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.

Engineering of VCAM-1-targeted nanostructured lipid carriers for delivery of melatonin against acute lung injury through SIRT1/NLRP3 mediated pyroptosis signaling pathway

Acute lung injury (ALI) is a prevalent and critical condition in clinical practice. Although certain pharmacological interventions have demonstrated benefits in preclinical studies, none have been proven entirely effective thus far. Therefore, the development of more efficient treatment strategies for ALI is imperative. In this study, we prepared nanostructured lipid carriers (NLCs) conjugated with anti-VCAM-1 antibodies to encapsulate melatonin (MLT), resulting in VCAM/MLT NLCs. This approach aimed to enhance the distribution of melatonin in lung vascular endothelial cells. The VCAM/MLT NLCs had an average diameter of 364 nm, high drug loading content, and a sustained drug release profile. Notably, the NLCs conjugated with anti-VCAM-1 antibodies demonstrated more specific cellular delivery mediated by the VCAM-1 receptors, increased cellular internalization, and enhanced accumulation in lung tissues. Treatment with VCAM/MLT NLCs effectively alleviated pulmonary inflammation by activating NLRP3 inflammasome-dependent pyroptosis through up-regulation of Sirtuin 1. Our findings suggest that VCAM/MLT NLCs demonstrate remarkable therapeutic effects on ALI in both in vitro and in vivo settings, making them a promising and efficient treatment strategy for ALI.

Ameliorative Effect of Morinda Officinalis Oligosaccharides on LPS-Induced Acute Lung Injury

Acute lung injury (ALI) is a disease characterized by extensive lung damage and rampant inflammation, with a high mortality rate and no effective treatments available. Morinda officinalis oligosaccharides (MOOs), derived from the root of the traditional Chinese medicinal herb Morinda officinalis, known for its immune-boosting properties, presents a novel therapeutic possibility. To date, the impact of MOOs on ALI has not been explored. Our study aimed to investigate the potential protective effects of MOOs against ALI and to uncover the underlying mechanisms through an integrated approach of network pharmacology, molecular docking, and experimental validation. We discovered that MOOs significantly mitigated the pathological damage and decreased the expression of pro-inflammatory cytokines in LPS-induced ALI in mice. Complementary in vitro studies further demonstrated that MOOs effectively attenuated the M1 polarization induced by LPS. Network pharmacology analysis identified HSP90AA1, HSP90AB1, and NF-κB as key overlapping targets within a protein-protein interaction (PPI) network. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses elucidated the biological processes and signaling pathways implicated in MOOs' therapeutic action on ALI. Subsequently, molecular docking affirmed the binding of MOOs to the active sites of these identified targets. Corroborating these findings, our in vivo and in vitro experiments consistently demonstrated that MOOs significantly inhibited the LPS-induced upregulation of HSP90 and NF-κB. Collectively, these findings suggest that MOOs confer protection against ALI through a multi-target, multi-pathway mechanism, offering a promising new therapeutic strategy to mitigate this severe pulmonary condition.

Identification of HK3 as a promising immunomodulatory and prognostic target in sepsis-induced acute lung injury

BACKGROUND

Sepsis is a life-threatening global disease with a significant impact on human health. Acute lung injury (ALI) has been identified as one of the primary causes of mortality in septic patients. This study aimed to identify candidate genes involved in sepsis-induced ALI through a comprehensive approach combining bioinformatics analysis and experimental validation.

METHODS

The datasets GSE65682 and GSE32707 obtained from the Gene Expression Omnibus database were merged to screen for sepsis-induced ALI related differentially expressed genes (DEGs). Functional enrichment and immune infiltration analyses were conducted on DGEs, with the construction of protein-protein interaction (PPI) networks to identify hub genes. In vitro and in vivo models of sepsis-induced ALI were used to study the expression and function of hexokinase 3 (HK3) using various techniques including Western blot, real-time PCR, immunohistochemistry, immunofluorescence, Cell Counting Kit-8, Enzyme-linked immunosorbent assay, and flow cytometry.

RESULTS

The results of bioinformatics analysis have identified HK3, MMP9, and S100A8 as hub genes with diagnostic and prognostic significance for sepsis-induced ALI. The HK3 has profound effects on sepsis-induced ALI and exhibits a correlation with immune regulation. Experimental results showed increased HK3 expression in lung tissue of septic mice, particularly in bronchial and alveolar epithelial cells. In vitro studies demonstrated upregulation of HK3 in lipopolysaccharide (LPS)-stimulated lung epithelial cells, with cytoplasmic localization around the nucleus. Interestingly, following the knockdown of HK3 expression, lung epithelial cells exhibited a significant decrease in proliferation activity and glycolytic flux, accompanied by an increase in cellular inflammatory response, oxidative stress, and cell apoptosis.

CONCLUSIONS

It was observed for the first time that HK3 plays a crucial role in the progression of sepsis-induced ALI and may be a valuable target for immunomodulation and therapy.Bioinformatics analysis identified HK3, MMP9, and S100A8 as hub genes with diagnostic and prognostic relevance in sepsis-induced ALI. Experimental findings showed increased HK3 expression in the lung tissue of septic mice, particularly in bronchial and alveolar epithelial cells. In vitro experiments demonstrated increased HK3 levels in lung epithelial cells stimulated with LPS, with cytoplasmic localization near the nucleus. Knockdown of HK3 expression resulted in decreased proliferation activity and glycolytic flux, increased inflammatory response, oxidative stress, and cell apoptosis in lung epithelial cells.

Desflurane alleviates LPS-induced acute lung injury by modulating let-7b-5p/HOXA9 axis

Acute lung injury (ALI) is characterized by acute respiratory failure with tachypnea and widespread alveolar infiltrates, badly affecting patients' health. Desflurane (Des) is effective against lung injury. However, its mechanism in ALI remains unknown. BEAS-2B cells were incubated with lipopolysaccharide (LPS) to construct an ALI cell model. Cell apoptosis was evaluated using flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was employed to examine the levels of inflammatory cytokines. Interactions among let-7b-5p, homeobox A9 (HOXA9), and suppressor of cytokine signaling 2 (SOCS2) were verified using Dual luciferase activity, chromatin immunoprecipitation (ChIP), and RNA pull-down analysis. All experimental data of this study were derived from three repeated experiments. Des treatment improved LPS-induced cell viability, reduced inflammatory cytokine (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6)) levels, decreased cell apoptosis, down-regulated the pro-apoptotic proteins (Bcl-2-associated X protein (Bax) and cleaved caspase 3) expression, and up-regulated the anti-apoptotic protein B-cell-lymphoma-2 (Bcl-2) expression in LPS-induced BEAS-2B cells. Des treatment down-regulated let-7b-5p expression in LPS-induced BEAS-2B cells. Moreover, let-7b-5p inhibition improved LPS-induced cell injury. let-7b-5p overexpression weakened the protective effects of Des. Mechanically, let-7b-5p could negatively modulate HOXA9 expression. Furthermore, HOXA9 inhibited the NF-κB signaling by enhancing SOCS2 transcription. HOXA9 overexpression weakened the promotion of let-7b-5p mimics in LPS-induced cell injury. Des alleviated LPS-induced ALI via regulating let-7b-5p/ HOXA9/NF-κB axis.

Heated tobacco product (IQOS) induced pulmonary infiltrates

Background

Heated tobacco products (HTPs) have been marketed as safer alternatives to conventional cigarettes, but emerging evidence suggests potential respiratory risks. We present a case of pulmonary complications associated with IQOS, a popular HTP, contributing to the growing understanding of these risks.

Case description

A 40-year-old chronic smoker switched to IQOS, consuming 1.5 packs per day. He presented with incidental chest radiographic abnormalities and peripheral eosinophilia. Computed tomography of chest revealed pulmonary nodules and ground glass opacities. Bronchoscopy indicated mild eosinophilia. After ruling out other causes, a lung biopsy was recommended but declined. Discontinuation of IQOS led to symptom resolution and radiographic improvement. This case adds to a limited literature on HTP-induced lung injury, with a unique presentation and favorable response to cessation.

Conclusions

The case highlights potential pulmonary complications and the first describing an organizing pattern of lung injury associated with IQOS use, emphasizing the importance of recognizing and discontinuing HTPs in patients with respiratory symptoms or radiographic abnormalities. Further research is needed to elucidate the mechanisms underlying the harmful effects of HTPs and inform public health policies. This case underscores the importance of monitoring and educating individuals about the potential risks of HTPs to respiratory health, especially in the context of smokers switching to these products.

Comprehensive profiling of amino acids and derivatives in biological samples: A robust UHPLC-MS/MS method for investigating acute lung injury

The severe respiratory dysfunctions associated with acute lung injury (ALI) and its sequelae have a high morbidity and mortality rate, are multifactorial, and lack a viable treatment. Considering the critical function that amino acids and derivatives play in the genesis of illnesses and the regulation of metabolic processes, monitoring the levels of metabolites associated with amino acids in biological matrices is necessary and interesting to study their pathological mechanisms. Exploring the dynamics of amino acids and derivatives level and searching for biomarkers provides improved clinical ideas for the diagnosis and treatment of ALI. Therefore, we developed an ultra-high-performance liquid chromatography-electrospray tandem mass spectrometry (UHPLC-MS/MS) method that can simultaneously determine the amino acid and derivatives metabolic levels to study amino acid profiles in different biological samples to facilitate clinical research of ALI. In this study, 48 amino acids and derivatives, including neurotransmitters, polyamines, purines, and other types, were quantified simultaneously in a fast, high-throughput, sensitive, and reliable manner within a 15-minute run time without derivatization. No relevant studies have been reported to quantify these 48 amino acid metabolites in three biological samples simultaneously. Satisfactory linearity (R > 0.995), inter-day and intra-day accuracy (85.17-112.67 % and 85.29-111.60 %, respectively), inter-day and intra-day precision (RSD < 13.80 % and RSD < 12.01 %, respectively), matrix effects (81.00 %-118.00 %), recovery (85.09 %-114.65 %) and stability (RSD < 14.72 %) were all demonstrated by the optimized method's successful validation for all analytes. In addition, the suggested method was effectively implemented in plasma, urine, and lung tissue from normal mice and mice with ALI, with the aim of finding potential biomarkers associated with ALI. Potential biomarkers were screened through multivariate statistical analysis and volcanic map analysis, and the changes of markers in ALI were again identified through heat map analysis and correlation analysis with biochemical indicators, which provided ideas and references for subsequent mechanism studies. Here, the technique created in this work offers a quick and dependable way to perform an integrated analysis of amino acids in a variety of biological materials, which can provide research ideas for understanding the physiopathological state of various diseases.

Huangqi Baihe Granules alleviate hypobaric hypoxia-induced acute lung injury in rats by suppressing oxidative stress and the TLR4/NF-κB/NLRP3 inflammatory pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Huangqi Baihe Granules (HQBHG) are a modified formulation based on the traditional recipe "Huangqi Baihe porridge" and the Dunhuang medical prescription "Cistanche Cistanche Soup." The Herbal medicine moistens the lungs and tones the kidneys in addition to replenishing Qi and feeding Yin, making it an ideal choice for enhancing adaptability to high-altitude hypoxic environments.

AIM OF THE STUDY

The purpose of this study was to examine a potential molecular mechanism for the treatment and prevention of hypoxic acute lung injury (ALI) in rats using Huangqi Baihe Granules.

MATERIALS AND METHODS

The HCP-III laboratory animal low-pressure simulation chamber was utilized to simulate high-altitude environmental exposure and establish an ALI model in rats. The severity of lung damage was evaluated using a battery of tests that included spirometry, a wet/dry lung ratio, H&E staining, and transmission electron microscopy. Using immunofluorescence, the amount of reactive oxygen species (ROS) in lung tissue was determined. Superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), and myeloperoxidase (MPO) levels in lung tissue were determined using this kit. Serum levels of proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1 beta), and antiinflammatory cytokines like interleukin-10 (IL-10) were measured using an enzyme-linked immunosorbent assay kit. Gene expression changes in lung tissue were identified using transcriptomics, and the relative expression of proteins and mRNA involved in the toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB p65)/Nod-like receptor protein 3 (NLRP3) pathway were determined using western blotting and quantitative real-time PCR.

RESULTS

HQBHG was shown to enhance lung function considerably, decrease the wet/dry ratio of the lungs, attenuate lung tissue damage, suppress ROS and MDA formation, and increase SOD activity and GSH expression. The research also demonstrated that HQBHG inhibited the activation of the TLR4/NF-κB p65/NLPR3 signaling pathway in lung tissue, reducing the release of downstream pro-inflammatory cytokines.

CONCLUSIONS

HQBHG exhibits potential therapeutic effects against ALI induced by altitude hypoxia through suppressing oxidative stress and inflammatory response. This suggests it may be a novel drug for treating and preventing ALI.

A novel mechanism for regulating lung immune homeostasis: Zukamu granules alleviated acute lung injury in mice by inhibiting NLRP3 inflammasome activation and regulating Th17/Treg cytokine balance

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury (ALI) is a severely acute lung inflammation with high morbidity and mortality. Zukamu granules (ZKMG) is one of the Uygur patent drugs commonly used in clinic, which is included in the National Essential Drugs List (2018 edition). Clinical studies have shown that ZKMG has a significant effect on acute upper respiratory tract infection, and has better anti-inflammatory and antipyretic effects. However, the immunomodulatory mechanism of ZKMG on ALI is still not clear.

AIM OF THE STUDY

The aim of this study is to investigate the lung protective effect and immunomodulatory mechanism of ZKMG on lipopolysaccharide (LPS) -induced ALI mice, and to provide an important basis for the treatment strategy and theoretical basis of ALI.

MATERIALS AND METHODS

First, network pharmacology was used to predict the potential signaling pathways and biological processes of ZKMG related to immunology. Molecular docking technique was used to predict the possibility between the core components of ZKMG acting on NLRP3 protein. In addition, protein levels of F4/80 in lung tissues were assessed by Immunohistochemistry (IHC). The contents of IL-1β, IL-18, IL-17A and IL-10 in the lung tissue and serum, MPO in the lung tissue were detected by enzyme-linked immunosorbent assay (ELISA). Real-time quantitative PCR analysis (RT-qPCR) was used to detect NLRP3 mRNA in lung tissue. Protein levels of NLRP3, Caspase-1, Cleaved caspase-1 p20, ASC, and GSDMD were detected by Western blot (WB).

RESULTS

The results of network pharmacology showed that the immune pathways of ZKMG were mainly Th17 signaling pathway, IL-17 signaling pathway, NOD-like receptor signaling pathway, etc. Molecular docking results showed that the core components of ZKMG had good binding ability to NLRP3 protein. The verification experiments showed that ZKMG can reduce the degree of lung injury, and reduce the level of inflammatory infiltration of neutrophils and macrophages by reducing the content of MPO and F4/80. In addition, ZKMG can reduce NLRP3 mRNA, inhibit the expression of NLRP3/Caspase-1/GSDMD and other related pathway proteins, and reduce inflammatory factors such as IL-1β and IL-18. It can also reduce the content of pro-inflammatory cytokine IL-17A, increase the content of anti-inflammatory cytokine IL-10 in lung tissue.

CONCLUSION

ZKMG can reduce the degree of lung tissue injury in ALI by inhibiting NLRP3/Caspase-1/GSDMD signaling pathway and restoring the IL-17A/IL-10 cytokine balance, and its protective mechanism may be related to the regulation of lung immune homeostasis. It will provide a new strategy for studying the regulation of lung immune homeostasis.

Crtc1 deficiency protects against sepsis-associated acute lung injury through activating akt signaling pathway

BACKGROUND

Interplay between systemic inflammation and programmed cell death contributes to the pathogenesis of acute lung injury (ALI). cAMP-regulated transcriptional coactivator 1 (CRTC1) has been involved in the normal function of the pulmonary system, but its role in ALI remains unclear.

METHODS AND RESULTS

We generated a Crtc1 knockout (KO; Crtc1-/-) mouse line. Sepsis-induced ALI was established by cecal ligation and puncture (CLP) for 24 h. The data showed that Ctrc1 KO substantially ameliorated CLP-induced ALI phenotypes, including improved lung structure destruction, reduced pulmonary vascular permeability, diminished levels of proinflammatory cytokines and chemokines, compared with the wildtype mice. Consistently, in lipopolysaccharide (LPS)-treated RAW264.7 cells, Crtc1 knockdown significantly inhibited the expression of inflammatory effectors, including TNF-α, IL-1β, IL-6 and CXCL1, whereas their expressions were significantly enhanced by Crtc1 overexpression. Moreover, both Crtc1 KO in mice and its knockdown in RAW264.7 cells dramatically reduced TUNEL-positive cells and the expression of pro-apoptotic proteins. In contrast, Crtc1 overexpression led to an increase in the pro-apoptotic proteins and LPS-induced TUNEL-positive cells. Mechanically, we found that the phosphorylation of Akt was significantly enhanced by Crtc1 knockout or knockdown, but suppressed by Crtc1 overexpression. Administration of Triciribine, an Akt inhibitor, substantially blocked the protection of Crtc1 knockdown on LPS-induced inflammation and cell death in RAW264.7 cells.

CONCLUSIONS

Our study demonstrates that CRTC1 contribute to the pathological processes of inflammation and apoptosis in sepsis-induced ALI, and provides mechanistic insights into the molecular function of CRTC1 in the lung. Targeting CRTC1 would be a promising strategy to treat sepsis-induced ALI in clinic.

Association between high-flow nasal cannula use and mortality in patients with sepsis-induced acute lung injury: a retrospective propensity score-matched cohort study

BACKGROUND

High-flow nasal cannula (HFNC) has emerged as a promising noninvasive method for delivering oxygen to critically ill patients, particularly those with sepsis and acute lung injury. However, uncertainties persist regarding its therapeutic benefits in this specific patient population.

METHODS

This retrospective study utilized a propensity score-matched cohort from the Medical Information Mart in Intensive Care-IV (MIMIC-IV) database to explore the correlation between HFNC utilization and mortality in patients with sepsis-induced acute lung injury. The primary outcome was 28-day all-cause mortality.

RESULTS

In the propensity score-matched cohort, the 28-day all-cause mortality rate was 18.63% (95 out of 510) in the HFNC use group, compared to 31.18% (159 out of 510) in the non-HFNC group. The use of HFNC was associated with a lower 28-day all-cause mortality rate (hazard ratio [HR] = 0.53; 95% confidence interval [CI] = 0.41-0.69; P < 0.001). HFNC use was also associated with lower ICU mortality (odds ratio [OR] = 0.52; 95% CI = 0.38-0.71; P < 0.001) and lower in-hospital mortality (OR = 0.51; 95% CI = 0.38-0.68; P < 0.001). Additionally, HFNC use was found to be associated with a statistically significant increase in both the ICU and overall hospitalization length.

CONCLUSIONS

These findings indicate that HFNC may be beneficial for reducing mortality rates among sepsis-induced acute lung injury patients; however, it is also associated with longer hospital stays.

ARC@DPBNPs suppress LPS-induced acute lung injury via inhibiting macrophage pyroptosis and M1 polarization by ERK pathway in mice

AIM OF THE STUDY

Exploring the protective effect of ARC@DPBNP on lipopolysaccharides (LPS)-induced ALI and its underlying mechanism.

MATERIALS AND METHODS

ALI model was established by intransally administrating LPS (4 mg/kg) into C57BL/6 mice. The suppression effects of ALI was first compared between ARC (intragastric administrated, with doses ranging from 10 to 80 mg/kg) and ARC@BPBNPs (intratracheally administrated, with doses ranging from 1 to 4 mg/kg). Changes in lung histology post intratracheal intervention of 3 mg/kg ARC@DPBNPs were detected. The expression of pyrotosis pathway-related proteins in lungs as well as in RAW264.7 cells was detected by western blotting. The ASC expression in lung macrophages was examined using immune-fluorescent staining. The polarization of RAW264.7 cells and lung macrophages were detected by flow cytometry. The network pharmacology was constructed by Cytoscape, and the molecular docking was perfomed by AutoDock Vina.

RESULTS

Docking predicted the high affinity of ARC to MAPK1 (ERK2). HE staining showed that ARC@DPBNPs attenuated LPS-induced ALI at a remarkably lower dose than ARC. The improved histopathological changes, lung W/D weight ratio, and decreased of inflammatory factor levels in lung collectively demonstrated the alleviation effects of ARC@DPBNPs. Compared with the LPS group, ARC@DPBNPs down-regulated the ERK pathway, resulted in a suppression of the macrophage pyroptosis and M1 polarization. This suppression effects could be removed by the ERK activator Ro 67-7476.

CONCLUSION

ARC@DPBNPs attenuated ALI by suppressing LPS-induced macrophage pyroptosis and polarization, probably through down-regulation of the ERK pathway.

[A case of acute inhalation dinitrogen tetroxide poisoning]

Dinitrogen tetroxide is often used as an oxidant in rocket propellant and has strong irritant and corrosive properties. This paper analyzes the clinical data of a patient with dinitrogen tetroxide poisoning admitted in the 63710 Army Hospital of Chinese People's Liberation Army, so as to further explore the poisoning mechanism, clinical characteristics and key points of acute inhaled dinitrogen tetroxide poisoning.

Physalin H ameliorates LPS-induced acute lung injury via KEAP1/NRF2 axis

Physalin H (PH), a withanolide isolated from Physalisangulata L. has been reported to have anti-inflammatory effect. However, its impact on acute lung injury (ALI) remains unexplored. In this study, we observed that PH significantly alleviated inflammation in LPS-stimulated macrophages by suppressing the release of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and down-regulating the expression of the inflammation-related genes. RNA sequencing analysis revealed a significant up-regulation of the NRF2 pathway by PH. Further investigation elucidated that PH attenuated the ubiquitination of NRF2 by impeding the interaction between NRF2 and KEAP1, thereby facilitating NRF2 nuclear translocation and up-regulating the expression of target genes. Consequently, it regulated redox system and exerted anti-inflammatory effect. Consistently, PH also significantly alleviated pathological damage and inflammation in LPS-induced ALI mice model, which could be reversed by administration of an NRF2 inhibitor. Collectively, these results suggest that PH ameliorates ALI by activating the KEAP1/NRF2 pathway. These findings provide a foundation for further development of pH as a new anti-inflammatory agent for ALI therapy.

Icariin ameliorates LPS-induced acute lung injury in mice via complement C5a-C5aR1 and TLR4 signaling pathways

Acute lung injury (ALI) is an acute respiratory-related progressive disorder, which lacks specific pharmacotherapy. Icariin (ICA) has been shown to be effective in treating ALI. However, the targets and pharmacological mechanisms underlying the effects of ICA in the treatment of ALI are relatively lacking. Based on network pharmacology and molecular docking analyses, the gene functions and potential target pathways of ICA in the treatment of ALI were determined. In addition, the underlying mechanisms of ICA were verified by immunohistochemistry, immunofluorescence, quantitative Real-time PCR, and Western blot in LPS-induced ALI mice. The biological processes targeted by ICA in the treatment of ALI included the pathological changes, inflammatory response, and cell signal transduction. Network pharmacology, molecular docking, and in vivo experimental results revealed that ICA inhibited the complement C5a-C5aR1 axis, TLR4 mediated NF-κB, MAPK, and JAK2-STAT3 signaling pathways related gene and protein expressions, and decreased inflammatory cytokine, chemokine, adhesion molecule expressions, and mitochondrial apoptosis in LPS-induced ALI.

Ischemia and reperfusion-injured liver-derived exosomes elicit acute lung injury through miR-122-5p regulated alveolar macrophage polarization

Acute lung injury (ALI) is a common postoperative complication, particularly in pediatric patients after liver transplantation. Hepatic ischemia-reperfusion (HIR) increases the release of exosomes (IR-Exos) in peripheral circulation. However, the role of IR-Exos in the pathogenesis of ALI induced by HIR remains unclear. Here, we explored the role of exosomes derived from the HIR-injured liver in ALI development. Intravenous injection of IR-Exos caused lung inflammation in naive rats, whereas pretreatment with an inhibitor of exosomal secretion (GW4869) attenuated HIR-related lung injury. In vivo and in vitro results show that IR-Exos promoted proinflammatory responses and M1 macrophage polarization. Furthermore, miRNA profiling of serum identified miR-122-5p as the exosomal miRNA with the highest increase in young rats with HIR compared with controls. Additionally, IR-Exos transferred miR-122-5p to macrophages and promoted proinflammatory responses and M1 phenotype polarization by targeting suppressor of cytokine signaling protein 1(SOCS-1)/nuclear factor (NF)-κB. Importantly, the pathological role of exosomal miR-122-5p in initiating lung inflammation was reversed by inhibition of miR-122-5p. Clinically, high levels of miR-122-5p were found in serum and correlated to the severity of lung injury in pediatric living-donor liver transplant recipients with ALI. Taken together, our findings reveal that IR-Exos transfer liver-specific miR-122-5p to alveolar macrophages and elicit ALI by inducing M1 macrophage polarization via the SOCS-1/NF-κB signaling pathway.

The role of FPR2-mediated ferroptosis in formyl peptide-induced acute lung injury against endothelial barrier damage and protective effect of the mitochondria-derived peptide MOTS-c

BACKGROUND

Acute lung injury (ALI) has garnered significant attention in the field of respiratory and critical care due to its high mortality and morbidity, and limited treatment options. The role of the endothelial barrier in the development of ALI is crucial. Several bacterial pathogenic factors, including the bacteria-derived formyl peptide (fMLP), have been implicated in damaging the endothelial barrier and initiating ALI. However, the mechanism by which fMLP causes ALI remains unclear. In this study, we aim to explore the mechanisms of ALI caused by fMLP and evaluate the protective effects of MOTS-c, a mitochondrial-derived peptide.

METHODS

We established a rat model of ALI and a human pulmonary microvascular endothelial cell (HPMVEC) model of ALI by treatment with fMLP. In vivo experiments involved lung histopathology assays, assessments of inflammatory and oxidative stress factors, and measurements of ferroptosis-related proteins and barrier proteins to evaluate the severity of fMLP-induced ALI and the type of tissue damage in rats. In vitro experiments included evaluations of fMLP-induced damage on HPMVEC using cell activity assays, assessments of inflammatory and oxidative stress factors, measurements of ferroptosis-related proteins, endothelial barrier function assays, and examination of the key role of FPR2 in fMLP-induced ALI. We also assessed the protective effect of MOTS-c and investigated its mechanism on the fMLP-induced ALI in vivo and in vitro.

RESULTS

Results from both in vitro and in vivo experiments demonstrate that fMLP promotes the expression of inflammatory and oxidative stress factors, activates ferroptosis and disrupts the vascular endothelial barrier, ultimately contributing to the development and progression of ALI. Mechanistically, ferroptosis mediated by FPR2 plays a key role in fMLP-induced injury, and the Nrf2 and MAPK pathways are involved in this process. Knockdown of FPR2 and inhibition of ferroptosis can attenuate ALI induced by fMLP. Moreover, MOTS-c could protect the vascular endothelial barrier function by inhibiting ferroptosis and suppressing the expression of inflammatory and oxidative stress factors through Nrf2 and MAPK pathways, thereby alleviating fMLP-induced ALI.

CONCLUSION

Overall, fMLP disrupts the vascular endothelial barrier through FPR2-mediated ferroptosis, leading to the development and progression of ALI. MOTS-c demonstrates potential as a protective treatment against ALI by alleviating the damage induced by fMLP.

Effects of Lung Inflammation and Injury on Pulmonary Tissue Penetration of Meropenem and Vancomycin in a Model of Unilateral Lung Injury

OBJECTIVE

Timing and dosing of antimicrobial therapy is key in the treatment of pneumonia in critically ill patients. It is uncertain whether presence of lung inflammation and injury affects tissue penetration of intravenously administered antimicrobial drugs. We determined the effects of lung inflammation and injury on tissue penetration of two commonly used antimicrobial drugs for pneumonia in an established model of unilateral lung injury.

METHODS

In 13 healthy pigs, unilateral lung injury was induced in the left lung through cyclic rinsing - the right healthy lung served as control. After infusion of meropenem and vancomycin, lung tissue, blood, and epithelial lining fluid concentrations were monitored and compared over a period of 6 hours.

RESULTS

Median vancomycin lung tissue concentrations as well as penetration ratio were higher in inflamed and injured lungs compared to uninflamed and uninjured lungs (AUC0-6h: P = 0.003 and AUCdialysate/AUCplasma ratio: P = 0.003), resulting in higher AUC0-24/MIC. Median meropenem lung tissue concentrations as well as penetration were not different in inflamed and injured lungs compared to uninflamed and uninjured lungs (AUC0-6 P = 0.094 and AUCdialysate/AUCplasma ratio P = 0.173). Penetration ratio for both vancomycin and meropenem into epithelial lining fluid was not different between injured and uninjured lungs.

CONCLUSION

Vancomycin penetration into lung tissue is enhanced by acute inflammation and injury, a phenomenon barely evident with meropenem. Therefore, inflammation in lung tissue influences the penetration into interstitial lung tissue, depending on the chosen antimicrobial drug. Measurement of ELF levels alone might not detect impact of inflammation and injury.

miR-186-5p improves alveolar epithelial barrier function by targeting the wnt5a/β-catenin signaling pathway in sepsis-acute lung injury

BACKGROUND

Alveolar epithelial barrier dysfunction is one of the pathological features of sepsis-acute lung injury(ALI). However, the molecular mechanisms that regulate the function of alveolar epithelial barrier remain unclear. This study aimed to determine the regulatory role of miR-186-5p in alveolar epithelial barrier function in sepsis-ALI and its underlying molecular mechanism.

METHODS

We established sepsis-ALI models in vivo and in vitro, detected the miR-186-5p and wnt5a/β-catenin expressions, and observed the functional changes of the alveolar epithelial barrier by miR-186-5p overexpression. We used rescue experiments to clarify whether miR-186-5p works through wnt5a/β-catenin.

RESULTS

miR-186-5p expression was decreased, wnt5a expression was increased, and the wnt5a/β-catenin signaling pathway was activated in mouse lung tissues and A549 cells after inflammatory stimulation. miR-186-5p overexpression resulted in wnt5a/β-catenin signaling pathway inhibition, decreased apoptosis in A549 cells, improved alveolar epithelial barrier function, reduced lung tissue injury in ALI mice, decreased IL-6 and TNF-α levels, and increased claudin4 and ZO-1 expression. Using miRNA-related database prediction and dual-luciferase reporter gene analysis, the targeting relationship between miR-186-5p and wnt5a was determined. The protective effect produced by miR-186-5p overexpression on the alveolar barrier was reversed after the application of the wnt5a/β-catenin activator Licl.

CONCLUSION

Our experimental data suggest miR-186-5p targets the wnt5a/β-catenin pathway, thereby regulating alveolar epithelial barrier function. Furthermore, both miR-186-5p and wnt5a/β-catenin are potential therapeutic targets that could impact sepsis-ALI.

SP-8356 inhibits acute lung injury by suppressing inflammatory cytokine production and immune cell infiltration

This study investigated the anti-inflammatory and protective properties of SP-8356, a synthetic derivative of (1S)-(-)-verbenone, in a mouse model of LPS-induced acute lung injury (ALI). By targeting intracellular signaling pathways and inflammatory responses, SP-8356 demonstrated a potent ability to attenuate deleterious effects of proinflammatory stimuli. Specifically, SP-8356 effectively inhibited the activation of crucial signaling molecules such as NF-κB and Akt, and subsequently dampened the expression of inflammatory cytokines in various lung cellular components. Intervention with SP-8356 treatment also preserved the structural integrity of the epithelial and endothelial barriers. By reducing immune cell infiltration into inflamed lung tissue, SP-8356 exerted a broad protective effect against ALI. These findings position SP-8356 as a promising therapeutic candidate for pulmonary inflammatory diseases that cause ALI.

MicroRNA-1258 suppresses oxidative stress and inflammation in septic acute lung injury through the Pknox1-regulated TGF-β1/SMAD3 cascade

AIM

The study was to clarify the mechanism of miR-1258 targeting Prep1 (pKnox1) to control Transforming Growth Factor β1 (TGF-β1)/SMAD3 pathway in septic Acute Lung Injury (ALI)-induced oxidative stress and inflammation.

METHODS

BEAS-2B cells and C57BL/6 mice were used to make in vitro and in vivo septic ALI models, respectively. miR-1258 expression was checked by RT-qPCR. After transfection in the in vitro experimental model, inflammation, oxidative stress, viability, and apoptosis were observed through ELISA, MTT, and flow cytometry.

RESULTS

In the in vivo model after miR-1258 overexpression treatment, inflammation, oxidative stress, and lung injury were further investigated. The targeting relationship between miR-1258 and Pknox1 was tested. Low miR-1258 was expressed in septic ALI patients, LPS-treated BEAS-2B cells, and mice. Upregulated miR-1258 prevented inflammation, oxidative stress, and apoptosis but enhanced the viability of LPS-treated BEAS-2B cells. The impact of upregulated miR-1258 on LPS-treated BEAS-2B cells was mitigated by inhibiting Pknox1 expression. MiR-1258 overexpression had the alleviating effects on inflammation, oxidative stress, and lung injury of LPS-injured mice through suppressing Pknox1 expression and TGF-β1/SMAD3 cascade activation.

CONCLUSIONS

The study concludes that miR-1258 suppresses oxidative stress and inflammation in septic ALI through the Pknox1-regulated TGF-β1/SMAD3 cascade.

Modulation of alveolar macrophage and mitochondrial fitness by medicinal plant-derived nanovesicles to mitigate acute lung injury and viral pneumonia

Acute lung injury (ALI) is generally caused by severe respiratory infection and characterized by overexuberant inflammatory responses and inefficient pathogens-containing, the two major processes wherein alveolar macrophages (AMs) play a central role. Dysfunctional mitochondria have been linked with distorted macrophages and hence lung disorders, but few treatments are currently available to correct these defects. Plant-derive nanovesicles have gained significant attention because of their therapeutic potential, but the targeting cells and the underlying mechanism remain elusive. We herein prepared the nanovesicles from Artemisia annua, a well-known medicinal plant with multiple attributes involving anti-inflammatory, anti-infection, and metabolism-regulating properties. By applying three mice models of acute lung injury caused by bacterial endotoxin, influenza A virus (IAV) and SARS-CoV-2 pseudovirus respectively, we showed that Artemisia-derived nanovesicles (ADNVs) substantially alleviated lung immunopathology and raised the survival rate of challenged mice. Macrophage depletion and adoptive transfer studies confirmed the requirement of AMs for ADNVs effects. We identified that gamma-aminobutyric acid (GABA) enclosed in the vesicles is a major molecular effector mediating the regulatory roles of ADNVs. Specifically, GABA acts on macrophages through GABA receptors, promoting mitochondrial gene programming and bioenergy generation, reducing oxidative stress and inflammatory signals, thereby enhancing the adaptability of AMs to inflammation resolution. Collectively, this study identifies a promising nanotherapeutics for alleviating lung pathology, and elucidates a mechanism whereby the canonical neurotransmitter modifies AMs and mitochondria to resume tissue homeostasis, which may have broader implications for treating critical pulmonary diseases such as COVID-19.

Essential oil from Cinnamomum cassia Presl bark regulates macrophage polarization and ameliorates lipopolysaccharide-induced acute lung injury through TLR4/MyD88/NF-κB pathway

BACKGROUND

Cinnamomum cassia Presl, a traditional Chinese medicine recorded in "Shennong's Herbal Classic," has been historically used to treat respiratory diseases and is employed to address inflammation. The essential oil derived from Cinnamomum cassia bark is a primary anti-inflammatory agent. However, there remains ambiguity regarding the chemical composition of cinnamon bark essential oil (BCEO), its principal anti-inflammatory components, and their potential efficacy in typical inflammatory respiratory conditions, such as acute lung injury (ALI).

PURPOSE

This study aimed to unveil the chemical composition of BCEO. In addition, the mechanism of action of BCEO in ameliorating ALI and regulating macrophage polarization through the TLR4/MyD88/NF-κB pathway was elucidated.

METHODS

BCEO was extracted using supercritical fluid extraction (SFE) and characterized through gas chromatography-mass spectrometry (GC-MS) analysis. Acute oral toxicity was observed in C57BL/6 J mice. The pharmacological effects and underlying mechanisms of BCEO were evaluated in a mouse model of ALI, which was induced by administering 5 mg/kg of lipopolysaccharide (LPS) through intratracheal instillation.

RESULTS

GC-MS analysis revealed 99.08% of the constituents of BCEO. The primary components of BCEO were trans-cinnamaldehyde, o-methoxycinnamaldehyde, (+)-α-muurolene, δ-cadinene, and copaene. Oral acute toxicity tests indicated that the maximum tolerated dose of BCEO was 12 g/kg/day. BCEO treatment significantly reduced lung W/D ratio, total protein concentration in BALF, levels of TNF-α, IL-6, and IL-1β in BALF, WBC count and NEU% in peripheral blood, and lung histological damage. Pulmonary function, IL-10 levels, and LYM% in peripheral blood also showed improvement. BCEO effectively decreased the proportion of M1 phenotype macrophages in BALF, M1/M2 ratio, and apoptotic cells in the lung tissue while increasing the proportion of M2 phenotype macrophages in BALF. Furthermore, BCEO treatment led to reduced protein and mRNA levels of TLR4, MyD88, and p-p65, alongside increased p65 expression, suggesting its potential to impede the TLR4/MyD88/NF-κB signaling pathway.

CONCLUSION

SFE-extracted BCEO or its major constituents could serve as a viable treatment for ALI by reducing lung inflammation, improving pulmonary function, and protecting against LPS-induced ALI in mice. This therapeutic effect is achieved by inhibiting M1 macrophage polarization, promoting M2 macrophage polarization, and suppressing the TLR4/MyD88/NF-κB signaling pathway.

Resveratrol alleviates acute lung injury in mice by promoting Pink1/Parkin-related mitophagy and inhibiting NLRP3 inflammasome activation

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are characterized by rapid onset and widespread inflammation in the lungs, often leading to respiratory failure. These conditions can be triggered by various factors, resulting in a severe inflammatory response within the lungs. Resveratrol, a polyphenolic compound found in grapes and peanuts, is renowned for its potent antioxidative and anti-inflammatory properties. In this study, we investigated how resveratrol protects against lipopolysaccharide (LPS)-induced ALI in mice. We established mouse models of LPS-induced ALI and inflammation in bronchoalveolar lavage fluid (BALF) macrophages. Through histopathological examination, immunofluorescence, western blot, enzyme-linked immunosorbent assay (ELISA), and transmission electron microscopy (TEM), we assessed the impact of resveratrol on the activation of NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasomes and the process of mitophagy. Our findings indicate that resveratrol significantly mitigated the lung injury and inflammation caused by LPS. This was achieved by inhibiting the oligomerization of apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and the activation of NLRP3 inflammasomes. Resveratrol also reduced the levels of IL-1β and IL-18 in serum and BALF, decreased caspase-1 expression, and diminished macrophage pyroptosis. Furthermore, it upregulated Pink1, Parkin, Beclin-1, Autophagy-Related 5 (Atg5), and Microtubule-Associated Proteins 1 A/1B Light Chain 3B (LC3B-II), thereby enhancing mitophagy. Conversely, mitophagy was inhibited by Pink1 siRNA. In conclusion, resveratrol ameliorated ALI in mice, potentially by inhibiting the activation of NLRP3 inflammasomes, activating the Pink1/Parkin pathway, and promoting mitophagy.

LRRK2 is involved in heat exposure-induced acute lung injury and alveolar type II epithelial cell dysfunction

Heat exposure induces excessive hyperthermia associated with systemic inflammatory response that leads to multiple organ dysfunction including acute lung injury. However, how heat impairs the lung remains elusive so far. We aimed to explore the underlying mechanism by focusing on leucine-rich repeat kinase 2 (LRRK2), which was associated with lung homeostasis. Both in vivo and in vitro models were induced by heat exposure. Firstly, heat exposure exerted core temperature (Tc) disturbance, pulmonary dysfunction, atelectasis, inflammation, impaired energy metabolism, and reduced surfactant proteins in the lung of mice. In addition, decreased LRRK2 expression and increased heat shock proteins (HSPs) 70 were observed with heat exposure in both the lung of mice and alveolar type II epithelial cells (AT2). Furthermore, LRRK2 inhibition aggravated heat exposure-initiated Tc dysregulation, injury in the lung and AT2 cells, and enhanced HSP70 expression. In conclusion, LRRK2 is involved in heat-induced acute lung injury and AT2 cell dysfunction.

Syringic acid attenuates acute lung injury by modulating macrophage polarization in LPS-induced mice

BACKGROUND

Acute lung injury (ALI) is a continuum of lung changes caused by multiple lung injuries, characterized by a syndrome of uncontrolled systemic inflammation that often leads to significant morbidity and death. Anti-inflammatory is one of its treatment methods, but there is no safe and available drug therapy. Syringic acid (SA) is a natural organic compound commonly found in a variety of plants, especially in certain woody plants and fruits. In modern pharmacological studies, SA has anti-inflammatory effects and therefore may be a potentially safe and available compound for the treatment of acute lung injury.

PURPOSE

This study attempts to reveal the protective mechanism of SA against ALI by affecting the polarization of macrophages and the activation of NF-κB signaling pathway. Trying to find a safer and more effective drug therapy for clinical use.

METHODS

We constructed the ALI model using C57BL/6 mice by intratracheal instillation of LPS (10 mg/kg). Histological analysis was performed with hematoxylin and eosin (H&E). The wet-dry ratio of the whole lung was measured to evaluate pulmonary edema. The effect of SA on macrophage M1-type was detected by flow cytometry. BCA protein quantification method was used to determine the total protein concentration in bronchoalveolar lavage fluid (BALF). The levels of Interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α in BALF were determined by the ELISA kits, and RT-qPCR was used to detect the expression levels of IL-6, IL-1β and TNF-α mRNA of lung tissue. Western blot was used to detect the expression levels of iNOS and COX-2 and the phosphorylation of p65 and IκBα in the NF-κB pathway in lung tissue. In vitro experiments were conducted with RAW267.4 cell inflammation model induced by 100 ng/ml LPS and A549 cell inflammation model induced by 10 μg/ml LPS. The effects of SA on M1-type and M2-type macrophages of RAW267.4 macrophages induced by LPS were detected by flow cytometry. The toxicity of compound SA to A549 cells was detected by MTT method which to determine the safe dose of SA. The expressions of COX-2 and the phosphorylation of p65 and IκBα protein in NF-κB pathway were detected by Western blot.

RESULTS

We found that the pre-treatment of SA significantly reduced the degree of lung injury, and the infiltration of neutrophils in the lung interstitium and alveolar space of the lung. The formation of transparent membrane in lung tissue and thickening of alveolar septum were significantly reduced compared with the model group, and the wet-dry ratio of the lung was also reduced. ELISA and RT-qPCR results showed that SA could significantly inhibit the production of IL-6, IL-1β, TNF-α. At the same time, SA could significantly inhibit the expression of iNOS and COX-2 proteins, and could inhibit the phosphorylation of p65 and IκBα proteins. in a dose-dependent manner. In vitro experiments, we found that flow cytometry showed that SA could significantly inhibit the polarization of macrophages from M0 type macrophages to M1-type macrophages, while SA could promote the polarization of M1-type macrophages to M2-type macrophages. The results of MTT assay showed that SA had no obvious cytotoxicity to A549 cells when the concentration was not higher than 80 μM, while LPS could promote the proliferation of A549 cells. In the study of anti-inflammatory effect, SA can significantly inhibit the expression of COX-2 and the phosphorylation of p65 and IκBα proteins in LPS-induced A549 cells.

CONCLUSION

SA has possessed a crucial anti-ALI role in LPS-induced mice. The mechanism was elucidated, suggesting that the inhibition of macrophage polarization to M1-type and the promotion of macrophage polarization to M2-type, as well as the inhibition of NF-κB pathway by SA may be the reasons for its anti-ALI. This finding provides important molecular evidence for the further application of SA in the clinical treatment of ALI.

Guben Qingfei decoction attenuates LPS-induced acute lung injury by modulating the TLR4/NF-κB and Keap1/Nrf2 signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury (ALI) is a life-threatening and widespread disease, with exceptionally high morbidity and mortality rates. Unfortunately, effective drugs for ALI treatment are currently lacking. Guben Qingfei decoction (GBQF) is a Chinese herbal compound known for its efficacy in treating viral pneumonia, yet the precise underlying mechanisms remain unknown.

AIM OF THE STUDY

This study aimed to validate the mitigating effect of GBQF on ALI and to further investigate its mechanism.

MATERIALS AND METHODS

An ALI mice model was established by infusing LPS into the endotracheal tube. The effects of GBQF on ALI were investigated by measuring lung W/D; MPO; BALF total protein concentration; total number of cells; TNF-α, IL-1β, and IL-6 levels; pathological changes in lung tissue, and oxidation products. Immunohistochemistry and Western Blotting were performed to verify the underlying mechanisms. MH-S and BEAS-2B cells were induced by LPS, and the effects of GBQF were confirmed by RT-PCR and immunofluorescence.

RESULTS

GBQF significantly reduced LPS-induced ALI in mice, improved lung inflammation, reduced the production of oxidative products, increased the activity of antioxidant enzymes, and reduced the degree of lung tissue damage. GBQF prevents MH-S cells from releasing inflammatory factors and reduces oxidative damage to BEAS-2B cells. In vivo studies have delved deeper into the mechanism of action of GBQF, revealing its correlation with the TLR4/NF-κB and Keap1/Nrf2 pathways.

CONCLUSIONS

Our study demonstrates that GBQF is an effective treatment for ALI, providing a new perspective on medication development for ALI treatment.

Protective effects of Prussian blue nanozyme against sepsis-induced acute lung injury by activating HO-1

Sepsis is a life-threatening condition involving dysfunctional organ responses stemming from dysregulated host immune reactions to various infections. The lungs are most prone to failure during sepsis, resulting in acute lung injury (ALI). ALI is associated with oxidative stress and inflammation, and current therapeutic strategies are limited. To develop a more specific treatment, this study aimed to synthesise Prussian blue nanozyme (PBzyme), which can reduce oxidative stress and inflammation, to alleviate ALI. PBzyme with good biosafety was synthesised using a modified hydrothermal method. PBzyme was revealed to be an activator of haem oxygenase-1 (HO-1), improving survival rate and ameliorating lung injury in mice. Zinc protoporphyrin, an inhibitor of HO-1, inhibited the prophylactic therapeutic efficacy of PBzyme on ALI, and affected the nuclear factor-κB signaling pathway and activity of HO-1. This study demonstrates that PBzyme can alleviate oxidative stress and inflammation through HO-1 and has a prophylactic therapeutic effect on ALI. This provides a new strategy and direction for the clinical treatment of sepsis-induced ALI.

Systemic meta-analysis: apigenin's effects on lung inflammation and oxidative stress

OBJECTIVE

This study aimed to investigate the potential anti-inflammatory and antioxidant effects of apigenin in rats with acute lung injury (ALI). We also examined changes in levels of inflammatory and antioxidant factors after apigenin treatment in a rat model of ALI.Methods: We searched several databases, including PubMed, Scopus, EMBASE, Web of Science, ProQuest, and GoogleScholar, to retrieve relevant articles for our systematic review and meta-analysis.Five studies with 226 rat models of ALI were included in this study. We investigated inflammatory factors and oxidative stress with the corresponding 95% confidence interval in three groups: 1. Group1 (control vs. ALI), 2. Group2 (ALI vs. apigenin10), and 3. Group3 (ALI vs. apigenin20).

RESULTS

Estimating the correlation and 95% confidence intervals for the inflammatory agents and oxidative stress in the intervention group (ALI), compared with that in the control group, respectively (correlation: 0.194; 95% confidence intervals, 0.101-0.282, p value = .001, z-value= 4.08) and (correlation: 0.099; 95% confidence intervals, 0.016-0.182, p value = .020, z value= 2.325). Estimating the correlation and 95% confidence intervals for the inflammatory agents and oxidative stress in the intervention group (apigenin 10 mg/kg), compared with that in the control group (ALI), respectively (correlation: 0.476; 95% confidence intervals, 0.391-0.553, p value = .001, z-value= 9.678) and (correlation: 0.415; 95% confidence intervals, 0.313-0.508, p value= .001, z-value= 7.349).

CONCLUSION

Apigenin may have potential anti-inflammatory and antioxidant effects in rat models of ALI. However, the efficacy of apigenin as a therapeutic strategy requires further investigation through prospective controlled randomized trials.

Alpinetin alleviates LPS-induced lung epithelial cell injury by inhibiting p38 and ERK1/2 signaling via aquaporin-1

Alpinetin has been reported to play a protective role in lung diseases, while its special mechanisms remain indistinct. In this study, acute lung injury (ALI) model was constructed by inducing MLE-12 cells with lipopolysaccharide (LPS). Cell activity together with apoptosis was judged employing cell counting kit-8 (CCK-8), flow cytometry along with western blot. Oxidative stress levels were measured by dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining and corresponding kits. In addition, enzyme-linked immunosorbent assay (ELISA) was to examine the levels of inflammatory factors. The protein expressions of aquaporin-1 (AQP1), p38 and extracellular signal-regulated kinase (ERK) 1/2 pathway were estimated utilizing western blot. The data showed that alpinetin increased the viability, reduced the apoptosis, oxidative stress and inflammation and inactivated p38 and ERK1/2 signaling in LPS-induced MLE-12 cells. Moreover, alpinetin also increased AQP1 expression and AQP1 knockdown reversed the impacts of alpinetin on LPS-induced MLE-12 cells. Additionally, AQP1 agonist AqF026 also exerted anti-apoptotic and anti-inflammatory activities in LPS-treated MLE-12 cells. Evidently, alpinetin may exert its protective role in LPS-induced ALI by inactivation of p38 and ERK1/2 signaling through regulating AQP1.

Liensinine reduces acute lung injury brought on by lipopolysaccharide by inhibiting the activation of the NF-κB signaling pathway through modification of the Src/TRAF6/TAK1 axis

ALI is characterized by macrophage-driven inflammation, causing severe lung damage. Currently, there are limited therapeutic options available for ALI. Liensinine (LIEN), with known anti-inflammatory properties, lacks extensive study in the ALI context. This study aimed to investigate the impact of LIEN on ALI and elucidate its molecular mechanisms. A total of thirty-six male BALB/c mice altogether were split into six groups: Control, LPS (10 mg/kg), Low (10 mg/kg LIEN + 10 mg/kg LPS), Middle (20 mg/kg LIEN + 10 mg/kg LPS), High (40 mg/kg LIEN + 10 mg/kg LPS), and DEX (2 mg/kg DEX + 10 mg/kg LPS). Lung tissue injury, pulmonary edema, and inflammatory factor levels were evaluated in lung tissues and LPS-stimulated bone marrow-derived macrophages (BMDM). TAK1 activation, TRAF6 ubiquitination, and their interactions were assessed to understand the involved molecular mechanisms. LIEN treatment ameliorated lung tissue injury and suppressed LPS-induced inflammatory factor levels in lung tissues and BMDM. Mechanistically, LIEN inhibited TAK1 activation by disrupting TRAF6-TAK1 interactions, limiting p65's nuclear translocation, and reducing the release of inflammatory factors. According to network pharmacology and molecular docking, LIEN most likely prevents inflammation by interfering directly with the Src. Overexpression of Src in BMDM abolished the regulation of TRAF6 by LIEN, supporting the involvement of the Src/TRAF6/TAK1 axis in its mechanism of action. Based on this study, LIEN treats ALI by modifying the Src/TRAF6/TAK1 axis and blocking the activation of the NF-κB pathway, regulating the release of inflammatory factors. These findings highlight the promise of LIEN as a prospective therapeutic option for the treatment of ALI.

Discovery of a doublecortin-like kinase 1 inhibitor to prevent inflammatory responses in acute lung injury

Doublecortin-like kinase 1 (DCLK1) is a microtubule-associated protein kinase involved in neurogenesis and human cancer. Recent studies have revealed a novel functional role for DCLK1 in inflammatory signaling, thus positioning it as a novel target kinase for respiratory inflammatory disease treatment. In this study, we designed and synthesized a series of NVP-TAE684-based derivatives as novel anti-inflammatory agents targeting DCLK1. Bio-layer interferometry binding screening and kinase assays of the NVP-TAE684 derivatives led to the discovery of an effective DCLK1 inhibitor (a24), with an IC50 of 179.7 nM. Compound a24 effectively inhibited lipopolysaccharide (LPS)-induced inflammation in macrophages with higher potency than the lead compound. Mechanistically, compound a24 inhibited LPS-induced inflammation by inhibiting DCLK1-mediated IKKβ phosphorylation. Furthermore, compound a24 showed in vivo anti-inflammatory activity in an LPS-challenged acute lung injury model. These findings suggest that compound a24 may serve as a novel candidate for the development of DCLK1 inhibitors and a potential therapeutic agent for the treatment of inflammatory diseases.

Adhesion molecule-targeted magnetic particle imaging nanoprobe for visualization of inflammation in acute lung injury

PURPOSE

Uncontrolled intra-alveolar inflammation is a central pathogenic feature, and its severity translates into a valid prognostic indicator of acute lung injury (ALI). Unfortunately, current clinical imaging approaches are unsuitable for visualizing and quantifying intra-alveolar inflammation. This study aimed to construct a small-sized vascular cell adhesion molecule-1 (VCAM-1)-targeted magnetic particle imaging (MPI) nanoprobe (ESPVPN) to visualize and accurately quantify intra-alveolar inflammation at the molecular level.

METHODS

ESPVPN was engineered by conjugating a peptide (VHPKQHRGGSK(Cy7)GC) onto a polydopamine-functionalized superparamagnetic iron oxide core. The MPI performance, targeting, and biosafety of the ESPVPN were characterized. VCAM-1 expression in HUVECs and mouse models was evaluated by western blot. The degree of inflammation and distribution of VCAM-1 in the lungs were assessed using histopathology. The expression of pro-inflammatory markers and VCAM-1 in lung tissue lysates was measured using ELISA. After intravenous administration of ESPVPN, MPI and CT imaging were used to analyze the distribution of ESPVPN in the lungs of the LPS-induced ALI models.

RESULTS

The small-sized (~10 nm) ESPVPN exhibited superior MPI performance compared to commercial MagImaging® and Vivotrax, and ESPVPN had effective targeting and biosafety. VCAM-1 was highly expressed in LPS-induced ALI mice. VCAM-1 expression was positively correlated with the LPS-induced dose (R = 0.9381). The in vivo MPI signal showed positive correlations with both VCAM-1 expression (R = 0.9186) and representative pro-inflammatory markers (MPO, TNF-α, IL-6, IL-8, and IL-1β, R > 0.7).

CONCLUSION

ESPVPN effectively targeted inflammatory lungs and combined the advantages of MPI quantitative imaging to visualize and evaluate the degree of ALI inflammation.

Inhalation Injury, Respiratory Failure, and Ventilator Support in Acute Burn Care

Sustaining an inhalation injury increases the risk of severe complications and mortality. Current evidential support to guide treatment of the injury or subsequent complications is lacking, as studies either exclude inhalation injury or design limit inferences that can be made. Conventional ventilator modes are most commonly used, but there is no consensus on optimal strategies. Settings should be customized to patient tolerance and response. Data for pharmacotherapy adjunctive treatments are limited.

Danshensu methyl ester attenuated LPS-induced acute lung injury by inhibiting TLR4/NF-κB pathway

Acute Lung Injury (ALI) manifests as an acute exacerbation of pulmonary inflammation with high mortality. The potential application of Danshensu methyl ester (DME, synthesized in our lab) in ameliorating ALI has not been elucidated. Our results demonstrated that DME led to a remarkable reduction in lung injury. DME promoted a marked increase in antioxidant enzymes, like superoxide dismutase (SOD), and glutathione (GSH), accompanied by a substantial decrease in reactive oxygen species (ROS), myeloperoxidase (MPO), and malondialdehyde (MDA). Moreover, DME decreased the production of IL-1β, TNF-α and IL-6, in vitro and in vivo. TLR4 and MyD88 expression is reduced in the DME-treated cells or tissues, which further leading to a decrease of p-p65 and p-IκBα. Meanwhile, DME effectively facilitated an elevation in cytoplasmic p65 expression. In summary, DME could ameliorate ALI by its antioxidant functionality and anti-inflammation effects through TLR4/NF-κB, which implied that DME may be a viable medicine for lung injury.

Effect fraction of Bletilla striata (Thunb.) Reichb.f. alleviates LPS-induced acute lung injury by inhibiting p47phox/NOX2 and promoting the Nrf2/HO-1 signaling pathway

BACKGROUND & AIMS

The effect fraction of Bletilla striata (Thunb.) Reichb.f. (EFBS), a phenolic-rich extract, has significant protective effects on lipopolysaccharide (LPS)-induced acute lung injury (ALI), but its composition and molecular mechanisms are unclear. This study elucidated its chemical composition and possible protective mechanisms against LPS-induced ALI from an antioxidant perspective.

METHODS

EFBS was prepared by ethanol extraction, enriched by polyamide column chromatography, and characterized using ultra-performance liquid chromatography/time-of-flight mass spectrometry. The LPS-induced ALI model and the RAW264.7 model were used to evaluate the regulatory effects of EFBS on oxidative stress, and transcriptome analysis was performed to explore its possible molecular mechanism. Then, the pathway by which EFBS regulates oxidative stress was validated through inhibitor intervention, flow cytometry, quantitative PCR, western blotting, and immunofluorescence techniques.

RESULTS

A total of 22 compounds in EFBS were identified. The transcriptome analyses of RAW264.7 cells indicated that EFBS might reduce reactive oxygen species (ROS) production by inhibiting the p47phox/NADPH oxidase 2 (NOX2) pathway and upregulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. Both in vitro and in vivo data confirmed that EFBS significantly inhibited the expression and phosphorylation of p47phox protein, thereby weakening the p47phox/NOX2 pathway and reducing ROS production. EFBS significantly increased the expression of Nrf2 in primary peritoneal macrophages and lung tissue and promoted its nuclear translocation, dose-dependent increase in HO-1 levels, and enhancement of antioxidant activity. In vitro, both Nrf2 and HO-1 inhibitors significantly reduced the scavenging effects of EFBS on ROS, further confirming that EFBS exerts antioxidant effects at least partially by upregulating the Nrf2/HO-1 pathway.

CONCLUSIONS

EFBS contains abundant phenanthrenes and dibenzyl polyphenols, which can reduce ROS production by inhibiting the p47phox/NOX2 pathway and enhance ROS clearance activity by upregulating the Nrf2/HO-1 pathway, thereby exerting regulatory effects on oxidative stress and improving LPS-induced ALI.

Sulfasalazine ameliorates lipopolysaccharide-induced acute lung injury by inhibiting oxidative stress and nuclear factor-kappaB pathways

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) has a high mortality rate and incidence of complications. The pathophysiology of ALI/ARDS is still not fully understood. The lipopolysaccharide (LPS)-induced mouse model of ALI has been widely used to study human ALI/ARDS. Sulfasalazine (SASP) has antibacterial and anti-inflammatory effects and is used for treating inflammatory bowel and rheumatic diseases. However, the effect of SASP on LPS-induced ALI in mice has not yet been reported. Therefore, we aimed to investigate the effect of SASP on LPS-induced ALI in mice. Mice were intraperitoneally injected with SASP 2 h before or 4 h after LPS modeling. Pulmonary pathological damage was measured based on inflammatory factor expression (malondialdehyde and superoxide dismutase levels) in the lung tissue homogenate and alveolar lavage fluid. The production of inflammatory cytokines and occurrence of oxidative stress in the lungs induced by LPS were significantly mitigated after the prophylactic and long-term therapeutic administration of SASP, which ameliorated ALI caused by LPS. SASP reduced both the production of inflammatory cytokines and occurrence of oxidative stress in RAW264.7 cells, which respond to LPS. Moreover, its mechanism contributed to the suppression of NF-κB and nuclear translocation. In summary, SASP treatment ameliorates LPS-induced ALI by mediating anti-inflammatory and antioxidant effects, which may be attributed to the inhibition of NF-κB activation and promotion of antioxidant defenses. Thus, SASP may be a promising pharmacologic agent for ALI therapy.

Immunometabolic reprogramming of macrophages with inhalable CRISPR/Cas9 nanotherapeutics for acute lung injury intervention

Acute lung injury (ALI) represents a critical respiratory condition typified by rapid-onset lung inflammation, contributing to elevated morbidity and mortality rates. Central to ALI pathogenesis lies macrophage dysfunction, characterized by an overabundance of pro-inflammatory cytokines and a shift in metabolic activity towards glycolysis. This study emphasizes the crucial function of glucose metabolism in immune cell function under inflammatory conditions and identifies hexokinase 2 (HK2) as a key regulator of macrophage metabolism and inflammation. Given the limitations of HK2 inhibitors, we propose the CRISPR/Cas9 system for precise HK2 downregulation. We developed an aerosolized core-shell liposomal nanoplatform (CSNs) complexed with CaP for efficient drug loading, targeting lung macrophages. Various CSNs were synthesized to encapsulate an mRNA based CRISPR/Cas9 system (mCas9/gHK2), and their gene editing efficiency and HK2 knockout were examined at both gene and protein levels in vitro and in vivo. The CSN-mCas9/gHK2 treatment demonstrated a significant reduction in glycolysis and inflammation in macrophages. In an LPS-induced ALI mouse model, inhaled CSN-mCas9/gHK2 mitigated the proinflammatory tumor microenvironment and reprogrammed glucose metabolism in the lung, suggesting a promising strategy for ALI prevention and treatment. This study highlights the potential of combining CRISPR/Cas9 gene editing with inhalation delivery systems for effective, localized pulmonary disease treatment, underscoring the importance of targeted gene modulation and metabolic reprogramming in managing ALI. STATEMENT OF SIGNIFICANCE: This study investigates an inhalable CRISPR/Cas9 gene editing system targeting pulmonary macrophages, with the aim of modulating glucose metabolism to alleviate Acute Lung Injury (ALI). The research highlights the role of immune cell metabolism in inflammation, as evidenced by changes in macrophage glucose metabolism and a notable reduction in pulmonary edema and inflammation. Additionally, observed alterations in macrophage polarization and cytokine levels in bronchoalveolar lavage fluid suggest potential therapeutic implications. These findings not only offer insights into possible ALI treatments but also contribute to the understanding of immune cell metabolism in inflammatory diseases, which could be relevant for various inflammatory and metabolic disorders.

Hydrogen ameliorates endotoxin-induced acute lung injury through AMPK-mediated bidirectional regulation of Caspase3

Septic lung injury is characterized by uncontrollable inflammatory infiltrations and acute onset bilateral hypoxemia. Evidence has emerged of the beneficial effect of hydrogen in acute lung injury (ALI), but the underlying mechanism is unclear. In this research, the recovery action of hydrogen on lipopolysaccharide (LPS)-induced ALI in mice and A549 cells was investigated. The 7-day survival rate and body weight of mice were measured after intraperitoneal injection of LPS. Lung function was determined by a whole body plethysmography (WBP) system using the indicators respiratory rate and enhanced pause. Hematoxylin and eosin (HE) staining confirmed the signs of pulmonary edema and inflammatory ooze. Reverse transcription-polymerase chain reaction (RT-PCR) quantification was used to detect the expression of inflammatory factors. Western blotting analysis evaluated the expression levels of involved proteins in the AMP-activated protein kinase (AMPK) pathway. The experimental results confirmed that hydrogen provided an essential solution to the dissipative effects of LPS on survival rate, weight loss and lung function. The LPS-stimulated inflammatory factors, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were also suppressed by hydrogen in A549 cells. Western blot analysis showed that hydrogen significantly upregulated the levels of phosphorylated AMPK (p-AMPK) and lowered the LPS-induced increased expression of dynamin-related protein 1 (Drp1) and Caspase3. These findings prove that hydrogen attenuated LPS-treated ALI by activating the AMPK pathway, supporting the feasibility of hydrogen treatment for sepsis.

Inhibition of CISD1 alleviates mitochondrial dysfunction and ferroptosis in mice with acute lung injury

The NET family member, CDGSH iron-sulfur domain-containing protein 1 (CISD1), is located in theoutermembrane of mitochondria, where it regulates energy and iron metabolism. CISD1 has vital functions in certain human diseases; however, its function in acute lung injury (ALI) is unknown. ALI pathogenesis critically involves mitochondrial dysfunction and ferroptosis, which might be regulated by CISD1. Therefore, we investigated CISD1's function in mitochondrial dysfunction and ferroptosis regulation in lipopolysaccharide (LPS)-induced ALI. We found that CISD1 was upregulated in LPS-induced ALI,and silencing Cisd1 prevented cell apoptosis and increased cell viability. When CISD1was inhibited by mitoNEET ligand-1 (NL-1) there was a significant mitigation of pathological injury and lung edema, and reduced numbers of total cells, polymorphonuclear leukocytes, and a decreased protein content in the bronchoalveolar lavage fluid (BALF). Moreover, inhibition of CISD1 markedly decreased the interleukin (IL)6, IL-1β, and tumor necrosis factor alpha (TNF-α) levels in the lungs and BALF of ALI-model mice. Silencing of Cisd1 prevented LPS-induced mitochondrial membrane potential depolarization, cellular ATP reduction, and reactive oxygen species (ROS) accumulation, suggesting mitochondrial protection. ALI activated ferroptosis, as evidenced by the increased lipid-ROS, intracellular Fe2+ level, reduced Gpx4 (glutathione peroxidase 4) expression, and the glutathione/glutathione disulfide ratio. Interestingly, inhibition of CISD1 reduced LPS-induced ferroptosis in vivo and in vitro. In conclusion, inhibition of CISD1 alleviated mitochondrial dysfunction and ferroptosis in LPS-induced ALI, identifying CISD1 as possible target for therapy of LPS-induced ALI.

QiShenYiQi pills preserve endothelial barrier integrity to mitigate sepsis-induced acute lung injury by inhibiting ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

The QiShengYiQi pill (QSYQ) is a traditional Chinese medicinal formulation. The effectiveness and safety of QSYQ in treating respiratory system disorders have been confirmed. Its pharmacological actions include anti-inflammation, antioxidative stress, and improving energy metabolism. However, the mechanism of QSYQ in treating sepsis-induced acute lung injury (si-ALI) remains unclear.

AIM OF THE STUDY

Si-ALI presents a clinical challenge with high incidence and mortality rates. This study aims to confirm the efficacy of QSYQ in si-ALI and to explore the potential mechanisms, providing a scientific foundation for its application and insights for optimizing treatment strategies and identifying potential active components.

MATERIALS AND METHODS

The impact of QSYQ on si-ALI was evaluated using the cecal ligation and puncture (CLP) experimental sepsis animal model. The effects of QSYQ on endothelial cells were observed through coculturing with LPS-stimulated macrophage-conditioned medium. Inflammatory cytokine levels, HE staining, Evans blue staining, lung wet/dry ratio, and cell count and protein content in bronchoalveolar lavage fluid were used to assess the degree of lung injury. Network pharmacology was utilized to investigate the potential mechanisms of QSYQ in treating si-ALI. Western blot and immunofluorescence analyses were used to evaluate barrier integrity and validate mechanistically relevant proteins.

RESULTS

QSYQ reduced the inflammation and alleviated pulmonary vascular barrier damage in CLP mice (all P < 0.05). A total of 127 potential targets through which QSYQ regulates si-ALI were identified, predominantly enriched in the RAGE pathway. The results of protein-protein interaction analysis suggest that COX2, a well-established critical marker of ferroptosis, is among the key targets. In vitro and in vivo studies demonstrated that QSYQ mitigated ferroptosis and vascular barrier damage in sepsis (all P < 0.05), accompanied by a reduction in oxidative stress and the inhibition of the COX2 and RAGE (all P < 0.05).

CONCLUSIONS

This study demonstrated that QSYQ maintains pulmonary vascular barrier integrity by inhibiting ferroptosis in CLP mice. These findings partially elucidate the mechanism of QSYQ in si-ALI and further clarify the active components of QSYQ, thereby providing a scientific theoretical basis for treating si-ALI with QSYQ.

Strictosamide ameliorates LPS-induced acute lung injury by targeting ERK2 and mediating NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury (ALI) ranks among the deadliest pulmonary diseases, significantly impacting mortality and morbidity. Presently, the primary treatment for ALI involves supportive therapy; however, its efficacy remains unsatisfactory. Strictosamide (STR), an indole alkaloid found in the Chinese herbal medicine Nauclea officinalis (Pierre ex Pit.) Merr. & Chun (Wutan), has been found to exhibit numerous pharmacological properties, particularly anti-inflammatory effects.

AIM OF THE STUDY

This study aimes to systematically identify and validate the specific binding proteins targeted by STR and elucidate its anti-inflammatory mechanism in lipopolysaccharide (LPS)-induced ALI.

MATERIALS AND METHODS

Biotin chemical modification, protein microarray analysis and network pharmacology were conducted to screen for potential STR-binding proteins. The binding affinity was assessed through surface plasmon resonance (SPR), cellular thermal shift assay (CETSA) and molecular docking, and the anti-inflammatory mechanism of STR in ALI treatment was assessed through in vivo and in vitro experiments.

RESULTS

Biotin chemical modification, protein microarray and network pharmacology identified extracellular-signal-regulated kinase 2 (ERK2) as the most important binding proteins among 276 candidate STR-interacting proteins and nuclear factor-kappaB (NF-κB) pathway was one of the main inflammatory signal transduction pathways. Using SPR, CETSA, and molecular docking, we confirmed STR's affinity for ERK2. In vitro and in vivo experiments demonstrated that STR mitigated inflammation by targeting ERK2 to modulate the NF-κB signaling pathway in LPS-induced ALI.

CONCLUSIONS

Our findings indicate that STR can inhibit the NF-κB signaling pathway to attenuate LPS-induced inflammation by targeting ERK2 and decreasing phosphorylation of ERK2, which could be a novel strategy for treating ALI.

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

BACKGROUND

Severe respiratory system illness caused by influenza A virus infection is associated with excessive inflammation and abnormal apoptosis in alveolar epithelial cells (AEC). However, there are limited therapeutic options for influenza-associated lung inflammation and apoptosis. Pterostilbene (PTE, trans-3,5-dimethoxy-4-hydroxystilbene) is a dimethylated analog of resveratrol that has been reported to limit influenza A virus infection by promoting antiviral innate immunity, but has not been studied for its protective effects on virus-associated inflammation and injury in AEC.

PURPOSE

Our study aimed to investigate the protective effects and underlying mechanisms of PTE in modulating inflammation and apoptosis in AEC, as well as its effects on macrophage polarization during influenza virus infection.

STUDY DESIGN AND METHODS

A murine model of influenza A virus-mediated acute lung injury was established by intranasal inoculation with 5LD50 of mouse-adapted H1N1 viruses. Hematoxylin and eosin staining, immunofluorescence, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, western blotting, Luminex and flow cytometry were performed.

RESULTS

PTE effectively mitigated lung histopathological changes and injury induced by H1N1 viruses in vivo. These beneficial effects of PTE were attributed to the suppression of inflammation and apoptosis in AEC, as well as the modulation of M1 macrophage polarization. Mechanistic investigations revealed that PTE activated the phosphorylated AMP-activated protein kinase alpha (P-AMPKα)/sirtui1 (Sirt1)/PPARγ coactivator 1-alpha (PGC1α) signal axis, leading to the inhibition of nuclear factor kappa-B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) signaling induced by H1N1 viruses, thereby attenuating inflammation and apoptosis in AEC. PTE also forced activation of the P-AMPKα/Sirt1/PGC1α signal axis in RAW264.7 cells, counteracting the activation of phosphorylated signal transducer and activator of transcription 1 (P-STAT1) induced by H1N1 viruses and the augment of P-STAT1 activation in RAW264.7 cells with interferon-gamma (IFN-γ) pretreatment before viral infection, thereby reducing H1N1 virus-mediated M1 macrophage polarization as well as the enhancement of macrophages into M1 phenotypes elicited by IFN-γ pretreatment. Additionally, the promotion of the transition of macrophages towards the M2 phenotype by PTE was also related to activation of the P-AMPKα/Sirt1/PGC1α signal axis. Moreover, co-culturing non-infected AEC with H1N1 virus-infected RAW264.7 cells in the presence of PTE inhibited apoptosis and tight junction disruption, which was attributed to the suppression of pro-inflammatory mediators and pro-apoptotic factors in an AMPKα-dependent manner.

CONCLUSION

In conclusion, our findings suggest that PTE may serve as a promising novel therapeutic option for treating influenza-associated lung injury. Its ability to suppress inflammation and apoptosis in AEC, modulate macrophage polarization, and preserve alveolar epithelial cell integrity highlights its potential as a therapeutic agent in influenza diseases.

Overexpression of Wnt5a promoted the protective effect of mesenchymal stem cells on Lipopolysaccharide-induced endothelial cell injury via activating PI3K/AKT signaling pathway

BACKGROUND

Lung endothelial barrier injury plays an important role in the pathophysiology of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Mesenchymal stem cells (MSCs) therapy has shown promise in ARDS treatment and restoration of the impaired barrier function. It has been reported that Wnt5a shows protective effects on endothelial cells. Therefore, the study aimed to investigate whether overexpression of Wnt5a could promote the protective effects of MSCs on Lipopolysaccharide (LPS)-induced endothelial cell injury.

METHODS

To evaluate the protective effects of MSCs overexpressing Wnt5a, we assessed the migration, proliferation, apoptosis, and angiogenic ability of endothelial cells. We assessed the transcription of protective cellular factors using qPCR and determined the molecular mechanism using Western blot analysis.

RESULTS

Overexpression of Wnt5a upregulated the transcription of protective cellular factors in MSCs. Co-culture of MSCWnt5a promoted endothelial migration, proliferation and angiogenesis, and inhibited endothelial cell apoptosis through the PI3K/AKT pathway.

CONCLUSIONS

Overexpression of Wnt5a promoted the therapeutic effect of MSCs on endothelial cell injury through the PI3K/AKT signaling. Our study provides a novel approach for utilizing genetically modified MSCs in the transplantation therapy for ARDS.

Engineered extracellular vesicles carrying let-7a-5p for alleviating inflammation in acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening respiratory condition characterized by severe inflammation and lung tissue damage, frequently causing rapid respiratory failure and long-term complications. The microRNA let-7a-5p is involved in the progression of lung injury, inflammation, and fibrosis by regulating immune cell activation and cytokine production. This study aims to use an innovative cellular electroporation platform to generate extracellular vesicles (EVs) carring let-7a-5p (EV-let-7a-5p) derived from transfected Wharton's jelly-mesenchymal stem cells (WJ-MSCs) as a potential gene therapy for ALI.

METHODS

A cellular nanoporation (CNP) method was used to induce the production and release of EV-let-7a-5p from WJ-MSCs transfected with the relevant plasmid DNA. EV-let-7a-5p in the conditioned medium were isolated using a tangential flow filtration (TFF) system. EV characterization followed the minimal consensus guidelines outlined by the International Society for Extracellular Vesicles. We conducted a thorough set of therapeutic assessments, including the antifibrotic effects using a transforming growth factor beta (TGF-β)-induced cell model, the modulation effects on macrophage polarization, and the influence of EV-let-7a-5p in a rat model of hyperoxia-induced ALI.

RESULTS

The CNP platform significantly increased EV secretion from transfected WJ-MSCs, and the encapsulated let-7a-5p in engineered EVs was markedly higher than that in untreated WJ-MSCs. These EV-let-7a-5p did not influence cell proliferation and effectively mitigated the TGF-β-induced fibrotic phenotype by downregulating SMAD2/3 phosphorylation in LL29 cells. Furthermore, EV-let-7a-5p regulated M2-like macrophage activation in an inflammatory microenvironment and significantly induced interleukin (IL)-10 secretion, demonstrating their modulatory effect on inflammation. Administering EVs from untreated WJ-MSCs slightly improved lung function and increased let-7a-5p expression in plasma in the hyperoxia-induced ALI rat model. In comparison, EV-let-7a-5p significantly reduced macrophage infiltration and collagen deposition while increasing IL-10 expression, causing a substantial improvement in lung function.

CONCLUSION

This study reveals that the use of the CNP platform to stimulate and transfect WJ-MSCs could generate an abundance of let-7a-5p-enriched EVs, which underscores the therapeutic potential in countering inflammatory responses, fibrotic activation, and hyperoxia-induced lung injury. These results provide potential avenues for developing innovative therapeutic approaches for more effective interventions in ALI.

Intact lung tissue and bronchoalveolar lavage fluid are both suitable for the evaluation of murine lung microbiome in acute lung injury

BACKGROUND

Accumulating clinical evidence suggests that lung microbiome is closely linked to the progression of pulmonary diseases; however, it is still controversial which specimen type is preferred for the evaluation of lung microbiome.

METHODS AND RESULTS

To address this issue, we established a classical acute lung injury (ALI) mice model by intratracheal instillation of lipopolysaccharides (LPS). We found that the bacterial DNA obtained from the bronchoalveolar lavage fluid (BALF), intact lung tissue [Lung(i)], lung tissue after perfused [Lung(p)], and feces of one mouse were enough for 16S rRNA sequencing, except the BALF of mice treated with phosphate buffer saline (PBS), which might be due to the biomass of lung microbiome in the BALF were upregulated in the mice treated with LPS. Although the alpha diversity among the three specimens from lungs had minimal differences, Lung(p) had higher sample-to-sample variation compared with BALF and Lung(i). Consistently, PCoA analysis at phylum level indicated that BALF was similar to Lung(i), but not Lung(p), in the lungs of mice treated with LPS, suggesting that BALF and Lung(i) were suitable for the evaluation of lung microbiome in ALI. Importantly, Actinobacteria and Firmicutes were identified as the mostly changed phyla in the lungs and might be important factors involved in the gut-lung axis in ALI mice. Moreover, Actinobacteria and Proteobacteria might play indicative roles in the severity of lung injury.

CONCLUSION

This study shows both Lung(i) and BALF are suitable for the evaluation of murine lung microbiome in ALI, and several bacterial phyla, such as Actinobacteria, may serve as potential biomarkers for the severity of ALI. Video Abstract.

Asiatic acid cyclodextrin inclusion micro-cocrystal for insoluble drug delivery and acute lung injury therapy enhancement

BACKGROUND

Acute lung injury (ALI) is a fatal respiratory disease caused by overreactive immune reactions (e.g., SARS-CoV-2 infection), with a high mortality rate. Its treatment is often compromised by inefficient drug delivery barriers and insufficient potency of the currently used drugs. Therefore, developing a highly effective lung-targeted drug delivery strategy is a pressing clinical need.

RESULTS

In this study, the micro-sized inclusion cocrystal of asiatic acid/γ-cyclodextrin (AA/γCD, with a stoichiometry molar ratio of 2:3 and a mean size of 1.8 μm) was prepared for ALI treatment. The dissolution behavior of the AA/γCD inclusion cocrystals followed a "spring-and-hover" model, which meaned that AA/γCD could dissolve from the cocrystal in an inclusion complex form, thereby promoting a significantly improved water solubility (nine times higher than free AA). This made the cyclodextrin-based inclusion cocrystals an effective solid form for enhanced drug absorption and delivery efficiency. The biodistribution experiments demonstrated AA/γCD accumulated predominantly in the lung (Cmax = 50 µg/g) after systemic administration due to the micron size-mediated passive targeting effect. The AA/γCD group showed an enhanced anti-inflammatory therapeutic effect, as evidenced by reduced levels of pro-inflammatory cytokines in the lung and bronchoalveolar lavage fluids (BALF). Histological examination confirmed that AA/γCD effectively inhibited inflammation reactions.

CONCLUSION

The micro-sized inclusion cocrystals AA/γCD were successfully delivered into the lungs by pulmonary administration and had a significant therapeutic effect on ALI.

Total synthesis and structural modification of the dibenzylbutane lignan LCA as a potent anti-inflammatory agent against LPS-induced acute lung injury

Acute lung injury (ALI) is a serious public health problem associated with high morbidity and mortality. However, few efficacious drugs are clinically available. Inhibition of proinflammatory cytokines is considered to be a promising method for the treatment of inflammatory diseases. Herein, the total synthesis of a dibenzylbutane lignan, 9'-O-di-(E)-feruloyl-meso-5,5'-dimethoxysecoisolariciresinol (LCA), was completed. A series of LCA derivatives were designed and synthesized, and their anti-inflammatory activities were evaluated. Derivative 14r significantly inhibited LPS-induced expression of NO and the proinflammatory cytokines TNF-α, IL-6, and IL-1β in RAW 264.7 cells and inhibited activation of the NF-κB pathway. Compound 14r reduced LPS-induced pulmonary inflammation and ALI in mice. It showed significant protective effects against LPS-induced ALI in mice and significantly reduced levels of proinflammatory cytokines in serum and bronchoalveolar lavage fluid. The ratio of wet weight to dry weight of lung tissue was normalized by compound 14r, which was consistent with suppression of neutrophil infiltration and production of proinflammatory cytokines. Compound 14r reduced the mRNA expression of some proinflammatory cytokines, improved histopathologic changes, and reduced macrophage infiltration in lung tissues. Collectively, these results suggest a new series of LCA derivatives that could be promising anti-inflammatory agents for ALI treatment.

Discovery of novel osthole derivatives exerting anti-inflammatory effect on DSS-induced ulcerative colitis and LPS-induced acute lung injury in mice

The modification based on natural products is a practical way to find anti-inflammatory drugs. In this study, 26 osthole derivatives were synthesized, and their anti-inflammatory properties were evaluated. The preliminary activity study revealed that most osthole derivatives could effectively inhibit inflammatory cytokines IL-6 secretion in LPS stimulated mouse macrophages J774A.1. Compound 7m exhibited the most effective anti-inflammatory activity (RAW264.7 IL-6 IC50: 4.57 μM, 32 times more active than osthole) in vitro with no significant influence on cell proliferation. Additionally, the mechanistic analysis demonstrated that compound 7m could block MAPK signal transduction by inhibiting the phosphorylation of JNK and p38, thereby inhibiting the release of inflammatory cytokines. Moreover, in vivo functional investigations revealed that 7m could substantially reduce DSS-induced ulcerative colitis and LPS-induced acute lung injury, with good therapeutic effects. The pharmacokinetics and acute toxicity experiments proved the safety and reliability of 7min vivo. Overall, Compound 7m could further be studied as potential anti-inflammatory candidate.

Mesenchymal stem cells inhibit ferroptosis by activating the Nrf2 antioxidation pathway in severe acute pancreatitis-associated acute lung injury

Severe acute pancreatitis-associated acute lung injury (SAP-ALI) remains a significant challenge for healthcare practitioners because of its high morbidity and mortality; therefore, there is an urgent need for an effective treatment. Mesenchymal stem cells (MSCs) have shown significant potential in the treatment of a variety of refractory diseases, including lung diseases. This study aimed to investigate the protective effects of MSCs against SAP-ALI and its underlying mechanisms. Our results suggest that MSCs mitigate pathological injury, hemorrhage, edema, inflammatory response in lung tissue, and lipopolysaccharide (LPS)-induced cell damage in RLE-6TN cells (a rat alveolar epithelial cell line). The results also showed that MSCs, similar to the effects of ferrostatin-1 (ferroptosis inhibitor), suppressed the ferroptosis response, which was manifested as down-regulated Fe2+, malondialdehyde, and reactive oxygen species (ROS) levels, and up-regulated glutathione peroxidase 4 (GPX4) and glutathione (GSH) levels in vivo and in vitro. The activation of ferroptosis by erastin (a ferroptosis agonist) reversed the protective effect of MSCs against SAP-ALI. Furthermore, MSCs activated the nuclear factor erythroid 2 associated factor 2 (Nrf2) transcription factor, and blocking the Nrf2 signaling pathway with ML385 abolished the inhibitory effect of MSCs on ferroptosis in vitro. Collectively, these results suggest that MSCs have therapeutic effects against SAP-ALI. The specific mechanism involves inhibition of ferroptosis by activating the Nrf2 transcription factor.