Acute lung injury in patients with COVID-19 infection

Targeted Modulation of Redox and Immune Homeostasis in Acute Lung Injury Using a Thioether-Functionalized Dendrimer

Acute lung injury (ALI) is the pathophysiological precursor of acute respiratory distress syndrome. It is characterized by increased oxidative stress and exaggerated inflammatory response that disrupts redox reactions and immune homeostasis in the lungs, thereby posing significant clinical challenges. In this study, an internally functionalized thioether-enriched dendrimer Sr-G4-PEG is developed, to scavenge both proinflammatory cytokines and reactive oxygen species (ROS) and restore homeostasis during ALI treatment. The dendrimers are synthesized using an efficient and orthogonal thiol-ene "click" chemistry approach that involves incorporating thioether moieties within the dendritic architectures to neutralize the ROS. The ROS scavenging of Sr-G4-PEG manifests in its capacity to sequester proinflammatory cytokines. The synergistic effects of scavenging ROS and sequestering inflammatory cytokines by Sr-G4-PEG contribute to redox remodeling and immune homeostasis, along with the modulation of the NLRP3-pyroptosis pathway. Treatment with Sr-G4-PEG enhances the therapeutic efficacy of ALIs by alleviating alveolar bleeding, reducing inflammatory cell infiltration, and suppressing the release of inflammatory cytokines. These results suggest that Sr-G4-PEG is a potent nanotechnological candidate for remodeling redox and immune homeostasis in the treatment of ALIs, demonstrating the great potential of dendrimer-based nanomedicine for the treatment of respiratory pathologies.

Integrative Analyses of Bulk and Single-Cell RNA Seq Identified the Shared Genes in Acute Respiratory Distress Syndrome and Rheumatoid Arthritis

Acute respiratory distress syndrome (ARDS), a progressive status of acute lung injury (ALI), is primarily caused by an immune-mediated inflammatory disorder, which can be an acute pulmonary complication of rheumatoid arthritis (RA). As a chronic inflammatory disease regulated by the immune system, RA is closely associated with the occurrence and progression of respiratory diseases. However, it remains elusive whether there are shared genes between the molecular mechanisms underlying RA and ARDS. The objective of this study is to identify potential shared genes for further clinical drug discovery through integrated analysis of bulk RNA sequencing datasets obtained from the Gene Expression Omnibus database, employing differentially expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA). The hub genes were identified through the intersection of common DEGs and WGCNA-derived genes. The Random Forest (RF) and least absolute shrinkage and selection operator (LASSO) algorithms were subsequently employed to identify key shared target genes associated with two diseases. Additionally, RA immune infiltration analysis and COVID-19 single-cell transcriptome analysis revealed the correlation between these key genes and immune cells. A total of 59 shared genes were identified from the intersection of DEGs and gene clusters obtained through WGCNA, which analyzed the integrated gene matrix of ALI/ARDS and RA. The RF and LASSO algorithms were employed to screen for target genes specific to ALI/ARDS and RA, respectively. The final set of overlapping genes (FCMR, ADAM28, HK3, GRB10, UBE2J1, HPSE, DDX24, BATF, and CST7) all exhibited a strong predictive effect with an area under the curve (AUC) value greater than 0.8. Then, the immune infiltration analysis revealed a strong correlation between UBE2J1 and plasma cells in RA. Furthermore, scRNA-seq analysis demonstrated differential expression of these nine target genes primarily in T cells and NK cells, with CST7 showing a significant positive correlation specifically with NK cells. Beyond that, transcriptome sequencing was conducted on lung tissue collected from ALI mice, confirming the substantial differential expression of FCMR, HK3, UBE2J1, and BATF. This study provides unprecedented evidence linking the pathophysiological mechanisms of ALI/ARDS and RA to immune regulation, which offers novel understanding for future clinical treatment and experimental research.

Preventive Effect of the Total Polyphenols from Nymphaea candida on Sepsis-Induced Acute Lung Injury in Mice via Gut Microbiota and NLRP3, TLR-4/NF-κB Pathway

This study aimed to investigate the preventive effects of the total polyphenols from Nymphaea candida (NCTP) on LPS-induced septic acute lung injury (ALI) in mice and its mechanisms. NCTP could significantly ameliorate LPS-induced lung tissue pathological injury in mice as well as lung wet/dry ratio and MPO activities (p < 0.05). NCTP could significantly decrease the blood leukocyte, neutrophil, monocyte, basophil, and eosinophil amounts and LPS contents in ALI mice compared with the model group (p < 0.05), improving lymphocyte amounts (p < 0.05). Moreover, compared with the model group, NCTP could decrease lung tissue TNF-α, IL-6, and IL-1β levels (p < 0.05) and downregulate the protein expression of TLR4, MyD88, TRAF6, IKKβ, IκB-α, p-IκB-α, NF-κB p65, p-NF-κB p65, NLRP3, ASC, and Caspase1 in lung tissues (p < 0.05). Furthermore, NCTP could inhibit ileum histopathological injuries, restoring the ileum tight junctions by increasing the expression of ZO-1 and occludin. Simultaneously, NCTP could reverse the gut microbiota disorder, restore the diversity of gut microbiota, increase the relative abundance of Clostridiales and Lachnospiraceae, and enhance the content of SCFAs (acetic acid, propionic acid, and butyric acid) in feces. These results suggested that NCTP has preventive effects on septic ALI, and its mechanism is related to the regulation of gut microbiota, SCFA metabolism, and the TLR-4/NF-κB and NLRP3 pathways.

Xuanbai Chengqi Decoction alleviates acute lung injury by inhibiting NLRP3 inflammasome

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a prevalent critical respiratory disorder caused mostly by infection and other factors. However, effective drug therapies are currently lacking. Xuanbai Chengqi Decoction (XCD), a traditional Chinese medicine (TCM) prescription, is commonly employed to treat lung diseases. It has been recommended by Chinese health authorities as one of the TCM prescriptions for COVID-19. Nonetheless, its underlying mechanism for the treatment of ALI has not been fully understood.

AIM OF THE STUDY

The study aims to investigate the therapeutic effect of XCD on lipopolysaccharide (LPS) -induced ALI in mice and explore its anti-inflammatory mechanism involving pyroptosis.

MATERIALS AND METHODS

Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was employed to identify the active compounds of XCD, and quantitative analysis of the main compounds was conducted. Male C57BL/6J mice were given different doses of XCD (4.5 and 9.0 g/kg/day) or dexamethasone (5 mg/kg/day) by oral gavage for 5 consecutive days. Subsequently, ALI was induced by injecting LPS (20 mg/kg) intraperitoneally 2 h after the last administration, and serum and lung tissues were collected 8 h later. J774A.1 cells were pretreated with different doses of XCD (100, 200, 400 μg/ml) for 12 h, then incubated with LPS (1 μg/ml) for 4 h and ATP (1 mM) for 2 h to induce pyroptosis. Supernatant and cells were collected. Moreover, J774A.1 cells were transfected with an NLRP3 overexpression plasmid for 24 h, followed by subsequent experiments with XCD (400 μg/ml). Lung histopathological changes were evaluated using hematoxylin and eosin (HE) staining. To assess the efficacy of XCD on ALI/ARDS, the levels of inflammatory factors, chemokines, and proteins associated with NLRP3 inflammasome signaling pathway were evaluated.

RESULTS

XCD was found to ameliorate lung inflammation injury in ALI mice, and reduce the protein expression of TNF-α, IL-1β, and IL-6 in both mouse serum and J774A.1 cell supernatant. Meanwhile, XCD significantly decreased the mRNA levels of IL-1β, pro-IL-1β, CXCL1, CXCL10, TNF-α, NLRP3, NF-κB P65, and the protein expression of NLRP3, Cleaved-Caspase1, and GSDMD-N in the lung and J774A.1 cells. These effects were consistent with the NLRP3 inhibitor MCC950. Furthermore, overexpression of NLRP3 reversed the anti-inflammatory effect of XCD.

CONCLUSION

The therapeutic mechanism of XCD in ALI treatment may involve alleviating inflammatory responses in lung tissues by inhibiting the activation of the NLRP3 inflammasome-mediated pyroptosis in macrophages.

ICAM-1 targeted and ROS-responsive nanoparticles for the treatment of acute lung injury

Acute lung injury (ALI) is an inflammatory disease caused by multiple factors such as infection, trauma, and chemicals. Without effective intervention during the early stages, it usually quickly progresses to acute respiratory distress syndrome (ARDS). Since ordinary pharmaceutical preparations cannot precisely target the lungs, their clinical application is limited. In response, we constructed a γ3 peptide-decorated and ROS-responsive nanoparticle system encapsulating therapeutic dexamethasone (Dex/PSB-γ3 NPs). In vitro, Dex/PSB-γ3 NPs had rapid H2O2 responsiveness, low cytotoxicity, and strong intracellular ROS removal capacity. In a mouse model of ALI, Dex/PSB-γ3 NPs accumulated at the injured lung rapidly, alleviating pulmonary edema and cytokine levels significantly. The modification of NPs by γ3 peptide achieved highly specific positioning of NPs in the inflammatory area. The ROS-responsive release mechanism ensured the rapid release of therapeutic dexamethasone at the inflammatory site. This combined approach improves treatment accuracy, and drug bioavailability, and effectively inhibits inflammation progression. Our study could effectively reduce the risk of ALI progressing to ARDS and hold potential for the early treatment of ALI.

Glucocorticoid Nanoparticles Show Full Therapeutic Efficacy in a Mouse Model of Acute Lung Injury and Concomitantly Reduce Adverse Effects

Glucocorticoids (GCs) are widely used to treat inflammatory disorders such as acute lung injury (ALI). Here, we explored inorganic-organic hybrid nanoparticles (IOH-NPs) as a new delivery vehicle for GCs in a mouse model of ALI. Betamethasone (BMZ) encapsulated into IOH-NPs (BNPs) ameliorated the massive infiltration of neutrophils into the airways with a similar efficacy as the free drug. This was accompanied by a potent inhibition of pulmonary gene expression and secretion of pro-inflammatory mediators, whereas the alveolar-capillary barrier integrity was only restored by BMZ in its traditional form. Experiments with genetically engineered mice identified myeloid cells and alveolar type II (AT II) cells as essential targets of BNPs in ALI therapy, confirming their high cell-type specificity. Consequently, adverse effects were reduced when using IOH-NPs for GC delivery. BNPs did not alter T and B cell numbers in the blood and also prevented the induction of muscle atrophy after three days of treatment. Collectively, our data suggest that IOH-NPs target GCs to myeloid and AT II cells, resulting in full therapeutic efficacy in the treatment of ALI while being associated with reduced adverse effects.

Irbesartan eases lipopolysaccharide-induced lung injury In Vitro and In Vivo

Acute lung injury (ALI) is classified as a devastating pulmonary disorder contributing to significant incidence and fatality rate. Irbesartan (IRB) is an angiotensin II receptor blocker that has been proposed to protect against oleic acid-induced ALI. To this end, the current study is concentrated on ascertaining the role of IRB in ALI and figuring out the probable action mechanism. First, cell counting kit-8 (CCK-8) appraised the viability of human pulmonary microvascular endothelial cells (HPMVECs) exposed to ascending concentrations of IRB. HPMVEC injury model and a mouse model of ALI induced by lipopolysaccharide (LPS) were pretreated by IRB. In vitro, cell viability was estimated by CCK-8 assay, and lactate dehydrogenase (LDH) release was tested by LDH assay kit. Enzyme-linked immunosorbent assay (ELISA) and Western blotting estimated the expression levels of inflammatory factors. Fluorescein isothiocyanate-dextran was used to assess HPMVEC permeability. Western blotting examined the expression of adherent and tight junction proteins. In vivo, hematoxylin and eosin staining evaluated lung tissue damage and lung wet/dry (W/D) weight was measured. ELISA analyzed the levels of inflammatory factors in the serum and bronchoalveolar lavage fluid (BALF), and Western blotting examined the expression of inflammatory factors. The total cell, neutrophil, and macrophage numbers in BALF were determined using a cell counter. Lung capillary permeability was assayed by Evans blue albumin and total protein concentration in BALF was measured using bicinchoninic acid method. Immunofluorescence assay and Western blotting examined the expression of adherent and tight junction proteins in lung tissues. It was observed that IRB dose-dependently enhanced the viability while reduced LDH release, inflammatory response as well as permeability in LPS-challenged HPMVECs in vitro. In addition, LPS-stimulated lung tissue damage, pulmonary edema, inflammatory response as well as lung capillary permeability in vivo were all reversed following IRB treatment. Collectively, IRB treatment might elicit protective behaviors against LPS-triggered ALI.

Targeted Delivery of the Pan-Inflammasome Inhibitor MM01 as an Alternative Approach to Acute Lung Injury Therapy

Acute lung injury (ALI) is a severe pulmonary disorder responsible for high percentage of mortality and morbidity in intensive care unit patients. Current treatments are ineffective, so the development of efficient and specific therapies is an unmet medical need. The activation of NLPR3 inflammasome during ALI produces the release of proinflammatory factors and pyroptosis, a proinflammatory form of cell death that contributes to lung damage spreading. Herein, it is demonstrated that modulating inflammasome activation through inhibition of ASC oligomerization by the recently described MM01 compound can be an alternative pharmacotherapy against ALI. Besides, the added efficacy of using a drug delivery nanosystem designed to target the inflamed lungs is determined. The MM01 drug is incorporated into mesoporous silica nanoparticles capped with a peptide (TNFR-MM01-MSNs) to target tumor necrosis factor receptor-1 (TNFR-1) to proinflammatory macrophages. The prepared nanoparticles can deliver the cargo in a controlled manner after the preferential uptake by proinflammatory macrophages and exhibit anti-inflammatory activity. Finally, the therapeutic effect of MM01 free or nanoparticulated to inhibit inflammatory response and lung injury is successfully demonstrated in lipopolysaccharide-mouse model of ALI. The results suggest the potential of pan-inflammasome inhibitors as candidates for ALI therapy and the use of nanoparticles for targeted lung delivery.

A natural sesquiterpene lactone isolinderalactone attenuates lipopolysaccharide-induced inflammatory response and acute lung injury through inhibition of NF-κB pathway and activation Nrf2 pathway in macrophages

Isolinderalactone is the main sesquiterpene lactone isolated from Lindera aggregata, a traditional Chinese medicine widely used to treat pain and inflammation. Although isolinderalactone has been demonstrated to possess anti-cancer effect, its anti-inflammatory activity and underlying mechanism has not been well characterized. Herein, isolinderalactone was able to significantly inhibit the production of NO and PGE2 by reducing the expressions of iNOS and COX2 in LPS-stimulated RAW264.7 macrophages and BMDMs, and decreased the mRNA levels of IL-1β, IL-6, and TNF-α in LPS-induced RAW264.7 cells. In vivo, isolinderalactone effectively alleviated LPS-induced acute lung injury (ALI), which manifested as reduction in pulmonary inflammatory infiltration, myeloperoxidase activity, and production of PGE2, IL-1β, IL-6, TNF-α, and malondialdehyde. Furthermore, isolinderalactone inhibited phosphorylation of IKKα/β, phosphorylation and degradation of IκBα, and nuclear translocation of NF-κB p65, thereby blocking NF-κB pro-inflammatory pathway. Meanwhile, isolinderalactone reduced the intracellular ROS through promoting the activation of Nrf2-HMOX1 antioxidant axis. By using drug affinity responsive target stability assay and molecular docking, isolinderalactone was found to covalently interact with IKKα/β and Keap1, which may contribute to its anti-inflammatory action. Additionally, a thiol donor β-mercaptoethanol significantly abolished isolinderalactone-mediated anti-inflammatory action in vitro, indicating the crucial role of the unsaturated lactone of isolinderalactone on its anti-inflammatory effects. Taken together, isolinderalactone protected against LPS-induced ALI in mice, which may be associated with its inhibition of NF-κB pathway and activation of Nrf2 signaling in macrophages.

The Effects of Hospitalisation on the Serum Metabolome in COVID-19 Patients

COVID-19, a systemic multi-organ disease resulting from infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is known to result in a wide array of disease outcomes, ranging from asymptomatic to fatal. Despite persistent progress, there is a continued need for more accurate determinants of disease outcomes, including post-acute symptoms after COVID-19. In this study, we characterised the serum metabolomic changes due to hospitalisation and COVID-19 disease progression by mapping the serum metabolomic trajectories of 71 newly hospitalised moderate and severe patients in their first week after hospitalisation. These 71 patients were spread out over three hospitals in Switzerland, enabling us to meta-analyse the metabolomic trajectories and filter consistently changing metabolites. Additionally, we investigated differential metabolite-metabolite trajectories between fatal, severe, and moderate disease outcomes to find prognostic markers of disease severity. We found drastic changes in serum metabolite concentrations for 448 out of the 901 metabolites. These results included markers of hospitalisation, such as environmental exposures, dietary changes, and altered drug administration, but also possible markers of physiological functioning, including carboxyethyl-GABA and fibrinopeptides, which might be prognostic for worsening lung injury. Possible markers of disease progression included altered urea cycle metabolites and metabolites of the tricarboxylic acid (TCA) cycle, indicating a SARS-CoV-2-induced reprogramming of the host metabolism. Glycerophosphorylcholine was identified as a potential marker of disease severity. Taken together, this study describes the metabolome-wide changes due to hospitalisation and COVID-19 disease progression. Moreover, we propose a wide range of novel potential biomarkers for monitoring COVID-19 disease course, both dependent and independent of the severity.

SARS-CoV-2-associated organs failure and inflammation: a focus on the role of cellular and viral microRNAs

SARS-CoV-2 has been responsible for the recent pandemic all over the world, which has caused many complications. One of the hallmarks of SARS-CoV-2 infection is an induced immune dysregulation, in some cases resulting in cytokine storm syndrome, acute respiratory distress syndrome and many organs such as lungs, brain, and heart that are affected during the SARS-CoV-2 infection. Several physiological parameters are altered as a result of infection and cytokine storm. Among them, microRNAs (miRNAs) might reflect this poor condition since they play a significant role in immune cellular performance including inflammatory responses. Both host and viral-encoded miRNAs are crucial for the successful infection of SARS-CoV-2. For instance, dysregulation of miRNAs that modulate multiple genes expressed in COVID-19 patients with comorbidities (e.g., type 2 diabetes, and cerebrovascular disorders) could affect the severity of the disease. Therefore, altered expression levels of circulating miRNAs might be helpful to diagnose this illness and forecast whether a COVID-19 patient could develop a severe state of the disease. Moreover, a number of miRNAs could inhibit the expression of proteins, such as ACE2, TMPRSS2, spike, and Nsp12, involved in the life cycle of SARS-CoV-2. Accordingly, miRNAs represent potential biomarkers and therapeutic targets for this devastating viral disease. In the current study, we investigated modifications in miRNA expression and their influence on COVID-19 disease recovery, which may be employed as a therapy strategy to minimize COVID-19-related disorders.

Reactive Oxygen Species-Triggered Curcumin Release from Hollow Mesoporous Silica Nanoparticles for PM2.5-Induced Acute Lung Injury Treatment

Exposure to fine particulate matter with a diameter ≤2.5 μm (PM_2.5) can result in serious inflammation and oxidative stress in lung tissue. However, there is presently very few effective treatments for PM_2.5-induced many pulmonary diseases, such as acute lung injury (ALI). Herein, curcumin-loaded reactive oxygen species (ROS)-responsive hollow mesoporous silica nanoparticles (Cur@HMSN-BSA) are proposed for scavenging the intracellular ROS and suppressing inflammatory responses against PM_2.5-induced ALI. The prepared nanoparticles were coated with bovine serum albumin (BSA) via an ROS-sensitive thioketal (TK)-containing linker, in which the TK-containing linker would be cleaved by the excessive amounts of ROS in inflammatory sites to induce the detachment of BSA from the nanoparticles surface and thus triggering release of loaded curcumin. The Cur@HMSN-BSA nanoparticles could be used as ROS scavengers because of their excellent ROS-responsiveness, which were able to efficiently consume high concentrations of intracellular ROS. Furthermore, it was also found that Cur@HMSN-BSA downregulated the secretion of several important pro-inflammatory cytokines and promoted the polarization from M1 phenotypic macrophages to M2 phenotypic macrophages for eliminating PM_2.5-induced inflammatory activation. Therefore, this work provided a promising strategy to synergistically scavenge intracellular ROS and suppress the inflammation responses, which may serve as an ideal therapeutic platform for pneumonia treatment.

A novel galactoxylan derived from Viola diffusa alleviates LPS-induced acute lung injury via antagonizing P-selectin-mediated adhesion function

Acute lung injury (ALI) greatly threatens human health worldwide. P-selectin is a potential target for the treatment of acute inflammatory diseases, and natural polysaccharides exhibit high-affinity for P-selectin. Viola diffusa, a traditional Chinese herbal, shows strong anti-inflammatory effects, but pharmacodynamic substances and underlying mechanisms are still unclear. In this study, a galactoxylan polysaccharide (VDPS) derived from Viola diffusa was isolated and characterized, evaluated the protective effect on LPS induced ALI and underlying mechanism. VDPS significantly alleviated LPS-induced pathological lung injury, and decreased the numbers of total cells and neutrophils as well as the total protein contents in the bronchoalveolar lavage fluid (BALF). Moreover, VDPS reduced proinflammatory cytokine production both in BALF and lung. Interestingly, VDPS significantly restrained the activation of NF-κB signaling in the lung of LPS-exposed mice, but it cannot inhibit LPS-induced inflammation in human pulmonary microvascular endothelial cells (HPMECs) in vitro. Additionally, VDPS disrupted neutrophil adhesion and rolling on the activated HPMECs. VDPS cannot impact the expression or cytomembrane translocation of endothelial P-selectin, but remarkably interrupt the binding of P-selectin and PSGL-1. Overall, this study demonstrated that VDPS can alleviate LPS-induced ALI via inhibiting P-selectin-dependent adhesion and recruitment of neutrophils on the activated endothelium, providing a potential treatment strategy for ALI.

Extracellular vesicle-encapsulated CC16 as novel nanotherapeutics for treatment of acute lung injury

Acute lung injury (ALI) is still associated with high mortality. Growing evidence suggests that Club Cell Protein 16 (CC16) plays a protective role against ALI. However, the doses of recombinant CC16 (rCC16) used in preclinical studies are supraphysiological for clinical applications. Extracellular vesicles (EVs) are nanovesicles endogenously generated by mammalian cells. Our study demonstrated that CC16 is released via small EVs and EV-encapsulated CC16 (sEV-CC16) and has anti-inflammatory activities, which protect mice from lipopolysaccharide (LPS) or bacteria-induced ALI. Additionally, sEV-CC16 can activate the DNA damage repair signaling pathways. Consistent with this activity, we observed more severe DNA damage in lungs from Cc16 knockout (KO) than wild-type (WT) mice. Mechanistically, we elucidated that CC16 suppresses nuclear factor κB (NF-κB) signaling activation by binding to heat shock protein 60 (HSP60). We concluded that sEV-CC16 could be a potential therapeutic agent for ALI by inhibiting the inflammatory and DNA damage responses by reducing NF-κB signaling.

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.

Review of Immunologic Manifestations of COVID-19 Infection and Vaccination

We herein summarize currently available and clinically relevant information regarding the human immune responses to SARS-CoV-2 infection and vaccination, in relation to COVID-19 outcomes with a focus on acute respiratory distress syndrome (ARDS) and myocarditis.

Licochalcone A protects against LPS-induced inflammation and acute lung injury by directly binding with myeloid differentiation factor 2 (MD2)

BACKGROUND AND PURPOSE

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a challenging clinical syndrome that leads to various respiratory sequelae and even high mortality in patients with severe disease. The novel pharmacological strategies and therapeutic drugs are urgently needed. Natural products have played a fundamental role and provided an abundant pool in drug discovery.

EXPERIMENTAL APPROACH

A compound library containing 160 natural products was used to screen potential anti-inflammatory compounds. Mice with LPS-induced ALI was then used to verify the preventive and therapeutic effects of the selected compounds.

KEY RESULTS

Licochalcone A was discovered from the anti-inflammatory screening of natural products in macrophages. A qPCR array validated the inflammation-regulatory effects of licochalcone A and indicated that the potential targets of licochalcone A may be the upstream proteins in LPS pro-inflammatory signalling. Further studies showed that licochalcone A directly binds to myeloid differentiation factor 2 (MD2), an assistant protein of toll-like receptor 4 (TLR4), to block both LPS-induced TRIF- and MYD88-dependent pathways. LEU61 and PHE151 in MD2 protein are the two key residues that contribute to the binding of MD2 to licochalcone A. In vivo, licochalcone A treatment alleviated ALI in LPS-challenged mice through significantly reducing immunocyte infiltration, suppressing activation of TLR4 pathway and inflammatory cytokine induction.

CONCLUSION AND IMPLICATIONS

In summary, our study identified MD2 as a direct target of licochalcone A for its anti-inflammatory activity and suggested that licochalcone A might serve as a novel MD2 inhibitor and a potential drug for developing ALI/ARDS therapy.

Propagation of an idealized infection in an airway tree, consequences of the inflammation on the oxygen transfer to blood

A mathematical model of infection, inflammation and immune response in an idealized bronchial tree is developed. This work is based on a model from the literature that is extended to account for the propagation dynamics of an infection between the airways. The inflammation affects the size of the airways, the air flows distribution in the airway tree, and, consequently, the oxygen transfers to blood. We test different infections outcomes and propagation speed. In the hypotheses of our model, the inflammation can reduce notably and sometimes drastically the oxygen flow to blood. Our model predicts how the air flows and oxygen exchanges reorganize in the tree during an infection. Our results highlight the links between the localization of the infection and the amplitude of the loss of oxygen flow to blood. We show that a compensation phenomena due to the reorganization of the flow exists, but that it remains marginal unless the power produced the ventilation muscles is increased. Our model forms a first step towards a better understanding of the dynamics of bronchial infections.

Protective effect of soloxolone derivatives in carrageenan- and LPS-driven acute inflammation: Pharmacological profiling and their effects on key inflammation-related processes

The anti-inflammatory potential of three cyanoenone-containing triterpenoids, including soloxolone methyl (SM), soloxolone (S) and its novel derivative bearing at the C-30 amidoxime moiety (SAO), was studied in murine models of acute inflammation. It was found that the compounds effectively suppressed the development of carrageenan-induced paw edema and peritonitis as well as lipopolysaccharide (LPS)-driven acute lung injury (ALI) with therapeutic outcomes comparable with that of the reference drugs indomethacin and dexamethasone. Non-immunogenic carrageenan-stimulated inflammation was more sensitive to the transformation of C-30 of SM compared with immunogenic LPS-induced inflammation: the anti-inflammatory properties of the studied compounds against carrageenan-induced paw edema and peritonitis decreased in the order of SAO > S > > SM, whereas the efficiency of these triterpenoids against LPS-driven ALI was similar (SAO ≈ S ≈ SM). Further studies demonstrated that soloxolone derivatives significantly inhibited a range of immune-related processes, including granulocyte influx and the expression of key pro-inflammatory cytokines and chemokines in the inflamed sites as well as the functional activity of macrophages. Moreover, SM was found to prevent inflammation-associated apoptosis of A549 pneumocytes and effectively inhibited the protease activity of thrombin (IC₅₀ = 10.3 µM) tightly associated with rodent inflammatome. Taken together, our findings demonstrate that soloxolone derivatives can be considered as novel promising anti-inflammatory drug candidates with multi-targeted mechanism of action.

Irigenin attenuates lipopolysaccharide-induced acute lung injury by inactivating the mitogen-activated protein kinase (MAPK) signaling pathway

Acute lung injury (ALI) is a serious pulmonary inflammation disease with high mortality. Irigenin, an isoflavone from rhizomes of the Belamcanda chinensis, has been reported to exert anti-inflammatory, anti-oxidative, and anti-apoptotic activities in several diseases. However, it is still unclear whether irigenin can exert a beneficial effect in ALI. A network pharmacology method was utilized to predict the hub targets and potential therapeutic mechanisms of irigenin against ALI. Lipopolysaccharide (LPS) was used to establish the mice model of ALI for evaluating the effects of irigenin. According to the protein-protein interaction (PPI) network, we identified EGFR, HRAS, AKT1, SRC, and HSP90AA1 as the top five significant genes. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment assays showed that irigenin might affect inflammatory response, cytokine production, and cell death by the mitogen-activated protein kinase (MAPK) signaling pathway. In vivo experiment results manifested that irigenin decreased pathological changes, lung Wet/Dry weight ratio, and total protein content in bronchoalveolar lavage fluid (BALF). Irigenin also reduced the production of inflammatory cytokines, including tumor necrosis factor-a (TNF-a), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-18 (IL-18), and neutrophil infiltration. Additionally, irigenin inhibited pulmonary apoptosis in LPS-treated ALI mice. Moreover, LPS-induced phosphorylation of p38, JNK, and ERK was significantly abated due to the treatment of irigenin. In summary, irigenin ameliorates LPS-induced ALI by suppressing pulmonary inflammation and apoptosis via inactivation of the MAPK signaling pathway. These findings indicated the therapeutic potential of irigenin in ALI.

Schisandrin B protects against LPS-induced inflammatory lung injury by targeting MyD88

BACKGROUND

Acute lung injury (ALI) is a challenging clinical syndrome that manifests as an acute inflammatory response. Schisandrin B (Sch B), a bioactive lignan from Schisandra genus plants, has been shown to suppress inflammatory responses and oxidative stress. However, the underlying molecular mechanisms have remained elusive.

HYPOTHESIS/PURPOSE

This study performed an in-depth investigation of the anti-inflammatory mechanism of Sch B in macrophages and in an animal model of ALI.

METHODS

qPCR array was used to probe the differential effects and potential target of Sch B. ALI was induced by intratracheal administration of LPS in experimental mice with or without Sch B treatment.

RESULTS

Our studies show that Sch B differentially modulates inflammatory factor induction by LPS in macrophages by directly binding myeloid differentiation response factor-88 (MyD88), an essential adaptor protein in the toll-like receptor-4 (TLR4) pathway. Sch B spares non-MyD88-pathways downstream of TLR4. Such inhibition suppressed key signaling mediators such as TAK1, MAPKs, and NF-κB, and pro-inflammatory factor induction. Pull down assay using biotinylated-Sch B validate the direct interaction between Sch B and MyD88 in macrophages. Treatment of mice with Sch B prior to LPS challenge reduced inflammatory cell infiltration in lungs, induction of MyD88-pathway signaling proteins, and prevented inflammatory cytokine induction.

CONCLUSION

In summary, our studies have identified MyD88 as a direct target of Sch B for its anti-inflammatory activity, and suggest that Sch B may have therapeutic value for acute lung injury and other MyD88-dependent inflammatory diseases.

Protection from acute lung injury by a peptide designed to inhibit the voltage-gated proton channel

There are no targeted medical therapies for Acute Lung Injury (ALI) or its most severe form acute respiratory distress syndrome (ARDS). Infections are the most common cause of ALI/ARDS and these disorders present clinically with alveolar inflammation and barrier dysfunction due to the influx of neutrophils and inflammatory mediator secretion. We designed the C6 peptide to inhibit voltage-gated proton channels (Hv1) and demonstrated that it suppressed the release of reactive oxygen species (ROS) and proteases from neutrophils in vitro. We now show that intravenous C6 counteracts bacterial lipopolysaccharide (LPS)-induced ALI in mice, and suppresses the accumulation of neutrophils, ROS, and proinflammatory cytokines in bronchoalveolar lavage fluid. Confirming the salutary effects of C6 are via Hv1, genetic deletion of the channel similarly protects mice from LPS-induced ALI. This report reveals that Hv1 is a key regulator of ALI, that Hv1 is a druggable target, and that C6 is a viable agent to treat ALI/ARDS.

Application of network composite module analysis and verification to explore the bidirectional immunomodulatory effect of Zukamu granules on Th1 / Th2 cytokines in lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Zukamu granules (ZKMG), as the preferred drug for the treatment of colds in Uygur medical theory, has been used for 1500 years. It is also widely used in China and included in the National Essential Drugs List (2018 edition). It has unique anti-inflammatory, antitussive and analgesic effects.

AIM OF THE STUDY

Aiming at the research of traditional Chinese medicine (TCM) with the characteristics of overall regulation of body diseases and the immune regulation mechanism with the concept of integrity, this paper put forward the integrated application of network composite module analysis and animal experiment verification to study the immune regulation mechanism of TCM.

MATERIALS AND METHODS

The active components and targets of ZKMG were predicted, and network module analysis was performed to explore their potential immunomodulatory mechanisms. Then acute lung injury (ALI) mice and idiopathic pulmonary fibrosis (IPF) rats were used as pathological models to observe the effects of ZKMG on the pathological conditions of infected ALI and IPF rats, determine the contents of Th1, Th2 characteristic cytokines and immunoglobulins, and study the intervention of GATA3/STAT6 signal pathway.

RESULTS

The results of network composite module analysis showed that ZKMG contained 173 pharmacodynamic components and 249 potential targets, and four key modules were obtained. The immunomodulatory effects of ZKMG were related to T cell receptor signaling pathway. The validation results of bioeffects that ZKMG could carry out bidirectional immune regulation on Th1/Th2 cytokines in the stage of ALI and IPF, so as to play the role of regulating immune homeostasis and organ protection.

CONCLUSIONS

The network composite module analysis and verification method is an exploration to study the immune regulation mechanism of TCM by combining the network module prediction analysis with animal experiments, which provides a reference for subsequent research.

A year of experience with COVID-19 in patients with cancer: A nationwide study

BACKGROUND

Cancer is a major public health problem and comorbidity associated with COVID-19 infection. According to previous studies, a higher mortality rate of COVID-19 in cancer patients has been reported.

AIMS

This study was undertaken to determine associated risk factors and epidemiological characteristics of hospitalized COVID-19 patients with cancer using a nationwide COVID-19 hospital data registry in Iran for the first time.

METHODS

In this retrospective study, we used a national data registry of hospitalized patients with Severe Acute Respiratory Syndrome (SARS) symptoms and patients with confirmed positive COVID-19 PCR between 18 February 2020 and 18 November 2020. The patients were classified into two groups patients with/without malignancy. Logistic regression model was utilized to analyze demographic factors, clinical features, comorbidities, and their associations with the disease outcomes.

RESULTS

In this study, 11 068 and 645 186 in-patients with SARS symptoms with and without malignancy were included, respectively. About 1.11% of our RT-PCR-positive patients had cancer. In patients with malignancy and COVID-19, older ages than 60 (OR: 1.88, 95% CI: 1.29-2.74, p-value: .001), male gender (OR: 1.43, 95% CI: 1.16-1.77, p-value: .001), concomitant chronic pulmonary diseases (CPD) (OR: 1.75, 95% CI: 1.14-2.68, p-value: .009), and presence of dyspnea (OR; 2.00, 95% CI: 1.60-2.48, p-value: <.001) were associated with increased mortality rate.

CONCLUSION

Given the immunocompromised state of patients with malignancy and their vulnerability to Covid-19 complications, collecting data on the comorbidities and their effects on the disease outcome can build on a better clinical view and help clinicians make decisions to manage these cases better; for example, determining special clinical care, especially in the shortage of health services.

Prevention of mortality in acute lung injury induced by oleic acid: Application of polyherbal decoction (bronco T)

Acute lung injury (ALI) is a lethal respiratory disorder; directed uncontrolled inflammation, sloughing of the alveolar cells and their diffusion, and altered cardiorespiratory parameters with a global mortality rate of 40%. This study was designed to assess the preventive effect of a polyherbal decoction (Bronco T, 1.5 g/kg b. w.) on cardiorespiratory variables in oleic acid-induced ALI in rats. Oleic acid increases the level of neutrophil infiltration leading to pulmonary edema and alters the cardiorespiratory dynamics. The adult male rats were surgically cannulated and treated with intravenous oleic acid (0.38 ml/kg b. w.) to establish the ALI model. Bronco T was pre-administered orally 3 hours before oleic acid. The biophysical, histological, biochemical, and molecular effects were compared with dexamethasone (5 mg/kg b. w. i. p.). The animals were randomly divided into control, lethal, standard, and treatment groups. Respiratory frequency (RF), heart rate (HR), and mean arterial pressure (MAP) were recorded on a computerized chart recorder; arterial blood sample was collected to determine PaO₂/FiO₂, TNF-α, and MPO. Lipid peroxidation, superoxide dismutase, and catalase activity were evaluated to measure oxidative stress in bronchoalveolar lavage. Additionally, the pulmonary water content, COX-2 expression and histological examination were determined in the lung. A molecular docking study of the active phytoconstituent of BT obtained from HR-LCMS analysis against reported targets (IL-6, COX-2, TNFα, MPO and ENaC) of ALI was carried out. The B.T. pretreatment prevents mortality in comparison to the oleic acid group. It protects the lungs and heart from the detrimental effect of oleic acid, on par with dexamethasone. COX-2 mRNA expression was significantly down-regulated in the treatment group. The reduced level of TNF-α, MPO, SOD and catalase supported the protective effect of B.T. The in silico study revealed strong binding interaction between the phytoconstituent (Galangin 3- [galactosyl-(1–4)-rhamnoside and Beta solamarine] of BT and the reported target. The B.T. pre-administration attenuates the oleic acid-induced mortality and cardiorespiratory toxicity.

Inducible general knockout of Runx3 profoundly reduces pulmonary cytotoxic CD8+ T cells with minimal effect on outcomes in mice following influenza infection

Respiratory viruses pose a continuing and substantive threat to human health globally. Host innate and adaptive immune responses are the critical antiviral defense mechanisms to control viral replication and spread. The present study is designed to determine the role of transcription factor Runx3 in the host immune response to influenza A virus (IAV) infection. As Runx3 is required for embryonic development, we generated an inducible Runx3 global knockout (KO) mouse model and found that Runx3 KO in adult C57BL/6 mice minimally affected thymic function under normal conditions and survival was at least 250 days post Runx3 deletion. We applied the mouse model to IAV infection and found that Runx3 KO resulted in a huge reduction (>85%) in numbers of total and antigen-specific pulmonary CD8⁺ cytotoxic T cells during IAV infection, while it had a minor effect on pulmonary generation of CD4⁺ T cells. To our surprise, this general KO of Runx3 did not significantly alter viral clearance and animal survival following IAV infection. Interestingly, we found that Runx3 KO significantly increased the numbers of pulmonary innate immune cells such as macrophages and neutrophils and the production of pro-inflammatory cytokines during IAV infection. We further found that Runx3 was strongly detected in CCR2⁺ immune cells in IAV-infected mouse lungs and was induced in activated macrophages and dendritic cells (DCs). As pulmonary CD8⁺ cytotoxic T cells play a central role in the clearance of IAV, our findings suggest that Runx3 KO may enhance host innate immunity to compensate for the loss of pulmonary CD8⁺ cytotoxic T cells during IAV infection.

Immunomodulatory role of Nanocurcumin in COVID-19 patients with dropped natural killer cells frequency and function

The ongoing COVID-19 pandemic is still a challenging problem in the case of infection treatment. The immunomodulatory effect of Nanocurcumin was investigated in the present study in an attempt to counterbalance the immune response and improve the patients' clinical symptoms. 60 confirmed COVID-19 patients and 60 healthy controls enrolled in the study. COVID-19 patients were divided into Nanocurcumin and placebo received groups. Due to the importance of the role of NK cells in this disease, the frequency, cytotoxicity, receptor gene expression of NK cells, and serum secretion levels of inflammatory cytokines IL-1β, IL-6, TNF-α, as well as circulating C5a as a chemotactic factor an inflammatory mediator was evaluated by flow cytometry, real-time PCR and enzyme-linked immunosorbent assay in both experimental groups before and after the intervention. Given the role of measured factors in the progression and pathogenesis of COVID-19 disease, the results can help find appropriate treatments. The results of this study indicated that the Nanocurcumin could significantly increase the frequency and function of NK cells compared to the placebo-treated group. As an immunomodulatory agent, Nanocurcumin may be a helpful choice to improve NK cell function in COVID-19 patients and improve the clinical outcome of patients.

The protective effects of Mai-Luo-Ning injection against LPS-induced acute lung injury via the TLR4/NF-κB signalling pathway

BACKGROUND

Acute lung injury (ALI) is a severe inflammatory disorder associated with high morbidity and mortality rates. Various therapeutic strategies for ALI have been proposed over the last few decades; however, the treatment options remain limited. Mai-Luo-Ning injection (MLN), a traditional Chinese medical formulation, has been extensively used for the treatment of respiratory diseases. Nevertheless, the effects of MLN on ALI remain unclear.

PURPOSE

This study aimed to investigate the protective and therapeutic effects of MLN on lipopolysaccharide-induced ALI mouse models and RAW 264.7 cells, and further explore the underlying mechanism of these effects.

METHODS

The therapeutic activity of MLN was evaluated using an in vivo ALI model and an in vitro model of RAW 264.7 macrophages. UHPLC-ESI-Q-TOF-MS/MS was used to investigate the chemical constituents of the MLN. The material basis and potential protective mechanism of MLN were analyzed using network pharmacology. The roles of MLN in inhibiting the Toll-like receptor 4 (TLR4)/ nuclear factor kappa B (NF-κB) signalling pathway were investigated via western blotting, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunofluorescence staining.

RESULTS

In vivo experiments demonstrated that MLN ameliorated LPS-induced histological changes in lung tissues and reduced lung wet/dry weight ratio, total protein concentration in the bronchoalveolar lavage fluid and myeloperoxidase activity. Furthermore, MLN downregulated the in vivo and in vitro expression of pro-inflammatory cytokines such as tumour necrosis factor-alpha, interleukin-6, and interleukin-1β. Network pharmacology analysis revealed that MLN could act synergistically through multiple targets and pathways and exert a protective effect, possibly through inhibiting TLR4/ NF-κB signalling pathways. Western blotting and immunofluorescence experiments further confirmed that MLN could regulate the expression of TLR4, MyD88, phospho-IκB-α, and phospho-NF-κB p65 in the TLR4/NF-κB signalling pathway and decrease the translocation of phospho-NF-κB p65 into the nucleus.

CONCLUSION

This study suggests that MLN has a potential protective effect against LPS-induced ALI, which might be associated with the inhibition of the TLR4/NF-κB signalling pathway. Therefore, MLN is worthy of further investigation as a potential candidate for the treatment of ALI in the future.

The human lung microbiome-A hidden link between microbes and human health and diseases

Once thought to be sterile, the human lung is now well recognized to harbor a consortium of microorganisms collectively known as the lung microbiome. The lung microbiome is altered in an array of lung diseases, including chronic lung diseases such as chronic obstructive pulmonary disease, asthma, and bronchiectasis, acute lung diseases caused by pneumonia, sepsis, and COVID-19, and other lung complications such as those related to lung transplantation, lung cancer, and human immunodeficiency virus. The effects of lung microbiome in modulating host immunity and inflammation in the lung and distal organs are being elucidated. However, the precise mechanism by which members of microbiota produce structural ligands that interact with host genes and pathways remains largely uncharacterized. Multiple unique challenges, both technically and biologically, exist in the field of lung microbiome, necessitating the development of tailored experimental and analytical approaches to overcome the bottlenecks. In this review, we first provide an overview of the principles and methodologies in studying the lung microbiome. We next review current knowledge of the roles of lung microbiome in human diseases, highlighting mechanistic insights. We finally discuss critical challenges in the field and share our thoughts on broad topics for future investigation.

Aurantiamide Acetate Ameliorates Lung Inflammation in Lipopolysaccharide-Induced Acute Lung Injury in Mice

Purpose

Aurantiamide acetate (AA) is a dipeptide derivative with complex pharmacological activities and remarkable effects on preventing and treating various diseases. In the current study, we aimed to investigate whether AA can exert protective effects in a mouse model of ALI induced by LPS.

Materials and Methods

In this model, mice were given intranasal LPS for 3 days prior to receiving AA (2.5, 5, and 10 mg/kg) via oral gavage. An assessment of histopathological changes was performed by hematoxylin and eosin (HE). Proinflammatory cytokines were detected in bronchoalveolar lavage fluids (BALFs) by enzyme-linked immunosorbent assays (ELISAs). The effects of AA on protein expression of NF-κB and PI3K/AKT signaling pathways were determined by Western blot. In addition, lung wet/dry (W/D) weight ratio, myeloperoxidase (MPO) activity, cell counts, and protein content were also measured.

Results

According to results, AA pretreatment significantly reduced lung pathological changes, W/D ratio, MPO activity, and protein content. Additionally, AA resulted in a significant reduction in the number of total cells, neutrophils, and proinflammatory cytokines in the BALF after LPS stimulation. The subsequent study revealed that pretreatment with AA dose dependently suppressed LPS-induced activation of NF-κB as well as PI3K/AKT phosphorylation.

Conclusion

The results indicated that the AA had a protective effect on LPS-induced ALI in mice and could be a potential drug for ALI.

Eupalinolide B attenuates lipopolysaccharide-induced acute lung injury through inhibition of NF-κB and MAPKs signaling by targeting TAK1 protein

Acute lung injury (ALI) is a life-threatening disease characterized by severe inflammatory response, which has no pharmacological therapy in clinic. In this study, we found that eupalinolide B (EB), a sesquiterpene lactone isolated from Eupatorium lindleyanum, significantly ameliorated lipopolysaccharide (LPS)-induced ALI in mice, which manifests as reduction in lung injury score, activity of myeloperoxidase, and release of cytokines interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1). In RAW264.7 murine macrophages, EB effectively inhibited LPS-induced production of nitric oxide (NO) and prostaglandin E2 (PGE₂) by down-regulating the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2), respectively. Mechanistically, EB not only blocked LPS-induced phosphorylation of inhibitor of nuclear factor kappa B kinase-α/β (IKKα/β), phosphorylation and degradation of inhibitor of nuclear factor-kappa B alpha (IκBα), and phosphorylation and nuclear translocation of nuclear factor-kappa B (NF-κB) P65, but also suppressed LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs) in vitro or in vivo. Through cellular thermal shift assay and western blotting, EB was demonstrated to target and inactivate transforming growth factor β activated kinase-1 (TAK1), which is an important upstream kinase for the activation of NF-κB and MAPKs pathways. Additionally, EB-mediated actions were markedly abolished by dithiothreitol in LPS-exposed RAW264.7 cells, suggesting a crucial role of the α,γ-unsaturated lactone for the anti-inflammatory activity of EB. In conclusion, our findings showed that EB could effectively alleviate ALI in mice, and attenuate inflammatory response by inhibiting the activation of TAK1, and TAK1-mediated activation of NF-κB and MAPKs cascades.

TCM2COVID: A resource of anti-COVID-19 traditional Chinese medicine with effects and mechanisms

In China, traditional Chinese medicine (TCM) has been widely used for coronavirus infectious disease 2019 (COVID-19) prevention, treatment, and recovery and has played a part in the battle against the disease. A variety of TCM treatments have been recommended for different stages of COVID-19. But, to the best of our knowledge, a comprehensive database for storing and organizing anti-COVID TCM treatments is still lacking. Herein, we developed TCM2COVID, a manually curated resource of anti-COVID TCM formulas, natural products (NPs), and herbs. The current version of TCM2COVID (1) documents over 280 TCM formulas (including over 300 herbs) with detailed clinical evidence and therapeutic mechanism information; (2) records over 80 NPs with detailed potential therapeutic mechanisms; and (3) launches a useful web server for querying, analyzing and visualizing documented formulas similar to those supplied by the user (formula similarity analysis). In summary, TCM2COVD provides a user-friendly and practical platform for documenting, querying, and browsing anti-COVID TCM treatments, and will help in the development and elucidation of the mechanisms of action of new anti-COVID TCM therapies to support the fight against the COVID-19 epidemic. TCM2COVID is freely available at http://zhangy-lab.cn/tcm2covid/.

Potential biomarkers for inflammatory response in acute lung injury

Acute lung injury (ALI) is a severe respiratory disorder occurring in critical care medicine, with high rates of mortality and morbidity. This study aims to screen the potential biomarkers for ALI. Microarray data of lung tissues from lung-specific geranylgeranyl pyrophosphate synthase large subunit 1 knockout and wild-type mice treated with lipopolysaccharide were downloaded. Differentially expressed genes (DEGs) between ALI and wild-type mice were screened. Functional analysis and the protein-protein interaction (PPI) modules were analyzed. Finally, a miRNA-transcription factor (TF)-target regulation network was constructed. Totally, 421 DEGs between ALI and wild-type mice were identified. The upregulated DEGs were mainly enriched in the peroxisome proliferator-activated receptor signaling pathway, and fatty acid metabolic process, while downregulated DEGs were related to cytokine-cytokine receptor interaction and regulation of cytokine production. Cxcl5, Cxcl9, Ccr5, and Cxcr4 were key nodes in the PPI network. In addition, three miRNAs (miR505, miR23A, and miR23B) and three TFs (PU1, CEBPA, and CEBPB) were key molecules in the miRNA-TF-target network. Nine genes including ADRA2A, P2RY12, ADORA1, CXCR1, and CXCR4 were predicted as potential druggable genes. As a conclusion, ADRA2A, P2RY12, ADORA1, CXCL5, CXCL9, CXCR1, and CXCR4 might be novel markers and potential druggable genes in ALI by regulating inflammatory response.

Brevilin A Ameliorates Acute Lung Injury and Inflammation Through Inhibition of NF-κB Signaling via Targeting IKKα/β

Acute lung injury (ALI) is life-threatening disease characterized by uncontrolled inflammatory response. IKKα/β, the key kinases in the activation of NF-κB pathway, are implicated in inflammatory pulmonary injury, and represent attractive targets for ALI therapy. Brevilin A (BVA) is a sesquiterpene lactone from Centipeda minima, a Chinese herb used to treat inflammatory diseases. This study aims to investigate the inhibition of BVA on ALI, with focus on clarifying the molecular mechanisms involved in BVA-mediated anti-inflammatory activity in macrophages. Briefly, BVA significantly inhibited the production of NO and PGE₂ by suppressing iNOS and COX2 expression, and suppressed the mRNA expression of IL-1β, IL-6, and TNFα in LPS/IFNγ-stimulated RAW264.7 macrophages. The anti-inflammatory activity of BVA was further confirmed in LPS/IFNγ-stimulated BMDMs and TNFα/IFNγ-exposed RAW264.7 cells. In vivo, BVA effectively attenuated LPS-induced lung damage, inflammatory infiltration, and production of pro-inflammatory cytokines, including MPO, IL-1β, IL-6, TNFα, and PGE₂. Mechanistically, BVA could covalently bind to the cysteine 114 of IKKα/β, and effectively inhibiting the activity and function of IKKα/β, thereby resulting in the suppression of phosphorylation and degradation of IκBα and the subsequent activation of NF-κB signaling. Furthermore, pretreatment of DTT, a thiol ligand donor, significantly abolished BVA-mediated effects in LPS/IFNγ-stimulated RAW264.7 cells, suggesting the crucial role of the electrophilic α, β-unsaturated ketone of BVA on its anti-inflammatory activity. These results suggest that BVA ameliorates ALI through inhibition of NF-κB signaling via covalently targeting IKKα/β, raising the possibility that BVA could be effective in the treatment of ALI and other diseases harboring aberrant NF-κB signaling.

Mesenchymal stem/stromal cell-based therapies for COVID-19: First iteration of a living systematic review and meta-analysis: MSCs and COVID-19

BACKGROUND

Mesenchymal stem/stromal cells (MSCs) and their secreted products are a promising therapy for COVID-19 given their immunomodulatory and tissue repair capabilities. Many small studies were launched at the onset of the pandemic, and repeated meta-analysis is critical to obtain timely and sufficient statistical power to determine efficacy.

METHODS AND FINDINGS

All English-language published studies identified in our systematic search (up to February 3, 2021) examining the use of MSC-derived products to treat patients with COVID-19 were identified. Risk of bias (RoB) was assessed for all studies. Nine studies were identified (189 patients), four of which were controlled (93 patients). Three of the controlled studies reported on mortality (primary analysis) and were pooled through random-effects meta-analysis. MSCs decreased the risk of death at study endpoint compared with controls (risk ratio, 0.18; 95% confidence interval [CI], 0.04 to 0.74; P = .02; I² = 0%), although follow-up differed. Among secondary outcomes, interleukin-6 levels were most commonly reported and were decreased compared with controls (standardized mean difference, -0.69; 95% CI, -1.15 to -0.22; P = .004; I² = 0%) (n = 3 studies). Other outcomes were not reported consistently, and pooled estimates of effect were not performed. Substantial heterogeneity was observed between studies in terms of study design. Adherence to published ISCT criteria for MSC characterization was low. In two of nine studies, RoB analysis revealed a low to moderate risk of bias in controlled studies, and uncontrolled case series were of good (3 studies) or fair (2 studies) quality.

CONCLUSION

Use of MSCs to treat COVID-19 appears promising; however, few studies were identified, and potential risk of bias was detected in all studies. More controlled studies that report uniform clinical outcomes and use MSC products that meet standard ISCT criteria should be performed. Future iterations of our systematic search should refine estimates of efficacy and clarify potential adverse effects.

Human Cell Organelles in SARS-CoV-2 Infection: An Up-to-Date Overview

Since the end of 2019, the whole world has been struggling with the life-threatening pandemic amongst all age groups and geographic areas caused by Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2). The Coronavirus Disease 2019 (COVID-19) pandemic, which has led to more than 468 million cases and over 6 million deaths reported worldwide (as of 20 March 2022), is one of the greatest threats to human health in history. Meanwhile, the lack of specific and irresistible treatment modalities provoked concentrated efforts in scientists around the world. Various mechanisms of cell entry and cellular dysfunction were initially proclaimed. Especially, mitochondria and cell membrane are crucial for the course of infection. The SARS-CoV-2 invasion depends on angiotensin converting enzyme 2 (ACE2), transmembrane serine protease 2 (TMPRSS2), and cluster of differentiation 147 (CD147), expressed on host cells. Moreover, in this narrative review, we aim to discuss other cell organelles targeted by SARS-CoV-2. Lastly, we briefly summarize the studies on various drugs.

PF-07321332 (Nirmatrelvir) Does Not Interact with Human ENT1 or ENT2: Implications for COVID-19 Patients

The ongoing pandemic of severe acute respiratory syndrome‐coronavirus 2 (SARS‐CoV‐2) and subsequently, coronavirus disease 2019 (COVID‐19), has led to the deaths of over 6.1 million people and sparked a greater interest in virology to expedite the development process for antivirals. The US Food and Drug Administration (FDA) granted emergency use authorization for three antivirals: remdesivir, molnupiravir, and nirmatrelvir. Remdesivir and molnupiravir are nucleoside analogs that undergo biotransformation to form active metabolites that incorporate into new viral RNA to stall replication. Unlike remdesivir or molnupiravir, nirmatrelvir is a protease inhibitor that covalently binds to the SARS‐CoV‐2 3C‐like protease to interrupt the viral replication cycle. A recent study identified that remdesivir and the active metabolite of molnupiravir, EIDD‐1931, are substrates of equilibrative nucleoside transporters 1 and 2 (ENT1 and 2). Despite the ubiquitous expression of the ENTs, the preclinical efficacy of remdesivir and molnupiravir is not reflected in wide‐scale SARS‐CoV‐2 clinical trials. Interestingly, downregulation of ENT1 and ENT2 expression has been shown in lung epithelial and endothelial cells in response to hypoxia and acute lung injury, although it has not been directly studied in patients with COVID‐19. It is possible that the poor efficacy of remdesivir and molnupiravir in these patients may be partially attributed to the repression of ENTs in the lungs, but further studies are warranted. This study investigated the interaction between nirmatrelvir and the ENTs and found that it was a poor inhibitor of ENT‐mediated [³H]uridine uptake at 300 μM. Unlike for remdesivir or EIDD‐1931, ENT activity is unlikely to be a factor for nirmatrelvir disposition in humans; however, whether this contributes to the similar in vitro and clinical efficacy will require further mechanistic studies.

Assessment of the association between dust storms and COVID-19 infection rate in southwest Iran

This study assesses a plausible correlation between a dust intrusion episode and a daily increase in COVID-19 cases. A surge in COVID-19 cases was observed a few days after a Middle East Dust (MED) event that peaked on 25^th April 2020 in southwest Iran. To investigate potential causal factors for the spike in number of cases, cross-correlations between daily combined aerosol optical depths (AODs) and confirmed cases were computed for Khuzestan, Iran. Additionally, atmospheric stability data time series were assessed by covering before, during, and after dust intrusion, producing four statistically clustered distinct city groups. Groups 1 and 2 had different peak lag times of 10 and 4-5 days, respectively. Since there were statistically significant associations between AOD levels and confirmed cases in both groups, dust incursion may have increased population susceptibility to COVID-19 disease. Group 3 was utilized as a control group with neither a significant level of dust incursion during the episodic period nor any significant associations. Group 4 cities, which experienced high dust incursion levels, showed no significant correlation with confirmed case count increases. Random Forest Analysis assessed the influence of wind speed and AOD, showing relative importance of 0.31 and 0.23 on the daily increase percent of confirmed cases, respectively. This study may serve as a reference for better understanding and predicting factors affecting COVID-19 transmission and diffusion routes, focusing on the role of MED intrusions.

Evaluation of Pulmonary Edema Using Ultrasound Imaging in Patients With COVID-19 Pneumonia Based on a Non-local Channel Attention ResNet

Recent research has revealed that COVID-19 pneumonia is often accompanied by pulmonary edema. Pulmonary edema is a manifestation of acute lung injury (ALI), and may progress to hypoxemia and potentially acute respiratory distress syndrome (ARDS), which have higher mortality. Precise classification of the degree of pulmonary edema in patients is of great significance in choosing a treatment plan and improving the chance of survival. Here we propose a deep learning neural network named Non-local Channel Attention ResNet to analyze the lung ultrasound images and automatically score the degree of pulmonary edema of patients with COVID-19 pneumonia. The proposed method was designed by combining the ResNet with the non-local module and the channel attention mechanism. The non-local module was used to extract the information on characteristics of A-lines and B-lines, on the basis of which the degree of pulmonary edema could be defined. The channel attention mechanism was used to assign weights to decisive channels. The data set contains 2220 lung ultrasound images provided by Huoshenshan Hospital, Wuhan, China, of which 2062 effective images with accurate scores assigned by two experienced clinicians were used in the experiment. The experimental results indicated that our method achieved high accuracy in classifying the degree of pulmonary edema in patients with COVID-19 pneumonia by comparison with previous deep learning methods, indicating its potential to monitor patients with COVID-19 pneumonia.

Discovery of Nitro-azolo[1,5-a]pyrimidines with Anti-Inflammatory and Protective Activity against LPS-Induced Acute Lung Injury

Acute lung injury remains a challenging clinical condition, necessitating the development of novel, safe and efficient treatments. The prevention of macrophage M1-polarization is a viable venue to tackle excessive inflammation. We performed a phenotypic screening campaign to identify azolopyrimidine compounds that effectively inhibit LPS-induced NO synthesis and interleukin 6 (IL-6) secretion. We identified lead compound 9g that inhibits IL-6 secretion with IC₅₀ of 3.72 µM without apparent cytotoxicity and with minimal suppression of macrophage phagocytosis in contrast to dexamethasone. In a mouse model of LPS-induced acute lung injury, 30 mg/kg i.p. 9g ameliorated anxiety-like behavior, inhibited IL-6 release, and limited neutrophil infiltration and pulmonary edema. A histological study confirmed the protective activity of 9g. Treatment with compound 9g prevented the migration of CD68⁺ macrophages and the incidence of hemorrhage. Hence, we have identified a promising pharmacological approach for the treatment of acute lung injury that may hold promise for the development of novel drugs against cytokine-mediated complications of bacterial and viral infections.

A new mouse unilateral model of diffuse alveolar damage of the lung

Objective and design

The existing biological models of diffuse alveolar damage (DAD) in mice have many shortcomings. To offset these shortcomings, we have proposed a simple, nonsurgical, and reproducible method of unilateral total damage of the left lung in ICR mice. This model is based on the intrabronchial administration of a mixture of bacterial lipopolysaccharide (LPS) from the cell wall of S. enterica and α-galactosylceramide (inducing substances) to the left lung.

Methods

Using computer tomography of the lungs with endobronchial administration of contrast material, we have been able to perform an operative intravital verification of the targeted delivery of the inducer. The model presented is characterized by more serious and homogeneous damage of the affected lung compared to the existing models of focal pneumonia; at the same time, our model is characterized by longer animal survival since the right lung remains intact.

Results

The model is also characterized by diffuse alveolar damage of the left lung, animal survival of 100%, abrupt increases in plasma levels of TNFa, INFg, and IL-6, and significant myocardial overload in the right heart. It can be used to assess the efficacy of innovative drugs for the treatment of DAD and ARDS as the clinical manifestations that are developed in patients infected with SARS-CoV-2. Morphological patterns of lungs in the noninfectious (“sterile”) model of DAD induced by LPS simultaneously with α-galactosylceramide (presented here) and in the infectious model of DAD induced by SARS-CoV-2 have been compared.

Conclusion

The DAD model we have proposed can be widely used for studying the efficacy of candidate molecules for the treatment of infectious respiratory diseases, such as viral pneumonias of different etiology, including SARS-CoV-2.

Clinical and translational values of spatial transcriptomics

The combination of spatial transcriptomics (ST) and single cell RNA sequencing (scRNA-seq) acts as a pivotal component to bridge the pathological phenomes of human tissues with molecular alterations, defining in situ intercellular molecular communications and knowledge on spatiotemporal molecular medicine. The present article overviews the development of ST and aims to evaluate clinical and translational values for understanding molecular pathogenesis and uncovering disease-specific biomarkers. We compare the advantages and disadvantages of sequencing- and imaging-based technologies and highlight opportunities and challenges of ST. We also describe the bioinformatics tools necessary on dissecting spatial patterns of gene expression and cellular interactions and the potential applications of ST in human diseases for clinical practice as one of important issues in clinical and translational medicine, including neurology, embryo development, oncology, and inflammation. Thus, clear clinical objectives, designs, optimizations of sampling procedure and protocol, repeatability of ST, as well as simplifications of analysis and interpretation are the key to translate ST from bench to clinic.

Interferon-γ Preferentially Promotes Necroptosis of Lung Epithelial Cells by Upregulating MLKL

Necroptosis, a form of programmed lytic cell death, has emerged as a driving factor in the pathogenesis of acute lung injury (ALI). As ALI is often associated with a cytokine storm, we determined whether pro-inflammatory cytokines modulate the susceptibility of lung cells to necroptosis and which mediators dominate to control necroptosis. In this study, we pretreated/primed mouse primary lung epithelial and endothelial cells with various inflammatory mediators and assessed cell type-dependent responses to different necroptosis inducers and their underlying mechanisms. We found that interferon-γ (IFNγ) as low as 1 ng/mL preferentially promoted necroptosis and accelerated the release of damage-associated molecular patterns from primary alveolar and airway epithelial cells but not lung microvascular endothelial cells. Type-I IFNα was about fifty-fold less effective than IFNγ. Conversely, TNFα or agonists of Toll-like receptor-3 (TLR3), TLR4, TLR7 and TLR9 had a minor effect. The enhanced necroptosis in IFNγ-activated lung epithelial cells was dependent on IFNγ signaling and receptor-interacting protein kinase-3. We further showed that necroptosis effector mixed lineage kinase domain-like protein (MLKL) was predominantly induced by IFNγ, contributing to the enhanced necroptosis in lung epithelial cells. Collectively, our findings indicate that IFNγ is a potent enhancer of lung epithelial cell susceptibility to necroptosis.

Fe-Curcumin Nanozyme-Mediated Reactive Oxygen Species Scavenging and Anti-Inflammation for Acute Lung Injury

Pneumonia, such as acute lung injury (ALI), has been a type of lethal disease that is generally caused by uncontrolled inflammatory response and excessive generation of reactive oxygen species (ROS). Herein, we report Fe-curcumin-based nanoparticles (Fe-Cur NPs) with nanozyme functionalities in guiding the intracellular ROS scavenging and meanwhile exhibiting anti-inflammation efficacy for curing ALI. The nanoparticles are noncytotoxic when directing these biological activities. Mechanism studies for the anti-inflammation aspects of Fe-Cur NPs were systematically carried out, in which the infected cells and tissues were alleviated through downregulating levels of several important inflammatory cytokines (such as TNF-α, IL-1β, and IL-6), decreasing the intracellular Ca2+ release, inhibiting NLRP3 inflammasomes, and suppressing NF-κB signaling pathways. In addition, we performed both the intratracheal and intravenous injection of Fe-Cur NPs in mice experiencing ALI and, importantly, found that the accumulation of such nanozymes was enhanced in lung tissue (better than free curcumin drugs), demonstrating its promising therapeutic efficiency in two different administration methods. We showed that the inflammation reduction of Fe-Cur NPs was effective in animal experiments and that ROS scavenging was also effectively achieved in lung tissue. Finally, we revealed that Fe-Cur NPs can decrease the level of macrophage cells (CD11bloF4/80hi) and CD3+CD45+ T cells in mice, which could help suppress the inflammation cytokine storm caused by ALI. Overall, this work has developed the strategy of using Fe-Cur NPs as nanozymes to scavenge intracellular ROS and as an anti-inflammation nanodrugs to synergistically cure ALI, which may serve as a promising therapeutic agent in the clinical treatment of this deadly disease. Fe-Cur NP nanozymes were designed to attenuate ALI by clearing intracellular ROS and alleviating inflammation synergistically. Relevant cytokines, inflammasomes, and signaling pathways were studied.

Roles of pulmonary telocytes in airway epithelia to benefit experimental acute lung injury through production of telocyte-driven mediators and exosomes

Background

Telocytes (TCs) are experimentally evidenced as an alternative of cell therapies for organ tissue injury and repair. The aims of the present studies are to explore direct roles of TCs and the roles of TC-derived exosomes in support of experimental acute lung injury (ALI) in vivo or in vitro.

Materials and methods

The roles of TCs in experimental ALI were firstly estimated. Phosphoinositide 3-kinase (PI3K) p110δ and α/δ/β isoform inhibitors were used in study dynamic alterations of bio-behaviors, and in expression of functional factors of TCs per se and TC-co-cultured airway epithelial cells during the activation with lipopolysaccharide (LPS). TC-driven exosomes were furthermore characterized for intercellular communication by which activated or non-activated TCs interacted with epithelia.

Results

Our results showed that TCs mainly prevented from lung tissue edema and hemorrhage and decreased the levels of VEGF-A and MMP9 induced by LPS. Treatment with CAL101 (PI3K p110δ inhibitor) and LY294002 (PI3Kα/δ/β inhibitor) could inhibit TC movement and differentiation and increase the number of dead TCs. The expression of Mtor, Hif1α, Vegf-a, or Mmp9 mRNA increased in TCs challenged with LPS, while Mtor, Hif1α, and Vegf-a even more increased after adding CAL101 or Mtor after adding LY. The rate of epithelial cell proliferation was higher in co-culture of human bronchial epithelial (HBE) and TCs than that in HBE alone under conditions with or without LPS challenge or when cells were treated with LPS and CAL101 or LY294002. The levels of mTOR, HIF1α, or VEGF-A significantly increased in mono-cultured or co-cultured cells, challenged with LPS as compared with those with vehicle. LPS-pretreated TC-derived exosomes upregulated the expression of AKT, p-AKT, HIF1α, and VEGF-A protein of HBE.

Conclusion

The present study demonstrated that intraperitoneal administration of TCs ameliorated the severity of lung tissue edema accompanied by elevated expression of VEGF-A. TCs could nourish airway epithelial cells through nutrients produced from TCs, increasing epithelial cell proliferation, and differentiation as well as cell sensitivity to LPS challenge and PI3K p110δ and α/δ/β inhibitors, partially through exosomes released from TCs.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10565-021-09670-5.

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