Sepsis Lung Injury Research Articles

PTP1B inhibitor alleviates deleterious septic lung injury through Src signaling.

Septic lung injury is an unmet clinical challenge due to its high mortality, and there is a lack of effective treatment. Accumulating evidence suggests that an uncontrolled pulmonary inflammatory response is important in the pathogenesis of lung injury in sepsis. Therefore, limiting excessive early inflammatory responses may be an effective strategy. We established a septic lung injury model using cecal ligation and puncture. Western blotting and immunofluorescence analyses were performed to assess the expression of PTP1B and endoplasmic reticulum (ER) stress and pyroptosis. Co-immunoprecipitation was used to analyze the binding of PTP1B and Src molecules. PTP1B is upregulated in both in vivo and in vitro models of septic lung injury. PTP1B directly binds to Src and aggravates inflammation by regulating the ER stress-pyroptosis axis. The inhibition of PTP1B alleviates inflammation and improves the prognosis of septic mice. Our study suggesting that PT1B inhibitors have clinical application value in the treatment of septic lung injury. This may provide a new strategy for the treatment of septic lung injury.

Natural hydrogen gas and engineered microalgae prevent acute lung injury in sepsis

BackgroundHydrogen gas and microalgae both exist in the natural environment. We aimed to integrate hydrogen gas and biology nano microalgae together to expand the treatment options in sepsis. MethodsPhosphoproteomics, metabolomics and proteomics data were obtained from mice undergoing cecum ligation and puncture (CLP) and inhalation of hydrogen gas. All omics analysis procedure were accordance with standards. Multi R packages were used in single cell and spatial transcriptomics analysis to identify primary cells expressing targeted genes, and the genes’ co-expression relationships in sepsis related lung landscape. Then, network pharmacology method was used to identify candidate drugs. We used hydrophobic-force-driving self-assembly method to construct dihydroquercetin (DQ) nanoparticle. To cooperate with molecular hydrogen, ammonia borane (B) was added to DQ surface. Then, Chlorella vulgaris (C) was used as biological carrier to improve self-assembly nanoparticle. Vivo and vitro experiments were both conducted to evaluate anti-inflammation, anti-ferroptosis, anti-infection and organ protection capability. ResultsAs a result, we identified Esam and Zo-1 were target phosphorylation proteins for molecular hydrogen treatment in lung. Ferroptosis and glutathione metabolism were two target pathways. Chlorella vulgaris improved the dispersion of DQB and reconstructed morphological features of DQB, formed DQB@C nano-system (size = 307.3 nm, zeta potential = −22mv), with well infection-responsive hydrogen release capability and biosafety. In addition, DQB@C was able to decrease oxidative stress and inflammation factors accumulation in lung cells. Through increasing expression level of Slc7a11/xCT and decreasing Cox2 level to participate with the regulation of ferroptosis. Also, DQB@C played lung and multi organ protection and anti-inflammation roles on CLP mice. ConclusionOur research proposed DQB@C as a novel biology nano-system with enormous potential on treatment for sepsis related acute lung injury to solve the limitation of hydrogen gas utilization in clinics.

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

Ethnopharmacological relevanceXBJ 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 studyThe 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 methodsAcute 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. ResultsXBJ 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. ConclusionsOur 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.

Suppression of Skp2 contributes to sepsis-induced acute lung injury by enhancing ferroptosis through the ubiquitination of SLC3A2

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. The inflammatory cytokine storm causes systemic organ damage, especially acute lung injury in sepsis. In this study, we found that the expression of S-phase kinase-associated protein 2 (Skp2) was significantly decreased in sepsis-induced acute lung injury (ALI). Sepsis activated the MEK/ERK pathway and inhibited Skp2 expression in the pulmonary epithelium, resulting in a reduction of K48 ubiquitination of solute carrier family 3 member 2 (SLC3A2), thereby impairing its membrane localization and cystine/glutamate exchange function. Consequently, the dysregulated intracellular redox reactions induced ferroptosis in pulmonary epithelial cells, leading to lung injury. Finally, we demonstrated that intravenous administration of Skp2 mRNA-encapsulating lipid nanoparticles (LNPs) inhibited ferroptosis in the pulmonary epithelium and alleviated lung injury in septic mice. Taken together, these data provide an innovative understanding of the underlying mechanisms of sepsis-induced ALI and a promising therapeutic strategy for sepsis.

Methylprednisolone alleviates lung injury in sepsis by regulating miR-151-5p/USP38 pathway

BackgroundAcute lung injury (ALI) is manifested by increased blood vessel permeability within the lungs and subsequent impairment of alveolar gas exchange. Methylprednisolone (MP) is commonly used as a treatment for ALI to reduce inflammation, yet its molecular mechanism remains unclear. This study aims to explore the underlying mechanisms of MP on ALI in a model induced by lipopolysaccharide (LPS). Material and MethodsThe proliferation, viability, apoptosis, and miR-151-5p expression of alveolar type II epithelial cells (AECII) were detected using the cell EdU assay, Annexin V/PI Apoptosis Kit, counting kit-8 (CCK-8) assay, and RT-qPCR. Western blot analysis was used to detect the Usp38 protein level. IL-6 and TNF-α were measured by ELISA. The combination of miR-151-5p and USP38 was determined by chromatin immunoprecipitation (ChIP)-PCR and dual-luciferase reporter assay. ResultsMP greatly improved pulmonary function in vivo, reduced inflammation, and promoted the proliferation of the alveolar type II epithelial cells (AECII) in vitro. By comparing the alterations of microRNAs in lung tissues between MP treatment and control groups, we found that miR-151-5p exhibited a significant increase after LPS-treated AECII, but decreased after MP treatment. Confirmed by a luciferase reporter assay, USP38, identified as a downstream target of miR-151-5p, was found to increase after MP administration. Inhibition of miR-151-5p or overexpression of USP38 in AECII significantly improved the anti-inflammatory, anti-apoptotic, and proliferation-promotive effects of MP. ConclusionIn summary, our data demonstrated that MP alleviates the inflammation and apoptosis of AECII induced by LPS, and promotes the proliferation of AECII partially via miR-151-5p suppression and subsequent USP38 activation.

The involvement of Sting in exacerbating acute lung injury in sepsis via the PARP-1/NLRP3 signaling pathway

BackgroundInterferon gene stimulator (Sting) is an indispensable adaptor protein that plays a crucial role in acute lung injury (ALI) induced by sepsis, and the PARP-1/NLRP3 signaling pathway may be an integral component of the inflammatory response mediated by Sting. However, the regulatory role of Sting in the PARP-1/NLRP3 pathway in ALI remains insufficiently elucidated. MethodsUsing lipopolysaccharide (LPS) to induce ALI in C57BL/6 mice and HUVEC cells, an in vivo and in vitro model was established. In vivo, Sting agonists and inhibitors were administered, while in vitro, Sting was knocked down using siRNA. ELISA was employed to quantify the levels of IL-1β, IL-6, and TNF-α. TUNEL staining was conducted to assess cellular apoptosis, while co-immunoprecipitation was utilized to investigate the interaction between Sting and NLRP3. Expression levels of Sting, NLRP3, PARP-1, among others, were assessed via Western blotting and RT-qPCR. Lung HE staining and lung wet/dry ratio were evaluated in the in vivo mouse model. To validate the role of the PARP-1/NLRP3 signaling pathway, PARP-1 inhibitors were employed both in vivo and in vitro. ResultsIn vitro experiments revealed that the Sting agonist group exacerbated LPS-induced pulmonary pathological damage, pulmonary edema, inflammatory response (increased levels of IL-6, TNF-α, and IL-1β), and cellular injury, whereas the Sting inhibitor group significantly ameliorated the aforementioned injuries, with further improvement observed in the combination therapy of Sting inhibitor and PARP-1 inhibitor. Western blotting and RT-qPCR results demonstrated significant suppression of ICAM-1, VCAM-1, NLRP3, and PARP-1 expression in the Sting inhibitor group, with this reduction further enhanced in the Sting inhibitor + PARP-1 inhibitor treatment group, exhibiting opposite outcomes to the agonist. Furthermore, in vitro experiments using HUVEC cell lines validated these findings. ConclusionsOur study provides new insights into the roles of Sting and the PARP-1/NLRP3 signaling pathway in inflammatory responses, offering novel targets for the development of therapeutic interventions against inflammatory reactions.

Atorvastatin combined with imipenem alleviates lung injury in sepsis by inhibiting neutrophil extracellular trap formation via the ERK/NOX2 signaling pathway

Sepsis is a systemic inflammatory response syndrome caused by the invasion of pathogenic microorganisms. Despite major advances in diagnosis and technology, morbidity and mortality remain high. The level of neutrophil extracellular traps (NETs) is closely associated with the progression and prognosis of sepsis, suggesting the regulation of NET formation as a new strategy in sepsis treatment. Owing to its pleiotropic effects, atorvastatin, a clinical lipid-lowering drug, affects various aspects of sepsis-related inflammation and immune responses. To align closely with clinical practice, we combined it with imipenem for the treatment of sepsis. In this study, we used a cecum ligation and puncture-induced lung injury mouse model and employed techniques including western blot, immunofluorescence, and enzyme-linked immunosorbent assay to measure the levels of NETs and other sepsis-related lung injury indicators. Our findings indicate that atorvastatin effectively inhibited the formation of NETs. When combined with imipenem, it significantly alleviated lung injury, reduced systemic inflammation, and improved the 7-day survival rate of septic mice. Additionally, we explored the inhibitory mechanism of atorvastatin on NET formation in vitro, revealing its potential action through the ERK/NOX2 pathway. Therefore, atorvastatin is a potential immunomodulatory agent that may offer new treatment strategies for patients with sepsis in clinical settings.

Knockdown of KBTBD7 attenuates septic lung injury by inhibiting ferroptosis and improving mitochondrial dysfunction

Lung injury in sepsis is caused by an excessive inflammatory response caused by the entry of pathogenic microorganisms into the body. It is also accompanied by the production of large amounts of ROS. Ferroptosis and mitochondrial dysfunction have also been shown to be related to sepsis. Finding suitable sepsis therapeutic targets is crucial for sepsis research. BTB domain-containing protein 7 (KBTBD7) is involved in regulating inflammatory responses, but its role and mechanism in the treatment of septic lung injury are still unclear. In this study, we evaluated the role and related mechanisms of KBTBD7 in septic lung injury. In in vitro studies, we established an in vitro model by inducing human alveolar epithelial cells with lipopolysaccharide (LPS) and found that KBTBD7 was highly expressed in the in vitro model. KBTBD7 knockdown could reduce the inflammatory response by inhibiting the secretion of pro-inflammatory factors and inhibit the production of ROS, ferroptosis and mitochondrial dysfunction. Mechanistic studies show that KBTBD7 interacts with FOXA1, promotes FOXA1 expression, and indirectly inhibits SLC7A11 transcription. In vivo studies have shown that knocking down KBTBD7 improves lung tissue damage in septic lung injury mice, inhibits inflammatory factors, ROS production and ferroptosis. Taken together, knockdown of KBTBD7 shows an alleviating effect on septic lung injury in vitro and in vivo, providing a potential therapeutic target for the treatment of septic lung injury.

Inhibition of Golgi stress alleviates sepsis-induced cardiomyopathy by reducing inflammation and apoptosis

BackgroundSepsis is often accompanied by multiple organ dysfunction, in which the incidence of cardiac injury is about 60%, and is closely related to high mortality. Recent studies have shown that Golgi stress is involved in liver injury, kidney injury, and lung injury in sepsis. However, whether it is one of the key mechanisms of sepsis-induced cardiomyopathy (SIC) is still unclear. The aim of this study is to investigate whether Golgi stress mediates SIC and the specific mechanism. MethodsSepsis model of male C57BL/6J mice was established by cecal ligation and puncture. To observe the effect of Golgi stress on SIC, mice were injected with Golgi stimulant (Brefeldin A) or Golgi inhibitor (Glutathione), respectively. The 7-day survival rate of mice were recorded, and myocardial injury indicators including cardiac function, myocardial enzymes, myocardial pathological tissue score, myocardial inflammatory factors, and apoptosis were detected. The morphology of Golgi was observed by immunofluorescence, and the Golgi stress indices including GM-130, GOLPH3 and Goligin97 were detected by WB and qPCR. ResultsAfter CLP, the cardiac function of mice was impaired and the levels of myocardial enzymes were significantly increased. Golgi stress was accompanied by increased myocardial inflammation and apoptosis. Moreover, the expressions of morphological proteins GM-130 and Golgin97 were decreased, and the expression of stress protein GOLPH3 was increased. In addition, Brefeldin A increased 7-day mortality and the above indicators in mice. The use of glutathione improves all of the above indicators. ConclusionGolgi stress mediates SIC, and the inhibition of Golgi stress can improve SIC by inhibiting apoptosis and inflammation.

Glycyrrhizic acid alleviates lung injury in sepsis through SIRT1/HMGB1 pathway

Glycyrrhizic acid alleviates lung injury in sepsis through SIRT1/HMGB1 pathway

HYDROGEN PREVENTS LIPOPOLYSACCHARIDE-INDUCED PULMONARY MICROVASCULAR ENDOTHELIAL CELL INJURY BY INHIBITING STORE-OPERATED Ca 2+ ENTRY REGULATED BY STIM1/ORAI1.

Background: Sepsis is a type of life-threatening organ dysfunction that is caused by a dysregulated host response to infection. The lung is the most vulnerable target organ under septic conditions. Pulmonary microvascular endothelial cells (PMVECs) play a critical role in acute lung injury (ALI) caused by severe sepsis. The impairment of PMVECs during sepsis is a complex regulatory process involving multiple mechanisms, in which the imbalance of calcium (Ca 2+ ) homeostasis of endothelial cells is a key factor in its functional impairment. Our preliminary results indicated that hydrogen gas (H 2 ) treatment significantly alleviates lung injury in sepsis, protects PMVECs from hyperpermeability, and decreases the expression of plasma membrane stromal interaction molecule 1 (STIM1), but the underlying mechanism by which H 2 maintains Ca 2+ homeostasis in endothelial cells in septic models remains unclear. Thus, the purpose of the present study was to investigate the molecular mechanism of STIM1 and Ca 2+ release-activated Ca 2+ channel protein1 (Orai1) regulation by H 2 treatment and explore the effect of H 2 treatment on Ca 2+ homeostasis in lipopolysaccharide (LPS)-induced PMVECs and LPS-challenged mice. Methods: We observed the role of H 2 on LPS-induced ALI of mice in vivo . The lung wet/dry weight ratio, total protein in the bronchoalveolar lavage fluid, and Evans blue dye assay were used to evaluate the pulmonary endothelial barrier damage of LPS-challenged mice. The expression of STIM1 and Orai1 was also detected using epifluorescence microscopy. Moreover, we also investigated the role of H 2 -rich medium in regulating PMVECs under LPS treatment, which induced injury similar to sepsis in vitro . The expression of STIM1 and Orai1 as well as the Ca 2+ concentration in PMVECs was examined. Results:In vivo , we found that H 2 alleviated ALI of mice through decreasing lung wet/dry weight ratio, total protein in the bronchoalveolar lavage fluid and permeability of lung. In addition, H 2 also decreased the expression of STIM1 and Orai1 in pulmonary microvascular endothelium. In vitro , LPS treatment increased the expression levels of STIM1 and Orai1 in PMVECs, while H 2 reversed these changes. Furthermore, H 2 ameliorated Ca 2+ influx under sepsis-mimicking conditions. Treatment with the sarco/endoplasmic reticulum Ca 2+ adenosine triphosphatase inhibitor, thapsigargin, resulted in a significant reduction in cell viability as well as a reduction in the expression of junctional proteins, including vascular endothelial-cadherin and occludin. Treatment with the store-operated Ca 2+ entry inhibitor, YM-58483 (BTP2), increased the cell viability and expression of junctional proteins. Conclusions: The present study suggested that H 2 treatment alleviates LPS-induced PMVEC dysfunction by inhibiting store-operated Ca 2+ entry mediated by STIM1 and Orai1 in vitro and in vivo .

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

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

Tamibarotene targets heparin-binding protein for attenuating lung injury in sepsis.

Excessively active pulmonary inflammation is a hallmark of sepsis-induced lung damage. A synthetic retinoid drug called tamibarotene reduces inflammation in a variety of conditions, including acute promyelocytic leukemia (APL), renal fibrosis, and neuroinflammation. Its effect on sepsis-related lung injury, however, has not been explained. The purpose of the study was to investigate how tamibarotene affected lung damage induced by cecal ligation and puncture (CLP) procedure. A CLP sepsis mouse model was developed, and tamibarotene was pretreated to determine whether it improved lung injury and survival. The degree of lung injury was evaluated using the Hematoxylin and eosin staining and lung injury score. In order to determine pulmonary vascular permeability, measurements were taken for total protein and cell content of bronchoalveolar lavage fluid (BALF), wet/dry ratio of the lung, and Evans blue stain. The BALF inflammatory mediators, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β, and IL-17A were discovered by enzyme-linked immunosorbent serologic assay (ELISA). Then, the levels of heparin-binding protein (HBP), and phospho-nuclear factor kappa-B (p-NF-κB) P65, and NF-κB P65 were determined using ELISA and Western blot analysis, respectively. Tamibarotene considerably increases survival and lessens lung damage stimulated by sepsis. Specifically, tamibarotene significantly relieves pulmonary vascular permeability and inhibits inflammation response in sepsis. Moreover, we further confirmed that these ameliorating effects of tamibarotene on sepsis may be exerted by targeting HBP and regulating the activation of NF-κB signaling pathway. These findings demonstrated that tamibarotene lessens sepsis-induced lung injury, and the effect could be exerted by targeting HBP and thereby deregulating the NF-κB signaling pathway.

Administration of protopine prevents mitophagy and acute lung injury in sepsis.

Introduction: Sepsis is a severe life-threatening infection that induces a series of dysregulated physiologic responses and results in organ dysfunction. Acute lung injury (ALI), the primary cause of respiratory failure brought on by sepsis, does not have a specific therapy. Protopine (PTP) is an alkaloid with antiinflammatory and antioxidant properties. However, the function of PTP in septic ALI has not yet been documented. This work sought to investigate how PTP affected septic ALI and the mechanisms involved in septic lung damage, including inflammation, oxidative stress, apoptosis, and mitophagy. Methods: Here, we established a mouse model induced by cecal ligation and puncture (CLP) and a BEAS-2B cell model exposed to lipopolysaccharide (LPS). Results: PTP treatment significantly reduced mortality in CLP mice. PTP mitigated lung damage and reduced apoptosis. Western blot analysis showed that PTP dramatically reduced the expression of the apoptosis-associated protein (Cleaved Caspase-3, Cyto C) and increased Bcl-2/Bax. In addition, PTP decreased the production of inflammatory cytokines (IL-6, IL-1β, TNF-α), increased glutathione (GSH) levels and superoxide dismutase (SOD) activity, and decreased malondialdehyde (MDA) levels. Meanwhile, PTP significantly reduced the expression of mitophagy-related proteins (PINK1, Parkin, LC-II), and downregulated mitophagy by transmission electron microscopy. Additionally, the cells were consistent with animal experiments. Discussion: PTP intervention reduced inflammatory responses, oxidative stress, and apoptosis, restored mitochondrial membrane potential, and downregulated mitophagy. The research shows that PTP prevents excessivemitophagy and ALI in sepsis, suggesting that PTP has a potential role in the therapy of sepsis.

Dulaglutide provides protection against sepsis-induced lung injury in mice by inhibiting inflammation and apoptosis

Sepsis is a dangerous condition with a high mortality rate. In addition to promoting insulin secretion in a glucose-dependent manner, glucagon-like peptide-1 (GLP-1) also exhibits anti-inflammatory properties. Dulaglutide is a glucagon-like peptide-1 receptor agonist (GLP-1 RA). In this study, we investigated the effects and mechanism of action of dulaglutide (Dul) in lipopolysaccharide (LPS) induced lung injury in mice with sepsis. In mice with LPS (15 mg/kg, ip, qd)-induced acute lung injury, the administration of dulaglutide (0.6 mg/kg, ip, qd) improved weight loss, reduced lung injury, reversed the increase in IL-1β, TNF-α, IL-6, CXCL1, CCL2 and CXCL2 expression in the lung, and reduced the infiltration of neutrophils and macrophages in the lung tissues. The decline in caspase-3, cleaved caspase-3, caspase-8, and Bcl-2/Bax expression and the increase in the number of TUNEL positive cells in the lung were reversed, suggesting that GLP-1RA could play a protective role in the lung by inhibiting inflammation and apoptosis. In addition, GLP-1RA could reduce the expression of P-STAT3 and NLRP3, suggesting that P-STAT3 and NLRP3 may be potential targets against lung injury in sepsis. Collectively, our data demonstrated that GLP-1RA exerts a protective effect against sepsis-induced lung injury through mechanisms related to the inhibition of inflammation, apoptosis, and STAT3 signaling.

MiR-125b-5p in adipose derived stem cells exosome alleviates pulmonary microvascular endothelial cells ferroptosis via Keap1/Nrf2/GPX4 in sepsis lung injury

BackgroundSepsis is a fatal disease with a high rate of morbidity and mortality, during which acute lung injury is the earliest and most serious complication. Injury of pulmonary microvascular endothelial cells (PMVECs) induced by excessive inflammation plays an important role in sepsis acute lung injury. This study is meant to explore the protective effect and mechanism of ADSCs exosomes on excessive inflammation PMVECs injury. ResultsWe successfully isolated ADSCs exosomes, the characteristic of which were confirmed. ADSCs exosomes reduced excessive inflammatory response induced ROS accumulation and cell injury in PMVECs. Besides, ADSCs exosomes inhibited excessive inflammatory response induced ferroptosis while upregulated expression of GPX4 in PMVECs. And further GPX4 inhibition experiments revealed that ADSCs exosomes alleviated inflammatory response induced ferroptosis via upregulating GPX4. Meanwhile, ADSCs exosomes could increase the expression and nucleus translocation of Nrf2, while decrease the expression of Keap1. miRNA analysis and further inhibition experiments verified that specific delivery of miR-125b-5p by ADSCs exosomes inhibited Keap1 and alleviated ferroptosis. In CLP induced sepsis model, ADSCs exosomes could relieve the lung tissue injury and reduced the death rate. Besides, ADSCs exosomes alleviated oxidative stress injury and ferroptosis of lung tissue, while remarkably increase expression of Nrf2 and GPX4. ConclusionCollectively, we illustrated a novel potentially therapeutic mechanism that miR-125b-5p in ADSCs exosomes could alleviate the inflammation induced PMVECs ferroptosis in sepsis induced acute lung injury via regulating Keap1/Nrf2/GPX4 expression, hence improve the acute lung injury in sepsis.

Pretreatment with Eupatilin Attenuates Inflammation and Coagulation in Sepsis by Suppressing JAK2/STAT3 Signaling Pathway.

Sepsis is an aggressive and life-threatening organ dysfunction induced by infection. Excessive inflammation and coagulation contribute to the negative outcomes for sepsis, resulting in high morbidity and mortality. In this study, we explored whether Eupatilin could alleviate lung injury, reduce inflammation and coagulation during sepsis. We constructed an in vitro sepsis model by stimulating RAW264.7 cells with 1 μg/mL lipopolysaccharide (LPS) for 6 hours. The cells were divided into control group, LPS group, LPS+ Eupatilin (Eup) group, and Eup group to detect their cell activity and inflammatory cytokines and coagulation factor levels. Cells in LPS+Eup and Eup group were pretreated with Eupatilin (10μM) for 2 hours. In vivo, mice were divided into sham operation group, cecal ligation and puncture (CLP) group and Eup group. Mice in the CLP and Eup groups were pretreated with Eupatilin (10mg/kg) for 2 hours by gavage. Lung tissue and plasma were collected and inflammatory cytokines, coagulation factors and signaling were measured. In vitro, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and tissue factor (TF) expression in LPS-stimulated RAW264.7 cells was downregulated by Eupatilin (10μM). Furthermore, Eupatilin inhibited phosphorylation of the JAK2/STAT3 signaling pathway and suppressed p-STAT3 nuclear translocation. In vivo, Eupatilin increased the survival rate of the mice. In septic mice, plasma concentrations of TNF-α, IL-1β and IL-6, as well as TF, plasminogen activator inhibitor 1 (PAI-1), D-dimer, thrombin-antithrombin complex (TAT) and fibrinogen were improved by Eupatilin. Moreover, Eupatilin alleviated lung injury by improving the expression of inflammatory cytokines and TF, fibrin deposition and macrophage infiltration in lung tissue. Our results revealed that Eupatilin may modulate inflammation and coagulation indicators as well as improve lung injury in sepsis via the JAK2/STAT3 signaling pathway.

Isoegomaketone alleviates inflammatory response and oxidative stress in sepsis lung injury.

Sepsis is a life-threatening condition characterized by acute organ dysfunction, which frequently leads to acute lung injury (ALI) in approximately 40% of cases. Isoegomaketone (IK) is a constituent of essential oil found in P. frutescens, known for its diverse biological properties, including anti-inflammatory and antitumor effects. However, the regulatory impact of IK on ALI in the context of sepsis remains poorly understood. Pathological alterations in lung tissues were assessed using hematoxylin and eosin staining. Enumeration of total leukocytes and neutrophils in bronchoalveolar lavage fluid (BALF) was performed using a hematocytometer, while the levels of interleukin (IL)-6, IL-1β, IL-10, and IL-17 in BALF were quantified using enzyme-linked immunosorbent serological assay. In addition, the levels of malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD), and glutathione (GSH) in lung tissues were assessed using respective commercial kits; cell apoptosis was evaluated using the terminal deoxynucleotide transferase--mediated dUTP nick end-labeling assay, and protein expressions were determined through Western blot analysis. Our findings revealed that cecal ligation and puncture (CLP) treatment in mice induced severe lung injury, characterized by increased lung injury scores, significant bleeding, neutrophil infiltration, and alveolar edema. However, treatment with IK at a dose of 10 mg/kg ameliorated CLP-induced lung injury, while IK dose of 5 mg/kg showed no significant effect. Additionally, IK treatment at 10 mg/kg reduced CLP-induced inflammation by decreasing levels of IL-6, IL-1β, IL-10, and IL-17. Furthermore, IK at 10 mg/kg attenuated CLP-induced oxidative stress by modulating levels of MDA, MPO, SOD, and GSH. Moreover, IK treatment with a dose of 10 mg/kg activated the nuclear factor erythroid 2-related factor 2-heme oxygenase-1 (Nrf2-HO-1) pathway by enhancing the protein expressions of Nrf2 and HO-1. This study demonstrates that IK could mitigate the inflammatory response and oxidative stress associated with sepsis-induced ALI, supporting IK as a promising therapeutic agent for the treatment of sepsis-associated ALI.

An engineered miRNA PS-OMe miR130 inhibits acute lung injury by targeting eCIRP in sepsis

BackgroundSepsis is caused by the dysregulated immune response due to an initial infection and results in significant morbidity and mortality in humans. Extracellular cold inducible RNA binding protein (eCIRP) is a novel mediator identified in sepsis. We have previously discovered that microRNA 130b-3p inhibits eCIRP mediated inflammation. As RNA mimics are very unstable in vivo, we hypothesize that an engineered miRNA 130b-3p mimic named PS-OMe miR130, improves stability of the miRNA by protection from nuclease activity. We further hypothesize that PS-OMe miR130 reduces not only eCIRP-mediated inflammation and but also acute lung injury in a murine model of polymicrobial sepsis.MethodsSingle stranded PS-OMe miR130 was synthesized and the binding affinity to eCIRP was evaluated using surface plasmon resonance (SPR) and computational modeling. Macrophages were treated with PS-OMe miR130 with and without eCIRP and cell supernatant analyzed for cytokines. In vitro stability and the in vivo half-life of PS-OMe miR130 were also assessed. The effect of PS-Ome miR130 on eCIRP’s binding to TLR4 was evaluated by SPR analysis and modeling. Finally, the effect of PS-OMe miR130 on inflammation and injury was assessed in a murine model of sepsis.ResultsWe demonstrate via SPR and computational modeling that PS-OMe miR130 has a strong binding affinity to eCIRP. This engineered miRNA decreases eCIRP induced TNF-α and IL-6 proteins, and it is highly stable in vitro and has a long in vivo half-life. We further demonstrate that PS-OMe miR130 blocks eCIRP binding to its receptor TLR4. Finally, we show that PS-OMe miR130 inhibits inflammation and lung injury, and improves survival in murine sepsis.ConclusionPS-OMe miR130 can be developed as a novel therapeutic by inhibiting eCIRP-mediated inflammation and acute lung injury in sepsis.

Tofacitinib reduces acute lung injury and improves survival in a rat model of sepsis by inhibiting the JAK-STAT/NF-κB pathway

Acute lung injury is a major cause of death in sepsis. Tofacitinib (TOFA), a JAK inhibitor, has anti-inflammatory activity in autoimmune diseases, but its role in acute lung injury in sepsis remains unclear. The purpose of this study is to establish a septic rat model by cecal ligation and perforation, and to evaluate the effect of tofacitinib on the survival rate of septic rat model and its role in acute lung injury in septic rats and the possible mechanism of action. In this study, TOFA (1 mg/kg, 3 mg/kg, 10 mg/kg) was used to observe the survival rate of septic rats. It was found that TOFA (10 mg/kg) significantly improved the survival rate of septic rats. We selected TOFA (10 mg/kg) and focused on the protective effect of TOFA on acute lung injury. The results confirmed that TOFA significantly inhibited the expression of TNF-α, IL-1β, IL-6 and IFN-γ inflammatory factors, reduced the W/D weight ratio of septic lung tissue, and significantly improved lung histopathological damage. These results may be related to the inhibitory effect of TOFA on JAK-STAT/NF-κ B signaling pathway. In conclusion, for the first time, we found that TOFA has a protective effect against sepsis-induced acute lung injury, and it may be a promising drug for the treatment of acute lung injury in sepsis.