosmetin alleviates benzo[a]pyrene-exacerbated H1N1 influenza virus-induced acute lung injury and dysregulation of inflammation through modulation of the PPAR-γ-NF-κB/P38 MAPK signaling axis.

The severity of a viral respiratory illness was greatly exacerbated after exposure to a contaminant containing benzo[a]pyrene (B[a]P). Flavonoid-rich fruit intake has gained intense interest due to their health-promoting benefits for viral respiratory diseases, including influenza viruses. In our study, diosmetin (3',5,7-trihydroxy-4'-methoxyflavone), a naturally occurring hydroxylated methoxyflavone that is abundant in Citrus fruits, was explored for its effects on B[a]P-exacerbated H1N1 influenza virus-mediated inflammation and lung injury. Initially, in vivo results demonstrated that diosmetin protected against H1N1 virus-elicited acute lung injury. Simultaneously, H1N1 virus or B[a]P-stimulated A549 cells treated with diosmetin inhibited NF-κB and P-P38 activation, resulting in suppression of pro-inflammatory cytokines and apoptosis. Interestingly, diosmetin obviously promoted the expression of PPAR-γ as well as nuclear translocation of PPAR-γ, whereas, PPAR-γ inhibition by GW9662 weakened the inhibitory effects of diosmetin on H1N1 virus or B[a]P-mediated activation of NF-κB and P-P38, elevated expression of pro-inflammatory mediators as well as apoptosis. Furthermore, it was surprising to discover that mice exposed to both B[a]P and H1N1 viruses contributed to exacerbated acute lung injury, which were significantly ameliorated by diosmetin administration. In vitro studies showed that A549 cells with the combination of B[a]P and H1N1 virus augmented NF-κB and P-P38 activation, accompanied by higher levels of pro-inflammatory mediators and apoptosis, all of which were also significantly reduced by diosmetin treatment. Repressing PPAR-γ abrogated the inhibitory effects of diosmetin on B[a]P-exacerbated H1N1 virus-mediated NF-κB and P-P38 activation, inflammation, and apoptosis in A549 cells. Our findings suggest that diosmetin protected against B[a]P-exacerbated H1N1 virus-mediated lung injury by suppressing the exacerbation of NF-κB and P38 kinase activation in a PPAR-γ-dependent manner, suggesting potential benefits for B[a]P-exacerbated influenza-related illness therapeutics.

Evidence for Interplay Between the Renin-Angiotensin System and Toll-Like Receptor 4 Signaling Pathways in the Induction of Virus-Induced Acute Lung Injury.

Dedication: This article is dedicated to Howard Young, an exceptional scientist who has provided outstanding mentorship to many postbaccalaureates, graduate students, and postdoctoral fellows during his career. Howard has been a colleague to many and was never tired of learning new things. He has brought "thinking out of the box" to the level of an art form and has always provided thoughtful and constructive suggestions to those who have sought his counsel. I am personally greatly indebted to Howard for his guidance in molecular biology over the past 30 years, and hope that we will continue to share a passion for learning and mentoring others for years to come. Thank you, Howard! -Stephanie N. Vogel The SARS-CoV-2 pandemic has led to an unprecedented explosion in studies that have sought to identify key mechanisms that underlie the ravaging aspects of this disease on individuals. SARS-CoV-2 virus gains access to cells by (1) binding of the viral spike (S) protein to cell-associated angiotensin-converting enzyme 2 (ACE2), a key receptor in the renin-angiotensin system (RAS), followed by (2) cleavage of S protein by a cellular serine protease ("S protein priming") to facilitate viral entry. Dysregulation of the RAS system has been implicated in the spectrum of clinical symptoms associated with SARS-CoV-2, including hypercytokinemia, elevated markers of endothelial injury and thrombosis, and both localized and systemic inflammation. However, the underlying mechanisms have yet to be fully delineated.

Melatonin Suppresses Macrophage M1 Polarization and ROS-Mediated Pyroptosis via Activating ApoE/LDLR Pathway in Influenza A-Induced Acute Lung Injury.

Influenza virus infection is one of the strongest pathogenic factors for the development of acute lung injury (ALI)/ acute respiratory distress syndrome (ARDS). However, the underlying cellular and molecular mechanisms have not been clarified. In this study, we aim to investigate whether melatonin modulates macrophage polarization, oxidative stress, and pyroptosis via activating Apolipoprotein E/low-density lipoprotein receptor (ApoE/LDLR) pathway in influenza A-induced ALI. Here, wild-type (WT) and ApoE-/- mice were instilled intratracheally with influenza A (H3N2) and injected intraperitoneally with melatonin for 7 consecutive days. In vitro, WT and ApoE-/- murine bone marrow-derived macrophages (BMDMs) were pretreated with melatonin before H3N2 stimulation. The results showed that melatonin administration significantly attenuated H3N2-induced pulmonary damage, leukocyte infiltration, and edema; decreased the expression of proinflammatory M1 markers; enhanced anti-inflammatory M2 markers; and switched the polarization of alveolar macrophages (AMs) from M1 to M2 phenotype. Additionally, melatonin inhibited reactive oxygen species- (ROS-) mediated pyroptosis shown by downregulation of malonaldehyde (MDA) and ROS levels as well as inhibition of the NLRP3/GSDMD pathway and lactate dehydrogenase (LDH) release. Strikingly, the ApoE/LDLR pathway was activated when melatonin was applied in H3N2-infected macrophages and mice. ApoE knockout mostly abrogated the protective impacts of melatonin on H3N2-induced ALI and its regulatory ability on macrophage polarization, oxidative stress, and pyroptosis. Furthermore, recombinant ApoE3 (re-ApoE3) inhibited H3N2-induced M1 polarization of BMDMs with upregulation of MT1 and MT2 expression, but re-ApoE2 and re-ApoE4 failed to do this. Melatonin combined with re-ApoE3 played more beneficial protective effects on modulating macrophage polarization, oxidative stress, and pyroptosis in H3N2-infected ApoE-/- BMDMs. Our study indicated that melatonin attenuated influenza A- (H3N2-) induced ALI by inhibiting the M1 polarization of pulmonary macrophages and ROS-mediated pyroptosis via activating the ApoE/LDLR pathway. This study suggested that melatonin-ApoE/LDLR axis may serve as a novel therapeutic strategy for influenza virus-induced ALI.

Therapeutic Potential of 2-Methylquinazolin-4(3H)-one as an Antiviral Agent against Influenza A Virus-Induced Acute Lung Injury in Mice.

Qingdai-Mabo (QM), a traditional Chinese herbal formula composed of medicinal herb and fungus, has been used for treatment of cough and viral pneumonia. However, the underlying mechanism and bioactive components against anti-influenza A virus remain unclear. In the present study, ethyl acetate (EA) extract of QM decoctions was tested for its biological activity against acute lung injury (ALI) and its main components were identified using UPLC-MS/MS. In total, 18 bioactive components were identified, including 2-Methylquinaozlin-4(3H)-one (C1), which showed significant antiviral activity in vitro with an IC50 of 23.8 μg/mL. Furthermore, we validated the efficacy of C1 in ameliorating ALI lesions and inflammation in influenza A virus-infected mice. The results showed that C1 significantly reduced the lung index, downregulated neuraminidase (NA) and nucleoprotein (NP), and decreased the expression of pro-inflammatory molecules IFN-α, TNF-α, MCP-1, IL-6, and IL-8; however, they enhanced levels of IL-10 and IFN-γ in lung homogenate from mice infected by influenza A virus. In addition, C1 inhibited the recruitment of macrophages. These in vitro and in vivo studies suggested that the significant anti-influenza A virus activity contributed to its curative effect on lesions and inflammation of viral pneumonia in mice. Given its potential antiviral activity against influenza A virus, C1 is determined to be a main active component in the EA extract of QM. Taken together, the antiviral activity of C1 suggests its potential as an effective treatment against viral pneumonia via the inhibition of virus replication, but the mechanism C1 on antiviral research needs to be explored further.

Extracellular vesicle-derived miR-1249–5p regulates influenza A virus-induced acute lung injury in RAW246.7 cells through targeting SLC4A1

Acute lung injury (ALI) is characterized by tissue damage that leads to pulmonary epithelial membrane dysfunction and macrophage activation. Currently however, the exact mechanism by which the initial mediators of mouse lung epithelial (MLE-12) cells induce inflammation remines unclear. We constructed co-culture systems of MLE-12 cells with mouse macrophage cells RAW246.7 which were realized by the supernatant and Transwell chamber. In previous study, we successfully constructed an influenza A virus-induced MLE-12 cells model. Extracellular Vesicles (EVs) from cells supernatant were isolated by differential ultracentrifugation and confirmed by transmission electron microscopy. High-throughput sequencing results showed that MLE-12 cells stimulated by influenza A virus had higher level of miR-1249–5p. The results were validated by RT-qPCR analysis. The research aimed to investigate the roles and mechanisms of miR-1249–5p in ALI. RAW246.7 cells were transfected with miR-1249–5p mimic/inhibitor. The concentrations of TNF-α, IL-6 were determined by ELISA and the uptake of EVs was monitored by confocal laser scanning microscope. Western blotting detected changes in the SLC4A1 and NF-κB signaling pathway. The results indicated that miR-1249–5p played an important role in ALI, and further investigation of its target gene SLC4A1 and NF-κB signaling pathway provides ideas for new therapeutic targets and strategies for ALI.

Withdrawn: Anisodamine (654-2) inhibits inflammation to alleviate influenza A virus-induced acute lung injury.

The article, from Journal of Medical Virology, "Anisodamine (654-2) inhibits inflammation to alleviate influenza A virus-induced acute lung injury" by Ning Du, Dapeng Liu, Xin Sun, Sida Qin, Hong Ren, published online on 02 June 2021 in Wiley Online Library (http://wileyonlinelibrary.com) has been withdrawn by agreement with the Journal Editor-in-Chief, Shou-Jiang Gao. The withdrawal has been agreed due to lack of response from author.

The Potential of Medicinal Plants and Bioactive Compounds in the Fight Against COVID-19

The Potential of Medicinal Plants and Bioactive Compounds in the Fight Against COVID-19

Effect of paeoniflorin on acute lung injury induced by influenza A virus in mice. Evidences of its mechanism of action

BackgroundInfluenza often leads to acute lung injury (ALI). Few therapeutics options such as vaccines and other antiviral drugs are available. Paeoniflorin is a monoterpene glucoside isolated from the roots of Paeonia lactiflora Pall. that has showed good anti-inflammatory and anti-fibrotic effects. However, it is not known whether paeoniflorin has an effect on influenza virus-induced ALI. PurposeTo investigative the protective effect and potential mechanism of paeoniflorin on ALI induced by influenza A virus (IAV). Study design and methodsThe anti-influenza activity of paeoniflorin in vitro was investigated. Influenza virus A/FM/1/47 was intranasally infected in mice to induce ALI, and paeoniflorin (50 and 100 mg/kg) was given orally to mice during 5 days, beginning 2 h after infection. On day 6 post-infection, body and lung weights, histology and survival were observed, and the lungs were examined for viral load, cytokine and cellular pathway protein expression. ResultsResults showed that paeoniflorin (50 and 100 mg/kg) reduced IAV-induced ALI. It reduces pulmonary oedema and improves histopathological changes in the lung, and also diminishes the accumulation of inflammatory cells in the lung. It was shown that paeoniflorin (50 and 100 mg/kg) alleviated IAV-induced ALI, as evidenced by improved survival in infected mice (40% and 50%, respectively), reduced viral titer in lung tissue, improved histological changes, and reduced lung inflammation. Paeoniflorin also improves pulmonary fibrosis by reducing the levels of pulmonary fibrotic markers (collagen type IV, alpha-smooth muscle actin, hyaluronic acid, laminin, and procollagen type III) and downregulating the expression levels of type I collagen (Col I) and type III collagen (Col III) in the lung tissues. Additionally, paeoniflorin inhibits the expression of αvβ3, TGF-β1, Smad2, NF-κB, and p38MAPK in the lung tissues. ConclusionThe results showed that paeoniflorin (50 and 100 mg/kg) protected against IAV-induced ALI, and the underlying mechanism may be related to the reduction of pro-inflammatory cytokine production and lung collagen deposition through down-regulation of activation of αvβ3/TGF-β1 pathway in lung tissue.

Salidroside Protects Against Influenza A Virus-Induced Acute Lung Injury in Mice.

Influenza A virus infections can cause acute lung injury (ALI) in humans; thus, the identification of potent antiviral agents is urgently required. Herein, the effects of salidroside on influenza A virus-induced ALI were investigated in a murine model. BALB/c mice were intranasally inoculated with H1N1 virus and treated with salidroside. The results of this study show that salidroside treatment (30 and 60 mg/kg) significantly attenuated the H1N1 virus-induced histological alterations in the lung and inhibited inflammatory cytokine production. Salidroside also decreased the wet/dry ratio, viral titers, and Toll-like receptor 4 expression in the lungs. Therefore, salidroside may represent a potential therapeutic reagent for the treatment of influenza A virus-induced ALI.

Genetic Dissection of the Regulatory Mechanisms of Ace2 in the Infected Mouse Lung.

Acute lung injury (ALI) is an important cause of morbidity and mortality after viral infections, including influenza A virus H1N1, SARS-CoV, MERS-CoV, and SARS-CoV-2. The angiotensin I converting enzyme 2 (ACE2) is a key host membrane-bound protein that modulates ALI induced by viral infection, pulmonary acid aspiration, and sepsis. However, the contributions of ACE2 sequence variants to individual differences in disease risk and severity after viral infection are not understood. In this study, we quantified H1N1 influenza-infected lung transcriptomes across a family of 41 BXD recombinant inbred strains of mice and both parents—C57BL/6J and DBA/2J. In response to infection Ace2 mRNA levels decreased significantly for both parental strains and the expression levels was associated with disease severity (body weight loss) and viral load (expression levels of viral NA segment) across the BXD family members. Pulmonary RNA-seq for 43 lines was analyzed using weighted gene co-expression network analysis (WGCNA) and Bayesian network approaches. Ace2 not only participated in virus-induced ALI by interacting with TNF, MAPK, and NOTCH signaling pathways, but was also linked with high confidence to gene products that have important functions in the pulmonary epithelium, including Rnf128, Muc5b, and Tmprss2. Comparable sets of transcripts were also highlighted in parallel studies of human SARS-CoV-infected primary human airway epithelial cells. Using conventional mapping methods, we determined that weight loss at two and three days after viral infection maps to chromosome X—the location of Ace2. This finding motivated the hierarchical Bayesian network analysis, which defined molecular endophenotypes of lung infection linked to Ace2 expression and to a key disease outcome. Core members of this Bayesian network include Ace2, Atf4, Csf2, Cxcl2, Lif, Maml3, Muc5b, Reg3g, Ripk3, and Traf3. Collectively, these findings define a causally-rooted Ace2 modulatory network relevant to host response to viral infection and identify potential therapeutic targets for virus-induced respiratory diseases, including those caused by influenza and coronaviruses.

The active GLP-1 analogue liraglutide alleviates H9N2 influenza virus-induced acute lung injury in mice

Influenza virus is responsible for significant morbidity and mortality worldwide. Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is the major cause of death in influenza virus infected patients. Recent studies indicated that active glucagon like peptide-1 (GLP-1) encoded by glucagon (GCG) gene exerts anti-inflammatory functions. The aim of this study was to determine the potential role of active GLP-1 in H9N2 influenza virus-induced ALI/ARDS in mice. First, we uncovered that GCG mRNA expression levels and GCG precursor protein levels were significantly increased, but total GLP-1 and active GLP-1 levels were decreased in the lungs of H9N2-infected mice. Next, liraglutide, an active GLP-1 analogue, was used to treat infected mice and to observe its effects on H9N2 virus-induced ALI. Liraglutide treatment ameliorated the declined body weight, decreased food intake and mortality observed in infected mice. It also alleviated the severity of lung injury, including lowering lung index, decreasing inflammatory cell infiltration and lowing total protein levels in bronchoalveolar lavage fluid (BALF). In addition, liraglutide did not influence viral titers in infected lungs, but decreased the levels of interleukin-1β, interleukin-6 and tumor necrosis factor-α in BALF. These results indicated that liraglutide alleviated H9N2 virus-induced ALI in mice most likely due to lower levels of pro-inflammatory cytokines.

The effect of aminoguanidine on acute lung injury induced by influenza A/H1N1/PDM09

Background. Acute lung injury is one of severe course of influenza infection with mortality up to 40% of patients, despite on etiological and pathogenetic therapy.
 The aim of the article to study of the effects of aminoguanidine on correcting on acute lung injury induced by influenza virus A/California/7/09MA (mouse-adapted) (H1N1)pdm09, collection Smorodintsev Research Institute of Influenza.
 Materials and methods. The study was performed on 95 outbred female mice. The mouse-adapted pandemic influenza virus A/California/7/09MA (H1N1)pdm09 was used for modeling viral infection at a dose of 1 LD50. The mortality was analysed. Levels of advanced glycation end-products (AGEs), proinflammatory cytokines in lung; saturation index and leukocytes marker parameters in blood; pathological and histological studies of lung were performed on 4 and 7 days post infection.
 Results. Aminoguanidine led to 2-fold decrease in mortality in mice with virus-induced acute lung injury; significantly suppressed the growth of AGEs and proinflammatory cytokine levels in lung; reduced decrease of saturation index and hematological inflammatory markers; decreased level of inflammatory injury in lung tissue.
 Conclusion. Aminoguanidine relieved virus-induced acute lung injury in mice. These AGEs inhibitor reduced the proinflammatory response and structural changes in respiratory tract epithelial cells induced by reactive carbonyl compounds on cell membrane.