Search Results (303)

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

Background: Acute lung injury (ALI) is a major contributor to mortality in neonatal sepsis, yet the mechanisms underlying early lung damage remain incompletely understood. Although extracellular traps (ETs) have been implicated in inflammatory injury, the cellular origin and regulatory pathways of ET formation in neonatal sepsis remain unclear. This study aimed to determine the source of ETs and to investigate the role of hypoxia-inducible factor-1α (HIF-1α) in regulating macrophage extracellular traps (METs) formation and lung injury. Methods: Neonatal sepsis was induced in mice by intraperitoneal injection of cecal slurry. METs formation was assessed by immunofluorescence staining, Western blotting, and extracellular DNA quantification. Selective depletion of macrophages or neutrophils was performed to determine the cellular source of ETs. In vitro experiments were conducted using macrophages stimulated with lipopolysaccharide or phorbol 12-myristate 13-acetate. RNA sequencing analysis and pharmacological inhibition were used to examine the roles of HIF-1α, glycolysis, and enolase 2 (ENO2) in METs formation, lung injury, and survival outcomes. Results: We identify macrophages as a predominant source of ETs in the lung and demonstrate that METs contribute to lung injury in neonatal sepsis. Depletion of macrophages or pharmacological inhibition of METs formation markedly attenuated lung injury and improved survival in neonatal sepsis mice. Mechanistically, we suggest that HIF-1α promotes METs formation by driving glycolysis in macrophages. Furthermore, this process appears to involve the upregulation of key glycolytic enzymes, including ENO2, potentially facilitating METs release. In turn, METs are implicated in enhancing macrophage inflammatory activation, which could exacerbate lung injury. Importantly, pharmacological targeting of HIF-1α pathways reduces METs formation, attenuates lung inflammation, and improves survival outcomes. Conclusions: These findings suggest a role for HIF-1α in regulating METs formation and support that targeting this pathway could represent a potential therapeutic strategy for neonatal sepsis-associated acute lung injury. Full article

The dipeptidyl peptidase (DPP) family comprises enzymes with important metabolic and immunomodulatory properties. This narrative review summarizes recent clinical and experimental evidence on the role of DPP-1, DPP-4, DPP-9, and DPP-10 in pulmonary diseases. The strongest translational evidence currently supports DPP-1 inhibition in non-cystic fibrosis bronchiectasis, where brensocatib reduces exacerbations and prolongs time to first exacerbation, with additional DPP-1 inhibitors in development. By contrast, the roles of DPP-4, DPP-9, and DPP-10 are supported mainly by preclinical studies in pulmonary hypertension, acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), pulmonary fibrosis, asthma, non-small cell lung cancer (NSCLC), and nonsteroidal anti-inflammatory drugs (NSAIDs)/aspirin-exacerbated respiratory disease. Across these models, DPP inhibition modulates inflammation, protease activation, epithelial- or endothelial-to- mesenchymal transition (EMT/ EndMT), extracellular matrix (ECM) remodeling, and related signaling pathways. Overall, DPP-targeted interventions are promising in pulmonary medicine, but broader clinical translation will require well-designed prospective trials. Full article

Background: Acute lung injury (ALI) is a major complication of sepsis, driven by oxidative stress, inflammation, and apoptosis. Paeoniflorin, a monoterpenoid glycoside, has demonstrated notable antioxidant and anti-inflammatory properties, suggesting potential therapeutic value in ALI. Methods: Sepsis-induced ALI was established in mice using the cecal ligation and puncture (CLP) model. The protective effects of paeoniflorin were evaluated by measuring oxidative stress markers (SOD, GSH, and MDA) and pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) using biochemical assays and RT-PCR. Histopathological examination and apoptosis assessment (Bax and Bcl-2 expression) were performed. Western blot analysis was conducted to investigate the involvement of the JAK2/STAT3 signaling pathway. Network pharmacology analysis was used to identify potential molecular targets, and molecular docking was performed to explore binding interactions. Results: CLP-induced ALI resulted in increased oxidative stress and inflammatory responses, as evidenced by elevated MDA and cytokine levels, along with reduced SOD and GSH levels. Paeoniflorin treatment significantly ameliorated these alterations. Histological damage and apoptosis were markedly reduced, accompanied by the downregulation of Bax and upregulation of Bcl-2. Additionally, paeoniflorin inhibited activation of the JAK2/STAT3 pathway. Network pharmacology identified key ALI-related targets, including IL6, TNF, IL1B, HIF1A, STAT3, NFKB1, CCL2, CYBB, CXCL8, and NOX4. Molecular docking revealed strong binding affinity of paeoniflorin toward HIF-1 and JUN, and moderate interactions with IL-1β, TNF-α, and Bax. Conclusions: Paeoniflorin exerts protective effects against sepsis-induced ALI by attenuating oxidative stress, inflammation, and apoptosis, partly through inhibition of the JAK2/STAT3 signaling pathway. These findings highlight its potential as a promising therapeutic candidate for ALI management. Full article

Macrophage-mediated inflammation is a key driver of sepsis-induced acute lung injury (ALI). M1 macrophage polarization relies on metabolic reprogramming, yet the upstream regulatory factors remain unclear. Lysine acetyltransferase 6A (KAT6A), a MYST-family acetyltransferase, regulates transcriptional programs in immune cells, but its role in macrophage function and ALI progression remains unknown. Public single-cell and bulk transcriptomic datasets were used to assess KAT6A expression changes and its association with inflammatory and metabolic pathways in macrophages. KAT6A inhibition with WM1119 was used to evaluate effects on M1 polarization, cytokine production, metabolic reprogramming, and PI3K-AKT-mTOR signaling. The therapeutic potential of KAT6A inhibition was validated in a cecal ligation and puncture (CLP)-induced sepsis model by assessing lung injury, bacterial clearance, and survival. KAT6A expression was upregulated in sepsis and particularly enriched in M1 macrophages. Inhibition of KAT6A reduced inflammatory and glycolytic transcriptional programs, suppressed glycolysis and enhanced oxidative phosphorylation, leading to decreased cytokine production and limited M1 polarization accompanied by suppression of PI3K-AKT-mTOR pathway. In CLP-induced septic mice, treatment with the KAT6A inhibitor WM1119 alleviated lung injury, improved bacterial clearance, and prolonged survival. KAT6A expression is associated with macrophage glucose metabolism, pro-inflammatory responses, and M1 macrophage polarization in sepsis-induced acute lung injury. Pharmacologic inhibition of KAT6A may provide a promising therapeutic strategy for reducing macrophage-driven lung injury. Full article