Effects In Acute Lung Injury Research Articles

Bergapten attenuates sepsis-induced acute lung injury in mice by regulating Th17/Treg balance

Background The abnormality of the immune system caused by infection is a contributor to the organ dysfunctions associated with sepsis. The balance between Th17/Treg cells is essential for maintaining immune homeostasis. Bergapten is a natural furocoumarin and has been reported to alleviate the Th17/Treg imbalance. Here, we explored the effects of bergapten on the inflammation and immune state in mouse models of sepsis. Methods The model was established using the cecal ligation and puncture method. Mice were administered 30 mg/kg bergapten. Histological examination, RT-qPCR, enzyme-linked immunosorbent assay, immunoblotting, immunofluorescence, immunohistochemistry, and flow cytometry were used to evaluate the effects of bergapten in vivo. Results Bergapten ameliorated lung damage, reduced lung wet/dry weight ratio, inhibited myeloperoxidase activity, and reduced inflammatory cell infiltration. Bergapten also restrained sepsis-induced inflammation via inhibition of inflammatory cytokines and NF-κB signaling. These effects were accompanied by the restored Th17/Treg balance induced by bergapten. Bergapten decreased the number of Th17 cells and elevated the number of Tregs, and this effect was mediated by the signal transducer and activator of transcription 5 (STAT5)/Forkhead box P3 (Foxp3) and STAT3/retinoid-related orphan receptor-γt (RORγt) pathways. Conclusions Bergapten exerted anti-inflammatory effects in acute lung injury by improving the Th17/Treg balance, which suggested a potential of bergapten as an immunomodulatory drug treating sepsis-associated diseases.

Impact of airway closure and lung collapse on inhaled nitric oxide effect in acute lung injury: an experimental study

BackgroundEfficacy of inhaled therapy such as Nitric Oxide (iNO) during mechanical ventilation may depend on airway patency. We hypothesized that airway closure and lung collapse, countered by positive end-expiratory pressure (PEEP), influence iNO efficacy. This could support the role of an adequate PEEP titration for inhalation therapy. The main aim of this study was to assess the effect of iNO with PEEP set above or below the airway opening pressure (AOP) generated by airway closure, on hemodynamics and gas exchange in swine models of acute respiratory distress syndrome. Fourteen pigs randomly underwent either bilateral or asymmetrical two-hit model of lung injury. Airway closure and lung collapse were measured with electrical impedance tomography as well as ventilation/perfusion ratio (V/Q). After AOP detection, the effect of iNO (10ppm) was studied with PEEP set randomly above or below regional AOP. Respiratory mechanics, hemodynamics, and gas-exchange were recorded.ResultsAll pigs presented airway closure (AOP > 0.5cmH2O) after injury. In bilateral injury, iNO was associated with an improved mean pulmonary pressure from 49 ± 8 to 42 ± 7mmHg; (p = 0.003), and ventilation/perfusion matching, caused by a reduction in pixels with low V/Q and shunt from 16%[IQR:13–19] to 9%[IQR:4–12] (p = 0.03) only at PEEP set above AOP. iNO had no effect on hemodynamics or gas exchange for PEEP below AOP (low V/Q 25%[IQR:16–30] to 23%[IQR:14–27]; p = 0.68). In asymmetrical injury, iNO improved pulmonary hemodynamics and ventilation/perfusion matching independently from the PEEP set. iNO was associated with improved oxygenation in all cases.ConclusionsIn an animal model of bilateral lung injury, PEEP level relative to AOP markedly influences iNO efficacy on pulmonary hemodynamics and ventilation/perfusion match, independently of oxygenation.

Astragaloside IV inhibits inflammation caused by influenza virus via reactive oxygen species/NOD-like receptor thermal protein domain associated protein 3/Caspase-1 signaling pathway.

Astragaloside IV (AS-IV) is the most active monomer in the traditional Chinese herbal medicine Radix Astragali, which has a wide range of antiviral, anti-inflammatory, and antifibrosis pharmacological effects, and shows protective effects in acute lung injury. This study utilized the immunofluorescence, flow cytometry, enzyme-linked immunosorbent assay, quantitative reverse transcription-polymerase chain reaction, western blot, and hematoxylin and eosin staining methods to investigate the mechanism of AS-IV in reducing viral pneumonia caused by influenza A virus in A549 cells and BALB/c mice. The results showed that AS-IV suppressed reactive oxygen species production in influenza virus-infected A549 cells in a dose-dependent manner, and subsequently inhibited the activation of nucleotide-binding oligomerization domain-like receptor thermal protein domain associated protein 3 inflammasome and Caspase-1, decreased interleukin (IL) -1β and IL-18 secretion. In BALB/c mice infected with Poly (I:C), oral administration of AS-IV can significantly reduce Poly (I:C)-induced acute pneumonia and lung pathological injury. AS-IV alleviates the inflammatory response induced by influenza virus in vitro and lung flammation and structural damage caused by poly (I:C) in vivo.

Urolithin A exerts a protective effect on lipopolysaccharide-induced acute lung injury by regulating HMGB1-mediated MAPK and NF-κB signaling pathways.

Acute lung injury (ALI) is a severe inflammatory disorder that has a high morbidity and mortality rate. Urolithin A (UA) is reported to have anti-inflammatory and anti-oxidative effects in ALI. However, its molecular mechanisms in ALI remain to be explored. Mice and BEAS-2B cells were administrated with lipopolysaccharide (LPS) to mimic the ALI model in vivo and in vitro. Hematoxylin-eosin (HE) staining was used to detect the pathological injury of lung tissues. The levels of proinflammatory cytokines in bronchoalveolar lavage fluid (BALF) and culture supernatant and the levels of oxidative stress markers in lung tissues were measured using ELISA. DCFH-DA probe was used to assess the reactive oxygen species (ROS) level. TUNEL staining and flow cytometry were performed to determine cell apoptosis. The key targets and pathways were confirmed by immunohistochemistry (IHC) and western blot. UA suppressed the pathologic damage, wet/dry weight ratio, and total protein and inflammatory cells in BALF. UA decreased neutrophil infiltration and proinflammatory cytokines production. UA reduced the level of malondialdehyde (MDA) and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in pulmonary tissues. UA also inhibited cell apoptosis in lung tissues by decreasing Bax expression and increasing Bcl-2 expression. In addition, UA suppressed LPS-induced inflammatory factor production, ROS level, and cell apoptosis in BEAS-2B. Importantly, UA decreased the expression of HMGB1 in LPS-treated mice and BEAS-2B cells. HMGB1 overexpression greatly abrogated the inhibition of UA on inflammation, ROS, and cell apoptosis in LPS-administrated BEAS-2B. Furthermore, UA treatment suppressed the phosphorylated levels of p38, JNK, ERK, and p65 in LPS-administrated mice and BEAS-2B cells. UA alleviated lung inflammation, oxidative stress, and apoptosis in ALI by targeting HMGB1 to inactivate the MAPK/NF-κB signaling, suggesting the potential of UA to treat ALI.

Veronica linariifolia subsp. dilatata ameliorates LPS-induced acute lung injury by attenuating endothelial cell barrier dysfunction via EGFR/Akt/ZO-1 pathway

Ethnopharmacological relevanceThe dried aerial parts of Veronica linariifolia subsp. dilatata (Nakai & Kitag.) D.Y.Hong named Shui Man Jing (SMJ) is a traditional Chinese medicine with a long history of clinical use in the treatment of chronic bronchitis and coughing up blood, however, its role on acute lung injury (ALI) has not been revealed yet. Aim of the studyTo assess the efficiency of SMJ on ALI and to investigate whether it inhibited endothelial barrier dysfunction by regulating the EGFR/Akt/ZO-1 pathway to alleviate ALI in vivo and in vitro based on the result of network pharmacology. Materials and methodsAn in vivo model of ALI was established using inhalation of atomized lipopolysaccharide (LPS), and the effects of SMJ on ALI were evaluated through histopathological examination and inflammatory cytokines, lung histology and edema, vascular and alveolar barrier disruption. Network pharmacology was applied to predict the mechanism of SMJ in the treatment of ALI. The crucial targets were validated by RT-PCR, Western Blotting, molecular docking, immunohistochemistry and immunofluorescence methods in vivo and in virto. ResultsAdministration of SMJ protected mice against LPS-induced ALI, including ameliorating the histological alterations in the lung tissues, and decreasing lung edema, protein content of bronchoalveolar lavage fluid, infiltration of inflammatory cell and secretion of cytokines. SMJ exerted protective effects in ALI by inhibiting endothelial barrier dysfunction in mice and bEnd.3 cell. SMJ relieved endothelial barrier dysfunction induced by LPS through upregulating the EGFR expression. SMJ also increased the phosphorylation of Akt, and ZO-1 expression both in vivo and in vitro. ConclusionSMJ attenuates vascular endothelial barrier dysfunction for LPS-induced ALI via EGFR/Akt/ZO-1 pathway, and is a promising novel therapeutic candidate for ALI.

Hypoxic bone marrow mesenchymal stem cell-derived exosomal lncRNA XIST attenuates lipopolysaccharide-induced acute lung injury via the miR-455-3p/Claudin-4 axis

Mesenchymal stem cell-derived exosomes and long non-coding RNAs (lncRNAs) have been identified to play a role in acute lung injury (ALI). In this study, we investigated whether exosomal lncRNAs could regulate ALI and the underlying mechanisms. Bone marrow mesenchymal stem cells (BM-MSCs) were pretreated with hypoxia or normoxia, and exosomes were subsequently extracted from normoxic BM-MSCs (Nor-exos) and hypoxic BM-MSCs (Hypo-exos). A rat model of ALI was established via an airway perfusion of lipopolysaccharide (LPS). Exosomes were administered via the tail vein to evaluate the in vivo effect of exosomes in ALI. LPS-exposed RLE-6TN cells were incubated with exosomes to explore their in vitro effect in ALI. A luciferase reporter assay was used to evaluate the interaction between lncRNA XIST and miR-455-3p, as well as miR-455-3p and Claudin-4. We found that the exosomes attenuated LPS-induced ALI and Hypo-Exos exerted a greater therapeutic effect compared with Nor-exos both in vitro and in vivo. Moreover, an abundance of lncRNA XIST was observed in Hypo-exos compared with Nor-exos. Mechanistically, LncRNA XIST functioned as a miR-455-3p sponge and targeted Claudin-4 in ALI. Our results provide novel insight into the role of exosomal lncRNA XIST for the treatment of ALI. Thus, hypoxic pretreatment may represent an effective method for improving the therapeutic effects of exosomes.

Combination therapy with budesonide and acetylcysteine alleviates LPS-induced acute lung injury via the miR-381/NLRP3 molecular axis.

Acute lung injury (ALI) usually has a high morbidity and mortality rate, but the current treatment is relatively scarce. Both budesonide (Bud) and N-acetylcysteine (NAC) exhibit protective effects in ALI, so we further investigated whether they have a synergistic effect on ALI when used together. Establishment of a rat model of ALI with Lipopolysaccharide (LPS). Bud and NAC were administered by nebulized inhalation alone or in combination. Subsequently, HE staining was performed to observe the pathological changes in lungs of rat. Evans blue staining was implemented to assess alveolar permeability, and the pulmonary edema was assessed by measuring the ratio of wet to dry weight of the lung. Moreover, a TUNEL kit was served to test apoptosis in lung tissues. Western blot and immunohistochemistry were analyzed for expression of scorch-related proteins and NLRP3 in lung tissue, respectively. ELISA was implemented to detect inflammatory factor levels in BALF. and RT-qPCR was utilized to assess the expression level of miR-381. After stable transfection of miR-381 inhibitor or OE-NLRP3 in BEAS-2B treated with LPS, Bud and NAC, miR-381 expression was assessed by RT-qPCR, scorch death-related protein expression was measured by western blot, cell proliferation/viability was assayed by CCK-8, apoptosis was measured by flow cytometry, and ELISA was implemented to assess inflammatory factor levels. Furthermore, the Dual-luciferase assay was used to verify the targeting relationship. Bud and NAC treatment alone or in combination with nebulized inhalation attenuated the increased alveolar permeability, pulmonary edema, inflammatory response and scorching in LPS-induced ALI rats, and combined treatment with Bud and NAC was the most effective. In addition, combined treatment with Bud and NAC upregulated miR-381 expression and inhibited NLRP3 expression in cellular models and LPS-induced ALI rats. Transfection of the miR-381 inhibitor and OE-NLRP3 partially reversed the protective effects of Bud and NAC combination treatment on BEAS-2B cell proliferation inhibition, apoptosis, focal death and the inflammatory response. Combined Bud and NAC nebulization therapy alleviates LPS-induced ALI by modulating the miR-381/NLRP3 molecular axis.

Network pharmacology and molecular docking to explore Polygoni Cuspidati Rhizoma et Radix treatment for acute lung injury.

Polygoni Cuspidati Rhizoma et Radix (PCRR), a well-known traditional Chinese medicine (TCM), inhibits inflammation associated with various human diseases. However, the anti-inflammatory effects of PCRR in acute lung injury (ALI) and the underlying mechanisms of action remain unclear. To determine the ingredients related to PCRR for treatment of ALI using multiple databases to obtain potential targets for fishing. Recognized and candidate active compounds for PCRR were obtained from Traditional Chinese Medicine Systems Pharmacology, STITCH, and PubMed databases. Target ALI databases were built using the Therapeutic Target, DrugBank, DisGeNET, Online Mendelian Inheritance in Man, and Genetic Association databases. Network pharmacology includes network construction, target prediction, topological feature analysis, and enrichment analysis. Bioinformatics resources from the Database for Annotation, Visualization and Integrated Discovery were utilized for gene ontology biological process and Kyoto Encyclopedia of Genes and Genomes network pathway enrichment analysis, and molecular docking techniques were adopted to verify the combination of major active ingredients and core targets. Thirteen bioactive compounds corresponding to the 433 PCRR targets were identified. In addition, 128 genes were closely associated with ALI, 60 of which overlapped with PCRR targets and were considered therapeutically relevant. Functional enrichment analysis suggested that PCRR exerted its pharmacological effects in ALI by modulating multiple pathways, including the cell cycle, cell apoptosis, drug metabolism, inflammation, and immune modulation. Molecular docking results revealed a strong associative relationship between the active ingredient and core target. PCRR alleviates ALI symptoms via molecular mechanisms predicted by network pharmacology. This study proposes a strategy to elucidate the mechanisms of TCM at the network pharmacology level.

Human menstrual blood-derived stem cells alleviate autoimmune hepatitis via JNK/MAPK signaling pathway in vivo and in vitro.

Autoimmune hepatitis (AIH) is a severe globally distributed liver disease that could occur at any age. Human menstrual blood-derived stem cells (MenSCs) have shown therapeutic effect in acute lung injury and liver failure. However, their role in the curative effect of AIH remains unclear. Here, a classic AIH mouse model was constructed through intravenous injection with concanavalin A (Con A). MenSCs were intravenously injected while Con A injection in the treatment groups. The results showed that the mortality by Con A injection was significantly decreased by MenSCs treatment and liver function tests and histological analysis were also ameliorated. The results of phosphoproteomic analysis and RNA-seq revealed that MenSCs improved AIH, mainly by apoptosis and c-Jun N-terminal kinase/mitogen-activated protein signaling pathways. Apoptosis analysis demonstrated that the protein expression of cleaved caspase 3 was increased by Con A injection and reduced by MenSCs transplantation, consistent with the TUNEL staining results. An AML12 co-culture system and JNK inhibitor (SP600125) were used to verify the JNK/MAPK and apoptosis signaling pathways. These findings suggested that MenSCs could be a promising strategy for AIH.

Irigenin attenuates lipopolysaccharide-induced acute lung injury by inactivating the mitogen-activated protein kinase (MAPK) signaling pathway.

Acute lung injury (ALI) is a serious pulmonary inflammation disease with high mortality. Irigenin, an isoflavone from rhizomes of the Belamcanda chinensis, has been reported to exert anti-inflammatory, anti-oxidative, and anti-apoptotic activities in several diseases. However, it is still unclear whether irigenin can exert a beneficial effect in ALI. A network pharmacology method was utilized to predict the hub targets and potential therapeutic mechanisms of irigenin against ALI. Lipopolysaccharide (LPS) was used to establish the mice model of ALI for evaluating the effects of irigenin. According to the protein-protein interaction (PPI) network, we identified EGFR, HRAS, AKT1, SRC, and HSP90AA1 as the top five significant genes. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment assays showed that irigenin might affect inflammatory response, cytokine production, and cell death by the mitogen-activated protein kinase (MAPK) signaling pathway. In vivo experiment results manifested that irigenin decreased pathological changes, lung Wet/Dry weight ratio, and total protein content in bronchoalveolar lavage fluid (BALF). Irigenin also reduced the production of inflammatory cytokines, including tumor necrosis factor-a (TNF-a), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-18 (IL-18), and neutrophil infiltration. Additionally, irigenin inhibited pulmonary apoptosis in LPS-treated ALI mice. Moreover, LPS-induced phosphorylation of p38, JNK, and ERK was significantly abated due to the treatment of irigenin. In summary, irigenin ameliorates LPS-induced ALI by suppressing pulmonary inflammation and apoptosis via inactivation of the MAPK signaling pathway. These findings indicated the therapeutic potential of irigenin in ALI.

Evaluation of the effects of empagliflozin on acute lung injury in rat intestinal ischemia-reperfusion model.

Empagliflozin is a selective sodium-glucose co-transporter (SGLT2) inhibitor that is approved for the treatment of type 2 diabetes. The beneficial effects of empagliflozin on other organ systems including the heart and kidneys have been proven. The aim of this study is to evaluate the role of empagliflozin on acute lung injury induced by intestinal ischemia-reperfusion (I/R). A total of 27 male Wistar albino rats were divided into three groups: sham, I/R, and I/R + empagliflozin; each group containing nine animals. Sham group rats underwent laparotomy without I/R injury. Rats in the I/R group underwent laparotomy, 1h of after ischemia-reperfusion injury (superior mesenteric artery ligation was followed by 2h of reperfusion). Rats in I/R were given empagliflozin (30mg/kg) by gastric gavage for 7days before the ischemia-reperfusion injury. All animals were killed at the end of reperfusion and lung tissue samples were obtained for immunohistochemical staining and histopathological investigation in all groups. Serum glucose, AST, ALT, creatinine, native thiol, total thiol, and disulfide levels and disulfide-native thiol, disulfide-total thiol, and native thiol-total thiol ratios as well as the IMA levels were analyzed and compared among the groups. While intestinal I/R significantly increases serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatinine levels; did not cause any change in homeostasis parameters and IMA level. Empagliflozin treatment had no significant effect on biochemical parameters. Empagliflozin treatment induced a significant decrease in positive immunostaining for IL-1, IL-6, TNF-alpha, caspase 3, caspase 8, and caspase 9 compared to the I/R group in lung tissue samples. Intestinal I/R caused severe histopathological injury including edema, hemorrhage, increased thickness of the alveolar wall, and infiltration of inflammatory cells into alveolar spaces. Empagliflozin treatment significantly attenuated the severity of intestinal I/R injury. It was concluded that empagliflozin treatment may have beneficial effects in acute lung injury, and, therefore, has the potential for clinical use.

Electroacupuncture pretreatment protects septic rats from acute lung injury by relieving inflammation and regulating macrophage polarization.

Macrophage polarization toward the M2 phenotype may attenuate inflammation and have a therapeutic effect in acute lung injury (ALI). To investigate the role of electroacupuncture (EA) pretreatment on the inflammatory response and macrophage polarization in a septic rat model of lipopolysaccharide (LPS)-induced ALI. Male Sprague Dawley rats (n = 24) were randomly divided into three groups (n = 8 each): control (Ctrl), ALI (LPS) and pre-EA (LPS + EA pretreatment). ALI and pre-EA rats were injected with LPS via the caudal vein. Pulmonary edema was assessed by left upper pulmonary lobe wet-to-dry (W/D) ratios. Lung injury scores were obtained from paraffin-embedded and hematoxylin and eosin-stained sections of the left lower pulmonary lobe. Inflammatory activation was quantified using serum tumor necrosis factor (TNF)-α, interleukin (IL)-1β, transforming growth factor (TGF)-β and IL-10 levels measured by enzyme linked immunosorbent assay (ELISA). Macrophage phenotype was determined by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting. Mean lung W/D ratio was significantly lower and serum IL-1β levels were decreased in pre-EA rats compared to ALI rats (P < 0.05). TNF-α mRNA expression was decreased and mannose receptor (MR) and Arg1 mRNA expression was increased in the lung tissues of pre-EA rats compared to ALI rats (P < 0.01). Arg1 protein expression was similarly increased in the lung tissues of pre-EA rats compared to ALI rats (P < 0.05). EA pretreatment may play a protective role by promoting macrophage polarization to the M2 phenotype in a septic rat model of LPS-induced ALI.

Sphingosine Kinase 1 Plays an Important Role in Atorvastatin-Mediated Anti-Inflammatory Effect against Acute Lung Injury.

Atorvastatin is a 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) inhibitor and inhibits cholesterol synthesis. Recently, atorvastatin also showed anti-inflammatory effect in acute lung injury, ameliorating pulmonary gas-blood exchanging function. Sphingosine kinase 1 plays a central role in endothelial (EC) cytoskeleton rearrangement and EC barrier integrity regulation. In this study, the role of sphingosine kinase 1 in atorvastatin anti-inflammatory effect against acute lung injury was investigated. Both wild-type (WT) and SphK1−/− mice were challenged with high tidal volume ventilation (40 ml/kg body weight, 65 breathing/min, 4 hours). The acute lung injury was evaluated and the mechanisms were explored. In WT mice, atorvastatin treatment significantly decreased acute lung injury responding to high tidal volume ventilation (HT), including protein, cellular infiltration, and cytokine releasing; comparing to WT mice, SphK1−/− mice showed significantly worsen pulmonary injuries on HT model. Moreover, the atorvastatin-mediated anti-inflammatory effect was diminished in SphK1−/− mice. To further confirm the role of SphK1 in VILI, we then compared the inflammatory response of endothelial cells that were isolated from WT and SphK1−/− mice to cyclic stretching. Similarly, atorvastatin significantly decreased cytokine generation from WT EC responding to cyclic stretching. Atorvastatin also significantly preserved endothelial junction integrity in WT EC against thrombin challenge. However, the inhibitory effect of atorvastatin on cytokine generation induced by cyclic stretching was abolished on SphK1−/− mice EC. The endothelial junction integrity effects of atorvastatin also diminished on SphK1−/− mouse EC. Signal analysis indicated that atorvastatin inhibited JNK activation induced by cyclic stretch. SphK1 knockout also blocked atorvastatin-mediated VE-cadherin junction enhancement. In summary, by inhibition of MAPK activity and maintenance of EC junction homeostasis, SphK1 plays a critical role in atorvastatin-mediated anti-inflammatory effects in both cellular and in vivo model. This study also offers an insight into mechanical stress-mediated acute lung injury and potential therapy in the future.

Hypaphorine exerts anti-inflammatory effects in sepsis induced acute lung injury via modulating DUSP1/p38/JNK pathway.

Sepsis is a systemic inflammatory response syndrome attributed to infection, while sepsis-induced acute lung injury (ALI) has high morbidity and mortality. Here, we aimed to explore the specific mechanism of hypaphorine's anti-inflammatory effects in ALI. Lipopolysaccharide (LPS) was adopted to construct ALI model both in vivo and in vitro. BEAS-2B cell viability and apoptosis was testified by the MTT assay and flow cytometry. Reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were performed to examine the expression of proinflammatory cytokines (IL-1β, IL-6, TNF-α, and IL-18), and Western blot was adopted to examine the expression of the apoptosis-related proteins (Bax, Bcl2, and Caspase3) and the DUSP1/p38/JNK signaling pathway. At the same time, lung injury score, lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity were monitored. The dry/wet weight method was used to examine lung edema, and the total protein content in BALF was determined to test pulmonary vascular permeability. As the data suggested, hypaphorine inhibited the LPS-mediated apoptosis of alveolar epithelial cells. What is more, hypaphorine attenuated the expression of inflammatory factors (IL-1β, IL-6, TNF-α, and IL-18) and inactivated the p38/JNK signaling pathway through upregulating DUSP1 in a dose-dependent manner. Meanwhile, DUSP1 knockdown weakened the anti-inflammatory effect of hypaphorine on LPS-mediated lung injury. Furthermore, hypaphorine also relieved LPS induced ALI in rats with anti-inflammatory effects. Taken together, hypaphorine prevented LPS-mediated ALI and proinflammatory response via inactivating the p38/JNK signaling pathway by upregulating DUSP1.

Sevoflurane inhibits ferroptosis: A new mechanism to explain its protective role against lipopolysaccharide-induced acute lung injury

Sevoflurane (Sev) has protective effects in acute lung injury (ALI), but the relevant mechanisms are still not fully understood. The present study aimed to determine whether Sev exerts a protective effect on lipopolysaccharide (LPS)-induced ALI by regulating ferroptosis. In this study, we found that Sev could protect mice from lung injury caused by LPS stimulation, including extenuating lung histological damage, pulmonary edema and pulmonary vascular permeability, and the content of inflammatory factors in Bronchoalveolar lavage fluid (BALF), as well as improving the survival rate of ALI mice, which was in line with the effects of ferroptosis inhibitor ferrostatin-1. Simultaneously, Sev could eliminate the worsening effects of ferroptosis inducer Fe-citrate on LPS-induced ALI to a certain extent. Additionally, the administration of Sev could inhibit ferroptosis caused by LPS, which was manifested by reducing the accumulation of MDA and Fe2+, and increasing the levels of GSH and GPX4 in the lung tissues of ALI mice. It was also observed in BEAS-2B cells that the increased MDA and Fe2+ levels and the decreased GSH and GPX4 levels caused by LPS could be rescued by ferrostatin-1 and Sev. LPS stimulation compensatory up-regulated heme oxygenase-1 (HO-1) expression in mouse lung tissues and BEAS-2B cells, which could be enhanced by Sev. Moreover, HO-1 depletion could offset the inhibitory effect of Sev on LPS-induced ferroptosis and inflammation in BEAS-2B cells. Taken together, Sev inhibited ferroptosis by up-regulating HO-1 expression to reduce LPS-induced ALI, which may provide a possible mechanism for the application of Sev in clinical anesthesia.

Ginkgolide C attenuates lipopolysaccharide‑induced acute lung injury by inhibiting inflammation via regulating the CD40/NF‑κB signaling pathway.

Excessive lung inflammation caused by endotoxins, including lipopolysaccharide (LPS), mediates the detrimental effects of acute lung injury (ALI), as evidenced by severe alveolar epithelial cell injury. CD40, a member of the tumor necrosis factor receptor superfamily, serves as a central activator in triggering and transducing a series of severe inflammatory events during the pathological processes of ALI. Ginkgolide C (GC) is an efficient and specific inhibitor of CD40. Therefore, the present study aimed to investigate whether GC alleviated LPS-induced ALI, as well as the potential underlying mechanisms. LPS-injured wild-type and CD40 gene conditional knockout mice, and primary cultured alveolar epithelial cells isolated from these mice served as in vivo and in vitro ALI models, respectively. In the present study, histopathological assessment, polymorphonuclear neutrophil (PMN) infiltration, lung injury score, myeloperoxidase activity, wet-to-dry (W/D) weight ratio and hydroxyproline (Hyp) activity were assessed to evaluate lung injury. In addition, immunohistochemistry was performed to evaluate intracellular adhesion molecule-1, vascular cell adhesion molecule-1 and inducible nitric oxide synthase expression levels, and TNF-α, IL-1β, IL-6 ELISAs and western blotting were conducted to elucidate the signaling pathway. The results demonstrated that GC alleviated LPS-induced lung injury, as evidenced by improvements in ultrastructural characteristics and histopathological alterations of lung tissue, inhibited PMN infiltration, as well as reduced lung injury score, W/D weight ratio and hydroxyproline content. In LPS-injured alveolar epithelial cells, GC significantly reduced IκBα phosphorylation, IKKβ activity and NF-κB p65 subunit translocation via downregulating CD40, leading to a significant decrease in downstream inflammatory cytokine levels and protein expression levels. In conclusion, the results of the present study demonstrated that GC displayed a protective effect against LPS-induced ALI via inhibition of the CD40/NF-κB signaling pathway; therefore, the present study suggested that the CD40/NF-κB signaling pathway might serve as a potential therapeutic target for ALI.

Non-muscle myosin II knockdown improves survival and therapeutic effects of implanted bone marrow-derived mesenchymal stem cells in lipopolysaccharide-induced acute lung injury.

BackgroundBone marrow-derived mesenchymal stem cells (BMSCs) have been shown to have some beneficial effects in acute lung injury (ALI), but the therapeutic effects are limited due to apoptosis or necrosis after transplantation into injured lungs. Here, we aim to explore whether Non-muscle myosin II (NM-II) knockdown could enhance BMSCs survival and improve therapeutic effects in ALI.MethodsMSCs, isolated from rat bone marrow, were transfected with the small interfering RNA (siRNA) targeted to NM-II mRNA by a lentivirus vector. Rats were equally randomized to four groups: the control group was given normal saline via tail vein; the other three groups underwent intratracheal lipopolysaccharide (LPS) instillation followed by administration with either normal saline, BMSCs transduced with lentivirus-enhanced green fluorescent protein (eGFP) empty vector, or BMSCs transduced with lentivirus-eGFP NM-II siRNA. Hematoxylin and eosin staining was used to evaluate lung histopathologic changes and Masson trichrome staining was used to assess lung fibrosis. The myeloperoxidase activity was also tested in lung tissues. The mRNA expression of inflammatory cytokines in lung tissues was determined via quantitative reverse transcription PCR. Sex-determining region of the Y chromosome gene expression was measured by fluorescence in situ hybridization (FISH) assay. The expression of self-renewal activity and apoptosis-associated proteins were measured by Western blot.ResultsTransplantation of NM-II siRNA-modified BMSCs could improve histopathological morphology, decrease inflammatory infiltrates, down-regulate the expression levels of inflammatory cytokines, and reduce pulmonary interstitial edema. NM-II siRNA-modified BMSCs showed antifibrotic properties and alleviated the degrees of pulmonary fibrosis induced by endotoxin. In addition, NM-II knockdown BMSCs showed slightly better therapeutic effect on lung inflammation when compared with control BMSCs. The beneficial effects of NM-II siRNA-modified BMSCs may be attributed to enhanced self-renewal activity and decreased apoptosis.ConclusionsNM-II knockdown could inhibit the apoptosis of implanted BMSCs in lung tissues and improve its self-renewal activity. NM-II siRNA-modified BMSCs have a slightly enhanced ability to attenuate lung injury after LPS challenge.

Cardiovascular Pharmacology in the Time of COVID-19: A Focus on Angiotensin-Converting Enzyme 2.

:Coronavirus disease-2019 (COVID-19) has emerged as a pandemic affecting millions of adults. Severe acute respiratory syndrome coronavirus-2019 (SARS-CoV-2), the causative virus of COVID-19, infects host cells through angiotensin-converting enzyme 2 (ACE2). Preclinical models suggest that ACE2 upregulation confers protective effects in acute lung injury. In addition, renin–angiotensin aldosterone system inhibitors reduce adverse atherosclerotic cardiovascular disease, heart failure, and chronic kidney disease outcomes, but may increase ACE2 levels. We review current knowledge of the role of ACE2 in cardiovascular physiology and SARS-CoV-2 virology, as well as clinical data to inform the management of patients with or at risk for COVID-19 who require renin–angiotensin–aldosterone system inhibitor therapy.

Suppression of NLRP3 Inflammasome by Erythropoietin via the EPOR/JAK2/STAT3 Pathway Contributes to Attenuation of Acute Lung Injury in Mice.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common and devastating clinical disorders with high mortality and no specific therapy. An excessive inflammatory response results in the progression of ALI/ARDS, and the NLRP3 inflammasome is a key participant in inflammation. Erythropoietin (EPO), which is clinically used for anemia, reportedly exerts pleiotropic effects in ALI. However, whether EPO could protect against lipopolysaccharide (LPS)-induced ALI by regulating the NLRP3 inflammasome and its underlying mechanisms remain poorly elucidated. This study aimed to explore whether the therapeutic effects of EPO rely on the suppression of the NLRP3 inflammasome and the specific mechanisms in an LPS-induced ALI mouse model. ALI was induced in C57BL/6 mice by intraperitoneal (i.p.) injection of LPS (15 mg/kg). EPO was administered intraperitoneally at 5 U/g after LPS challenge. The mice were sacrificed 8 h later. Our findings indicated that application of EPO markedly diminished LPS-induced lung injury by restoring histopathological changes, lessened lung wet/dry (W/D) ratio, protein concentrations in bronchoalveolar lavage fluid (BALF) and myeloperoxidase (MPO) levels. Meanwhile, EPO evidently decreased interleukin-1β (IL-1β) and interleukin-18 (IL-18) secretion, the expression of NLRP3 inflammasome components including pro-IL-1β, NLRP3, and cleaved caspase-1 as well as phosphorylation of nuclear factor-κB (NF-κB) p65, which may be associated with activation of EPO receptor (EPOR), phosphorylation of Janus-tyrosine kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). However, all the beneficial effects of EPO on ALI and modulation NLRP3 inflammasome were remarkably abrogated by the inhibition of EPOR/JAK2/STAT3 pathway and knockout (KO) of NLRP3 gene. Taken together, this study indicates that EPO can effectively attenuate LPS-induced lung injury in mice by suppressing the NLRP3 inflammasome, which is dependent upon activation of EPOR/JAK2/STAT3 signaling and inhibition of the NF-κB pathway.

Sevoflurane suppresses oxidation-induced stress and inflammatory responses, via promotion of Nrf2-induced antioxidant signaling

This study aimed to investigate the role of sevoflurane on anti-oxidant effects in sepsis-induced multiple organ failure. Western blot and quantitative RT–PCR were used to measure the expression of Nrf2 and its downstream genes. The DCFH-DA fluorescence probe assay was performed to assess the intracellular levels in HUVECs and LMVECs. Electrophoretic mobility shift assay was used to assess the DNA binding activities of Nrf2. Better survival, reduced expression of inflammatory cytokines, and improved pathological infiltration in the lungs and kidneys were observed in septic rats treated with sevoflurane. SOD activity increased and Nrf2–ARE signaling pathway was activated following sevoflurane treatment. The protective effect was lost in sepsis-induced acute lung injury (ALI) following inhibition of Nrf2 by intratracheal delivery of siRNA-Nrf2. In vitro experiments, we found the sevoflurane could suppress ROS production after stimulation with LPS and the application of sevoflurane augments the DNA-binding activity of Nrf2 in HUVECs and LMVECs. However, knockdown of Nrf2 by siRNA-Nrf2, the Protein kinase C (PKC) inhibitor, and the Nrf2 inhibitor ML385 could partially recover ROS production, inhibit the activity of SOD, and repress the expression of anti-oxidant genes following sevoflurane treatment. Sevoflurane could have protective effects in ALI and septic multiple organ disorders (MODs).