Treatment Of Acute Lung Injury Research Articles

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.

Recent progress in mesenchymal stem cell-based therapy for acute lung injury.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening diseases in critically ill patients. Although pathophysiology of ALI/ARDS has been investigated in many studies, effective therapeutic strategies are still limited. Mesenchymal stem cell (MSC)-based therapy is emerging as a promising therapeutic intervention for patients with ALI. During the last two decades, researchers have focused on the efficacy and mechanism of MSC application in ALI animal models. MSC derived from variant resources exhibited therapeutic effects in preclinical studies of ALI with different mechanisms. Based on this, clinical studies on MSC treatment in ALI/ARDS has been tried recently, especially in COVID-19 caused lung injury. Emerging clinical trials of MSCs in treating COVID-19-related conditions have been registered in past two years. The advantages and potential of MSCs in the defense against COVID-19-related ALI or ARDS have been confirmed. This review provides a brief overview of recent research progress in MSC-based therapies in preclinical study and clinical trials in ALI treatment, as well as the underlying mechanisms.

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.

Tempol alleviates acute lung injury by affecting glutathione synthesis through Nrf2 and inhibiting ferroptosis in lung epithelial cells.

As a life-threatening disease, acute lung injury (ALI) may progress to chronic pulmonary fibrosis. For the treatment of lung injury, Tempol is a superoxide dismutase mimetic and intracellular redox agent that can be a potential drug. This study investigated the regulatory mechanism of Tempol in the treatment of ALI. A mouse model of ALI was established, and HE staining was used to examine histomorphology. The CCK-8 assay was used to measure cell viability, and oxidative stress was assessed by corresponding kits. Flow cytometry and dichlorodihydrofluorescein diacetatestaining assays were used to detect reactive oxygen species (ROS)levels. Protein expression levels were measured by Western blot analysis and ELISA. Pulmonary vascular permeability was used to measure the lung wet/dry weight ratio. The level of oxidative stress was increased in ALI mice, and the level of ferroptosis was upregulated. Tempol inhibited this effect and alleviated ALI. The administration of Tempol alleviated the pathological changes in ALI, inhibited pulmonary vascular permeability, and improved lung injury in ALI mice. The upregulation of genes essential for glutathione (GSH) metabolism induced by lipopolysaccharide(LPS) was inhibited by Tempol. In addition,nuclear factor-related factor 2 (Nrf2)is activated by Tempol therapy to regulate the de novo synthesis pathway of GSH, thereby alleviating LPS-induced lung epithelial cell damage. The results showed that Tempol alleviated ALI by activating the Nrf2 pathway to inhibit oxidative stress and ferroptosis in lung epithelial cells. In conclusion, this study demonstrates that Tempol alleviates ALI by inhibiting ferroptosis in lung epithelial cells through the effect of Nrf2 on GSH synthesis.

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.

Efferocytosis-Inspired Biomimetic Nanoplatform for Targeted Acute Lung Injury Therapy.

Acute lung injury (ALI) is a serious inflammatory disease that causes impairment of pulmonary function. Phenotypic modulation of macrophage in the lung using fibroblast growth factor 21 (FGF21) may be a potential strategy to alleviate lung inflammation. Consequently, achieving specific delivery of FGF21 to the inflamed lung and subsequent efficient FGF21 internalization by macrophages within the lung becomes critical for effective ALI treatment. Here, an apoptotic cell membrane-coated zirconium-based metal-organic framework UiO-66 is reported for precise pulmonary delivery of FGF21 (ACM@U-FGF21) whose design is inspired by the process of efferocytosis. ACM@U-FGF21 with apoptotic signals is recognized and internalized by phagocytes in the blood and macrophages in the lung, and then the intracellular ACM@U-FGF21 can inhibit the excessive secretion of pro-inflammatory cytokines by these cells to relieve the inflammation. Utilizing the homologous targeting properties inherited from the source cells and the spontaneous recruitment of immune cells to inflammatory sites, ACM@U-FGF21 can accumulate preferentially in the lung after injection. The results prove that ACM@U-FGF21 effectively reduces inflammatory damage to the lung by modulating lung macrophage polarization and suppressing the excessive secretion of pro-inflammatory cytokines by activated immune cells. This study demonstrates the usefulness of efferocytosis-inspired ACM@U-FGF21 in the treatment of ALI.

Decreased LPS-induced lung injury in pigs treated with a lung surfactant protein A-derived nonapeptide that inhibits peroxiredoxin 6 activity and subsequent NOX1,2 activation.

This study addressed the efficacy of a liposome-encapsulated nine amino acid peptide [peroxiredoxin 6 PLA2 inhibitory peptide-2 (PIP-2)] for the prevention or treatment of acute lung injury (ALI) +/- sepsis. PIP-2 inhibits the PLA2 activity of peroxiredoxin 6 (Prdx6), thereby preventing rac release and activation of NADPH oxidases (NOXes), types 1 and 2. Female Yorkshire pigs were infused intravenously with lipopolysaccharide (LPS) + liposomes (untreated) or LPS + PIP-2 encapsulated in liposomes (treated). Pigs were mechanically ventilated and continuously monitored; they were euthanized after 8 h or earlier if preestablished humane endpoints were reached. Control pigs (mechanical ventilation, no LPS) were essentially unchanged over the 8 h study. LPS administration resulted in systemic inflammation with manifestations of clinical sepsis-like syndrome, decreased lung compliance, and a marked decrease in the arterial Po2 with vascular instability leading to early euthanasia of 50% of untreated animals. PIP-2 treatment significantly reduced the requirement for supportive vasopressors and the manifestations of lung injury so that only 25% of animals required early euthanasia. Bronchoalveolar lavage fluid from PIP-2-treated versus untreated pigs showed markedly lower levels of total protein, cytokines (TNF-α, IL-6, IL-1β), and myeloperoxidase. Thus, the porcine LPS-induced sepsis-like model was associated with moderate to severe lung pathophysiology compatible with ALI, whereas treatment with PIP-2 markedly decreased lung injury, cardiovascular instability, and early euthanasia. These results indicate that inhibition of reactive oxygen species (ROS) production via NOX1/2 has a beneficial effect in treating pigs with LPS-induced ALI plus or minus a sepsis-like syndrome, suggesting a potential role for PIP-2 in the treatment of ALI and/or sepsis in humans.NEW & NOTEWORTHY Currently available treatments that can alter lung inflammation have failed to significantly alter mortality of acute lung injury (ALI). Peroxiredoxin 6 PLA2 inhibitory peptide-2 (PIP-2) targets the liberation of reactive O2 species (ROS) that is associated with adverse cell signaling events, thereby decreasing the tissue oxidative injury that occurs early in the ALI syndrome. We propose that treatment with PIP-2 may be effective in preventing progression of early disease into its later stages with irreversible lung damage and relatively high mortality.

GTS-21 attenuates ACE/ACE2 ratio and glycocalyx shedding in lipopolysaccharide-induced acute lung injury by targeting macrophage polarization derived ADAM-17

Acute lung injury (ALI) has received considerable attention in intensive care owing to its high mortality rate. It has been demonstrated that the selective alpha7 nicotinic acetylcholine receptor agonist Gainesville Tokushima scientists (GTS)-21 is promising for treating ALI caused by lipopolysaccharides (LPS). However, the precise underlying mechanism remains unknown. This study aimed to investigate the potential efficacy of GTS-21 in the treatment of ALI. We developed mouse models of ALI and alveolar epithelial type II cells (AT2s) injury following treatment with LPS and different polarized macrophage supernatants, respectively. Pathological changes, pulmonary edema, and lung compliance were assessed. Inflammatory cells count, protein content, and pro-inflammatory cytokine levels were analysed in the bronchoalveolar lavage fluid. The expression of angiotensin-converting enzyme (ACE), ACE2, syndecan-1 (SDC-1), heparan sulphate (HS), heparanase (HPA), exostosin (EXT)-1, and NF-κB were tested in lung tissues and cells. GTS-21-induced changes in macrophage polarization were verified in vivo and in vitro. Polarized macrophage supernatants with or without recombination a disintegrin and metalloproteinase-17 (ADAM-17) and small interfering (si)RNA ADAM-17 were used to verify the role of ADAM-17 in AT2 injury. By reducing pathological alterations, lung permeability, inflammatory response, ACE/ACE2 ratio, and glycocalyx shedding, as well as by downregulating the HPA and NF-κB pathways and upregulating EXT1 expression in vivo, GTS-21 significantly diminished LPS-induced ALI compared to that of the LPS group. GTS-21 significantly attenuated macrophage M1 polarization and augmented M2 polarization in vitro and in vivo. The destructive effects of M1 polarization supernatant can be inhibited by GTS-21 and siRNA ADAM-17. GTS-21 exerted a protective effect against LPS-induced ALI, which was reversed by recombinant ADAM-17. Collectively, GTS-21 alleviates LPS-induced ALI by attenuating AT2s ACE/ACE2 ratio and glycocalyx shedding through the inhibition of macrophage M1 polarization derived ADAM-17.

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.

The mechanism of Xuebijing injection in preventing and treating lung injury induced by cardiopulmonary bypass by regulating the apoptosis of alveolar polymorphonuclear neutrophil

To investigate the protective effect of Xuebijing injection on acute lung injury (ALI) associated with cardiopulmonary bypass (CPB) by regulating the apoptosis of polymorphonuclear neutrophils (PMN). Thirty male Sprague-Dawley (SD) rats were randomly divided into sham operation group (Sham group), CPB model group (CPB group) and Xuebijing pretreatment group (XBJ group) according to the random number table method, with 10 rats in each group. Rats in the CPB group and XBJ group undergoing CPB procedures for 60 minutes. Rats in the Sham group did not undergo CPB. Rats in the XBJ group received intraperitoneal injection of 4 mL/kg Xuebijing injection 2 hours before CPB. Rats in the Sham group and CPB group were injected with an equal amount of normal saline. 4 hours after CPB, arterial blood was collected for blood gas analysis to calculate respiratory index (RI), and lung tissue of rats was collected for determination of lung index (LI) and pulmonary water containing rate. PMN in bronchoalveolar lavage fluid (BALF) were collected and the activity of caspase-3 was detected. The apoptosis rate was detected by flow cytometry. The expressions of microRNA-142-3p (miR-142-3p) and FoxO1 mRNA were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). The protein expression of FoxO1 was detected by Western blotting. In addition, HL-60 cells were divided into control oligonucleotide transfection group, miR-142-3p mimics transfection group, and miR-142-3p inhibitor transfection group. After 48 hours of transfection, the activity of miR-142-3p binding to FoxO1 was detected using dual luciferase reporter genes. Compared with Sham group, RI, LI and pulmonary water containing rate were significantly increased in CPB group. The caspase-3 activity and apoptosis rate of PMN obtained from BALF were significantly decreased, the expression of miR-142-3p was decreased, and the expression of FoxO1 protein was increased. However, compared with CPB group, RI, LI and pulmonary water containing rate were significantly decreased in XBJ group [RI: 0.281±0.066 vs. 0.379±0.071, LI: 4.50±0.26 vs. 5.71±0.42, pulmonary water containing rate: (80.31±32.50)% vs. (84.59±3.41)%, all P < 0.01]. The caspase-3 activity and apoptosis rate of PMN obtained from BALF were significantly increased [caspase-3 activity: 0.350±0.021 vs. 0.210±0.014, apoptosis rate: (15.490±1.382)% vs. (8.700±0.701)%, both P < 0.01], the expression of miR-142-3p was significantly up-regulated (2-ΔΔCt: 2.61±0.17 vs. 0.62±0.05, P < 0.01), and the protein expression of FoxO1 was decreased [FoxO1/GAPDH (relative expression level): 0.81±0.04 vs. 1.22±0.06, P < 0.01]. However, there was no statistically significant difference in FoxO1 mRNA expression among the three groups. The bioinformatics analysis results showed that miR-142-3p can bind to the FoxO1 3'untranslated region (3'UTR). In HL-60 cells, compared with control oligonucleotide transfection group, the transfection of miR-142-3p mimics could reduce the expression of FoxO1 protein [FoxO1/GAPDH (relative expression level): 0.48±0.06 vs. 1.00±0.05, P < 0.01], however, the transfection of miR-142-3p inhibitor increased the expression of FoxO1 protein [FoxO1/GAPDH (relative expression level): 1.37±0.21 vs. 1.00±0.05, P < 0.05]. But, transfection with miR-142-3p mimics or inhibitor had no effect on FoxO1 mRNA expression. The luciferase reporter gene showed that miR-142-3p could bind to the FoxO1 3'UTR to inhibit FoxO1 expression. Xuebijing injection may promote the apoptosis of pulmonary alveolar PMN through the miR-142-3p/FoxO1 axis, and play a role in the prevention and treatment of CPB-induced ALI.

Mesenchymal stem cells alleviate sepsis-induced acute lung injury by blocking neutrophil extracellular traps formation and inhibiting ferroptosis in rats.

Acute lung injury (ALI) is one of the most serious complications of sepsis, characterized by high morbidity and mortality rates. Ferroptosis has recently been reported to play an essential role in sepsis-induced ALI. Excessive neutrophil extracellular traps (NETs) formation induces exacerbated inflammation and is crucial to the development of ALI. In this study, we explored the effects of ferroptosis and NETs and observed the therapeutic function of mesenchymal stem cells (MSCs) on sepsis-induced ALI. First, we produced a cecal ligation and puncture (CLP) model of sepsis in rats. Ferrostain-1 and DNase-1 were used to inhibit ferroptosis and NETs formation separately, to confirm their effects on sepsis-induced ALI. Next, U0126 was applied to suppress the MEK/ERK signaling pathway, which is considered to be vital to NETs formation. Finally, the therapeutic effect of MSCs was observed on CLP models. The results demonstrated that both ferrostain-1 and DNase-1 application could improve sepsis-induced ALI. DNase-1 inhibited ferroptosis significantly in lung tissues, showing that ferroptosis could be regulated by NETs formation. With the inhibition of the MEK/ERK signaling pathway by U0126, NETs formation and ferroptosis in lung tissues were both reduced, and sepsis-induced ALI was improved. MSCs also had a similar protective effect against sepsis-induced ALI, not only inhibiting MEK/ERK signaling pathway-mediated NETs formation, but also alleviating ferroptosis in lung tissues. We concluded that MSCs could protect against sepsis-induced ALI by suppressing NETs formation and ferroptosis in lung tissues. In this study, we found that NETs formation and ferroptosis were both potential therapeutic targets for the treatment of sepsis-induced ALI, and provided new evidence supporting the clinical application of MSCs in sepsis-induced ALI treatment.

CPT1A as a potential therapeutic target for lipopolysaccharide-induced acute lung injury in mice

Acute lung injury (ALI) remains a high mortality rate with dramatic lung inflammation and alveolar epithelial cell death. Although fatty acid β-oxidation (FAO) impairment has been implicated in the pathogenesis of ALI, whether Carnitine palmitoyltransferase 1A (CPT1A), the rate-limiting enzyme for FAO, plays roles in lipopolysaccharide (LPS)-induced ALI remains unclear. Accordingly, we focused on exploring the effect of CPT1A in the context of ALI and the underlying mechanisms. We found that overexpression of CPT1A (AAV-CPT1A) effectively alleviated lung injury by reduction of lung wet-to-dry ratio, inflammatory cell infiltration, and protein levels in the BALF of ALI mice. Meanwhile, AAV-CPT1A significantly lessened histopathological changes and several cytokines’ secretions. In contrast, blocking CPT1A with etomoxir augmented inflammatory responses and lung injury in ALI mice. Furthermore, we found that overexpression of CPT1A with lentivirus reduced the apoptosis rates of alveolar epithelial cells and the expression of apoptosis-related proteins induced by LPS in MLE12 cells, while etomoxir increased the apoptosis of MLE12 cells. Overexpression of CPT1A prevented the drop in bioenergetics, palmitate oxidation, and ATP levels. In conclusion, the results rendered CPT1A worthy of further development into a pharmaceutical drug for the treatment of ALI.

Human Umbilical Cord Mesenchymal Stem Cell Exosome-derived miR-335-5p Alleviated Lipopolysaccharide-induced Acute Lung Injury by Regulating the m6A Level of ITGβ4 Gene.

Acute lung injury (ALI) is a serious complication that may accompany severe pneumonia in children. Derived from exosomes of human umbilical cord mesenchymal stem cell exosome (HucMSC-Exo) can contribute to the regeneration of damaged lung tissue. This study aims to investigate the impact of HucMSC-Exo on ALI and its potential mechanisms. Firstly, RT-qPCR was performed to assess the expression of miR-335-5p. Subsequently, Pearson correlation analysis was performed to examine the correlation between METTL14 and miR-335-5p, as well as the correlation between METTL14 and ITGB4., while RNA immunoprecipitation (RIP) was used to determine the m6A modification level of ITGβ4. Additionally, molecular biology techniques were employed to evaluate the expression of glycolysis-related factors. Definitively, an LPS-induced ALI model was established to investigate the effect of miR-335-5p on mice lung tissue. miR-335-5p was found to be highly expressed in HucMSC-Exo. Transfection with miR-335-5p mimics resulted in increased glucose uptake. Pearson correlation analysis revealed a negative correlation between METTL14 and miR-335-5p, as well as between METTL14 and ITGβ4. The m6A level of ITGβ4 was elevated in ALI. Overexpression of METTL14 was found to reduce the expression and glucose uptake of ITGβ4, while overexpression of ITGβ4 reversed the effects of METTL14 overexpression. in vivo, results demonstrated that miR-335-5p can improve the extent of lung tissue lesions and reduce glycolytic levels. This study reveals the mechanism by which miR-335-5p derived from HucMSC-Exo could alleviate LPS-induced ALI by regulating the m6A modification of ITGβ4, providing a new direction for the treatment of ALI.

Umbilical cord MSC-derived exosomes improve alveolar macrophage function and reduce LPS-induced acute lung injury.

Acute lung injury (ALI) is a severe condition that can progress to acute respiratory distress syndrome (ARDS), with a high mortality rate. Currently, no specific and compelling drug treatment plan exists. Mesenchymal stem cells (MSCs) have shown promising results in preclinical and clinical studies as a potential treatment for ALI and other lung-related conditions due to their immunomodulatory properties and ability to regenerate various cell types. The present study focuses on analyzing the role of umbilical cord MSC (UC-MSC))-derived exosomes in reducing lipopolysaccharide-induced ALI and investigating the mechanism involved. The study demonstrates that UC-MSC-derived exosomes effectively improved the metabolic function of alveolar macrophages and promoted their shift to an anti-inflammatory phenotype, leading to a reduction in ALI. The findings also suggest that creating three-dimensional microspheres from the MSCs first can enhance the effectiveness of the exosomes. Further research is needed to fully understand the mechanism of action and optimize the therapeutic potential of MSCs and their secretome in ALI and other lung-related conditions.

Exosomes Derived from hucMSCs Primed with IFN-γ Suppress the NF-κB Signal Pathway in LPS-Induced ALI by Modulating the miR-199b-5p/AFTPH Axis.

Exosomes (exos) are primarily responsible for the process of mesenchymal stem cells (MSCs) treatment for acute lung injury (ALI), but the mechanism remains unclear, particularly in altered microenvironment. Therefore, this study aimed to investigate the potential mechanism of exos derived from human umbilical cord mesenchymal stem cells (hucMSCs) primed with interferon-gamma (IFN-γ) on ALI and to propose a promising and cell-free strategy. This study extracted exos from hucMSCs supernatant primed and unprimed with IFN-γ marked with IFN-γ-exos and CON-exos, which were identified and traced. IFN-γ-exos administration to ALI models suppressed the NF-κB signaling pathway compared to CON-exos, which were quantified through western blot and immunohistochemical staining. Reverse transcription-quantitative polymerase chain reaction validated miR-199b-5p expression in the IFN-γ-exos and CON-exos treatment groups. Data analysis, a dual-luciferase reporter assay, and cell transfection were conducted to investigate the target binding between miR-199b-5p and Aftiphilin (AFTPH), with AFTPH expression analyzed via cell immunofluorescence and western blot. Co-immunoprecipitation was conducted for the interaction between AFTPH and NF-κB p65. The result revealed that miR-199b-5p was down-regulated in the IFN-γ-exos treatment group, which had a target binding site with AFTPH, and an interaction with NF-κB p65. Consequently, IFN-γ-exos inhibited the NF-κB signaling pathway in ALI in vitro and in vivo through the miR-199b-5p/AFTPH axis. Our results demonstrated new directions of novel and targeted treatment for ALI.

Salecan ameliorates LPS-induced acute lung injury through regulating Keap1-Nrf2/HO-1 pathway in mice

Acute lung injury (ALI) is a severe clinical condition with high mortality, characterized by rapid onset and limited treatment options. The pathogenesis of ALI involves inflammation and oxidative stress. The polysaccharide salecan, a water-soluble β-(1,3)-D-glucan, has been found to possess numerous pharmaceutical effects, including anti-inflammatory properties, inhibition of oxidative stress, and anti-fatigue effects. This study aims to investigate the protective effect and underlying mechanism of salecan against LPS-induced ALI in mice. Using an in vivo LPS-induced ALI mouse model and an in vitro RAW264.7 cell system, we investigated the role of salecan in ALI with various experimental approaches, including histological staining, quantitative real-time PCR, flow cytometry, western blot analysis, and other relevant assays. Pre-treatment with salecan effectively attenuated LPS-induced ALI in vivo, reducing the severity of pulmonary edema, inflammation, and oxidative stress. NMR-based metabolomic profiling analysis revealed that salecan attenuated LPS-induced metabolic imbalances associated with ALI. Furthermore, salecan downregulated Keap1 and upregulated Nrf2 and HO-1 protein levels, indicating its modulation of the Keap1-Nrf2/HO-1 signaling pathway as a potential mechanism underlying its protective effects against ALI. In vitro studies on RAW264.7 cells revealed that salecan exhibited binding affinity towards macrophages, thereby alleviating LPS-induced apoptosis and inflammation, which underpin its therapeutic potential against ALI. Our study suggests that salecan can alleviate LPS-induced ALI by modulating oxidative stress, inflammatory response, and apoptosis through the activation of the Keap1-Nrf2/HO-1 pathway. These findings provide novel insights into the potential therapeutic use of salecan for the treatment of ALI.

Fe-Capsaicin Nanozymes Attenuate Sepsis-Induced Acute Lung Injury via NF-κB Signaling.

In sepsis, the lungs are one of the most severely affected organs, usually resulting in acute lung injury (ALI). Capsaicin (CAP) is a natural compound found in chili peppers that has pain-relieving and anti-inflammatory properties. Here, we report that nanoparticles containing capsaicin and iron (Fe-CAP NPs) exhibited anti-inflammatory effects in the treatment of ALI. The morphological characteristics of nanozymes were detected. RAW 264.7 cells were divided into four groups: control, lipopolysaccharide (LPS), CAP+LPS and Fe-CAP+LPS groups. The expression of inducible nitric oxide synthase (iNOS), transforming growth factor-β (TGF-β), and tumor necrosis factor-α (TNF-α) was assessed by immunofluorescence, Western blot, and enzyme-linked immunosorbent assay (ELISA). Nuclear factor kappa-B (NF-κB) expression was determined by Western blot. C57 mice were divided into control, LPS, CAP+LPS and Fe-CAP+LPS groups. Interleukin-6 (IL-6) and iNOS expression in the lung was detected by Western Blot. IL-6 and TNF-α expression in serum was detected by ELISA. Extravasated Evans blue, histopathological evaluation and wet-to-dry (W/D) weight ratio were used to assess pulmonary capillary permeability. The blood and major organs (heart, liver, spleen, lung and kidney) of mice were tested for the toxicity of Fe-CAP NPs. In the LPS group, TNF-α, iNOS, p-NF-κB and p-IKBα expression increased. However, their expression was significantly decreased in the Fe-CAP+LPS group. TGF-β expression showed the opposite trend. In vivo, IL-6 and iNOS expression was notably increased in the lungs of LPS group of mice but decreased with Fe-CAP pretreatment. Fe-CAP significantly ameliorated lung EB leakage, improved the histopathology of lung tissue and reduced the W/D weight ratio. The nanoparticles showed non-cytotoxicity, when studying these biological activities. Fe-CAP NPs could alleviated inflammation by inhibiting the expression of pro-inflammatory factors in macrophages, increasing the expression of anti-inflammatory factors, and alleviating lung tissue damage.

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

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

Neutrophil membrane-engineered Panax ginseng root-derived exosomes loaded miRNA 182-5p targets NOX4/Drp-1/NLRP3 signal pathway to alleviate acute lung injury in sepsis: experimental studies.

The purpose of this study was to prepare neutrophil membrane-engineered Panax ginseng root-derived exosomes (N-exo) and investigate the effects of N-exo microRNA (miRNA) 182-5p (N-exo-miRNA 182-5p) on acute lung injury (ALI) in sepsis. Panax ginseng root-derived exosomes were separated by differential centrifugation. Neutrophil membrane engineering was performed on exo to obtain N-exo. miRNA182-5p was transmitted into N-exo by electroporation technology to obtain N-exo-miRNA 182-5p. LPS was used to establish an in-vivo and in-vitro model of ALI of sepsis to evaluate the anti-inflammatory effect of N-exo-miRNA 182-5p. The results of transmission electron microscope showed that exo was a double-layer membrane structure like a saucer. Nanoparticle size analysis showed that the average particle size of exo was 129.7nm. Further, compared with exo, the level of miRNA182-5p was significantly increased in N-exo. The experimental results showed that N-exo-miRNA 182-5p significantly improved ALI via target regulation of NOX4/Drp-1/NLRP3 signal pathway in vivo and in vitro . In conclusion, this study prepared a novel engineered exosome (N-exo and N-exo-miRNA 182-5p significantly improved ALI in sepsis via target regulation of NOX4/Drp-1/NLRP3 signal pathway, providing new ideas and methods for treatment of ALI in sepsis.

Intratracheal administration of programmable DNA nanostructures combats acute lung injury by targeting microRNA-155

Acute lung injury (ALI) is an acute inflammatory process that can result in life-threatening consequences. Programmable DNA nanostructures have emerged as excellent nanoplatforms for microRNA-based therapeutics, offering potential nanomedicines for ALI treatment. Nonetheless, the traditional systematic administration of nanomedicines is constrained by low delivery efficiency, poor pharmacokinetics, and nonspecific side effects. Here, we identify macrophage microRNA-155 as a novel therapeutic target using the magnetic bead sorting technique. We further construct a DNA nanotubular nucleic acid drug antagonizing microRNA-155 (NT-155) for ALI treatment through intratracheal administration. Flow cytometry results demonstrate that NT-155, when inhaled, is taken up much more effectively by macrophages and dendritic cells in the bronchoalveolar lavage fluid of ALI mice. Furthermore, NT-155 effectively silences the overexpressed microRNA-155 in macrophages and exerts excellent inflammation inhibition effects in vitro and ALI mouse models. Mechanistically, NT-155 suppresses microRNA-155 expression and activates its target gene SOCS1, inhibiting the p-P65 signaling pathway and suppressing proinflammatory cytokine secretion. The current study suggests that deliberately designed nucleic acid drugs are promising nanomedicines for ALI treatment and the local administration may open up new practical applications of DNA in the future.