Role of chemokines in the pathogenesis of acute lung injury

Total flavonoids from the aerial parts of Tetrastigma hemsleyanum prevent LPS-induced ALI by modulating the TLR4/NF-κB pathway in mice

BACKGROUND

The traditional Chinese medicine Tetrastigma Hemsleyanum (TH) is employed in treating respiratory diseases; however, the aerial parts by which its total flavonoids alleviate acute lung injury (ALI) are still unknown. This study investigated the protective effect and mechanism of Tetrastigma Hemsleyanum flavonoids (THF) in lipopolysaccharide (LPS)-induced ALI in mice.

METHODS

Firstly, the total flavonoids from the above-ground part of TH were extracted. Subsequently, the composition of THF was analyzed using LC-MS. In vivo, the impact of THF on ALI mice was assessed through lung histopathology and the evaluation of various inflammatory factors' expression in mice. After treating RAW264.7 cells with THF in vitro, changes in inflammatory markers were examined upon LPS stimulation, and mRNA expression levels of inflammatory factors were detected using RT-qPCR. Finally, Western blot analysis was performed to determine TLR4/NF-κB pathway-associated proteins expression.

RESULTS

In summary, a total of 24 flavonoids have been identified in THF. In vivo and vitro results show that THF effectively reduces the damage caused by LPS inflammation by blocking the expression and release of inflammatory factors. THF alleviates inflammatory injury by modulating the TLR4/NF-KB pathway.

CONCLUSION

The results suggest that flavonoids exhibit a potent anti-inflammatory effect and effectively mitigate LPS-induced injury both in vivo and in vitro. We suggested that these flavonoids exert their therapeutic effects by modulating the TLR4/NF-KB pathway. In conclusion, the development of THF is anticipated to represent a promising new pharmaceutical for treatingALI.

Neutrophils: a key component in ECMO-related acute organ injury

Extracorporeal membrane oxygenation (ECMO), as an extracorporeal life support technique, can save the lives of reversible critically ill patients when conventional treatments fail. However, ECMO-related acute organ injury is a common complication that increases the risk of death in critically ill patients, including acute kidney injury, acute brain injury, acute lung injury, and so on. In ECMO supported patients, an increasing number of studies have shown that activation of the inflammatory response plays an important role in the development of acute organ injury. Cross-cascade activation of the complement system, the contact system, and the coagulation system, as well as the mechanical forces of the circuitry are very important pathophysiological mechanisms, likely leading to neutrophil activation and the production of neutrophil extracellular traps (NETs). NETs may have the potential to cause organ damage, generating interest in their study as potential therapeutic targets for ECMO-related acute organ injury. Therefore, this article comprehensively summarized the mechanism of neutrophils activation and NETs formation following ECMO treatment and their actions on acute organ injury.

Inter- and Intra-donor variability in bone marrow-derived mesenchymal stromal cells: implications for clinical applications

BACKGROUND AIMS

Mesenchymal stromal cells (MSCs) are attractive as a therapeutic modality in multiple disease conditions characterized by inflammation and vascular compromise. Logistically they are advantageous because they can be isolated from adult tissue sources, such as bone marrow (BM). The phase 2a START clinical trial determined BM-MSCs to be safe in patients with moderate-to-severe acute respiratory distress syndrome (ARDS). Herein, we examine a subset of the clinical doses of MSCs generated for the phase 2a START trial from three unique donors (1-3), where one of the donors' donated BM on two separate occasions (donor 3 and 3W).

METHODS

The main objective of this study was to correlate properties of the cells from the four lots with plasma biomarkers from treated patients and relevant to ARDS outcomes. To do this we evaluated MSC donor lots for (i) post-thaw viability, (ii) growth kinetics, (iii) metabolism, (iv) surface marker expression, (v) protein expression, (vi) immunomodulatory ability and (vii) their functional effects on regulating endothelial cell permeability.

RESULTS

MSC-specific marker expression and protection of thrombin-challenged endothelial barrier permeability was similar among all four donor lots. Inter and intra-donor variability was observed in all the other in vitro assays. Furthermore, patient plasma ANG-2 and protein C levels at 6 hours post-transfusion were correlated to cell viability in an inter- and intra-donor dependent manner.

CONCLUSIONS

These findings highlight the potential of donor dependent (inter-) and collection dependent (intra-) effects in patient biomarker expression.

Mechanism of Lian Hua Qing Wen capsules regulates the inflammatory response caused by M1 macrophage based on cellular experiments and computer simulations

PURPOSE

The polarization of macrophages with the resulting inflammatory response play a crucial part in tissue and organ damage due to inflammatory. Study has proved Lian Hua Qing Wen capsules (LHQW) can reduce activation of inflammatory response and damage of tissue derived from the inflammatory reactions. However, the mechanism of LHQW regulates the macrophage-induced inflammatory response is unclear. Therefore, we investigated the mechanism of LHQW regulated the inflammatory response of M1 macrophages by cellular experiments and computer simulations.

METHODS

This study has analysed the targets and mechanisms of macrophage regulating inflammatory response at gene and protein levels through bioinformatics. The monomeric components of LHQW were analyzed by High Performance Liquid Chromatography (HPLC). We established the in vitro cell model by M1 macrophages (Induction of THP-1 cells into M1 macrophages). RT-qPCR and immunofluorescence were used to detect changes in gene and protein levels of key targets after LHQW treatment. Computer simulations were utilized to verify the binding stability of monomeric components and protein targets.

RESULTS

Macrophages had 140,690 gene targets, inflammatory response had 12,192 gene targets, intersection gene targets were 11,772. Key monomeric components (including: Pinocembrin, Fargesone-A, Nodakenin and Bowdichione) of LHQW were screened by HPLC. The results of cellular experiments indicated that LHQW could significantly reduce the mRNA expression of CCR5, CSF2, IFNG and TNF, thereby alleviating the inflammatory response caused by M1 macrophage. The computer simulations further validated the binding stability and conformation of key monomeric components and key protein targets, and IFNG/Nodakenin was able to form the most stable binding conformation for its action.

CONCLUSION

In this study, the mechanism of LHQW inhibits the polarization of macrophages and the resulting inflammatory response was investigated by computer simulations and cellular experiments. We found that LHQW may not only reduce cell damage and death by acting on TNF and CCR5, but also inhibit the immune recognition process and inflammatory response by regulating CSF2 and IFNG to prevent polarization of macrophages. Therefore, these results suggested that LHQW may act through multiple targets to inhibit the polarization of macrophages and the resulting inflammatory response.

Diterpene Coronarin Attenuates Lipopolysaccharide-Induced Acute Lung Injury in Both In Vivo and In Vitro Models

Acute lung injury (ALI) is a clinical condition occurs due to severe systemic inflammatory response for clinical stimulus like pneumonia, sepsis, trauma, aspiration, inhalation of toxic gases, and pancreatitis. Disruption of alveolar barriers, activation of macrophages, infiltration of neutrophils, and proinflammatory cytokines are the vital events occurs during ALI. The drugs which inhibit these inflammatory response can protect lungs from inflammatory insults. In this study, we examined the potency of phytochemical coronarin, a diterpene which have been proven to possess anti-inflammatory, antioxidant, antiangiogenic, and antitumor activities. Healthy BALB/c mice were induced to acute lung injury with intra-tracheal administration of LPS and then treated with 5 and 10 mg/kg concentration of coronarin. The wet/dry lung weight of mice were estimated to assess the induction of pulmonary edema. BALF fluid was analyzed for protein concentrations and immune cells count. Myeloperoxidase activity and levels of chemokines MCP-2 and MIP-2, iNOS, COX-2, and PGE-2 were quantified to assess the immunomodulatory effect of coronarin against LPS-induced ALI. The levels of proinflammatory cytokines was measured to examine the anti-inflammatory property of coronarin, and it was confirmed with histopathological analysis of the lung tissue. Murine RAW 264.7 cells were utilized for the in vitro analysis. Cell cytoxicity and cytoprotective property of coronarin was assessed with MTT assay in LPS-treated Murine RAW 264.7. The anti-inflammatory property of coronarin was further confirmed in in vitro condition by estimating the levels of pro-inflammatory cytokines in coronarin-treated and untreated LPS-induced cells. Overall, our in vivo and in vitro results confirm coronarin significantly inhibited the infiltration of neutrophils prevented immunodulatory activity and synthesis of proinflammatory cytokines and alleviated the acute lung injury induced by LPS. Coronarin is a potent anti-inflammatory drug which can be subjected to further research to be prescribed as drug for ALI.

Long COVID Definition, Symptoms, Risk Factors, Epidemiology and Autoimmunity: A Narrative Review

The virus called SARS-CoV-2 emerged in 2019 and quickly spread worldwide, causing COVID-19. It has greatly impacted on everyday life, healthcare systems, and the global economy. In order to save as many lives as possible, precautions such as social distancing, quarantine, and testing policies were implemented, and effective vaccines were developed. A growing amount of data collected worldwide allowed the characterization of this new disease, which turned out to be more complex than other common respiratory tract infections. An increasing number of convalescents presented with a variety of nonspecific symptoms emerging after the acute infection. This possible new global health problem was identified and labelled as long COVID. Since then, a great effort has been made by clinicians and the scientific community to understand the underlying mechanisms and to develop preventive measures and effective treatment. The role of autoimmunity induced by SARS-CoV-2 infection in the development of long COVID is discussed in this review. We aim to deliver a description of several conditions with an autoimmune background observed in COVID-19 convalescents, including Guillain-Barré syndrome, antiphospholipid syndrome and related thrombosis, and Kawasaki disease highlighting a relationship between SARS-CoV-2 infection and the development of autoimmunity. However, further studies are required to determine its true clinical significance.

Short- and long-term outcomes of pulmonary exposure to a sublethal dose of ricin in mice

Ricin, an extremely potent toxin produced from the seeds of castor plant, Ricinus communis, is ribosome-inactivating protein that blocks cell-protein synthesis. It is considered a biological threat due to worldwide availability of castor beans, massive quantities as a by-product of castor oil production, high stability and ease of production. The consequence of exposure to lethal dose of ricin was extensively described in various animal models. However, it is assumed that in case of aerosolized ricin bioterror attack, the majority of individuals would be exposed to sublethal doses rather than to lethal ones. Therefore, the purpose of current study was to assess short- and long-term effects on physiological parameters and function following sublethal pulmonary exposure. We show that in the short-term, sublethal exposure of mice to ricin resulted in acute lung injury, including interstitial pneumonia, cytokine storm, neutrophil influx, edema and cellular death. This damage was manifested in reduced lung performance and physiological function. Interestingly, although in the long-term, mice recovered from acute lung damage and restored pulmonary and physiological functionality, the reparative process was associated with lasting fibrotic lesions. Therefore, restriction of short-term acute phase of the disease and management of long-term pulmonary fibrosis by medical countermeasures is expected to facilitate the quality of life of exposed survivors.

Mitigation of acute lung injury by human bronchial epithelial cell-derived extracellular vesicles via ANXA1-mediated FPR signaling

Acute lung injury (ALI) is characterized by respiratory failure resulting from the disruption of the epithelial and endothelial barriers as well as immune system. In this study, we evaluated the therapeutic potential of airway epithelial cell-derived extracellular vesicles (EVs) in maintaining lung homeostasis. We isolated human bronchial epithelial cell-derived EVs (HBEC-EVs), which endogenously express various immune-related surface markers and investigated their immunomodulatory potential in ALI. In ALI cellular models, HBEC-EVs demonstrated immunosuppressive effects by reducing the secretion of proinflammatory cytokines in both THP-1 macrophages and HBECs. Mechanistically, these effects were partially ascribed to nine of the top 10 miRNAs enriched in HBEC-EVs, governing toll-like receptor-NF-κB signaling pathways. Proteomic analysis revealed the presence of proteins in HBEC-EVs involved in WNT and NF-κB signaling pathways, pivotal in inflammation regulation. ANXA1, a constituent of HBEC-EVs, interacts with formyl peptide receptor (FPR)2, eliciting anti-inflammatory responses by suppressing NF-κB signaling in inflamed epithelium, including type II alveolar epithelial cells. In a mouse model of ALI, intratracheal administration of HBEC-EVs reduced lung injury, inflammatory cell infiltration, and cytokine levels. Collectively, these findings suggest the therapeutic potential of HBEC-EVs, through their miRNAs and ANXA1 cargo, in mitigating lung injury and inflammation in ALI patients.

Preclinical evidence using synthetic compounds and natural products indicates that AMPK represents a potential pharmacological target for the therapy of pulmonary diseases

Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) is a highly conserved eukaryotic enzyme discovered as a key regulator of cellular energy homeostasis, with anti-inflammation, antioxidative stress, anticancer, and antifibrosis beneficial effects. AMPK is dysregulated in human pulmonary diseases such as acute lung injury, nonsmall cell lung cancer, pulmonary fibrosis, chronic obstructive pulmonary disease, and asthma. This review provides an overview of the beneficial role of natural, synthetic, and Chinese traditional medicines AMPK modulators in pulmonary diseases, and highlights the role of the AMPK signaling pathway in the lung, emphasizing the importance of finding lead compounds and drugs that can target and modulate AMPK to treat the lung diseases.

Emerging application of nanomedicine-based therapy in acute respiratory distress syndrome

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are serious lung injuries caused by various factors, leading to increased permeability of the alveolar-capillary barrier, reduced stability of the alveoli, inflammatory response, and hypoxemia. Despite several decades of research since ARDS was first formally described in 1967, reliable clinical treatment options are still lacking. Currently, supportive therapy and mechanical ventilation are prioritized, and there is no medication that can be completely effective in clinical treatment. In recent years, nanomedicine has developed rapidly and has exciting preclinical treatment capabilities. Using a drug delivery system based on nanobiotechnology, local drugs can be continuously released in lung tissue at therapeutic levels, reducing the frequency of administration and improving patient compliance. Furthermore, this novel drug delivery system can target specific sites and reduce systemic side effects. Currently, many nanomedicine treatment options for ARDS have demonstrated efficacy. This review briefly introduces the pathophysiology of ARDS, discusses various research progress on using nanomedicine to treat ARDS, and anticipates future developments in related fields.

GSTP alleviates acute lung injury by S-glutathionylation of KEAP1 and subsequent activation of NRF2 pathway

Oxidative stress plays an important role in the pathogenesis of acute lung injury (ALI). As a typical post-translational modification triggered by oxidative stress, protein S-glutathionylation (PSSG) is regulated by redox signaling pathways and plays diverse roles in oxidative stress conditions. In this study, we found that GSTP downregulation exacerbated LPS-induced injury in human lung epithelial cells and in mice ALI models, confirming the protective effect of GSTP against ALI both in vitro and in vivo. Additionally, a positive correlation was observed between total PSSG level and GSTP expression level in cells and mice lung tissues. Further results demonstrated that GSTP inhibited KEAP1-NRF2 interaction by promoting PSSG process of KEAP1. By the integration of protein mass spectrometry, molecular docking, and site-mutation validation assays, we identified C434 in KEAP1 as the key PSSG site catalyzed by GSTP, which promoted the dissociation of KEAP1-NRF2 complex and activated the subsequent anti-oxidant genes. In vivo experiments with AAV-GSTP mice confirmed that GSTP inhibited LPS-induced lung inflammation by promoting PSSG of KEAP1 and activating the NRF2 downstream antioxidant pathways. Collectively, this study revealed the novel regulatory mechanism of GSTP in the anti-inflammatory function of lungs by modulating PSSG of KEAP1 and the subsequent KEAP1/NRF2 pathway. Targeting at manipulation of GSTP level or activity might be a promising therapeutic strategy for oxidative stress-induced ALI progression.

Rapidly improving ARDS differs clinically and biologically from persistent ARDS

BACKGROUND

Rapidly improving acute respiratory distress syndrome (RIARDS) is an increasingly appreciated subgroup of ARDS in which hypoxemia improves within 24 h after initiation of mechanical ventilation. Detailed clinical and biological features of RIARDS have not been clearly defined, and it is unknown whether RIARDS is associated with the hypoinflammatory or hyperinflammatory phenotype of ARDS. The purpose of this study was to define the clinical and biological features of RIARDS and its association with inflammatory subphenotypes.

METHODS

We analyzed data from 215 patients who met Berlin criteria for ARDS (endotracheally intubated) and were enrolled in a prospective observational cohort conducted at two sites, one tertiary care center and one urban safety net hospital. RIARDS was defined according to previous studies as improvement of hypoxemia defined as (i) PaO2:FiO2 > 300 or (ii) SpO2: FiO2 > 315 on the day following diagnosis of ARDS (day 2) or (iii) unassisted breathing by day 2 and for the next 48 h (defined as absence of endotracheal intubation on day 2 through day 4). Plasma biomarkers were measured on samples collected on the day of study enrollment, and ARDS phenotypes were allocated as previously described.

RESULTS

RIARDS accounted for 21% of all ARDS participants. Patients with RIARDS had better clinical outcomes compared to those with persistent ARDS, with lower hospital mortality (13% vs. 57%; p value < 0.001) and more ICU-free days (median 24 vs. 0; p value < 0.001). Plasma levels of interleukin-6, interleukin-8, and plasminogen activator inhibitor-1 were significantly lower among patients with RIARDS. The hypoinflammatory phenotype of ARDS was more common among patients with RIARDS (78% vs. 51% in persistent ARDS; p value = 0.001).

CONCLUSIONS

This study identifies a high prevalence of RIARDS in a multicenter observational cohort and confirms the more benign clinical course of these patients. We report the novel finding that RIARDS is characterized by lower concentrations of plasma biomarkers of inflammation compared to persistent ARDS, and that hypoinflammatory ARDS is more prevalent among patients with RIARDS. Identification and exclusion of RIARDS could potentially improve prognostic and predictive enrichment in clinical trials.

The glycosaminoglycan-binding chemokine fragment CXCL9(74-103) reduces inflammation and tissue damage in mouse models of coronavirus infection

Introduction

Pulmonary diseases represent a significant burden to patients and the healthcare system and are one of the leading causes of mortality worldwide. Particularly, the COVID-19 pandemic has had a profound global impact, affecting public health, economies, and daily life. While the peak of the crisis has subsided, the global number of reported COVID-19 cases remains significantly high, according to medical agencies around the world. Furthermore, despite the success of vaccines in reducing the number of deaths caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there remains a gap in the treatment of the disease, especially in addressing uncontrolled inflammation. The massive recruitment of leukocytes to lung tissue and alveoli is a hallmark factor in COVID-19, being essential for effectively responding to the pulmonary insult but also linked to inflammation and lung damage. In this context, mice models are a crucial tool, offering valuable insights into both the pathogenesis of the disease and potential therapeutic approaches.

Methods

Here, we investigated the anti-inflammatory effect of the glycosaminoglycan (GAG)-binding chemokine fragment CXCL9(74-103), a molecule that potentially decreases neutrophil transmigration by competing with chemokines for GAG-binding sites, in two models of pneumonia caused by coronavirus infection.

Results

In a murine model of betacoronavirus MHV-3 infection, the treatment with CXCL9(74-103) decreased the accumulation of total leukocytes, mainly neutrophils, to the alveolar space and improved several parameters of lung dysfunction 3 days after infection. Additionally, this treatment also reduced the lung damage. In the SARS-CoV-2 model in K18-hACE2-mice, CXCL9(74-103) significantly improved the clinical manifestations of the disease, reducing pulmonary damage and decreasing viral titers in the lungs.

Discussion

These findings indicate that CXCL9(74-103) resulted in highly favorable outcomes in controlling pneumonia caused by coronavirus, as it effectively diminishes the clinical consequences of the infections and reduces both local and systemic inflammation.

Therapeutic Effects of a Novel Aptamer on Coronaviral Infection-Induced Lung Injury and Systemic Inflammatory Responses

BACKGROUND

Coronaviral infection-induced acute lung injury has become a major threat to public health, especially through the ongoing pandemic of COVID-19. Apta-1 is a newly discovered Aptamer that has anti-inflammatory effects on systemic septic responses. The therapeutic effects of Apta-1 on coronaviral infection-induced acute lung injury and systemic responses were evaluated in the present study.

METHODS

Female A/J mice (at 12-14 weeks of age) were challenged with murine hepatitis virus 1 (MHV-1), a coronavirus, at 5000 PFU intranasally, followed by Apta-1 intravenously administered (100 mg/kg, twice) 1.5 h or 2 days after viral delivery. Animals were sacrificed at Day 2 or Day 4. Lung tissues were examined with H&E, immunohistochemistry staining, and western blotting. RT-qPCR was used for cytokine gene expression. Serum and plasma were collected for laboratory assessments.

RESULTS

Apta-1 treatment reduced viral titers, prevented MHV-1-induced reduction of circulating blood volume and hemolysis, reduced alveolar space hemorrhage, and protease-activated receptor 1 (PAR-1) cleavage. Apta-1 treatment also significantly reduced chemokine (MKC, MCP-1, and RANTES) levels, as well as AST, ALT, total bilirubin, and reduced unconjugated bilirubin levels in the serum.

CONCLUSION

Apta-1 showed therapeutic benefits in coronaviral infection-induced hemorrhage and PAR-1 cleavage in the lung. It also has anti-inflammatory effects systemically.

FGF10 protects against LPS-induced epithelial barrier injury and inflammation by inhibiting SIRT1-ferroptosis pathway in acute lung injury in mice

Pulmonary alveolar epithelial cell injury is considered the main pathological and physiological change in acute lung injury. Ferroptosis in alveolar epithelial cells is one of crucial factors contributing to acute lung injury (ALI). Therefore, reducing ferroptosis and repair epithelial barrier is very necessary. More and more evidence suggested that FGF10 plays an important role in lung development and repair after injury. However, the relationship between FGF10 and ferroptosis remains unclear. This study aims to explore the regulatory role of FGF10 on ferroptosis in ALI. Differential gene expression analysis indicated that genes associated with ferroptosis showed that FGF10 can significantly alleviate LPS induced lung injury and epithelial barrier damage by decreasing levels of malonaldehyde(MDA), and lipid ROS. SIRT1 activator (Resveratrol) and inhibitor (EX527) are used in vivo showed that FGF10 protects ferroptosis of pulmonary epithelial cells through SIRT1 signal. Furthermore, knockdown of FGFR2 gene reduced the protective effect of FGF10 on acute lung injury in mice and SIRT1 activation. After the application of NRF2 inhibitor ML385 in vitro, the results showed that SIRT1 regulated the expression of ferroptosis related proteins NRF2, GPX4 and FTH1 are related to activation of NRF2. These data indicate that SIRT-ferroptosis was one of the critical mechanisms contributing to LPS-induced ALI. FGF10 is promising as a therapeutic candidate against ALI through inhibiting ferroptosis.

Efficacies of S-nitrosoglutathione (GSNO) and GSNO reductase inhibitor in SARS-CoV-2 spike protein induced acute lung disease in mice

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which initially surfaced in late 2019, often triggers severe pulmonary complications, encompassing various disease mechanisms such as intense lung inflammation, vascular dysfunction, and pulmonary embolism. Currently, however, there's no drug addressing all these mechanisms simultaneously. This study explored the multi-targeting potential of S-nitrosoglutathione (GSNO) and N6022, an inhibitor of GSNO reductase (GSNOR) on markers of inflammatory, vascular, and thrombotic diseases related to COVID-19-induced acute lung disease. For this, acute lung disease was induced in C57BL/6 mice through intranasal administration of recombinant SARS-CoV-2 spike protein S1 domain (SP-S1). The mice exhibited fever, body weight loss, and increased blood levels and lung expression of proinflammatory cytokines (e.g., TNF-α and IL-6) as well as increased vascular inflammation mediated by ICAM-1 and VCAM-1 and lung infiltration by immune cells (e.g., neutrophils, monocytes, and activated cytotoxic and helper T cells). Further, the mice exhibited increased lung hyperpermeability (lung Evans blue extravasation) leading to lung edema development as well as elevated blood coagulation factors (e.g., fibrinogen, thrombin, activated platelets, and von Willebrand factor) and lung fibrin deposition. Similar to the patients with COVID-19, male mice showed more severe disease than female mice, along with higher GSNOR expression in the lungs. Optimization of GSNO by treatment with exogenous GSNO or inhibition of GSNOR by N6022 (or GSNO knockout) protects against SP-S1-induced lung diseases in both genders. These findings provide evidence for the potential efficacies of GSNO and GSNOR inhibitors in addressing the multi-mechanistic nature of SARS-CoV-2 SP-associated acute-lung disease.

Interesting effects of interleukins and immune cells on acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a medical condition characterized by widespread inflammation in the lungs with consequent proportional loss of gas exchange function. ARDS is linked with severe pulmonary or systemic infection. Several factors, including secretory cytokines, immune cells, and lung epithelial and endothelial cells, play a role in the development and progression of this disease. The present study is based on Pubmed database information (1987-2022) using the words "Acute respiratory distress syndrome", "Interleukin", "Cytokines" and "Immune cells". Cytokines and immune cells play an important role in this disease, with particular emphasis on the balance between pro-inflammatory and anti-inflammatory factors. Neutrophils are one of several important mediators of Inflammation, lung tissue destruction, and malfunction during ARDS. Some immune cells, such as macrophages and eosinophils, play a dual role in releasing inflammatory mediators, recruitment inflammatory cells and the progression of ARDS, or releasing anti-inflammatory mediators, clearing the lung of inflammatory cells, and helping to improve the disease. Different interleukins play a role in the development or inhibition of ARDS by helping to activate various signaling pathways, helping to secrete other inflammatory or anti-inflammatory interleukins, and playing a role in the production and balance between immune cells involved in ARDS. As a result, immune cells and, inflammatory cytokines, especially interleukins play an important role in the pathogenesis of this disease Therefore, understanding the relevant mechanisms will help in the proper diagnosis and treatment of this disease.

Eicosanoids Signals in SARS-CoV-2 Infection: A Foe or Friend

SARS-CoV-2 mediated infection instigated a scary pandemic state since 2019. They created havoc comprising death, imbalanced social structures, and a wrecked global economy. During infection, the inflammation and associated cytokine storm generate a critical pathological situation in the human body, especially in the lungs. By the passage of time of infection, inflammatory disorders, and multiple organ damage happen which might lead to death, if not treated properly. Until now, many pathological parameters have been used to understand the progress of the severity of COVID-19 but with limited success. Bioactive lipid mediators have the potential of initiating and resolving inflammation in any disease. The connection between lipid storm and inflammatory states of SARS-CoV-2 infection has surfaced and got importance to understand and mitigate the pathological states of COVID-19. As the role of eicosanoids in COVID-19 infection is not well defined, available information regarding this issue has been accumulated to address the possible network of eicosanoids related to the initiation of inflammation, promotion of cytokine storm, and resolution of inflammation, and highlight possible strategies for treatment and drug discovery related to SARS-CoV-2 infection in this study. Understanding the involvement of eicosanoids in exploration of cellular events provoked by SARS-CoV-2 infection has been summarized as an important factor to deescalate any upcoming catastrophe imposed by the lethal variants of this micro-monster. Additionally, this study also recognized the eicosanoid based drug discovery, treatment, and strategies for managing the severity of SARS-COV-2 infection.

Integrated Analysis of Non-Coding RNA and mRNA Expression Profiles in Exosomes from Lung Tissue with Sepsis-Induced Acute Lung Injury

Background

Acute lung injury (ALI) is associated with a high mortality rate; however, the underlying molecular mechanisms are poorly understood. The purpose of this study was to investigate the expression profile and related networks of long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs in lung tissue exosomes obtained from sepsis-induced ALI.

Methods

A mouse model of sepsis was established using the cecal ligation and puncture method. RNA sequencing was performed using lung tissue exosomes obtained from mice in the sham and CLP groups. Hematoxylin-eosin staining, Western blotting, immunofluorescence, quantitative real-time polymerase chain reaction, and nanoparticle tracking analysis were performed to identify relevant phenotypes, and bioinformatic algorithms were used to evaluate competitive endogenous RNA (ceRNA) networks.

Results

Thirty lncRNA-miRNA-mRNA interactions were identified, including two upregulated lncRNAs, 30 upregulated miRNAs, and two downregulated miRNAs. Based on the expression levels of differentially expressed mRNAs(DEmRNAs), differentially expressed LncRNAs(DELncRNAs), and differentially expressed miRNAs(DEmiRNAs), 30 ceRNA networks were constructed.

Conclusion

Our study revealed, for the first time, the expression profiles of lncRNA, miRNA, and mRNA in exosomes isolated from the lungs of mice with sepsis-induced ALI, and the exosome co-expression network and ceRNA network related to ALI in sepsis.

n-3 Polyunsaturated Fatty Acids Modulate LPS-Induced ARDS and the Lung-Brain Axis of Communication in Wild-Type versus Fat-1 Mice Genetically Modified for Leukotriene B4 Receptor 1 or Chemerin Receptor 23 Knockout

Specialized pro-resolving mediators (SPMs) and especially Resolvin E1 (RvE1) can actively terminate inflammation and promote healing during lung diseases such as acute respiratory distress syndrome (ARDS). Although ARDS primarily affects the lung, many ARDS patients also develop neurocognitive impairments. To investigate the connection between the lung and brain during ARDS and the therapeutic potential of SPMs and its derivatives, fat-1 mice were crossbred with RvE1 receptor knockout mice. ARDS was induced in these mice by intratracheal application of lipopolysaccharide (LPS, 10 µg). Mice were sacrificed at 0 h, 4 h, 24 h, 72 h, and 120 h post inflammation, and effects on the lung, liver, and brain were assessed by RT-PCR, multiplex, immunohistochemistry, Western blot, and LC-MS/MS. Protein and mRNA analyses of the lung, liver, and hypothalamus revealed LPS-induced lung inflammation increased inflammatory signaling in the hypothalamus despite low signaling in the periphery. Neutrophil recruitment in different brain structures was determined by immunohistochemical staining. Overall, we showed that immune cell trafficking to the brain contributed to immune-to-brain communication during ARDS rather than cytokines. Deficiency in RvE1 receptors and enhanced omega-3 polyunsaturated fatty acid levels (fat-1 mice) affect lung-brain interaction during ARDS by altering profiles of several inflammatory and lipid mediators and glial activity markers.

Targeting cytokine storm as the potential anti-viral therapy: Implications in regulating SARS-CoV-2 pathogenicity

The latest global pandemic corona virus disease - 2019 (COVID-19) caused by the virus SARS-CoV-2 is still a matter of worrying concern both for the scientific communities and health care organizations. COVID-19 disease is proved to be a highly contagious disease transmitted through respiratory droplets and even close contact with affected individuals. COVID-19 disease is also understood to exhibit diverse symptoms of ranging severities i.e., from mild fatigue to death. Affected individuals' susceptibility to induce immunologic dysregulation phenomena termed 'cytokine storm' seems to be playing the damaging role of escalating the disease manifestation from mild to severe. Cytokine storm in patients with severe symptoms is understood to be characterized by enhanced serum levels of many cytokines including interleukin-1β, interleukin-6, IL-10, TNF, interferon-γ, MIP-1α, MIP-1β and VEGF. Since cytokine production in general is the most important antiviral defense response, understanding the COVID-19 associated cytokine storm in particular and differentiating it from the regular cytokine production response becomes crucial in developing an effective therapeutic strategy.This review focuses on the potential targeting of COVID-19 associated cytokine storm and its challenges.

Sex-Based Disparities in Leukocyte Migration and Activation in Response to Inhalation Lung Injury: Role of SDF-1/CXCR4 Signaling

The aim of the study was to determine whether sex-related differences exist in immune response to inhalation lung injury. C57BL/6 mice were exposed to Cl2 gas (500 ppm for 15, 20, or 30 min). Results showed that male mice have higher rates of mortality and lung injury than females. The binding of the chemokine ligand C-X-C motif chemokine 12 (CXCL12), also called stromal-derived-factor-1 (SDF-1), to the C-X-C chemokine receptor type 4 (CXCR4) on lung cells promotes the migration of leukocytes from circulation to lungs. Therefore, the hypothesis was that elevated SDF-1/CXCR4 signaling mediates exaggerated immune response in males. Plasma, blood leukocytes, and lung cells were collected from mice post-Cl2 exposure. Plasma levels of SDF-1 and peripheral levels of CXCR4 in lung cells were higher in male vs. female mice post-Cl2 exposure. Myeloperoxidase (MPO) and elastase activity was significantly increased in leukocytes of male mice exposed to Cl2. Lung cells were then ex vivo treated with SDF-1 (100 ng/mL) in the presence or absence of the CXCR4 inhibitor, AMD3100 (100 nM). SDF-1 significantly increased migration, MPO, and elastase activity in cells obtained from male vs. female mice post-Cl2 exposure. AMD3100 attenuated these effects, suggesting that differential SDF-1/CXCR4 signaling may be responsible for sex-based disparities in the immune response to inhalation lung injury.

Characterization of Chemotaxis-Associated Gene Dysregulation in Myeloid Cell Populations in the Lungs during Lipopolysaccharide-Mediated Acute Lung Injury

During endotoxin-induced acute lung injury (ALI), immune cell recruitment resulting from chemotaxis is mediated by CXC and CC chemokines and their receptors. In this study, we investigated the role of chemokines and their receptors in the regulation of myeloid cell populations in the circulation and the lungs of C57BL/6J mice exhibiting LPS-mediated ALI using single-cell RNA sequencing. During ALI, there was an increase in the myeloid cells, M1 macrophages, monocytes, neutrophils, and other granulocytes, whereas there was a decrease in the residential alveolar macrophages and M2 macrophages. Interestingly, LPS triggered the upregulation of CCL3, CCL4, CXCL2/3, and CXCL10 genes associated with cellular migration of various subsets of macrophages, neutrophils, and granulocytes. Furthermore, there was an increase in the frequency of myeloid cells expressing CCR1, CCR3, CCR5, and CXCR2 receptors during ALI. MicroRNA sequencing studies of vehicle versus LPS groups identified several dysregulated microRNAs targeting the upregulated chemokine genes. This study suggests that chemokine ligand-receptors interactions are responsible for myeloid cell heterogenicity and cellular recruitment to the lungs during ALI. The single-cell transcriptomics allowed for an in-depth assessment and characterization of myeloid cells involved in immune cell trafficking during ALI.

The inflammatory profiles of pulmonary alveolar macrophages and alveolar type 2 cells in SCD

The lung microenvironment plays a crucial role in maintaining lung homeostasis as well as the initiation and resolution of both acute and chronic lung injury. Acute chest syndrome (ACS) is a complication of sickle cell disease (SCD) like acute lung injury. Both the endothelial cells and peripheral blood mononuclear cells are known to secrete proinflammatory cytokines elevated during ACS episodes. However, in SCD, the lung microenvironment that may favor excessive production of proinflammatory cytokines and the contribution of other lung resident cells, such as alveolar macrophages and alveolar type 2 epithelial (AT-2) cells, to ACS pathogenesis is not completely understood. Here, we sought to understand the pulmonary microenvironment and the proinflammatory profile of lung alveolar macrophages (LAMs) and AT-2 cells at steady state in Townes sickle cell (SS) mice compared to control mice (AA). In addition, we examined lung function and micromechanics molecules essential for pulmonary epithelial barrier function in these mice. Our results showed that bronchoalveolar lavage (BAL) fluid in SS mice had elevated protein levels of pro-inflammatory cytokines interleukin (IL)-1β and IL-12 (p ⩽ 0.05) compared to AA controls. We showed for the first time, significantly increased protein levels of inflammatory mediators (Human antigen R (HuR), Toll-like receptor 4 (TLR4), MyD88, and PU.1) in AT-2 cells (1.4 to 2.2-fold) and LAM (17-21%) isolated from SS mice compared to AA control mice at steady state. There were also low levels of anti-inflammatory transcription factors (Nrf2 and PPARy) in SS mice compared to AA controls (p ⩽ 0.05). Finally, we found impaired lung function and a dysregulated composition of surfactant proteins (B and C). Our results demonstrate that SS mice at steady state had a compromised lung microenvironment with elevated expression of proinflammatory cytokines by AT-2 cells and LAM, as well as dysregulated expression of surfactant proteins necessary for maintaining the alveolar barrier integrity and lung function.

Ventilator-induced Lung Injury Is Modulated by the Circadian Clock

Rationale: Mechanical ventilation (MV) is life-saving but may evoke ventilator-induced lung injury (VILI). Objectives: To explore how the circadian clock modulates severity of murine VILI via the core clock component BMAL1 (basic helix-loop-helix ARNT like 1) in myeloid cells. Methods: Myeloid cell BMAL1-deficient (LysM (lysozyme 2 promoter/enhancer driving cre recombinase expression)Bmal1-/-) or wild-type control (LysMBmal1+/+) mice were subjected to 4 hours MV (34 ml/kg body weight) to induce lung injury. Ventilation was initiated at dawn or dusk or in complete darkness (circadian time [CT] 0 or CT12) to determine diurnal and circadian effects. Lung injury was quantified by lung function, pulmonary permeability, blood gas analysis, neutrophil recruitment, inflammatory markers, and histology. Neutrophil activation and oxidative burst were analyzed ex vivo. Measurements and Main Results: In diurnal experiments, mice ventilated at dawn exhibited higher permeability and neutrophil recruitment compared with dusk. Experiments at CT showed deterioration of pulmonary function, worsening of oxygenation, and increased mortality at CT0 compared with CT12. Wild-type neutrophils isolated at dawn showed higher activation and reactive oxygen species production compared with dusk, whereas these day-night differences were dampened in LysMBmal1-/- neutrophils. In LysMBmal1-/- mice, circadian variations in VILI severity were dampened and VILI-induced mortality at CT0 was reduced compared with LysMBmal1+/+ mice. Conclusions: Inflammatory response and lung barrier dysfunction upon MV exhibit diurnal variations, regulated by the circadian clock. LysMBmal1-/- mice are less susceptible to ventilation-induced pathology and lack circadian variation of severity compared with LysMBmal1+/+ mice. Our data suggest that the internal clock in myeloid cells is an important modulator of VILI.

Dynamic changes in radiological parameters, immune cells, selected miRNAs, and cytokine levels in peripheral blood of patients with severe COVID‑19

The present study aimed to investigate the dynamic changes in peripheral blood leucocyte subpopulations, cytokine and miRNA levels, and changes in computed tomography (CT) scores in patients with severe coronavirus disease 2019 (COVID-19) (n=14) and age-matched non-COVID-19 volunteers (n=17), which were included as a reference control group. All data were collected on the day of patient admission (day 0) and on the 7th, 14th and 28th days of follow-up while CT of the lungs was performed on weeks 2, 8, 24 and 48. On day 0, lymphopenia and leucopenia were detected in most patients with COVID-19, as well as an increase in the percentage of banded neutrophils, B cells, and CD4+ Treg cells, and a decrease in the content of PD-1low T cells, classical, plasmacytoid, and regulatory dendritic cells. On day 7, the percentage of T and natural killer cells decreased with a concurrent increase in B cells, but returned to the initial level after treatment discharge. The content of different T and dendritic cell subsets among CD45+ cells increased during two weeks and remained elevated, suggesting the activation of an adaptive immune response. The increase of PD-1-positive subpopulations of T and non-T cells and regulatory CD4 T cells in patients with COVID-19 during the observation period suggests the development of an inflammation control mechanism. The levels of interferon γ-induced protein 10 (IP-10), tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 decreased on day 7, but increased again on days 14 and 28. C-reactive protein and granulocyte colony-stimulating factor (G-CSF) levels decreased gradually throughout the observation period. The relative expression levels of microRNA (miR)-21-5p, miR-221-3p, miR-27a-3p, miR-146a-5p, miR-133a-3p, and miR-126-3p were significantly higher at the beginning of hospitalization compared to non-COVID-19 volunteers. The plasma levels of all miRs, except for miR-126-3p, normalized within one week of treatment. At week 48, CT scores were most prominently correlated with the content of lymphocytes, senescent memory T cells, CD127+ T cells and CD57+ T cells, and increased concentrations of G-CSF, IP-10, and macrophage inflammatory protein-1α.

Dulaglutide provides protection against sepsis-induced lung injury in mice by inhibiting inflammation and apoptosis

Sepsis is a dangerous condition with a high mortality rate. In addition to promoting insulin secretion in a glucose-dependent manner, glucagon-like peptide-1 (GLP-1) also exhibits anti-inflammatory properties. Dulaglutide is a glucagon-like peptide-1 receptor agonist (GLP-1 RA). In this study, we investigated the effects and mechanism of action of dulaglutide (Dul) in lipopolysaccharide (LPS) induced lung injury in mice with sepsis. In mice with LPS (15 mg/kg, ip, qd)-induced acute lung injury, the administration of dulaglutide (0.6 mg/kg, ip, qd) improved weight loss, reduced lung injury, reversed the increase in IL-1β, TNF-α, IL-6, CXCL1, CCL2 and CXCL2 expression in the lung, and reduced the infiltration of neutrophils and macrophages in the lung tissues. The decline in caspase-3, cleaved caspase-3, caspase-8, and Bcl-2/Bax expression and the increase in the number of TUNEL positive cells in the lung were reversed, suggesting that GLP-1RA could play a protective role in the lung by inhibiting inflammation and apoptosis. In addition, GLP-1RA could reduce the expression of P-STAT3 and NLRP3, suggesting that P-STAT3 and NLRP3 may be potential targets against lung injury in sepsis. Collectively, our data demonstrated that GLP-1RA exerts a protective effect against sepsis-induced lung injury through mechanisms related to the inhibition of inflammation, apoptosis, and STAT3 signaling.

Efficacy of CU06-1004 via regulation of inflammation and endothelial permeability in LPS-induced acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening condition that fundamentally results from inflammation and edema in the lung. There are no effective treatments available for clinical use. Previously, we found that as a leakage blocker CU06-1004 prevents endothelial barrier disruption and enhances endothelial cell survival under inflammatory conditions. In this study, we aimed to elucidate the effect of CU06-1004 in terms of prevention of inflammation and endothelial dysfunction in an ALI mouse model.

METHODS

An ALI model was established that included intraperitoneal administration of LPS. Following LPS administration, survival rates and lung wet/dry ratios were assessed. Histological analysis was performed using hematoxylin and eosin staining. Scanning electron microscopy was used to examine alveolar and capillary morphology. Cytokines such as IL-1β, IL-6, and TNF-α were analyzed using an ELISA assay of bronchoalveolar lavage fluid (BALF) and serum. Neutrophil infiltration was observed in BALF using Wright-Giemsa staining, and myeloperoxidase (MPO) activity was assessed. Pulmonary vascular leakage was confirmed using Evans-blue dye, and the expression of junctional proteins was evaluated using immunofluorescent staining. Expression of adhesion molecules was observed using immunofluorescence staining. NF-κB activation was determined using immunohistochemistry and western blot analysis.

RESULTS

Survival rates and pulmonary edema were ameliorated with CU06-1004 treatment. Administration of CU06-1004 normalized histopathological changes induced by LPS, and alveolar-capillary wall thickening was reduced. Compared with the LPS-challenged group, after CU06-1004 treatment, the infiltration of immune cells was decreased in the BALF, and MPO activity in lung tissue was reduced. Similarly, in the CU06-1004 treatment group, pro-inflammatory cytokines were significantly inhibited in both BALF and serum. Evans-blue leakage was reduced, and the expression of junctional proteins was recovered in the CU06-1004 group. Adhesion molecules were downregulated and NF-κB activation was inhibited after CU06-1004 treatment.

CONCLUSIONS

These results suggested that CU06-1004 had a therapeutic effect against LPS-induced ALI via alleviation of the inflammatory response and protection of vascular integrity.

Release of extracellular superoxide dismutase into alveolar fluid protects against acute lung injury and inflammation in Staphylococcus aureus pneumonia

Acute respiratory distress syndrome (ARDS) remains a significant cause of morbidity and mortality in critically ill patients. Oxidative stress and inflammation play a crucial role in the pathogenesis of ARDS. Extracellular superoxide dismutase (EC-SOD) is abundant in the lung and is an important enzymatic defense against superoxide. Human single-nucleotide polymorphism in matrix binding region of EC-SOD leads to the substitution of arginine to glycine at position 213 (R213G) and results in release of EC-SOD into alveolar fluid, without affecting enzyme activity. We hypothesized that R213G EC-SOD variant protects against lung injury and inflammation via the blockade of neutrophil recruitment in infectious model of methicillin-resistant S. aureus (MRSA) pneumonia. After inoculation with MRSA, wild-type (WT) mice had impaired integrity of alveolar-capillary barrier and increased levels of IL-1β, IL-6, and TNF-α in the broncho-alveolar lavage fluid (BALF), while infected mice expressing R213G EC-SOD variant maintained the integrity of alveolar-capillary interface and had attenuated levels of proinflammatory cytokines. MRSA-infected mice expressing R213G EC-SOD variant also had attenuated neutrophil numbers in BALF and decreased expression of neutrophil chemoattractant CXCL1 by the alveolar epithelial ATII cells, compared with the infected WT group. The decreased neutrophil numbers in R213G mice were not due to increased rate of apoptosis. Mice expressing R213G variant had a differential effect on neutrophil functionality-the generation of neutrophil extracellular traps (NETs) but not myeloperoxidase (MPO) levels were attenuated in comparison with WT controls. Despite having the same bacterial load in the lung as WT controls, mice expressing R213G EC-SOD variant were protected from extrapulmonary dissemination of bacteria.

Exosomal Non-Coding RNAs: Novel Regulators of Macrophage-Linked Intercellular Communication in Lung Cancer and Inflammatory Lung Diseases

Macrophages are innate immune cells and often classified as M1 macrophages (pro-inflammatory states) and M2 macrophages (anti-inflammatory states). Exosomes are cell-derived nanovesicles that range in diameter from 30 to 150 nm. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), are abundant in exosomes and exosomal ncRNAs influence immune responses. Exosomal ncRNAs control macrophage-linked intercellular communication via their targets or signaling pathways, which can play positive or negative roles in lung cancer and inflammatory lung disorders, including acute lung injury (ALI), asthma, and pulmonary fibrosis. In lung cancer, exosomal ncRNAs mediated intercellular communication between lung tumor cells and tumor-associated macrophages (TAMs), coordinating cancer proliferation, migration, invasion, metastasis, immune evasion, and therapy resistance. In inflammatory lung illnesses, exosomal ncRNAs mediate macrophage activation and inflammation to promote or inhibit lung damage. Furthermore, we also discussed the possible applications of exosomal ncRNA-based therapies for lung disorders.

Aerosolized nicotine from e-cigarettes alters gene expression, increases lung protein permeability, and impairs viral clearance in murine influenza infection

E-cigarette use has rapidly increased as an alternative means of nicotine delivery by heated aerosolization. Recent studies demonstrate nicotine-containing e-cigarette aerosols can have immunosuppressive and pro-inflammatory effects, but it remains unclear how e-cigarettes and the constituents of e-liquids may impact acute lung injury and the development of acute respiratory distress syndrome caused by viral pneumonia. Therefore, in these studies, mice were exposed one hour per day over nine consecutive days to aerosol generated by the clinically-relevant tank-style Aspire Nautilus aerosolizing e-liquid containing a mixture of vegetable glycerin and propylene glycol (VG/PG) with or without nicotine. Exposure to the nicotine-containing aerosol resulted in clinically-relevant levels of plasma cotinine, a nicotine-derived metabolite, and an increase in the pro-inflammatory cytokines IL-17A, CXCL1, and MCP-1 in the distal airspaces. Following the e-cigarette exposure, mice were intranasally inoculated with influenza A virus (H1N1 PR8 strain). Exposure to aerosols generated from VG/PG with and without nicotine caused greater influenza-induced production in the distal airspaces of the pro-inflammatory cytokines IFN-γ, TNFα, IL-1β, IL-6, IL-17A, and MCP-1 at 7 days post inoculation (dpi). Compared to the aerosolized carrier VG/PG, in mice exposed to aerosolized nicotine there was a significantly lower amount of Mucin 5 subtype AC (MUC5AC) in the distal airspaces and significantly higher lung permeability to protein and viral load in lungs at 7 dpi with influenza. Additionally, nicotine caused relative downregulation of genes associated with ciliary function and fluid clearance and an increased expression of pro-inflammatory pathways at 7 dpi. These results show that (1) the e-liquid carrier VG/PG increases the pro-inflammatory immune responses to viral pneumonia and that (2) nicotine in an e-cigarette aerosol alters the transcriptomic response to pathogens, blunts host defense mechanisms, increases lung barrier permeability, and reduces viral clearance during influenza infection. In conclusion, acute exposure to aerosolized nicotine can impair clearance of viral infection and exacerbate lung injury, findings that have implications for the regulation of e-cigarette products.

Fingolimod attenuates ovalbumin-induced airway inflammation via inhibiting MAPK/ERK signaling in mice

The current study was designed to investigate the potential anti-inflammatory and antioxidant effects of fingolimod against Ovalbumin (Ova)-induced allergic airway inflammation compared to dexamethasone. Fingolimod was given (0.5 mg/kg/day, p.o.) for sensitized mice 1 h before Ova challenge from Days 19 to 24. Fingolimod significantly inhibited Ova-induced elevation of inflammatory cells and eosinophils numbers in bronchoalveolar lavage fluid (BALF) and reduced concentrations of immunoglobulin E in serum and of sphingosine-1-phosphate, interleukin (IL)-4, and IL-13 in BALF. Fingolimod inhibited microvascular leakage and edema as reflected by the decreased lung/body weight index. These findings were supported by histopathological examination results showing that fingolimod substantially decreased perivascular edema and inflammatory cell infiltration. Fingolimod also attenuated Ova-induced oxidative stress as evidenced by decreased malondialdehyde concentration along with increasing concentrations of reduced glutathione and superoxide dismutase in lung tissues. Fingolimod also significantly decreased monocyte chemoattractant protein-1 (MCP-1), p-ERK, and p-P38 in lung tissues of Ova-challenged mice. In conclusion, the current study demonstrated the anti-inflammatory and antioxidant effects of fingolimod in allergic airway inflammation that might be associated with the downregulation of mitogen activated kinases signaling to decrease T helper 2 cytokine secretion (IL-4 and IL-13) and MCP-1 expression, along with the inhibition of oxidative stress.

Serum cytokine levels and other associated factors as possible immunotherapeutic targets and prognostic indicators for lung cancer

Lung cancer is one of the most prevalent cancer types and the leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for 80-85% of all cancer incidences. Lung cancer therapy and prognosis largely depend on the disease's degree at the diagnosis time. Cytokines are soluble polypeptides that contribute to cell-to-cell communication, acting paracrine or autocrine on neighboring or distant cells. Cytokines are essential for developing neoplastic growth, but they are also known to operate as biological inducers following cancer therapy. Early indications are that inflammatory cytokines such as IL-6 and IL-8 play a predictive role in lung cancer. Nevertheless, the biological significance of cytokine levels in lung cancer has not yet been investigated. This review aimed to assess the existing literature on serum cytokine levels and additional factors as potential immunotherapeutic targets and lung cancer prognostic indicators. Changes in serum cytokine levels have been identified as immunological biomarkers for lung cancer and predict the effectiveness of targeted immunotherapy.

Cationic phosphorus dendron nanomicelles deliver microRNA mimics and microRNA inhibitors for enhanced anti-inflammatory therapy of acute lung injury

The development of efficient nanomedicines to repress the repolarization of M1 phenotype macrophages and therefore inhibit pro-inflammatory cytokine overexpression for anti-inflammatory therapy is still a challenging task. We report here an original gene delivery nanoplatform based on pyrrolidinium-modified amphiphilic generation 1 phosphorus dendron (C12G1) nanomicelles with a rigid phosphorous dendron structure. The nanomicelles display higher gene delivery efficiency than the counterpart materials of pyrrolidinium-modified G1 phosphorus dendrimers, and meanwhile exhibit excellent cytocompatibility. The C12G1 nanomicelles can be employed to co-deliver the miRNA-146a mimic (miR-146a mimic) and miRNA-429 inhibitor (miR-429i) to inhibit the Toll-like receptor-4 signaling pathway and p38 mitogen-activated protein kinase signaling pathway, respectively, thus causing repression of M1 phenotype alveolar macrophage polarization. The developed C12G1/miR-mixture polyplexes enable efficient therapy of lipopolysaccharide-activated alveolar macrophages in vitro and an acute lung injury mouse model in vivo. The generated cationic phosphorus dendron nanomicelles may hold promising potential for anti-inflammatory gene therapy of other inflammatory diseases.

JAK-STAT signaling as an ARDS therapeutic target: Status and future trends

Acute respiratory distress syndrome (ARDS) is characterized by noncardiogenic pulmonary edema. It has a high mortality rate and lacks effective pharmacotherapy. With the outbreak of COVID-19 worldwide, the mortality of ARDS has increased correspondingly, which makes it urgent to find effective targets and strategies for the treatment of ARDS. Recent clinical trials of Janus kinase (JAK) inhibitors in treating COVID-19-induced ARDS have shown a positive outcome, which makes the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway a potential therapeutic target for treating ARDS. Here, we review the complex cause of ARDS, the molecular JAK/STAT pathway involved in ARDS pathology, and the progress that has been made in strategies targeting JAK/STAT to treat ARDS. Specifically, JAK/STAT signaling directly participates in the progression of ARDS or colludes with other pathways to aggravate ARDS. We summarize JAK and STAT inhibitors with ARDS treatment benefits, including inhibitors in clinical trials and preclinical studies and natural products, and discuss the side effects of the current JAK inhibitors to reveal future trends in the design of JAK inhibitors, which will help to develop effective treatment strategies for ARDS in the future.

An In Vitro Model for Assessing Acute Lung Injury During Pancreatitis Development Using Primary Mouse Cell Co-cultures

Acute pancreatitis is a serious inflammatory disease of the pancreas that can lead to lung injury. Despite extensive research, the mechanisms underlying this complication are ill-defined. In recent years, in vitro co-culture systems have emerged as powerful tools for studying complex interactions between different cell types in disease. In the context of pancreatitis, pancreatic acinar epithelial cells produce and secrete digestive enzymes, and their cellular damage, death, and/or dysfunction is a major contributing factor to the onset of pancreatitis. Here, in this chapter we describe a co-culture system of acinar cells and lung epithelial progenitor/stem cells to model for lung injury associated with pancreatitis.

Blocking RAGE expression after injury reduces inflammation in mouse model of acute lung injury

BACKGROUND

Receptor for Advanced Glycated Endproducts (RAGE) plays a major role in the inflammatory response to infectious and toxin induced acute lung injury. We tested the hypothesis that a RAGE blocking antibody when administered after the onset of injury can reduce lung inflammation compared to control antibody.

METHODS

Male and female C57BL/6 (WT) mice were used. Forty-six received lipopolysaccharide (LPS) and 26 PBS by nasal instillation on day one, repeated on day three. On day 2, 36 mice receiving LPS were divided into two groups of 18, one treated with 200 μg of non-immune isotype control IgG and the second group treated with 200 μg of anti-RAGE Ab, each dose divided between IV and IP. Ten of the 46 were not treated. On day 4, before euthanasia, mice were injected with fluorescein isothiocyanate (FITC) labelled albumen. BALF and serum samples were collected as well as lung tissue for immunohistochemistry (IHC). BALF was analyzed for cell (leukocyte) counts, for FITC BALF/serum ratios indicating pulmonary vascular leak, and for cytokines/chemokines using bead based multiplex assays. Quantitative IHC was performed for MPO and RAGE.

RESULTS

Ten LPS mice showed minimal inflammation by all measures indicating poor delivery of LPS and were excluded from analysis leaving n = 11 in the LPS + IgG group and n = 12 in the LPS + anti-RAGE group. BALF cell counts were low in the PBS administered mice (4.9 ± 2.1 × 10⁵/ml) and high in the LPS injured untreated mice (109 ± 34) and in the LPS + IgG mice (91 ± 54) while in comparison, LPS + anti-RAGE ab mice counts were significantly lower (51.3 ± 18 vs. LPS + IgG, P = 0.03). The BALF/serum FITC ratios were lower for the LPS + anti-RAGE mice than for the LPS + IgG mice indicating less capillary leakiness. Quantitative IHC RAGE staining was lower in the LPS + anti-RAGE ab mice than in the LPS + IgG treated mice (P = 0.02).

CONCLUSIONS

These results describe a four-day LPS protocol to sustain lung injury and allow for treatment and suggests that treatment aimed at blocking RAGE when given after onset of injury can reduce lung inflammation.

Time-Dependent Oxidative Alterations in Plasma and Lung Tissue after Meconium Aspiration in a Rabbit Model

Aspirated meconium into a newborn's airways induces the transcription of pro-oxidative mediators that cooperate in the pathogenesis of inflammatory changes and may negatively affect the commonly used exogenous surfactant therapy. However, inflammation is not treated at present, nor is the time dependence of oxidative damage known. The aim of our study was to describe the time course of oxidative stress marker production during meconium aspiration syndrome (MAS) and its relationship to leukocyte infiltration. New Zealand rabbits were instilled with saline or meconium suspension and ventilated for 5.5 h. Respiratory parameters were recorded and blood samples were taken before meconium application and in time intervals of 15 and 30 min, 1.0, 1.5, 3.5 and 5.5 h after application to evaluate oxidative markers and differential leukocytes count. Meconium aspiration led to a worsening of respiratory parameters and a decrease in leukocytes in the first 15 min. Changes in leukocytes were correlated both with nitrotyrosine (3NT) levels and thiobarbituric acid reactive substance (TBARS) levels, with the latter also related to changes in neutrophil count. The production of 3NT and TBARS increased in 1.5 and 3.5 h, respectively, in different ways, suggesting more than one source of oxidative agents and a potential risk of exogenous surfactant inactivation in a short time. We observed that MAS triggered neutrophil migration to the alveolar space and activation, as shown by the increased expression of pro-inflammatory cytokines and generation of indicators of oxidative damage to proteins and lipids during the time period when iNOS and NO metabolites were released.

Metabolomics coupled with network pharmacology study on the protective effect of Keguan-1 granules in LPS-induced acute lung injury

CONTEXT

Keguan-1 (KG-1) plays a vital role in enhancing the curative effects, improving quality of life, and reducing the development of acute lung injury (ALI).

OBJECTIVE

To unravel the protective effect and underlying mechanism of KG-1 against ALI.

MATERIALS AND METHODS

C57BL/6J mice were intratracheally instilled with lipopolysaccharide to establish the ALI model. Then, mice in the KG-1 group received a dose of 5.04 g/kg for 12 h. The levels of proinflammatory cytokines, chemokines, and pathological characteristics were determined to explore the effects of KG-1. Next, untargeted metabolomics was used to identify the differential metabolites and involved pathways for KG-1 anti-ALI. Network pharmacology was carried out to predict the putative active components and drug targets of KG-1 anti-ALI.

RESULTS

KG-1 significantly improved the levels of TNF-α (from 2295.92 ± 529.87 pg/mL to 1167.64 ± 318.91 pg/mL), IL-6 (from 4688.80 ± 481.68 pg/mL to 3604.43 ± 382.00 pg/mL), CXCL1 (from 4361.76 ± 505.73 pg/mL to 2981.04 ± 526.18 pg/mL), CXCL2 (from 5034.09 ± 809.28 pg/mL to 2980.30 ± 747.63 pg/mL), and impaired lung histological damage. Untargeted metabolomics revealed that KG-1 significantly regulated 12 different metabolites, which mainly related to lipid, amino acid, and vitamin metabolism. Network pharmacology showed that KG-1 exhibited anti-ALI effects through 17 potentially active components acting on seven putative drug targets to regulate four metabolites.

DISCUSSION AND CONCLUSIONS

This work elucidated the therapeutic effect and underlying mechanism by which KG-1 protects against ALI from the view of the metabolome, thus providing a scientific basis for the usage of KG-1.

MMP-9/BDNF ratio predicts more severe COVID-19 outcomes

COVID-19 clinically manifests from asymptomatic to the critical range. Immune response provokes the pro-inflammatory interactions, which lead to the cytokines, reactive oxygen/nitrogen species, peptidases, and arachidonic acid metabolites enlargement and activation of coagulation components. Matrix metalloproteinases (MMPs) contribute to tissue destruction in the development of COVID-19. Due to the endothelial, systemic course of the disease, VEGF A participates actively in COVID-19 development, while neurotrophic and metabolic effects of BDNF recommends for the prediction of complications in COVID-19 patients. Searching for a marker that would improve and simplify the ranking in COVID-19, the study intended to evaluate the relationship of MMP-9 with VEGF A, BDNF, and MMP-8 with the COVID-19 severity. Upon admission to the hospital and before the therapy administration, 77 patients were classified into a mild, moderate, severe, or critical group. Due to the inflammatory stage in COVID-19, a comparison between groups showed related differences in leukocytes, neutrophils, lymphocytes, and platelets counts as anticipated. Only in seriously ill patients, there is a significant increase in the serum concentration of MMP-9, MMP-8, and VEGF A, while BDNF values did not show significant variations between groups. However, all those parameters positively correlated with each other. The ratio of MMP-9/BDNF markedly decreased in the severe and critically patients compared to the mild group. Testing the capability of this ratio to predict the COVID-19 stage by ROC curves, we found the MMP-9/BDNF could be a suitable marker for differentiating stages I/II (AUC 0.7597), stage I/III (AUC 0.9011), and stage I/IV (AUC 0.7727). Presented data describe for the first time the high-level systemic MMP-9/BDNF ratio in patients with COVID-19. This parameter could contribute to a more precise determination of the phase of the disease.

Natriuretic peptide receptor-C mediates the inhibitory effect of atrial natriuretic peptide on neutrophil recruitment to the lung during acute lung injury

Atrial natriuretic peptide (ANP) protects against acute lung injury (ALI), but the receptor that mediates this effect is not known. Transgenic mice with 0 (knockout), 1 (heterozygote), or 2 (wild-type) functional copies of Npr3, the gene that encodes for natriuretic peptide receptor-C (NPR-C), were treated with intravenous infusion of ANP or saline vehicle before oropharyngeal aspiration of Pseudomonas aeruginosa (PA103) or saline vehicle. Lung injury was assessed 4 h following aspiration by measurement of lung wet/dry (W/D) weight, whole lung leukocyte and cytokine levels, and protein, leukocyte, and cytokine concentration in bronchoalveolar lavage fluid (BALF). PA103 induced acute lung injury as evidenced by increases in lung W/D ratio and protein concentration in BALF. The severity of PA103-induced lung injury did not differ between NPR-C genotypes. Treatment with intravenous ANP infusion reduced PA103-induced increases in lung W/D and BALF protein concentration in all three NPRC genotypes. PA103 increased the percentage of leukocytes that were neutrophils and cytokine levels in whole lung and BALF in NPR-C wild-type and knockout mice. This effect was blunted by ANP in wild-type mice but not in the NPR-C knockout mice. NPR-C does not mediate the protective effect of ANP on endothelial cell permeability in settings of PA103-induced injury but may mediate the effect of ANP on inhibition of the recruitment of neutrophils to the lung and thereby attenuate the release of inflammatory cytokines.

Effect of cardiac output - guided hemodynamic management on acute lung injury in pediatric living donor liver transplantation

BACKGROUND

Acute lung injury (ALI) after liver transplantation (LT) may lead to acute respiratory distress syndrome, which is associated with adverse postoperative outcomes, such as prolonged hospital stay, high morbidity, and mortality. Therefore, it is vital to maintain hemodynamic stability and optimize fluid management. However, few studies have reported cardiac output-guided (CO-G) management in pediatric LT.

AIM

To investigate the effect of CO-G hemodynamic management on early postoperative ALI and hemodynamic stability during pediatric living donor LT.

METHODS

A total of 130 pediatric patients scheduled for elective living donor LT were enrolled as study participants and were assigned to the control group (65 cases) and CO-G group (65 cases). In the CO-G group, CO was considered the target for hemodynamic management. In the control group, hemodynamic management was based on usual perioperative care guided by central venous pressure, continuous invasive arterial pressure, urinary volume, etc. The primary outcome was early postoperative ALI. Secondary outcomes included other early postoperative pulmonary complications, readmission to the intense care unit (ICU) for pulmonary complications, ICU stay, hospital stay, and in-hospital mortality.

RESULTS

The incidence of early postoperative ALI was 27.7% in the CO-G group, which was significantly lower than that in the control group (44.6%) (P < 0.05). During the surgery, the incidence of postreperfusion syndrome was lower in the CO-G group (P < 0.05). The level of intraoperative positive fluid transfusions was lower and the rate of dobutamine use before portal vein opening was higher, while the usage and dosage of epinephrine during portal vein opening and vasoactive inotropic score after portal vein opening were lower in the CO-G group (P < 0.05). Compared to the control group, serum inflammatory factors (interleukin-6 and tumor necrosis factor-α), cardiac troponin I, and N-terminal pro-brain natriuretic peptide were lower in the CO-G group after the operation (P < 0.05).

CONCLUSION

CO-G hemodynamic management in pediatric living-donor LT decreases the incidence of early postoperative ALI due to hemodynamic stability through optimized fluid management and appropriate administration of vasopressors and inotropes.

CXC Chemokines in the Pathogenesis of Pulmonary Disease and Pharmacological Relevance

Chemokines and their receptors play important roles in the pathophysiology of many diseases by regulating the cellular migration of major inflammatory and immune players. The CXC motif chemokine subfamily is the second largest family, and it is further subdivided into ELR motif CXC (ELR+) and non-ELR motif (ELR-) CXC chemokines, which are effective chemoattractants for neutrophils and lymphocytes/monocytes, respectively. These chemokines and their receptors are expected to have a significant impact on a wide range of lung diseases, many of which have inflammatory or immunological underpinnings. As a result, manipulations of this subfamily of chemokines and their receptors using small molecular agents and other means have been explored for potential therapeutic benefit in the setting of several lung pathologies. Furthermore, encouraging preclinical data has necessitated the progression of a few of these drugs into clinical trials in order to make the most effective use of interventions in the development of viable targeted therapeutics. The current review presents the understanding of the roles of CXC ligands (CXCLs) and their cognate receptors (CXCRs) in the pathogenesis of several lung diseases such as allergic rhinitis, COPD, lung fibrosis, lung cancer, pneumonia, and tuberculosis. The potential therapeutic benefits of pharmacological or other CXCL/CXCR axis manipulations are also discussed.

Focus on long non-coding RNA MALAT1: Insights into acute and chronic lung diseases

Acute lung injury (ALI) is a pulmonary illness with a high burden of morbidity and mortality around the world. Chronic lung diseases also represent life-threatening situations. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a type of long non-coding RNA (lncRNA) and is highly abundant in lung tissues. MALAT1 can function as a competitive endogenous RNA (ceRNA) to impair the microRNA (miRNA) inhibition on targeted messenger RNAs (mRNAs). In this review, we summarized that MALAT1 mainly participates in pulmonary cell biology and lung inflammation. Therefore, MALAT1 can positively or negatively regulate ALI and chronic lung diseases (e.g., chronic obstructive pulmonary disease (COPD), bronchopulmonary dysplasia (BPD), pulmonary fibrosis, asthma, and pulmonary hypertension (PH)). Besides, we also found a MALAT1-miRNA-mRNA ceRNA regulatory network in acute and chronic lung diseases. Through this review, we hope to cast light on the regulatory mechanisms of MALAT1 in ALI and chronic lung disease and provide a promising approach for lung disease treatment.

Renalase Challenges the Oxidative Stress and Fibroproliferative Response in COVID-19

The hallmark of the coronavirus disease 2019 (COVID-19) pathophysiology was reported to be an inappropriate and uncontrolled immune response, evidenced by activated macrophages, and a robust surge of proinflammatory cytokines, followed by the release of reactive oxygen species, that synergistically result in acute respiratory distress syndrome, fibroproliferative lung response, and possibly even death. For these reasons, all identified risk factors and pathophysiological processes of COVID-19, which are feasible for the prevention and treatment, should be addressed in a timely manner. Accordingly, the evolving anti-inflammatory and antifibrotic therapy for severe COVID-19 and hindering post-COVID-19 fibrosis development should be comprehensively investigated. Experimental evidence indicates that renalase, a novel amino-oxidase, derived from the kidneys, exhibits remarkable organ protection, robustly addressing the most powerful pathways of cell trauma: inflammation and oxidative stress, necrosis, and apoptosis. As demonstrated, systemic renalase administration also significantly alleviates experimentally induced organ fibrosis and prevents adverse remodeling. The recognition that renalase exerts cytoprotection via sirtuins activation, by raising their NAD⁺ levels, provides a “proof of principle” for renalase being a biologically impressive molecule that favors cell protection and survival and maybe involved in the pathogenesis of COVID-19. This premise supports the rationale that renalase's timely supplementation may prove valuable for pathologic conditions, such as cytokine storm and related acute respiratory distress syndrome. Therefore, the aim for this review is to acknowledge the scientific rationale for renalase employment in the experimental model of COVID-19, targeting the acute phase mechanisms and halting fibrosis progression, based on its proposed molecular pathways. Novel therapies for COVID-19 seek to exploit renalase's multiple and distinctive cytoprotective mechanisms; therefore, this review should be acknowledged as the thorough groundwork for subsequent research of renalase's employment in the experimental models of COVID-19.

Oral Sabizabulin for High-Risk, Hospitalized Adults with Covid-19: Interim Analysis

BACKGROUND: Sabizabulin is an oral, novel microtubule disruptor that has dual antiviral and anti-inflammatory activities in preclinical models. METHODS: A randomized, multicenter placebo-controlled phase 3 clinical trial was conducted with hospitalized patients with moderate to severe Covid-19 who were at high risk for acute respiratory distress syndrome (ARDS) and death. Patients were randomly assigned (2:1) to 9 mg of oral sabizabulin or placebo daily (up to 21 days). The primary end point was all-cause mortality up to day 60. Key secondary end points were days in the intensive care unit (ICU), days on mechanical ventilation, and days in the hospital. RESULTS: A total of 204 patients were randomly assigned to treatment: 134 to sabizabulin and 70 to placebo. Baseline characteristics were similar. Sabizabulin superiority was demonstrated by a planned interim analysis for the first 150 randomized patients. Sabizabulin treatment resulted in a 24.9 percentage point absolute reduction and a 55.2% relative reduction in deaths compared with placebo (odds ratio, 3.23; 95% CI confidence interval, 1.45 to 7.22; P=0.0042). The mortality rate was 20.2% (19 of 94) for sabizabulin versus 45.1% (23 of 51) for placebo. For the key secondary end points, sabizabulin treatment resulted in a 43% relative reduction in ICU days (P=0.0013), a 49% relative reduction in days on mechanical ventilation (P=0.0013), and a 26% relative reduction in days in the hospital (P=0.0277) versus placebo. Adverse and serious adverse events were lower in the sabizabulin group compared with the placebo group. CONCLUSIONS: Sabizabulin treatment resulted in a 24.9% absolute reduction in deaths compared with placebo in hospitalized patients with moderate to severe Covid-19 at high risk for ARDS and death, with a lower incidence of adverse and serious adverse events compared with placebo. (Funded by Veru, Inc.; ClinicalTrials.gov number, NCT04842747.)

Fucoxanthin decreases lipopolysaccharide-induced acute lung injury through the inhibition of RhoA activation and the NF-κB pathway

Fucoxanthin is a natural pigment widely distributed in macroalgae and microalgae. An orange-colored xanthophyll, it has several bioactive effects, including anticancer, anti-obesity, oxidative stress reduction, and anti-inflammation. Acute lung injury (ALI) caused by acute infections or injurious stimuli to the lung tissues is a severe pulmonary inflammatory disease. To date, no evidence has shown ALI to be reduced by fucoxanthin through activation of Ras homolog family member A (RhoA) and the nuclear factor (NF)-κB pathway in lipopolysaccharide (LPS)-treated mice. Pretreatment with fucoxanthin inhibited histopathological changes in lung tissues and neutrophil infiltration into bronchoalveolar lavage fluid induced by LPS in ALI mice. Moreover, LPS-induced proinflammatory cytokine expression and neutrophil infiltration were inhibited by fucoxanthin in a concentration-dependent manner. Pretreatment of mice with fucoxanthin inhibited NF-κB phosphorylation and IκB degradation in the lungs of mice with LPS-induced ALI. We further found that phosphorylation of Akt and p38 mitogen-activated protein KINASE (MAPK) was inhibited by fucoxanthin. By contrast, the phosphorylation of extracellular signal-regulated kinase and c-Jun N-terminal kinase was not inhibited by fucoxanthin. Furthermore, we found that the activation of RhoA was inhibited by fucoxanthin in LPS-induced ALI. On the basis of these results, we propose that fucoxanthin disrupts the RhoA activation-mediated phosphorylation of Akt and p38 MAPK, leading to NF-κB activation in mice with LPS-induced ALI.

COVID-19 and the potential of Janus family kinase (JAK) pathway inhibition: A novel treatment strategy

Recent evidence proposed that the severity of the coronavirus disease 2019 (COVID-19) in patients is a consequence of cytokine storm, characterized by increased IL-1β, IL-6, IL-18, TNF-α, and IFN-γ. Hence, managing the cytokine storm by drugs has been suggested for the treatment of patients with severe COVID-19. Several of the proinflammatory cytokines involved in the pathogenesis of COVID-19 infection recruit a distinct intracellular signaling pathway mediated by JAKs. Consequently, JAK inhibitors, including baricitinib, pacritinib, ruxolitinib, and tofacitinib, may represent an effective therapeutic strategy for controlling the JAK to treat COVID-19. This study indicates the mechanism of cytokine storm and JAK/STAT pathway in COVID-19 as well as the medications used for JAK/STAT inhibitors.

The Renshen Chishao Decoction Could Ameliorate the Acute Lung Injury but Could Not Reduce the Neutrophil Extracellular Traps Formation

The acute lung injury (ALI) causes severe pulmonary diseases, leading to a high mortality rate. The Renshen and Chishao have protective and anti-inflammatory effects against the ALI. To explore the protective effects of the Renshen Chishao (RC) decoction against the ALI, we established the lipopolysaccharide-indued ALI model and randomly divided the mice into seven groups: control group, ALI group, high-dose RC group, middle-dose RC group, low-dose RC group, middle-dose RC group + CXCR2 antagonist group, and ALI + CXCR2 antagonist group. We estimated the lung injury by the hematoxylin and eosin staining, the neutrophil extracellular traps (NETs) formations by the immunofluorescence colocalization and enzyme-linked immunosorbent assay (ELISA), and the CXCR2/CXCL2 pathway by the flow cytometry, ELISA, and real-time polymerase chain reaction. We conducted the high-throughput sequencing and enrichment analyses to explore the potential mechanisms. The results showed that the RC decoction pathologically ameliorated the lipopolysaccharide-induced lung injury and inflammatory response but failed to reduce the circulating and lung tissue NETs formation and the blood neutrophil percent. The high-dose RC decoction increased the plasma CXCL2 level, but the RC decoction had no effects on the neutrophilic CXCR2 levels. Under the inhibition of the CXCR2, the middle-dose RC decoction still decreased the lung injury score but as yet had unobvious influence on the NETs formation. Other potential mechanisms of the RC decoction against the ALI involved the pathways of ribosome and coronavirus disease 2019 (COVID-19); the target genes of inflammatory factors, such as Ccl17, Cxcl17, Cd163, Cxcr5, and Il31ra, and lncRNAs; and the regulations of the respiratory cilia. In conclusion, the RC decoction pathologically ameliorated the lipopolysaccharide-induced lung inflammatory injury via upregulating the CXCL2/CXCR2 pathway but could not reduce the circulating or lung tissue NETs formation.