Senescence in Alveolar Epithelial Type II Cells Promotes Acute Lung Injury and Impairs Regeneration.

Mortality of acute lung injury (ALI) increases with age. Alveolar epithelial type 2 cells (AEII) are the progenitor cells of the alveolar epithelium and crucial for repair after injury. We hypothesize that telomere dysfunction-mediated AEII senescence impairs regeneration and promotes the development of ALI. To discriminate between the impact of old age and AEII senescence in ALI, young (3 months) and old (18 months) Sftpc-Ai9 mice and young Sftpc-Ai9-Trf1 mice with inducible Trf1 knockout-mediated senescence in AEII were treated with 1 µg lipopolysaccharide (LPS)/g BW (n=9-11). Control mice received saline (n=7). Mice were sacrificed 4 or 7 days later. Lung mechanics, pulmonary inflammation and proteomes were analyzed and parenchymal injury, AEII proliferation and AEI differentiation rate were quantified using stereology. Old mice showed 55% mortality by day 4, whereas all young mice survived. Pulmonary inflammation was most severe in old mice, followed by Sftpc-Ai9-Trf1 mice. Young Sftpc-Ai9 mice recovered almost completely by day 7, while Sftpc-Ai9-Trf1 mice still showed mild signs of injury. An expansion of AEII was only measured in young Sftpc-Ai9 mice at day 7. Aging and telomere dysfunction-mediated senescence had no impact on AEI differentiation rate in controls, but the reduced number of AEII in Sftpc-Ai9-Trf1 mice also affected de-novo differentiation after injury. In conclusion, telomere dysfunction-mediated AEII senescence promoted parenchymal inflammation in ALI, but did not enhance mortality like old age. While Differentiation rate remained functional with old age and AEII senescence, AEII proliferative capacity was impaired in ALI, affecting the regenerative ability.

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.

Wedelolactone inhibits ferroptosis and alleviates hyperoxia-induced acute lung injury via the Nrf2/HO-1 signaling pathway.

Hyperoxia-induced acute lung injury (HALI) is a complication of oxygen therapy. Ferroptosis is a vital factor in HALI. This paper was anticipated to investigate the underlying mechanism of Wedelolactone (WED) on ferroptosis in HALI. The current study used hyperoxia to injure two models, one HALI mouse model and one MLE-12 cell injury model. We found that WED treatment attenuated HALI by decreasing the lung injury score and lung wet/dry weight ratio and alleviating pathomorphological changes. Then, the inflammatory reaction and apoptosis in HALI mice and hyperoxia-mediated MLE-12 cells were inhibited by WED treatment. Moreover, WED alleviated ferroptosis with less iron accumulation and reversed expression alterations of ferroptosis markers, including MDA, GSH, GPX4, SLC7A11, FTH1, and TFR1 in hyperoxia-induced MLE-12 cells in vitro and in vivo. Nrf2-KO mice and Nrf2 inhibitor (ML385) decreased WED's ability to protect against apoptosis, inflammatory response, and ferroptosis in hyperoxia-induced MLE-12 cells. Collectively, our data highlighted the alleviatory role of WED in HALI by activating the Nrf2/HO-1 pathway.

Liraglutide alleviates sepsis-induced acute lung injury by regulating pulmonary surfactant through inhibiting autophagy.

BACKGROUND: Pulmonary surfactant (PS) plays an important role in the treatment of sepsis-induced acute lung injury (ALI). Liraglutide, a glucagon-like peptide-1 (GLP-1) analog, improves the secretion and function of PS in ALI, but the underlying mechanism remains unknown. This study aimed to investigate how liraglutide regulates PS secretion in ALI. METHODS: C57BL/6 mice were injected subcutaneously with normal saline containing different concentrations of liraglutide after the establishment of the ALI model. MLE-12 cells were treated with liraglutide after LPS stimulation. The survival rate of mice, wet/dry weight ratio, inflammatory factors in bronchoalveolar lavage fluid (BALF), pulmonary injury, and apoptosis were analyzed. Cell viability, proliferation, apoptosis, the expression of SP-A, SP-B, and expression of autophagy-related proteins in cells were measured. RESULTS: ALI mice showed reduced pulmonary injury, less apoptosis, and less inflammation compared to the controls. Liraglutide prolonged survival, decreased the wet/dry weight ratio, reduced inflammatory responses, and attenuated pulmonary edema compared with the ALI group. Moreover, LPS-induced cell damage and reduction of SP-A and SP-B expression were markedly reversed by liraglutide in MLE-12 cells. Furthermore, the protective effects of liraglutide were reversed by rapamycin. CONCLUSION: Liraglutide alleviate sepsis-induced ALI by inhibiting autophagy and regulating PS.

Breviscapine Reduces Sepsis-Induced Acute Lung Injury by Targeting CASP8 to Regulate Neutrophil Apoptosis and Inflammation.

Background: Breviscapine has been demonstrated to have beneficial effects in ameliorating acute lung injury (ALI), yet its potential therapeutic value and molecular mechanisms in sepsis-induced ALI remain unexplored. Methods: We utilized network pharmacology approach to identify the potential targets and mechanisms of breviscapine in treating sepsis-induced ALI. To construct a murine model of sepsis, we performed cecal ligation and puncture (CLP). Hematoxylin and eosin (HE) staining and enzyme-linked immunosorbent assay (ELISA) were employed to respectively determine the pathologic changes and levels of inflammatory factors. Neutrophil count and total protein level in bronchoalveolar lavage fluid (BALF) were detected by corresponding kit. Additionally, we utilized flow cytometry, immunofluorescence, Western blotting, and real-time reverse transcription PCR (qRT-PCR) to detect cell apoptosis, protein expression, and gene expression. Finally, we used ELISA kits to detect the activity of myeloperoxidase (MPO) and caspase-8 (CASP8). Results: Breviscapine was revealed to target 81 potential proteins in the treatment of sepsis-induced ALI, while CASP8 was the most important one as demonstrated by network analysis. In vivo experiments demonstrated that breviscapine effectively reduced the severity of sepsis-induced ALI and inflammation, and significantly suppressed neutrophil infiltration in the lung tissues of CLP mice and promoted neutrophil apoptosis in the peripheral blood. In vitro experiments revealed that lipopolysaccharide (LPS)-induced neutrophil apoptosis was inhibited, and the expression and activity of CASP8 were down-regulated. Breviscapine intervention markedly up-regulated the expression and activity of CASP8, consequently activating neutrophil apoptosis and inhibiting inflammatory response by activating the NF-κB signaling pathway. Conclusion: Breviscapine is remarkably effective in improving sepsis-induced ALI, and its mechanism of action may be to induce neutrophil apoptosis, inhibit inflammatory overreaction and reduce its infiltration in pulmonary tissues by up-regulating the expression and activity of CASP8.

Impact of acute stress disorder on surfactant protein D levels in acute lung injury.

Many people sustain acute lung injuries in road traffic collisions, but few studies have dealt with such injuries in live models. This study aimed to explore the basic pathophysiological and inflammatory changes in adult rabbits following acute thoracic trauma. We randomly assigned 50 rabbits to control and injury groups. Rabbits in the injury group were subjected to right chest pressure (2600 g) using a Hopkinson bar. Measurements were taken in the control group and 0, 24, 48, and 72 h after injury in the injury group. Injury severity was evaluated in gross view; with haematoxylin and eosin (H&E) staining; and through the serum changes of tumor necrosis factor alpha (TNF-α), surfactant protein D (SP-D), and neutrophils. Secretion changes in SP-D in right lung injured tissues were estimated by western blotting and qPCR. Serum TNF-α levels increased rapidly immediately after injury, gradually recovering after 24, 48, and 72 h (p < 0.01). The percentage of neutrophils in the accompanying blood showed a consistent trend. Gross necropsy and H&E staining indicated different levels of bleeding, alveoli exudation, and inflammatory transformation after impact. ELISA depicted the same trend in circulation (F = 22.902, p < 0.01). Western blotting showed that SP-D protein levels in tissues decreased at 0 h and increased at 24, 48, and 72 h. We demonstrate the feasibility of a model of impact lung injury. Primary impact caused injury without external signs. Inflammation began immediately, and the lungs began recovering at 24, 48, and 72 h, as shown by increased SP-D levels in circulation and tissues.With complaints of ALI and inflammation, SP-D may be a potential biomarker after chest trauma.

[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.

iRhom2 deficiency reduces sepsis-induced mortality associated with the attenuation of lung macrophages in mice.

Sepsis has a high mortality rate and leads to multi-organ failure, including lung injury. Inactive rhomboid protease family protein (iRhom2) has been identified as accountable for the release of TNF-α, a crucial mediator in the development of sepsis. This study aimed to evaluate the role of iRhom2 in sepsis and sepsis-induced acute lung injury (ALI). TNF-α and IL-6 secretion in vitro by peritoneal macrophages from wild-type (WT) and iRhom2 knoukout (KO) mice was assessed by enzyme-linked immunosorbent assay. Cecal ligation and puncture (CLP)-induced murine sepsis model was used for in vivo experiments. To evaluate the role of iRhom2 deficiency on survival during sepsis, both WT and iRhom2 KO mice were monitored for 8 consecutive days following the CLP. For histologic and biochemical examination, the mice were killed 18 h after CLP. iRhom2 deficiency improved the survival of mice after CLP. iRhom2 deficiency decreased CD68+ macrophage infiltration in lung tissues. Multiplex immunohistochemistry revealed that the proportion of Ki-67+ CD68+ macrophages was significantly lower in iRhom2 KO mice than that in WT mice after CLP. Moreover, CLP-induced release of TNF-α and IL-6 in the serum were significantly inhibited by iRhom2 deficiency. iRhom2 deficiency reduced NF-kB p65 and IκBα phosphorylation after CLP. iRhom2 deficiency reduces sepsis-related mortality associated with attenuated macrophage infiltration and proliferation in early lung injury. iRhom2 may play a pivotal role in the pathogenesis of sepsis and early stage of sepsis-induced ALI. Thus, iRhom2 may be a potential therapeutic target for the management of sepsis and sepsis-induced ALI.

Cyclic-di-GMP induces inflammation and acute lung injury through direct binding to MD2.

BACKGROUND: Severe bacterial infections can trigger acute lung injury (ALI) and acute respiratory distress syndrome, with bacterial pathogen-associated molecular patterns (PAMPs) exacerbating the inflammatory response, particularly in COVID-19 patients. Cyclic-di-GMP (CDG), one of the PAMPs, is synthesized by various Gram-positve and Gram-negative bacteria. Previous studies mainly focused on the inflammatory responses triggered by intracellular bacteria-released CDG. However, how extracellular CDG, which is released by bacterial autolysis or rupture, activates the inflammatory response remains unclear. METHODS: The interaction between extracellular CDG and myeloid differentiation protein 2 (MD2) was investigated using in vivo and in vitro models. MD2 blockade was achieved using specific inhibitor and genetic knockout mice. Site-directed mutagenesis, co-immunoprecipitation, SPR and Bis-ANS displacement assays were used to identify the potential binding sites of MD2 on CDG. RESULTS: Our data show that extracellular CDG directly interacts with MD2, leading to activation of the TLR4 signalling pathway and lung injury. Specific inhibitors or genetic knockout of MD2 in mice significantly alleviated CDG-induced lung injury. Moreover, isoleucine residues at positions 80 and 94, along with phenylalanine at position 121, are essential for the binding of MD2 to CDG. CONCLUSION: These results reveal that extracellular CDG induces lung injury through direct interaction with MD2 and activation of the TLR4 signalling pathway, providing valuable insights into bacteria-induced ALI mechanisms and new therapeutic approaches for the treatment of bacterial co-infection in COVID-19 patients.

Perilla frutescens leaf extracts alleviate acute lung injury in mice by inhibiting KAT2A.

ETHNOPHARMACOLOGICAL RELEVANCE: Acute lung injury (ALI) can lead to respiratory failure and even death. KAT2A is a key target to suppress the development of inflammation. A herb, perilla frutescens, is an effective treatment for pulmonary inflammatory diseases with anti-inflammatory effects; however, its mechanism of action remains unclear. AIM OF THE STUDY: The purpose of this study was to investigate the therapeutic effect and underlying mechanism of perilla frutescens leaf extracts (PLE), in the treatment of ALI by focusing on its ability to treat inflammation. MATERIALS AND METHODS: In vivo and in vitro models of ALI induced by LPS. Respiratory function, histopathological changes of lung, and BEAS-2B cells damage were assessed upon PLE. This effect is also tested under conditions of KAT2A over expression and KAT2A silencing. RESULTS: PLE significantly attenuated LPS-induced histopathological changes in the lungs, improved respiratory function, and increased survival rate from LPS stimuation background in mice. PLE remarkably suppressed the phosphorylation of STAT3, AKT, ERK (1/2) and the release of cytokines (IL-6, TNF-α, and IL-1ß) induced by LPS via inhibiting the expression of KAT2A. CONCLUSIONS: PLE has a dose-dependent anti-inflammatory effect by inhibiting KAT2A expression to suppress LPS-induced ALI n mice. Our study expands the clinical indications of the traditional medicine PLE and provide a theoretical basis for clinical use of acute lung injury.

XueBiJing injection improves the symptoms of sepsis-induced acute lung injury by mitigating oxidative stress and ferroptosis.

ETHNOPHARMACOLOGICAL RELEVANCE: XBJ injection is approved by the China Food and Drug Administration for the adjunctive treatment of sepsis, and it is derived from the traditional Chinese medicine (TCM) prescription XuefuZhuyu Decoction. It consists of five Chinese herbal extracts: Carthamus tinctorius, Paeonia lactiflora, Salvia miltiorrhiza, Conioselinum anthriscoides 'Chuanxiong' and Angelica sinensis. AIM OF THE STUDY: The purpose of this study was to explore the relationship between ferroptosis and acute septic lung injury, and to evaluate the improvement effect of XBJ injection on acute lung injury in sepsis. MATERIALS AND METHODS: Acute lung injury was induced in rats by cecum ligation and puncture, and these rats were treated with XBJ injection. Oxidative stress and inflammation levels were assessed in serum and lung tissue, and tissue samples were collected for histological and protein analyses. To illustrate the mechanism of the improvement effect of XBJ on acute lung injury in sepsis, serum lipidomics was carried out to investigate whether XBJ prevents oxidative stress-induced lipid metabolism disorders. Furthermore, protein expression of ferroptosis-related genes was also examined. RESULTS: XBJ was shown to be effective in alleviating sepsis-induced ALI. XBJ also improves sepsis-induced acute lung injury by reducing lipid peroxidation and inflammation and modulating ferroptosis pathways. Specifically, compared with the sham group, XBJ downregulated the levels of Fe2+, MDA and GSSG, and reversed the decrease in the levels of GSH and GSH/GSSH in lung tissue. Metabolic pathways such as glycerophospholipid metabolism, phospholipid metabolism, and lipid metabolism associated with ferroptosis were obtained by lipidomic analysis of differential lipid metabolite enrichment, suggesting that ferroptosis occurs in septic rats, and that XBJ inhibits ferroptosis and thereby improves sepsis-induced ALI. Furthermore, XBJ optimises iron metabolism and lipid oxide metabolism by regulating the expression of a series of proteins that are closely related to ferroptosis, such as GPX4, ACSL4, x-CT, and FTH1. CONCLUSIONS: Our findings, initially, indicated that XBJ ameliorates sepsis-induced ALI by reducing oxidative stress and ferroptosis, revealing a previously unrecognised mechanism by which XBJ ameliorates sepsis-induced ALI.

Imaging Identifies Superior Inflammation Targeting of M1 Macrophages for Cryo-Shocked Cell Pulmonary Drug Delivery to Treat Acute Lung Injury.

In the realm of combating acute lung injury (ALI) induced by a myriad of triggers including sepsis, pneumonia, aspiration, trauma, and pancreatitis, macrophages emerge as crucial players. However, traditional treatments such as systemic administration of glucocorticoids come with the baggage of severe side effects, curtailing their utility. Enter an innovative solution: a biomimetic drug delivery system fashioned from cryo-shocked macrophages, tailored for pulmonary drug delivery. Positron emission tomography (PET) imaging has shed light on the remarkable targeting abilities of live M1 macrophages, showcasing their unparalleled efficacy in homing in on local inflammatory foci when contrasted with naive, M1, and M2 macrophages. Building upon this foundation, liquid nitrogen-treated (LNT) M1 macrophages are developed, engineered to preserve their inflammation-targeting prowess while sidestepping the release of pro-inflammatory cytokines. This breakthrough allows for the delivery of glucocorticoids directly to inflamed lung tissues, efficiently quelling inflammation and mitigating pulmonary edema while drastically reducing systemic drug exposure. Inspired by the effectiveness of live M1 macrophages, the potential of glucocorticoid-loaded LNT M1 macrophages are harnessed, utilizing them as a stealthy "Trojan horse" in the battle against pneumonia-induced ALI. This innovative approach holds promise as a safe and potent treatment avenue for acute lung injury.

Pre-treatment with tocilizumab reduces lipopolysaccharide-induced acute lung injury in biliary cirrhotic rats.

Infection-related lipopolysaccharide (LPS) release causes cytokine storm and acute lung injury. Emerging data show that the interleukin 6 (IL-6) inhibitor tocilizumab can improve lung damage in patients with sepsis. This study aimed to investigate the therapeutic effect of tocilizumab on acute lung injury in cirrhotic rats. Biliary cirrhosis was induced in Sprague-Dawley rats with common bile duct ligation (BDL). Sham-operated rats served as surgical controls. Tocilizumab was administered on post-operative day 21, and LPS was injected intraperitoneally on day 29. Three hours after LPS injection, hemodynamic parameters, biochemistry data, and arterial blood gas analysis were evaluated, along with measurements of IL-6 and tumor necrosis factor-α (TNF-α). Liver and lung histology was examined, and protein levels were analyzed. LPS administration reduced portal pressure, portal venous flow and cardiac index in the BDL rats. In addition, LPS administration induced acute lung injury, hypoxia and elevated TNF-α and IL-6 levels. Pre-treatment with tocilizumab did not affect hemodynamic and biochemistry data, but it ameliorated lung injury and decreased TNF-α, IL-6, and CD68-positive macrophage infiltration. Moreover, tocilizumab administration improved hypoxia and gas exchange in the BDL rats, and downregulated hepatic and pulmonary inflammatory protein expression. In conclusion, LPS administration induced acute lung injury in biliary cirrhotic rats. Pre-treatment with tocilizumab reduces lung damage and hypoxia, possibly by downregulating inflammatory proteins and reducing IL-6, TNF-α and CD68-positive macrophage recruitment in the lung.

Research progress on the use of Salvia miltiorrhiza Bunge extracts in the treatment of pulmonary diseases.

Salvia miltiorrhiza Bunge extracts, known for their diverse biological activities, often have remarkable efficacy in treating pulmonary diseases overlooked due to their specific cardiovascular actions. With the recent outbreak of COVID-19, research into pulmonary-related diseases has garnered significant attention. Salvia miltiorrhiza Bunge extracts can be broadly categorized into lipophilic and hydrophilic components; however, a comprehensive summary of their mechanisms in treating pulmonary diseases is lacking. Therefore, this review aims to systematically summarize the therapeutic mechanisms of 10 major Salvia miltiorrhiza Bunge extracts in treating pulmonary fibrosis, lung cancer, acute lung injury, and chronic obstructive pulmonary disease, with the goal of identifying promising options for efficacious therapies.

Bay-117082 treats sepsis by inhibiting neutrophil extracellular traps (NETs) formation through down-regulating NLRP3/N-GSDMD.

During the inflammatory storm of sepsis, a significant quantity of neutrophil extracellular traps (NETs) are generated, which act as a double-edged sword and not only impede the invasion of foreign microorganisms but also exacerbate organ damage. This study provides evidence that NETs can cause damage to alveolar epithelial cells in vitro. The sepsis model developed in this study showed a significant increase in NETs in the bronchoalveolar lavage fluid (BALF). The development of NETs has been shown to increase the lung inflammatory response and aggravate injury to alveolar epithelial cells. Bay-117082, a well-known NF-κB suppressor, is used to modulate inflammation. This analysis revealed that Bay-117082 efficiently reduced total protein concentration, myeloperoxidase activity, and inflammatory cytokines in BALF. Moreover, Bay-117082 inhibited the formation of NETs, which in turn prevented the activation of the pore-forming protein gasdermin D (GSDMD). In summary, these results indicated that excessive NET production during sepsis exacerbated the onset and progression of acute lung injury (ALI). Therefore, Bay-117082 could serve as a novel therapeutic approach for ameliorating sepsis-associated ALI.

Impact of interleukin 6 levels on acute lung injury risk and disease severity in critically ill sepsis patients.

BACKGROUND: Sepsis is a life-threatening condition characterized by a dysregulation of the host response to infection that can lead to acute lung injury (ALI) and multiple organ dysfunction syndrome (MODS). Interleukin 6 (IL-6) is a pro-inflammatory cytokine that plays a crucial role in the pathogenesis of sepsis and its complications. AIM: To investigate the relationship among plasma IL-6 levels, risk of ALI, and disease severity in critically ill patients with sepsis. METHODS: This prospective and observational study was conducted in the intensive care unit of a tertiary care hospital between January 2021 and December 2022. A total of 83 septic patients were enrolled. Plasma IL-6 levels were measured upon admission using an enzyme-linked immunosorbent assay. The development of ALI and MODS was monitored during hospitalization. Disease severity was evaluated by Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores. RESULTS: Among the 83 patients with sepsis, 38 (45.8%) developed ALI and 29 (34.9%) developed MODS. Plasma IL-6 levels were significantly higher in patients who developed ALI than in those without ALI (median: 125.6 pg/mL vs 48.3 pg/mL; P < 0.001). Similarly, patients with MODS had higher IL-6 levels than those without MODS (median: 142.9 pg/mL vs 58.7 pg/mL; P < 0.001). Plasma IL-6 levels were strongly and positively correlated with APACHE II (r = 0.72; P < 0.001) and SOFA scores (r = 0.68; P < 0.001). CONCLUSION: Elevated plasma IL-6 levels in critically ill patients with sepsis were associated with an increased risk of ALI and MODS. Higher IL-6 levels were correlated with greater disease severity, as reflected by higher APACHE II and SOFA scores. These findings suggest that IL-6 may serve as a biomarker for predicting the development of ALI and disease severity in patients with sepsis.

Huperzine a ameliorates sepsis-induced acute lung injury by suppressing inflammation and oxidative stress via α7 nicotinic acetylcholine receptor.

Sepsis, characterized by high mortality rates, causes over 50 % of acute lung injury (ALI) cases, primarily due to the heightened susceptibility of the lungs during this condition. Suppression of the excessive inflammatory response is critical for improving the survival of patients with sepsis; nevertheless, no specific anti-sepsis drugs exist. Huperzine A (HupA) exhibits neuroprotective and anti-inflammatory properties; however, its underlying mechanisms and effects on sepsis-induced ALI have yet to be elucidated. In this study, we demonstrated the potential of HupA for treating sepsis and explored its mechanism of action. To investigate the in vivo impacts of HupA, a murine model of sepsis was induced through cecal ligation and puncture (CLP) in both wild-type (WT) and α7 nicotinic acetylcholine receptor (α7nAChR) knockout mice. Our results showed that HupA ameliorates sepsis-induced acute lung injury by activating the α7nAChR. We used the CLP sepsis model in wild-type and α7nAChR -/- mice and found that HupA significantly increased the survival rate through α7nAChR, reduced the pro-inflammatory cytokine levels and oxidative stress, ameliorated histopathological lung injury, altered the circulating immune cell composition, regulated gut microbiota, and promoted short-chain fatty acid production through α7nAChR in vivo. Additionally, HupA inhibited Toll-like receptor NF-κB signaling by upregulating the α7nAChR/protein kinase B/glycogen synthase kinase-3 pathways. Our data elucidate HupA's mechanism of action and support a "new use for an old drug" in treating sepsis. Our findings serve as a basis for further in vivo studies of this drug, followed by application to humans. Therefore, the findings have the potential to benefit patients with sepsis.

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.

Haploinsufficiency of Cnot3 Aggravates Acid-Induced Acute Lung Injury Likely Through Transcriptional and Post-Transcriptional Upregulation of Pro-Inflammatory Genes.

Background: Acute lung injury (ALI) is caused by a variety of illnesses, including aspiration pneumonia and sepsis. The CCR4-NOT complex is a large multimeric protein complex that degrades mRNA through poly(A) tail shortening, whereas it also contributes to regulation of transcription and translation. Cnot3 is a scaffold component of the CCR4-NOT complex and is essential for the integrity of the complex; loss of Cnot3 leads to depletion of whole complex. While the significance of cytokine mRNA degradation in limiting inflammation has been established, the roles of CCR4-NOT complex-mediated in ALI remain elusive. Methods: The effects of Cnot3 haploinsufficiency in the pathology and cytokine expression were analyzed in the mouse lungs of acid aspiration-induced acute lung injury. The decay rate and transcription activity of cytokine mRNAs under Cnot3 heterozygous deletion were analyzed in lipopolysaccharide (LPS) -stimulated mouse embryonic fibroblasts (MEFs). Results: Tamoxifen-induced heterozygous deletion of Cnot3 in adult mice (Cnot3 Hetz) did not show body weight loss or any apparent abnormality. Under acid aspiration-induced acute lung injury, Cnot3 Hetz mice exhibited increased pulmonary edema, worse lung pathologies and more severe inflammation compared with wild type mice. mRNA expression of pro-inflammatory genes Il1b and Nos2 were significantly upregulated in the lungs of Cnot3 Hetz mice. Consistently, mRNA expression of Il1b and Nos2 was upregulated in LPS-stimulated Cnot3 Hetz MEFs. Mechanistically, while heterozygous depletion of Cnot3 stabilized both Il1b and Nos2 mRNAs, the nascent pre-mRNA level of Il1b was upregulated in Cnot3 Hetz MEFs, implicating Cnot3-mediated transcriptional repression of Il1b expression in addition to destabilization of Il1b and Nos2 mRNAs. PU.1 (Spi1) was identified as a causative transcription factor to promote Il1b expression under Cnot3 haploinsufficient conditions. Conclusion: CNOT3 plays a protective role in ALI by suppressing expression of pro-inflammatory genes Il1b and Nos2 through both post-transcriptional and transcriptional mechanisms, including mRNA stability control of Spi1.

Role and mechanisms of autophagy, ferroptosis, and pyroptosis in sepsis-induced acute lung injury.

Sepsis-induced acute lung injury (ALI) is a major cause of death among patients with sepsis in intensive care units. By analyzing a model of sepsis-induced ALI using lipopolysaccharide (LPS) and cecal ligation and puncture (CLP), treatment methods and strategies to protect against ALI were discussed, which could provide an experimental basis for the clinical treatment of sepsis-induced ALI. Recent studies have found that an imbalance in autophagy, ferroptosis, and pyroptosis is a key mechanism that triggers sepsis-induced ALI, and regulating these death mechanisms can improve lung injuries caused by LPS or CLP. This article summarized and reviewed the mechanisms and regulatory networks of autophagy, ferroptosis, and pyroptosis and their important roles in the process of LPS/CLP-induced ALI in sepsis, discusses the possible targeted drugs of the above mechanisms and their effects, describes their dilemma and prospects, and provides new perspectives for the future treatment of sepsis-induced ALI.