Search Results (307)

Introduction: Acute lung injury (ALI) is characterized by severe inflammation and oxidative stress. However, effective pharmacological interventions for ALI remain limited. Carnosine, an endogenous dipeptide known for its redox-regulating and immunomodulatory activities, has demonstrated promising protective effects. In the present study, inhalable carnosine-loaded liposomes (Cn-Ls) were developed to enhance pulmonary delivery and achieve localized treatment in a lipopolysaccharide (LPS)-induced ALI model in mice. Methods: Cn-Ls were prepared and systematically evaluated for their morphology, stability, drug-loading capacity, and release kinetics. In vitro assays were performed to evaluate their cytocompatibility, antioxidant activity, and effects on LPS-induced reactive oxygen species (ROS) generation. In an ALI model, inhaled Cn-Ls were administered to assess pulmonary retention and therapeutic efficacy, including lung inflammation, oxidative stress, circulating levels of C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-6, lung architecture, and respiratory function. Results: Encapsulation of carnosine within liposomes markedly prolonged its pulmonary retention (t₁/₂ = 1.7 h vs. 1.0 h for free carnosine), providing a more sustained lung-retentive delivery profile for up to 12 h. In vitro assays showed that Cn-Ls had excellent cytocompatibility, reduced cell death, exhibited potent antioxidant activity, and effectively suppressed LPS-induced ROS generation. In an ALI model, inhaled Cn-Ls markedly mitigated lung inflammation and oxidative stress, reduced circulating levels of CRP, TNF-α, and IL-6, preserved lung architecture, and improved respiratory function. Compared with free carnosine, Cn-Ls exhibited enhanced pulmonary retention and superior therapeutic efficacy. Conclusions: These results identified inhalable Cn-Ls as a potential nanotherapeutic approach for targeted ALI management and provided a foundation for further translational development. However, additional investigations are required to assess the long-term safety of Cn-Ls, optimize formulation stability and scalability, and further elucidate the underlying therapeutic mechanisms before clinical translation. Full article

Sepsis-induced acute lung injury (SI-ALI) is a severe complication of sepsis characterized by dysregulated inflammatory responses and impaired immune homeostasis. Growing evidence indicates that extracellular vesicles (EVs), particularly exosomes, are important mediators of intercellular communication. Despite the heterogeneity of infectious sources underlying sepsis, EVs can regulate macrophage polarization and functional reprogramming by transferring diverse bioactive cargo. Consequently, EVs are involved in the pathophysiological progression of SI-ALI arising from sepsis of different etiologies. However, the mechanisms through which distinct EV cargos regulate macrophage function and contribute to SI-ALI pathogenesis remain incompletely understood. To address these issues, this review summarizes how different EV subtypes and their cargos, including RNAs, proteins, lipids, and DNA, modulate macrophage functional states through multiple signaling pathways. The effect of such processes further contributes to inflammatory reaction, immune balance, and tissue regeneration in acute lung injury caused by damage to the SI-ALI. Particularly, the EV-mediated modulation of macrophage function goes beyond the rigid M1/M2 dichotomy, being rather based on the dynamic functional repertoire involving both pro-inflammatory response and immune regulation as well as tissue regeneration. The article finally concludes with EV-based treatment approaches aimed at cargo delivery or blocking and the main problems related to translational medicine. Overall, the review article identifies the macrophage regulatory network controlled by EVs, thus helping to understand immunopathogenesis of SI-ALI as well as laying the theoretical foundation for developing EV-based precision medicine. Full article

Background: Sepsis-induced acute lung injury (SI-ALI) leads to high mortality in critically ill patients, and no specific targeted treatments are available. Current studies mainly characterize intercellular crosstalk via protein–ligand–receptor frameworks, while metabolite-derived immune signal transmission is largely unclarified. Alveolar macrophages are located at the alveolar barrier and may act as central metabolic coordinators to trigger neutrophil-mediated lung inflammation, yet the complete metabolite signaling network has not been systematically mapped. Methods: We integrated single-cell and bulk transcriptomic datasets from CLP-induced septic mouse lungs. CellChat and MEBOCOST were jointly used to reconstruct protein–metabolite dual communication networks. LASSO regression and random forest were combined to screen core metabolic hub genes, followed by single-cell expression mapping and in vivo histology & qPCR validation. Results: We identified a pivotal alveolar macrophage–neutrophil immunometabolic axis dominated by iron-Slc40a1 and LTB4-Ltb4r1 signaling. Three hub genes (Pmvk, Slc2a1, Slc7a11) coordinately regulate inflammatory pathways, among which myeloid-enriched Slc7a11 balances cellular redox and paracrine inflammatory responses. Conclusions: This study establishes the first dual-layer cell communication atlas for SI-ALI, proposes a macrophage-centered metabolic inflammatory regulatory model, and highlights Slc7a11 as a potential therapeutic target for septic lung injury. Full article

Acute lung injury (ALI) seriously impairs health and well-being. Although Scutellaria baicalensis Georgi (SBG) extract has been shown to alleviate ALI, the effects of SBG acidic polysaccharides on ALI have not been revealed. In this study, a homogeneous acidic polysaccharide (SBGP1) was purified and characterized, and its impact on ALI was evaluated. Our findings illustrated that the average molecular weight of SBGP1 was 40764.6 Da, and it was mainly composed of GalA (53.14%), Ara (26.99%), Gal (7.75%), Glc (5.95%), and Rha (6.17%). The main chain of SBGP1 consisted of →4)-α-GalpA-6-OMe-(1→ and →4)-α-GalpA-(1→. Furthermore, SBGP1 exhibited a significant alleviating effect on ALI, as evidenced by decreased levels of TNF-α, IL-1β, IL-6, GSSG, and MDA, and increased levels of IL-4, IL-10, GSH, and SOD. Mechanistically, SBGP1’s role in alleviating ALI may be associated with the activation of the Rap1 signaling pathway. SBGP1 improved intestinal homeostasis, manifested as increased abundance of beneficial bacteria (Lactobacillus and norank_f_Muribaculaceae) and decreased abundance of harmful bacteria (Adlercreutzia, Ligilactobacillus, Massiliomicrobiota, and Mucispirillum). Interestingly, SBGP1-derived Lactobacillus johnsonii and propionic acid evidently improved the inflammatory response and oxidative stress in ALI mice. Overall, this study provides novel insights into SBGP1 as a potential therapeutic option for ALI. Full article

Early detection of acute lung injury (ALI) remains challenging, as conventional diagnostics rarely capture initial molecular changes. We therefore examined whether extracellular vesicles (EVs) in bronchoalveolar lavage fluid (BALF) can detect early regional injury and distinguish initial stress mechanisms in a porcine ALI model. Unilateral ALI was induced using Triton X-100, followed by six hours of mechanical ventilation with either fixed positive end-expiratory pressure (PEEP) at 5 cmH₂O or transpulmonary-pressure (TPP)-guided PEEP. Spatially separated BALF sampling allowed direct comparison between injured and contralateral mechanically stressed lungs. EV concentration and size distribution were quantified by nano-flow cytometry, while vesicular identity was confirmed by transmission electron microscopy and tetraspanin dot blot analyses. Furthermore, EV metrics were related to corresponding histologic injury scores. Across both PEEP strategies, EV concentration was markedly higher in both directly injured and contralateral mechanically stressed lungs compared with sham controls, indicating alveolar stress beyond the primary injury site. Median EV size differed significantly by injury type and correlated inversely with histologic injury, particularly with alveolar neutrophil infiltration. BALF-derived EV concentration and size may therefore provide complementary, spatially resolved molecular readouts of early ALI. Full article

Mucosal microbiota contribute broadly to host defense and immune homeostasis, while the lung and gut microbiota form a particularly important bidirectional ecological and immunological network that shapes pulmonary host defense, inflammatory injury, and tissue repair. In pneumonia, loss of colonization resistance and altered microbial metabolite production may weaken innate and adaptive immunity; respiratory infection, antibiotics, and critical-care exposures can, in turn, remodel both microbial communities. In acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), intestinal barrier failure, circulating microbial products, immune cell trafficking and, in selected settings, lymphatic or hematogenous dissemination of gut-derived organisms may aggravate alveolar–capillary injury. Alveolar macrophages integrate these signals through pattern-recognition, metabolic, and epigenetic pathways, linking microbial ecology to pathogen clearance and inflammatory resolution. The evidence, however, remains uneven. Mechanistic causality rests largely on animal studies, most human data are associative, and trials of microbiota-directed interventions are heterogeneous and strain-specific. This Review examines bacterial and viral pneumonia, sepsis-associated ALI and ventilator-associated injury; separates mechanistic, observational, and interventional evidence; and evaluates probiotics, live biotherapeutic products, microbial metabolites, and dietary approaches. Translation will depend on longitudinal sampling, source-resolved microbial tracking, metabolite-informed patient stratification, and adequately powered trials with clinically relevant endpoints. Full article

Objective: In a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model, the present study sought to assess the therapeutic efficacy of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) and characterize their anti-inflammatory mechanistic basis. Methods: Forty mice were randomly divided into four groups: control, LPS model, LPS + DEX (positive control), and LPS + hUC-MSCs. Except for the control group, mice received intratracheal instillation of LPS to establish ALI. One hour after LPS administration, animals in the hUC-MSC group were intravenously infused with hUC-MSCs. The positive control group was given an intraperitoneal injection of DEX for 3 consecutive days, starting at 24 h after modeling. On day 4 after cell transplantation or at 24 h after the completion of DEX injection, lung function indicators were detected. Bronchoalveolar lavage fluid (BALF), serum, and lung tissues were subsequently obtained for evaluation of inflammatory cell infiltration, histopathological injury, lung wet-to-dry (W/D) ratio, and cytokine levels. Additionally, the localization of transplanted hUC-MSCs in lungs was examined, and the mRNA and protein expression levels of TLR4, MyD88, and NF-κB p65 were quantified. Results: LPS exposure markedly impaired pulmonary function and induced robust inflammatory responses, evidenced by elevated levels of pro-inflammatory cytokines, increased inflammatory cell counts in BALF and serum, and extensive histological lung damage. Moreover, hUC-MSC injection improved lung function, decreased inflammatory cytokine production and alleviated pulmonary edema, while inhibiting the TLR4/MyD88/NF-κB pathway at transcriptional and protein levels. Conclusions: Intravenous hUC-MSC administration alleviates LPS-induced ALI in mice, an effect associated with suppression of the TLR4/MyD88/NF-κB cascade. These results indicate that this signaling cascade partially mediates the observed anti-inflammatory effects. Full article

Tamarix chinensis Lour. (T. chinensis) is a traditional herb with functions for releasing the exterior to promote the eruption of rashes, among other ailments. However, these function-related pharmacological effects, such as anti-complement, anti-oxidative, and anti-inflammatory, remain unclear. This study aims to reveal the aforementioned effects and the molecular mechanisms of the ethanol extract of T. chinensis (TCE). Our results demonstrated that TCE inhibited classical- and lectin-mediated complement activation, reduced intracellular ROS via NADPH oxidase inhibition, and directly scavenged DPPH radicals and superoxide anions. By using lipopolysaccharide (LPS)-stimulated macrophages, along with LPS-induced acute lung injury (ALI) and endotoxemia mice, the anti-inflammatory activity and the underlying molecular mechanisms of TCE were deeply investigated. In LPS-activated macrophages, it suppressed iNOS, CCL2, IL-6 and IL-1β transcriptionally and translationally. Mechanistically, TCE inhibited NF-κB signaling by blocking IκBα phosphorylation and p65 nuclear translocation, as well as suppresses AP-1 signaling by reducing ERK and JNK phosphorylation. In vivo, TCE lowered serum multiple pro-inflammatory cytokines of endotoxemic mice and alleviated lung injury of ALI mice. Collectively, our results demonstrated that TCE possesses anti-complement and anti-oxidative activities and exerts anti-inflammatory effects through inhibiting NF-κB and AP-1 signaling. These findings provide scientific evidence for supporting the traditional use of T. chinensis. Full article

Adipose tissue has emerged as a pivotal endocrine organ, secreting bioactive proteins termed adipokines that regulate metabolic and immune processes across multiple organ systems. In the context of sepsis and critical illness, conditions defined by a dysregulated host response to infection with life-threatening organ dysfunction, the role of novel adipokines has attracted considerable research interest. This review focuses on three novel adipokines: chemerin, vaspin (SERPINA12), and omentin-1 (intelectin-1). We will discuss current in vitro, in vivo experimental animal models, and clinical evidence, emphasizing their biology, mechanisms of action, and potential as diagnostic and prognostic biomarkers in critically ill patients. All three adipokines are elevated in sepsis compared with healthy controls and correlate with established severity scores, including APACHE II and SOFA. Chemerin and omentin-1 have both been independently associated with 28-day mortality in prospective cohort studies. Vaspin exhibits robust cardioprotective effects in murine sepsis models via inhibition of kallikrein 7 (KLK7) and attenuates lipopolysaccharide (LPS)-induced acute lung injury (ALI) both in vitro and in vivo. Omentin-1 suppresses LPS-induced macrophage activation through TLR4/MyD88/NF-κB inhibition in vitro and protects against LPS-induced ALI in murine models. Despite these promising findings, substantial methodological heterogeneity and limited large-scale clinical data currently preclude clinical implementation. Future research that standardizes assays, expands to multicenter cohorts, and investigates therapeutic modulation of these pathways is urgently needed. Full article

Experimental acute lung injury (ALI) models are widely used to investigate pulmonary inflammation and evaluate therapeutic strategies for acute respiratory distress syndrome (ARDS). Kaempferia marginata is a traditional medicinal plant used to treat fever and has been reported to possess anti-inflammatory properties in lipopolysaccharide (LPS)-activated macrophages. 6β-Acetoxysandaracopimaradien-1α,9α-diol (ASPD), a major isopimarane-type diterpenoid isolated from this plant, has not previously been investigated for its effects on ALI. This study employed an integrated network pharmacology, molecular docking, and experimental validation strategy to investigate the protective effects and potential mechanisms of ASPD against LPS-induced ALI. Network pharmacology analysis identified several inflammation-related hub targets associated with Src, MAPK, and PI3K/Akt signalling. In LPS-stimulated MLE-12 cells, ASPD reduced inflammatory cytokine production and inhibited the phosphorylation of JNK1/2, ERK1/2, p38 MAPK, Akt, and GSK-3β. In mice with LPS-induced ALI, ASPD alleviated histopathological lung injury, pulmonary oedema, and inflammatory cell infiltration while reducing IL-6, TNF-α, and myeloperoxidase activity without apparent toxicity. Immunohistochemical analysis demonstrated reduced Src and ERK1/2 expression in lung tissue. Molecular docking analysis predicted favourable binding affinities between ASPD and selected Src- and MAPK-related signalling proteins. These findings suggest that ASPD attenuates LPS-induced ALI and is associated with alterations in Src-, MAPK-, and Akt/GSK-3β-related signalling. Full article

Background/Objectives: Acute lung injury (ALI) currently lacks safe and effective therapeutic strategies with low toxicity. Lonicerae japonicae flos, a traditional herb and functional food, contains polyphenols as its principal active components. This study investigated whether Lonicerae japonicae flos polyphenols (LJP) could exert protective effects against lipopolysaccharide (LPS)-induced ALI in mice. Methods: Eighty-four male C57BL/6J mice were randomly divided into seven groups and treated daily for 7 days with LJP (200, 100, or 50 mg/kg), liproxstatin-1 (10 mg/kg), dexamethasone (5 mg/kg), or saline (control and model groups). Subsequently, another thirty-six mice were used for the fecal microbiota transplantation (FMT) experiment. All groups except the control group received intratracheal instillation of LPS (5 mg/kg) to induce ALI. Results: LJP treatment significantly ameliorated lung histopathological damage and gut microbiota dysbiosis. Lung proteomics analysis revealed the enrichment of the NF-κB and ferroptosis pathways. Mechanistically, LJP downregulated pro-inflammatory factors (IL-6, TNF-α, and IL-1β) by suppressing activation of the TLR4/MyD88/NF-κB pathway. Meanwhile, LJP upregulated SOD and GSH levels, thereby suppressing the accumulation of ROS, GSSG, Fe²⁺, and MDA, which were closely related to the activation of the Nrf2/HO-1 and Sirt3/Nrf2/GPX4 pathways. Furthermore, LJP modulated the gut microbiota and promoted short-chain fatty acid (SCFA) production by elevating the relative abundance of Akkermansia muciniphila and Faecalibaculum. Intriguingly, FMT results confirmed that the LJP-derived gut microbiota markedly alleviated lung tissue injury and intestinal barrier damage in ALI mice. Conclusions: This study demonstrated that LJP could reshape the gut microbiota to enhance the production of SCFAs and inhibit inflammation-related ferroptosis in ALI mice. Full article

Objectives: Inflammatory bowel disease (IBD) is associated with extraintestinal comorbidities, and lung diseases are widespread manifestations. Respiratory bacterial insult is a common illness that results in acute lung injury (ALI) in critical patients. IBD concurrence with respiratory infection may further exacerbate lung injury. Tryptophan (Try), an essential amino acid, is processed by gut microbiota and produces aryl hydrocarbon receptor (AhR) ligands. These ligands can activate the AhR pathway that exerts anti-inflammatory properties and provides protection against mucosal barrier injury. This study investigated the effects of dietary Try on lipopolysaccharide (LPS)-stimulated ALI in mice with colitis induced by dextran sodium sulfate (DSS). Methods: Mice with colitis were allocated to four groups: (1) ND-Sal: normal diet + DSS + intratracheal saline injection; (2) ND-LPS: normal diet + DSS + intratracheal LPS injection; (3) TD-Sal: Try diet + DSS + intratracheal saline injection; (4) TD-LPS: Try diet + DSS + intratracheal LPS injection. Mice were sacrificed 24 h after the intratracheal injection. Results: Results showed that colitis resulted in a high disease activity index. Following induction of ALI in colitis mice, neutrophil populations and inflammatory cytokine levels in bronchoalveolar lavage fluid increased. Gene expression levels associated with toll-like receptor (TLR)4/nuclear factor (NF)-κB signaling were upregulated, and tight junction proteins decreased in the lungs. Dietary Try supplementation decreased circulating LPS levels, suppressed pulmonary TLR4/NF-κB signaling, upregulated AhR/interleukin-22 expression, attenuated oxidative stress and improved the capillary–epithelial barrier integrity in DSS-treated mice. Conclusions: These findings imply that Try may have potential therapeutic significance in bacterial-induced ALI in a colitis condition. Full article

Oxidative stress is a central pathogenic mechanism in acute and chronic respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and pulmonary fibrosis. Excessive production of reactive oxygen and nitrogen species (ROS/RNS), combined with impaired antioxidant defenses, contributes to epithelial and endothelial injury, inflammation, mitochondrial dysfunction, airway remodeling, and progressive loss of lung function. Plant-derived polyphenols and polyphenol-rich herbal mixtures have emerged as promising candidates for respiratory protection due to their multimodal activity. They exert effects through direct antioxidant action, enhancement of glutathione-dependent and enzymatic defenses, activation of the Nrf2/HO-1 pathway, and suppression of NF-κB, MAPK, inflammasome, and profibrotic signaling. Experimental studies have demonstrated protective effects of compounds such as quercetin, resveratrol, rosmarinic acid, epigallocatechin gallate, and phenolic-rich extracts. However, clinical translation remains limited by poor bioavailability, variability of botanical preparations, lack of standardization, and insufficient high-quality human studies. This review summarizes key mechanisms of oxidative lung injury and critically evaluates the therapeutic potential and translational challenges of herbal polyphenolic mixtures in respiratory diseases. Full article

Background/Objectives: Sepsis is a life-threatening syndrome arising from a dysregulated host response to infection, frequently leading to multiple organ dysfunction, with the lungs being among the most severely affected organs. Oxidative stress, inflammation, apoptosis, and DNA damage play key roles in the pathogenesis of sepsis-induced acute lung injury (ALI). Beyond its lipid-lowering effects, rosuvastatin possesses anti-inflammatory and antioxidant properties that may confer protective effects in sepsis. This study was designed to investigate the dose-dependent prophylactic efficacy of rosuvastatin in mitigating pulmonary damage in rats with cecal ligation and puncture (CLP)-induced sepsis. Methods: Sprague–Dawley rats were randomly divided into six groups: Sham, Sham + rosuvastatin (10 mg/kg), Sham + rosuvastatin (20 mg/kg), CLP, CLP + rosuvastatin (10 mg/kg), and CLP + rosuvastatin (20 mg/kg). Rosuvastatin was administered via oral gavage 4 h before the surgical procedures in the experimental groups. All animals were sacrificed 16 h following surgical procedures. Lung tissues were analyzed for biochemical markers, including malondialdehyde (MDA) and reduced glutathione (GSH), as well as histopathological changes and immunohistochemical expression of NF-κB/p65, caspase-3, and 8-OHdG. Results: CLP-induced sepsis significantly increased MDA levels while decreasing GSH levels, indicating enhanced oxidative stress. Rosuvastatin treatment significantly reversed these changes. Histopathological analysis revealed marked lung injury in the CLP group, including alveolar inflammation, interstitial inflammation, vascular congestion, and increased alveolar septal thickness, all of which were significantly reduced following rosuvastatin administration. Immunohistochemical findings demonstrated increased expression of NF-κB/p65, caspase-3, and 8-OHdG in the CLP group, whereas rosuvastatin significantly attenuated these expressions. No significant difference in prophylactic efficacy was observed between the 10 mg/kg and 20 mg/kg doses of rosuvastatin. Conclusions: Rosuvastatin demonstrated a protective effect against sepsis-induced pulmonary damage by reducing oxidative stress, inflammation, apoptosis, and DNA damage. These findings suggest that rosuvastatin may have prophylactic potential in sepsis; however, further support is needed from investigations of cellular pathways in different mechanistic directions. Full article

Endotoxemia represents a life-threatening clinical disorder driven by an aberrant host immune response to pathogenic infection, often resulting in severe multiple organ dysfunction. Among its most devastating complications are acute lung injury (ALI) and endotoxemia-associated encephalopathy (EAE), both of which are associated with elevated mortality and currently lack effective targeted interventions. This study evaluated the therapeutic efficacy and underlying molecular mechanisms of recombinant human thymosin β4 (rhTβ4) in a murine model of lipopolysaccharide (LPS)-induced endotoxemia. Our results showed that treatment with rhTβ4 markedly enhanced survival rates and diminished the systemic overproduction of diverse proinflammatory cytokines and chemokines in endotoxemic mice. These systemic protective actions were achieved through the inhibition of the TLR4/NF-κB signaling cascade, the reduction in M1 macrophage polarization, and the simultaneous alleviation of mitochondrial impairment and oxidative stress. Moreover, rhTβ4 treatment significantly rescued EAE-related cognitive deficits and attenuated neuronal damage, primarily through the suppression of neuroinflammation and microglial overactivation. Integrative transcriptomic profiling and functional assays identified lysophosphatidic acid receptor 3 (LPAR3) as an important contributor, suggesting that rhTβ4 suppresses microglial-mediated neurotoxicity at least in part through LPAR3 downregulation. In conclusion, rhTβ4 confers robust multi-organ protection against endotoxemic injury by orchestrating the inhibition of systemic and central neuroinflammatory cascades, positioning it as a promising candidate for the treatment of endotoxemia-induced ALI and EAE. Full article