[Role and mechanism of ginsenoside Rg1 in ameliorating sepsis-induced acute lung injury based on PERK/eIF2α/ATF4/CHOP-induced alveolar epithelial cell apoptosis].

The study investigates the therapeutic effects and mechanisms of ginsenoside Rg_1(GRg_1) on sepsis-induced acute lung injury(SALI). A murine model of SALI was created using cecal ligation and puncture(CLP) surgery, and mice were randomly assigned to groups for GRg_1 intervention. Survival and body weight changes were recorded, lung function was assessed with a non-invasive lung function test system, and lung tissue damage was evaluated through HE staining. The content and expression of inflammatory factors were measured by ELISA and qRT-PCR. Apoptosis was examined using flow cytometry and TUNEL staining. The activation and expression of apoptosis-related molecules cysteinyl aspartate specific proteinase 3(caspase-3), B-cell lymphoma-2(Bcl-2), Bcl-2 associated X protein(Bax), and endoplasmic reticulum stress-related molecules protein kinase R-like endoplasmic reticulum kinase(PERK), eukaryotic initiation factor 2α(eIF2α), activating transcription factor 4(ATF4), and C/EBP homologous protein(CHOP) were studied using Western blot and qRT-PCR. In addition, an in vitro model of lipopolysaccharide(LPS)-induced lung alveolar epithelial cell injury was used, with the application of the endoplasmic reticulum stress inducer tunicamycin to validate the action mechanism of GRg_1. RESULTS:: indicated that, when compared to the model group, GRg_1 intervention significantly enhanced the survival time of CLP mice, mitigated body weight loss, and improved impaired lung function indices. The GRg_1-treated mice also displayed reduced lung tissue pathological scores, a reduced lung tissue wet-to-dry weight ratio, and lower protein content in the bronchoalveolar lavage fluid. Serum levels of interleukin-6(IL-6), interleukin-1ß(IL-1ß), and tumor necrosis factor-α(TNF-α), as well as the mRNA expressions of these cytokines in lung tissues, were decreased. There was a notable decrease in the proportion of apopto-tic alveolar epithelial cells, and down-regulated expressions of caspase-3, Bax, PERK, eIF2α, ATF4, and CHOP and up-regulated expression of Bcl-2 were observed. In vitro findings showed that the apoptosis-lowering and apoptosis-related protein down-regulating effects of GRg_1 were significantly inhibited with the co-application of tunicamycin. Altogether, GRg_1 reduces apoptosis of alveolar epithelial cells, inhibits inflammation in the lungs, alleviates lung injury, and enhances lung function, possibly through the PERK/eIF2α/ATF4/CHOP pathway.

CPT1A-IL-10-mediated macrophage metabolic and phenotypic alterations ameliorate acute lung injury.

BACKGROUND: Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a common acute respiratory failure due to diffuse pulmonary inflammation and oedema. Elaborate regulation of macrophage activation is essential for managing this inflammatory process and maintaining tissue homeostasis. In the past decades, metabolic reprogramming of macrophages has emerged as a predominant role in modulating their biology and function. Here, we observed reduced expression of carnitine palmitoyltransferase 1A (CPT1A), a key rate-limiting enzyme of fatty acid oxidation (FAO), in macrophages of lipopolysaccharide (LPS)-induced ALI mouse model. We assume that CPT1A and its regulated FAO is involved in the regulation of macrophage polarization, which could be positive regulated by interleukin-10 (IL-10). METHODS: After nasal inhalation rIL-10 and/or LPS, wild type (WT), IL-10-/-, Cre-CPT1Afl/fl and Cre+CPT1Afl/fl mice were sacrificed to harvest bronchoalveolar lavage fluid, blood serum and lungs to examine cell infiltration, cytokine production, lung injury severity and IHC. Bone marrow-derived macrophages (BMDMs) were extracted from mice and stimulated by exogenous rIL-10 and/or LPS. The qRT-PCR, Seahorse XFe96 and FAO metabolite related kits were used to test the glycolysis and FAO level in BMDMs. Immunoblotting assay, confocal microscopy and fluorescence microplate were used to test macrophage polarization as well as mitochondrial structure and function damage. RESULTS: In in vivo experiments, we found that mice lacking CPT1A or IL-10 produced an aggravate inflammatory response to LPS stimulation. However, the addition of rIL-10 could alleviate the pulmonary inflammation in mice effectively. IHC results showed that IL-10 expression in lung macrophage decreased dramatically in Cre+CPT1Afl/fl mice. The in vitro experiments showed Cre+CPT1Afl/fl and IL-10-/- BMDMs became more "glycolytic", but less "FAO" when subjected to external attacks. However, the supplementation of rIL-10 into macrophages showed reverse effect. CPT1A and IL-10 can drive the polarization of BMDM from M1 phenotype to M2 phenotype, and CPT1A-IL-10 axis is also involved in the process of maintaining mitochondrial homeostasis. CONCLUSIONS: CPT1A modulated metabolic reprogramming and polarisation of macrophage under LPS stimulation. The protective effects of CPT1A may be partly attributed to the induction of IL-10/IL-10 receptor expression.

Potential pharmaceuticals targeting neuroimmune interactions in treating acute lung injury.

BACKGROUND AND MAIN BODY: Although interactions between the nervous and immune systems have been recognized decades ago, it has become increasingly appreciated that neuroimmune crosstalk is among the driving factors of multiple pulmonary inflammatory diseases including acute lung injury (ALI). Here, we review the current understanding of nerve innervations towards the lung and summarize how the neural regulation of immunity and inflammation participates in the onset and progression of several lung diseases, especially ALI. We then present advancements in the development of potential drugs for ALI targeting neuroimmune interactions, including cholinergic anti-inflammatory pathway, sympathetic-immune pathway, purinergic signalling, neuropeptides and renin-angiotensin system at different stages from preclinical investigation to clinical trials, including the traditional Chinese medicine. CONCLUSION: This review highlights the importance of considering the therapeutic strategy of inflammatory diseases within a conceptual framework that integrates classical inflammatory cascade and neuroimmune circuits, so as to deepen the understanding of immune modulation and develop more sophisticated approaches to treat lung diseases represented by ALI. KEY POINTS: The lungs present abundant nerve innervations. Neuroimmune interactions exert a modulatory effect in the onset and progression of lung inflammatory diseases, especially acute lung injury. The advancements of potential drugs for ALI targeting neuroimmune crosstalk at different stages from preclinical investigation to clinical trials are elaborated. Point out the direction for the development of neuroimmune pharmacology in the future.

Intracellularly Synthesized Artificial Exosome Treats Acute Lung Injury.

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), induce high morbidity and mortality rates, which challenge the present approaches for the treatment of ALI/ARDS. The clinically used photosensitizer verteporfin (VER) exhibits great potential in the treatment of acute lung injury and acute respiratory distress syndrome (ALI/ARDS) by regulating macrophage polarization and reducing inflammation. Nevertheless, its hydrophobic characteristics, nonspecificity, and constrained bioavailability hinder its therapeutic efficacy. In this work, we developed a type of VER-cored artificial exosome (EVM), which was produced by using mesoporous silica nanoparticles (MSNs) to load VER, followed by the exocytosis of internalized VER-MSNs from mouse bone marrow-derived mesenchymal stem cells (mBMSCs) without further modification. Both in vitro and in vivo assessments confirmed the powerful anti-inflammation induced by EVM. EVM also showed significant higher accumulation to inflammatory lungs compared with healthy ones, which was beneficial to the treatment of ALI/ARDS. EVM improved pulmonary function, attenuated lung injury, and reduced mortality in ALI mice with high levels of biocompatibility, exhibiting a 5-fold higher survival rate than the control. This type of artificial exosome emitted near-infrared light in the presence of laser activation, which endowed EVM with trackable ability both in vitro and in vivo. Our work developed a type of clinically used photosensitizer-loaded artificial exosome with membrane integrity and traceability. To the best of our knowledge, this kind of intracellularly synthesized artificial exosome was developed and showed great potential in ALI/ARDS therapy.

Aqueous extract of Descuraniae Semen attenuates lipopolysaccharide-induced inflammation by inhibiting ER stress and WNK4-SPAK-NKCC1 pathway.

Sepsis causes systemic inflammatory responses and acute lung injury (ALI). Despite modern treatments, sepsis-related ALI mortality remains high. Aqueous extract of Descuraniae Semen (AEDS) exerts anti-endoplasmic reticulum (ER) stress, antioxidant and anti-inflammatory effects. AEDS alleviates inflammation and oedema in ALI. Sodium-potassium-chloride co-transporter isoform 1 (NKCC1) is essential for regulating alveolar fluid and is important in ALI. The NKCC1 activity is regulated by upstream with-no-lysine kinase-4 (WNK4) and STE20/SPS1-related proline/alanine-rich kinase (SPAK). This study aimed to investigate the effects of AEDS on lipopolysaccharide (LPS)-induced ALI model in A549 cells, considering the regulation of ER stress, WNK4-SPAK-NKCC1 cascades, inflammation and apoptosis. Cell viability was investigated by the CCK-8 assay. The expressions of the proteins were assessed by immunoblotting analysis assays. The levels of pro-inflammatory cytokines were determined by ELISA. The expression of cytoplasmic Ca2+ in A549 cells was determined using Fluo-4 AM. AEDS attenuates LPS-induced inflammation, which is associated with increased pro-inflammatory cytokine expression and activation of the WNK4-SPAK-NKCC1 pathway. AEDS inhibits the WNK4-SPAK-NKCC1 pathway by regulating of Bcl-2, IP3R and intracellular Ca2+. WNK4 expression levels are significantly higher in the WNK4-overexpressed transfected A549 cells and significantly decrease after AEDS treatment. AEDS attenuates LPS-induced inflammation by inhibiting the WNK4-SPAK-NKCC1 cascade. Therefore, AEDS is regarded as a potential therapeutic agent for ALI.

[Astragali Radix-Salviae Miltiorrhizae Radix et Rhizoma alleviates acute lung injury in rats by regulating autophagy via PI3K/Akt/mTOR pathway].

This study aims to reveal the effects of the herb pair Astragali Radix-Salviae Miltiorrhizae Radix et Rhizoma(AR-SMRR) on phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR) pathway and autophagy in the lung tissue of the rat model of acute lung injury(ALI). Fifty adult male SD rats were randomized into sham, model, autophagy inhibition(intraperitoneal injection of chloroquine at 10 mg·kg~(-1)), autophagy induction(intraperitoneal injection of rapamycin at 15 mg·kg~(-1)), and AR-SMRR(5 g·kg~(-1), gavage) groups. The rats in the sham group received intratracheal instillation of normal saline, and those in other groups received intratracheal instillation of lipopolysaccharide(LPS, 5 mg·kg~(-1)) for the modeling of ALI. Seven days before the operation, the rats in the sham and model groups were administrated with normal saline, and those in other groups with corresponding drugs. Specimens were collected 24 h after modeling. The pathological changes of the lung tissue were observed under a light microscope. The lung wet/dry weight ratio and the lactate dehydrogenase(LDH) activity and total protein concentration in the bronchoalveolar lavage fluid(BALF) were measured. Western blot was employed to measure the protein levels of microtubule-associated protein 1-light chain 3(LC3), beclin-1, p62, PI3K, Akt, and mTOR. Compared with the sham group, the model group showed increased histopathological score of the lung tissue, lung wet/dry weight ratio, and LDH activity and protein concentration in BALF. Autophagy inhibition further increased these indicators compared with the model group, while autophagy induction and AR-SMRR lowered the levels. In addition, AR-SMRR up-regulated the protein levels of LC3-Ⅱ and beclin-1, down-regulated the expression of p62, and inhibited the expression of p-PI3K, p-Akt, and p-mTOR in the lung tissue of ALI rats. The findings suggest that AR-SMRR can alleviate the lung injury and edema in the rat model of ALI induced by LPS by enhancing autophagy via down-regulating PI3K/Akt/mTOR signaling pathway.

Evaluation of the Therapeutic Potential of Sulfonyl Urea Derivatives as Soluble Epoxide Hydrolase (sEH) Inhibitors.

The inhibition of soluble epoxide hydrolase (sEH) can reduce the level of dihydroxyeicosatrienoic acids (DHETs) effectively maintaining endogenous epoxyeicosatrienoic acids (EETs) levels, resulting in the amelioration of inflammation and pain. Consequently, the development of sEH inhibitors has been a prominent research area for over two decades. In the present study, we synthesized and evaluated sulfonyl urea derivatives for their potential to inhibit sEH. These compounds underwent extensive in vitro investigation, revealing their potency against human and mouse sEH, with 4f showing the most promising sEH inhibitory potential. When subjected to lipopolysaccharide (LPS)-induced acute lung injury (ALI) in studies in mice, compound 4f manifested promising anti-inflammatory efficacy. We investigated the analgesic efficacy of sEH inhibitor 4f in a murine pain model of tail-flick reflex. These results validate the role of sEH inhibition in inflammatory diseases and pave the way for the rational design and optimization of sEH inhibitors based on a sulfonyl urea template.

The protective effect of karanjin against sepsis-induced acute lung injury in mice is involved in the suppression of the TLR4 pathway.

Sepsis-induced acute lung injury (ALI) is a severe complication of sepsis. Karanjin, a natural flavonoid compound, has been proved to have anti-inflammatory function, but its role in sepsis-stimulated ALI is uncertain. Herein, the effect of karanjin on sepsis-stimulated ALI was investigated. We built a mouse model of lipopolysaccharide (LPS)-stimulated ALI. The histopathological morphology of lung tissues was scrutinized by hematoxylin-eosin (H&E) staining. The lung injury score and lung wet/dry weight ratio were detected. The myeloperoxidase (MPO) activity and malondialdehyde (MDA) content were scrutinized by commercial kits. Murine alveolar lung epithelial (MLE-12) cells were treated with LPS to mimic a cellular model of ALI. The cell viability was scrutinized by the CCK-8 assay. The contents of proinflammatory cytokines were scrutinized by qRT-PCR and ELISA. The TLR4 and MyD88 contents were scrutinized by qRT-PCR and western blotting. Results showed that karanjin alleviated LPS-stimulated ALI in mice by inhibiting lung tissue lesions, edema, and oxidative stress. Moreover, karanjin inhibited LPS-stimulated inflammation and TLR4 pathway activation in mice. However, treatment with GSK1795091, an agonist of TLR4, attenuated the effects of karanjin on LPS-induced ALI. Furthermore, karanjin repressed LPS-stimulated inflammatory response and TLR4 pathway activation in MLE-12 cells. Overexpression of TLR4 attenuated karanjin effects on LPS-stimulated inflammatory responses in MLE-12 cells. In conclusion, karanjin repressed sepsis-stimulated ALI in mice by suppressing the TLR4 pathway.

Broncho-Vaxom Attenuates Lipopolysaccharide-Induced Inflammation in a Mouse Model of Acute Lung Injury.

Acute lung injury (ALI) is a condition associated with acute respiratory failure, resulting in significant morbidity and mortality. It involves cellular changes such as disruption of the alveolar-capillary membrane, excessive neutrophil migration, and release of inflammatory mediators. Broncho-Vaxom® (BV), a lyophilized product containing cell membrane components derived from eight bacteria commonly found in the respiratory tract, is known for its potential to reduce viral and bacterial lung infections. However, the specific effect of BV on ALI has not been clearly defined. This study explored the preventive effects of BV and its underlying mechanisms in a lipopolysaccharide (LPS)-induced ALI mouse model. Oral BV (1 mg/kg) gavage was administered one hour before the intratracheal injection of LPS to evaluate its preventive effect on the ALI model. The pre-administration of BV significantly mitigates inflammatory parameters, including the production of inflammatory mediators, macrophage infiltration, and NF-κB activation in lung tissue, and the increase in inflammatory cells in bronchoalveolar lavage fluid (BALF). Moreover, BV (3 µg/mL) pretreatment reduced the expression of M1 macrophage markers, interleukins (IL-1ß, IL-6), tumor necrosis factor α, and cyclooxygenase-2, which are activated by LPS, in both mouse alveolar macrophage MH-S cells and human macrophage THP-1 cells. These findings showed that BV exhibits anti-inflammatory effects by suppressing inflammatory mediators through the NF-κB pathway, suggesting its potential to attenuate bronchial and pulmonary inflammation.

The impact of Astragaloside IV on the inflammatory response and gut microbiota in cases of acute lung injury is examined through the utilization of the PI3K/AKT/mTOR pathway.

OBJECTIVES: Astragaloside IV (AS-IV) is a natural triterpenoid saponin compound with a variety of pharmacological effects, and several studies have clarified its anti-inflammatory effects, which may make it an effective alternative treatment against inflammation. In the study, we aimed to investigate whether AS-IV could attenuate the inflammatory response to acute lung injury and its mechanisms. METHODS: Different doses of AS-IV (20mg·kg-1, 40mg·kg-1, and 80mg·kg-1) were administered to the ALI rat model, followed by collection of serum and broncho alveolar lavage fluid (BALF) for examination of the inflammatory response, and HE staining of the lung and colon tissues, and interpretation of the potential molecular mechanisms by quantitative real-time PCR (qRT-PCR), Western blotting (WB). In addition, fecal samples from ALI rats were collected and analyzed by 16S rRNA sequencing. RESULTS: AS-IV decreased the levels of TNF-α, IL-6, and IL-1ß in serum and BALF of mice with Acute lung injury (ALI). Lung and colon histopathology confirmed that AS-IV alleviated inflammatory infiltration, tissue edema, and structural changes. qRT-PCR and WB showed that AS-IV mainly improved inflammation by inhibiting the expression of PI3K, AKT and mTOR mRNA, and improved the disorder of intestinal microflora by increasing the number of beneficial bacteria and reducing the number of harmful bacteria. CONCLUSION: AS-IV reduces the expression of inflammatory factors by inhibiting the PI3K/AKT/mTOR pathway and optimizes the composition of the gut microflora in AIL rats.

Berberine protects against sepsis-related acute lung injury in rats via PPAR-γ signaling pathway upregulation and improvement at the cellular level: Functional, biochemical, and immunohistochemistry study.

This study aimed to assess the prophylactic effects of Berberine on experimentally induced lung sepsis and examine its effects on selected cytokines, genes, and protein expression besides the histopathological evaluation. Berberine significantly reduced the wet/dry lung ratio, the broncho-alveolar lavage fluid (BALF) protein, cells, neutrophils percentage, and cytokines levels. In addition, pretreatment with Berberine decreased the myeloperoxidase (MPO) and malondialdehyde (MDA) levels and decreased gene expression of nuclear factor kappa B (NF-κB), monocyte chemoattractant protein-1 (MCP-1), and the intracellular adhesion molecule 1 (ICAM-1) by RT-qPCR analysis, revealing Berberine's antioxidant and anti-inflammatory mode of action. Western blot analysis revealed increased peroxisome proliferator-activated receptor gamma (PPAR-γ) expression in the Berberine pretreated group compared to the cecal ligation and puncture (CLP) group, in which the histopathological examination evidenced this improvement. In conclusion, Berberine improved lung sepsis via its PPAR-γ mediated antioxidant and anti-inflammatory effects.

The protective effect of ginsenoside Rg1 against sepsis-induced lung injury through PI3K-Akt pathway: insights from molecular dynamics simulation and experimental validation.

Sepsis-induced acute lung injury (SALI) poses a significant threat with high incidence and mortality rates. Ginsenoside Rg1 (GRg1), derived from Ginseng in traditional Chinese medicine, has been found to reduce inflammation and protect lung epithelial cells against tissue damage. However, the specific roles and mechanisms by which GRg1 mitigates SALI have yet to be fully elucidated. In this context, we employed a relevant SALI mouse model, alongside network pharmacology, molecular docking, and molecular dynamics simulation to pinpoint GRg1's action targets, complemented by in vitro assays to explore the underlying mechanisms. Our research shows that GRg1 alleviates CLP-induced SALI, decreasing lung tissue damage and levels of serum proinflammatory factor IL-6, TNF-α, and IL-1ß, also enhancing the survival rate of CLP mice. A total of 116 common targets between GRg1 and ALI, with specific core targets including AKT1, VEGFA, SRC, IGF1, ESR1, STAT3, and ALB. Further in vitro experiments assessed GRg1's intervention effects on MLE-12 cells exposed to LPS, with qRT-PCR analysis and molecular dynamics simulations confirming AKT1 as the key target with the favorable binding activity for GRg1. Western blot results indicated that GRg1 increased the Bcl-2/Bax protein expression ratio to reduce apoptosis and decreased the high expression of cleaved caspase-3 in LPS-induced MLE-12 cells. More results showed significant increases in the phosphorylation of PI3K and AKT1. Flow cytometric analysis using PI and Annexin-V assays further verified that GRg1 decreased the apoptosis rate in LPS-stimulated MLE-12 cells (from 14.85 to 6.54%, p < 0.05). The employment of the AKT1 inhibitor LY294002 confirmed these trends, indicating that AKT1's inhibition negates GRg1's protective effects on LPS-stimulated MLE-12 cells. In conclusion, our research highlights GRg1's potential as an effective adjunct therapy for SALI, primarily by inhibiting apoptosis in alveolar epithelial cells and reducing pro-inflammatory cytokine secretion, thus significantly enhancing the survival rates of CLP mice. These beneficial effects are mediated through targeting AKT1 and activating the PI3K-AKT pathway.

The effect of ethanol extracts of loulu flower on LPS-induced acute lung injury in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: In Mongolian medicine, Loulu flower (LLF), the dried inflorescence of Rhaponticum uniflorum (L.) DC. from the Compositae family, has been used to clear heat and relieve toxicity for millennia, particularly in the treatment of pneumonia. AIM OF THIS STUDY: To reveal the effects of LLF on mice with lipopolysaccharide (LPS)-stimulated acute lung injury (ALI) and elucidate the underlying mechanisms. MATERIALS AND METHODS: ALI was established in BALB/c mice via nasal drops administration of LPS (5 mg/kg). The mice were then orally administrated with various doses of LLF extracts and the positive drug dexamethasone (DEX, 5 mg/kg), once daily for seven consecutive days. Last day, after being stimulated with LPS for 6h, the mice were closed dislocation of cervical vertebra, the serum, bronchus alveolar lavage fluid (BALF) and lung tissue were put into the EP tube and stored at -80 °C for further analysis. The changes of histopathology were tested by hematoxylin and eosin stain (H&E), the levels of, IL-1ß, IL-18, TNF-α and IL-4 in BALF and serum were measured by ELISA. The pathways related to the treatment of ALI were predicted by network pharmacology. The expression levels of TLR4/NF-κB and NLRP3 signaling pathway-associated proteins, COX-2 and ERK were tested by western blotting. The levels of P65 and NLRP3 in lung tissues were determined by immunofluorescence analysis. RESULTS: LLF total extract and the extract parts could alleviate the inflammatory cell infiltration, thicken the alveolar walls in lung tissues, reduce the levels of IL-18, IL-1ß in BALF, the TNF-α in both BALF and serum, meantime enhance the level of IL-4 in BALF and serum in mice with LPS-induced ALI. Our network pharmacology and comprehensive gene ontology analyses revealed the active constituents of LLF and the pathways, including TLR4/NF-κB, NLRP3 and MAPK signaling pathways, which play significant roles in ALI. Furthermore, both the total extract and its extraction portions suppressed the expressions of proteins related with the COX-2, p-ERK and TLR4/NF-κB signaling pathway (TLR4, p-IκB, p-p65), as well as the NLRP3 signaling pathway (NLRP3, cleaved caspase-1, caspase-1, IL-1ß). CONCLUSION: LLF could improve the pathological changes and reducing inflammatory reactions in mice induced by LPS. The mechanism may be related to the modulation of the TLR4/NLRP3 signaling pathways.

Integration of microbiomics, metabolomics, and transcriptomics reveals the therapeutic mechanism underlying Fuzheng-Qushi decoction for the treatment of lipopolysaccharide-induced lung injury in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Fuzheng-Qushi decoction (FZQS) is a practical Chinese herbal formula for relieving cough and fever. Therefore, the action and specific molecular mechanism of FZQS in the treatment of lung injury with cough and fever as the main symptoms need to be further investigated. AIMS OF THE STUDY: To elucidate the protective effects of FZQS against lung injury in mice and reveal its potential targets and key biological pathways for the treatment of lung injury based on transcriptomics, microbiomics, and untargeted metabolomics analyses. MATERIALS AND METHODS: Lipopolysaccharide (LPS) was used to induce a mouse model of lung injury, followed by the administration of FZQS. ELISA was used to detect IL-1ß, IL-6, IL-17A, IL-4, IL-10, and TNF-α, in mouse lung tissues. Macrophage polarization and neutrophil activation were measured by flow cytometry. RNA sequencing (RNA-seq) was applied to screen for differentially expressed genes (DEGs) in lung tissues. RT-qPCR and Western blot assays were utilized to validate key DEGs and target proteins in lung tissues. 16S rRNA sequencing was employed to characterize the gut microbiota of mice. Metabolites in the gut were analyzed using untargeted metabolomics. RESULTS: FZQS treatment significantly ameliorated lung histopathological damage, decreased pro-inflammatory cytokine levels, and increased anti-inflammatory cytokine levels. M1 macrophage levels in the peripheral blood decreased, M2 macrophage levels increased, and activated neutrophils were inhibited in mice with LPS-induced lung injury. Importantly, transcriptomic analysis showed that FZQS downregulated macrophage and neutrophil activation and migration and adhesion pathways by reversing 51 DEGs, which was further confirmed by RT-qPCR and Western blot analysis. In addition, FZQS modulated the dysbiosis of the gut microbiota by reversing the abundance of Corynebacterium, Facklamia, Staphylococcus, Paenalcaligenes, Lachnoclostridium, norank_f_Muribaculaceae, and unclassified_f_Lachnospiraceae. Meanwhile, metabolomics analysis revealed that FZQS significantly regulated tryptophan metabolism by reducing the levels of 3-Indoleacetonitrile and 5-Hydroxykynurenine. CONCLUSION: FZQS effectively ameliorated LPS-induced lung injury by inhibiting the activation, migration, and adhesion of macrophages and neutrophils and modulating gut microbiota and its metabolites.

Andrographolide ameliorates sepsis-induced acute lung injury by promoting autophagy in alveolar macrophages via the RAGE/PI3K/AKT/mTOR pathway.

Autophagy in alveolar macrophages (AMs) is an important mechanism for maintaining immune homeostasis and normal lung tissue function, and insufficient autophagy in AMs may mediate the development of sepsis-induced acute lung injury (SALI). Insufficient autophagy in AMs and the activation of the NLRP3 inflammasome were observed in a mouse model with SALI induced by cecal ligation and puncture (CLP), resulting in the release of a substantial quantity of proinflammatory factors and the formation of SALI. However, after andrographolide (AG) intervention, autophagy in AMs was significantly promoted, the activation of the NLRP3 inflammasome was inhibited, the release of proinflammatory factors and pyroptosis were suppressed, and SALI was then ameliorated. In the MH-S cell model stimulated with LPS, insufficient autophagy was discovered to promote the overactivation of the NLRP3 inflammasome. AG was found to significantly promote autophagy, inhibit the activation of the NLRP3 inflammasome, and attenuate the release of proinflammatory factors. The primary mechanism of AG promoting autophagy was to inhibit the activation of the PI3K/AKT/mTOR pathway by binding RAGE to the membrane. In addition, it inhibited the activation of the NLRP3 inflammasome to ameliorate SALI. Our findings suggest that AG promotes autophagy in AMs through the RAGE/PI3K/AKT/mTOR pathway to inhibit the activation of the NLRP3 inflammasome, remodel the functional homeostasis of AMs in SALI, and exert anti-inflammatory and lung-protective effects. It has also been the first to suggest that RAGE is likely a direct target through which AG regulates autophagy, providing theoretical support for a novel therapeutic strategy in sepsis.

Plumbagin ameliorates LPS-induced acute lung injury by regulating PI3K/AKT/mTOR and Keap1-Nrf2/HO-1 signalling pathways.

Acute lung injury (ALI) is a major pathophysiological problem characterized by severe inflammation, resulting in high morbidity and mortality. Plumbagin (PL), a major bioactive constituent extracted from the traditional Chinese herb Plumbago zeylanica, has been shown to possess anti-inflammatory and antioxidant pharmacological activities. However, its protective effect on ALI has not been extensively studied. The objective of this study was to investigate the protective effect of PL against ALI induced by LPS and to elucidate its possible mechanisms both in vivo and in vitro. PL treatment significantly inhibited pathological injury, MPO activity, and the wet/dry ratio in lung tissues, and decreased the levels of inflammatory cells and inflammatory cytokines TNF-α, IL-1ß, IL-6 in BALF induced by LPS. In addition, PL inhibited the activation of the PI3K/AKT/mTOR signalling pathway, increased the activity of antioxidant enzymes CAT, SOD, GSH and activated the Keap1/Nrf2/HO-1 signalling pathway during ALI induced by LPS. To further assess the association between the inhibitory effects of PL on ALI and the PI3K/AKT/mTOR and Keap1/Nrf2/HO-1 signalling, we pretreated RAW264.7 cells with 740Y-P and ML385. The results showed that the activation of PI3K/AKT/mTOR signalling reversed the protective effect of PL on inflammatory response induced by LPS. Moreover, the inhibitory effects of PL on the production of inflammatory cytokines induced by LPS also inhibited by downregulating Keap1/Nrf2/HO-1 signalling. In conclusion, the results indicate that the PL ameliorate LPS-induced ALI by regulating the PI3K/AKT/mTOR and Keap1-Nrf2/HO-1 signalling, which may provide a novel therapeutic perspective for PL in inhibiting ALI.

Propolis Alleviates Acute Lung Injury Induced by Heat-Inactivated Methicillin-Resistant Staphylococcus aureus via Regulating Inflammatory Mediators, Gut Microbiota and Serum Metabolites.

Propolis has potential anti-inflammatory properties, but little is known about its efficacy against inflammatory reactions caused by drug-resistant bacteria, and the difference in efficacy between propolis and tree gum is also unclear. Here, an in vivo study was performed to study the effects of ethanol extract from poplar propolis (EEP) and poplar tree gum (EEG) against heat-inactivated methicillin-resistant Staphylococcus aureus (MRSA)-induced acute lung injury (ALI) in mice. Pre-treatment with EEP and EEG (100 mg/kg, p.o.) resulted in significant protective effects on ALI in mice, and EEP exerted stronger activity to alleviate lung tissue lesions and ALI scores compared with that of EEG. Furthermore, EEP significantly suppressed the levels of pro-inflammatory mediators in the lung, including TNF-α, IL-1ß, IL-6, and IFN-γ. Gut microbiota analysis revealed that both EEP and EEG could modulate the composition of the gut microbiota, enhance the abundance of beneficial microbiota and reduce the harmful ones, and partly restore the levels of short-chain fatty acids. EEP could modulate more serum metabolites and showed a more robust correlation between serum metabolites and gut microbiota. Overall, these results support the anti-inflammatory effects of propolis in the treatment of ALI, and the necessity of the quality control of propolis.

Anthrahydroquinone­2,6­disulfonate attenuates PQ­induced acute lung injury through decreasing pulmonary microvascular permeability via inhibition of the PI3K/AKT/eNOS pathway.

In paraquat (PQ)­induced acute lung injury (ALI)/ acute respiratory distress syndrome, PQ disrupts endothelial cell function and vascular integrity, which leads to increased pulmonary leakage. Anthrahydroquinone­2,6­disulfonate (AH2QDS) is a reducing agent that attenuates the extent of renal injury and improves survival in PQ­intoxicated Sprague­Dawley (SD) rats. The present study aimed to explore the beneficial role of AH2QDS in PQ­induced ALI and its related mechanisms. A PQ­intoxicated ALI model was established using PQ gavage in SD rats. Human pulmonary microvascular endothelial cells (HPMECs) were challenged with PQ. Superoxide dismutase, malondialdehyde, reactive oxygen species and nitric oxide (NO) fluorescence were examined to detect the level of oxidative stress in HPMECs. The levels of TNF­α, IL­1ß and IL­6 were assessed using an ELISA. Transwell and Cell Counting Kit­8 assays were performed to detect the migration and proliferation of the cells. The pathological changes in lung tissues and blood vessels were examined by haematoxylin and eosin staining. Evans blue staining was used to detect pulmonary microvascular permeability. Western blotting was performed to detect target protein levels. Immunofluorescence and immunohistochemical staining were used to detect the expression levels of target proteins in HPMECs and lung tissues. AH2QDS inhibited inflammatory responses in lung tissues and HPMECs, and promoted the proliferation and migration of HPMECs. In addition, AH2QDS reduced pulmonary microvascular permeability by upregulating the levels of vascular endothelial­cadherin, zonula occludens­1 and CD31, thereby attenuating pathological changes in the lungs in rats. Finally, these effects may be related to the suppression of the phosphatidylinositol­3­kinase (PI3K)/protein kinase B (AKT)/endothelial­type NO synthase (eNOS) signalling pathway in endothelial cells. In conclusion, AH2QDS ameliorated PQ­induced ALI by improving alveolar endothelial barrier disruption via modulation of the PI3K/AKT/eNOS signalling pathway, which may be an effective candidate for the treatment of PQ­induced ALI.

Protective effects of butorphanol in oleic acid-endotoxin "two-hit" induced rat lung injury by suppression of inflammation and apoptosis.

Butorphanol is widely used as an anesthetic drug, whether butorphanol could reduce organ injury and protecting lung tissue is unknown. This study explored the effects of butorphanol on ALI and investigated its underlying mechanisms. We established a "two-hit" rat model and "two-hit" cell model to prove our hypothesis. Rats were divided into four groups [control, "two-hit" (OA + LPS), "two-hit" + butorphanol (4 mg/kg and 8 mg/kg) (OA + LPS + B1 and OA + LPS + B2)]. RPMVE cells were divided into four groups [control, "two-hit" (OA + LPS), "two-hit" + butorphanol (4 µM and 8 µM) (OA + LPS + 4 µM and OA + LPS + 8 µM)]. Inflammatory injury was assessed by the histopathology and W/D ratio, inflammatory cytokines, and arterial blood gas analysis. Apoptosis was assessed by Western blotting and flow cytometry. The effect of NF-κB p65 was detected by ELISA. Butorphanol could relieve the "two-hit" induced lung injury, the expression of TNF, IL-1ß, IL-6, and improve lung ventilation. In addition, butorphanol decreased Bax and cleaved caspase-3, increased an antiapoptotic protein (Bcl-2), and inhibited the "two-hit" cell apoptosis ratio. Moreover, butorphanol suppressed NF-κB p65 activity in rat lung injury. Our research showed that butorphanol may attenuate "two-hit"-induced lung injury by regulating the activity of NF-κB p65, which may supply more evidence for ALI treatment.

Advances in nanomaterial-targeted treatment of acute lung injury after burns.

Acute lung injury (ALI) is a common complication in patients with severe burns and has a complex pathogenesis and high morbidity and mortality rates. A variety of drugs have been identified in the clinic for the treatment of ALI, but they have toxic side effects caused by easy degradation in the body and distribution throughout the body. In recent years, as the understanding of the mechanism underlying ALI has improved, scholars have developed a variety of new nanomaterials that can be safely and effectively targeted for the treatment of ALI. Most of these methods involve nanomaterials such as lipids, organic polymers, peptides, extracellular vesicles or cell membranes, inorganic nanoparticles and other nanomaterials, which are targeted to reach lung tissues to perform their functions through active targeting or passive targeting, a process that involves a variety of cells or organelles. In this review, first, the mechanisms and pathophysiological features of ALI occurrence after burn injury are reviewed, potential therapeutic targets for ALI are summarized, existing nanomaterials for the targeted treatment of ALI are classified, and possible problems and challenges of nanomaterials in the targeted treatment of ALI are discussed to provide a reference for the development of nanomaterials for the targeted treatment of ALI.