MicroRNA-451 from Human Umbilical Cord-Derived Mesenchymal Stem Cell Exosomes Inhibits Alveolar Macrophage Autophagy via Tuberous Sclerosis Complex 1/Mammalian Target of Rapamycin Pathway to Attenuate Burn-Induced Acute Lung Injury in Rats

Objective Our previous studies established that microRNA(miR)-451 from human umbilical cord mesenchymal stem cell-derived exosomes(hUC-MSC-Exos)alleviates acute lung injury(ALI).This study aims to elucidate the mechanisms by which miR-451 in hUC-MSC-Exos reduces ALI by modulating macrophage autophagy.Methods Exosomes were isolated from hUC-MSCs.Severe burn-induced ALI rat models were treated with hUC-MSC-Exos carrying the miR-451 inhibitor.Hematoxylin-eosin staining evaluated inflammatory injury.Enzyme-linked immunosorbnent assay measured lipopolysaccharide(LPS),tumor necrosis factor-α,and interleukin-1βlevels.qRT-PCR detected miR-451 and tuberous sclerosis complex 1(TSC1)expressions.The regulatory role of miR-451 on TSC1 was determined using a dual-luciferase reporter system.Western blotting determined TSC1 and proteins related to the mammalian target of rapamycin(mTOR)pathway and autophagy.Immunofluorescence analysis was conducted to examine exosomes phagocytosis in alveolar macrophages and autophagy level.Results hUC-MSC-Exos with miR-451 inhibitor reduced burn-induced ALI and promoted macrophage autophagy.MiR-451 could be transferred from hUC-MSCs to alveolar macrophages via exosomes and directly targeted TSC1.Inhibiting miR-451 in hUC-MSC-Exos elevated TSC1 expression and inactivated the mTOR pathway in alveolar macrophages.Silencing TSC1 activated mTOR signaling and inhibited autophagy,while TSC1 knockdown reversed the autophagy from the miR-451 inhibitor-induced.Conclusion miR-451 from hUC-MSC exosomes improves ALI by suppressing alveolar macrophage autophagy through modulation of the TSC1/mTOR pathway,providing a potential therapeutic strategy for ALI.

Mogroside IIE,an in vivo metabolite of sweet agent,alleviates acute lung injury via Pla2g2a-EGFR inhibition

In the face of increasingly serious environmental pollution,the health of human lung tissues is also facing serious threats.Mogroside IIE(M2E)is the main metabolite of sweetening agents mogrosides from the anti-tussive Chinese herbal Siraitia grosvenori.The study elucidated the anti-inflammatory action and molecular mechanism of M2E against acute lung injury(ALI).A lipopolysaccharide(LPS)-induced ALI model was established in mice and MH-S cells were employed to explore the protective mechanism of M2E through the western blotting,co-immunoprecipitation,and quantitative real time-PCR analysis.The results indicated that M2E alleviated LPS-induced lung injury through restraining the activation of secreted phospholipase A2 type IIA(Pla2g2a)-epidermal growth factor receptor(EGFR).The interaction of Pla2g2a and EGFR was identified by co-immunoprecipitation.In addition,M2E protected ALI induced with LPS against inflammatory and damage which were significantly dependent upon the downregulation of AKT and m TOR via the inhibition of Pla2g2a-EGFR.Pla2g2a may represent a potential target for M2E in the improvement of LPS-induced lung injury,which may represent a promising strategy to treat 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).CONCLUSIONElevated plasma IL-6 levels in critically ill patients with sepsis were associated with an increased risk of ALI andMODS.Higher IL-6 levels were correlated with greater disease severity,as reflected by higher APACHE II andSOFA scores.These findings suggest that IL-6 may serve as a biomarker for predicting the development of ALI anddisease severity in patients with sepsis.

Research Progress on the Pathogenesis of Acute Lung Injury(ALI)

In this review,the databases searched were PubMed and Web of Science.It is believed that the main causes of acute lung injury(ALI)and acute respiratory distress syndrome(ARDS)are inflammatory response disorders,excessive oxidative stress,cell death,endoplasmic reticulum stress,coagulation dysfunction,and weakened aquaporin function.

Mechanisms and Research Progress of Traditional Chinese Medicine Regulating NF-κB in the Treatment of Acute Lung Injury/Acute Respiratory Distress Syndrome

Acute lung injury(ALI)has multiple causes and can easily progress to acute respiratory distress syndrome(ARDS)if not properly treated.Nuclear factorκB(NF-κB)is a key pathway in the treatment of ALI/ARDS.By exploring the relevance of NF-κB and the pathogenesis of this disease,it was found that this disease was mainly associated with inflammation,dysfunction of the endothelial barrier,oxidative stress,impaired clearance of alveolar fluid,and coagulation disorders.Traditional Chinese medicine(TCM)has the characteristics of multitargeting,multipathway effects,and high safety,which can directly or indirectly affect the treatment of ALI/ARDS.This article summarizes the mechanism and treatment strategies of TCM in recent years through intervention in the NF-κB-related signaling pathways for treating ALI/ARDS.It provides an overview from the perspectives of Chinese herbal monomers,TCM couplet medicines,TCM injections,Chinese herbal compounds,and Chinese herbal preparations,offering insights into the prevention and treatment of ALI/ARDS with TCM.

Modulating the crosstalk between macrophage and Th17: potential mechanism of natural products on acute lung injury

Sepsis is a life-threatening multiple organ dysfunction syndrome caused by the imbalance of the immune response to infection,featuring complex and variable conditions,and is one of the leading causes of mortality in ICU patients.Lung injury is a common organ damage observed in sepsis patients.Macrophages and Th17 cells,as crucial components of innate and adaptive immunity,play pivotal roles in the development of sepsis-induced acute lung injury(ALI).This review summarizes the alterations and mechanisms of macrophages and Th17 cells in sepsis-induced ALI.By focusing on the“cross-talk”between macrophages and Th17 cells,this review aims to provide a solid theoretical foundation for further exploring the therapeutic targets of traditional Chinese medicine formulas in the treatment of sepsis complicated with ALI,thereby offering insights and guidance for the clinical application of traditional Chinese medicine in managing sepsis-associated ALI.

Acute lung injury and ARDS in acute pancreatitis: Mechanisms and potential intervention

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) in acute pancreatitis still represents a substantial problem,with a mortality rate in the range of 30%-40%.The present review evaluates underlying pathophysiological mechanisms in both ALI and ARDS and potential clinical implications.Several mediators and pathophysiological pathways are involved during the different phases of ALI and ARDS.The initial exudative phase is characterized by diffuse alveolar damage,microvascular injury and influx of inflammatory cells.This phase is followed by a fibro-proliferative phase with lung repair,type Ⅱ pneumocyte hypoplasia and proliferation of fibroblasts.Proteases derived from polymorphonuclear neutrophils,various pro-inflammatory mediators,and phospholipases are all involved,among others.Contributing factors that promote pancreatitis-associated ALI may be found in the gut and mesenteric lymphatics.There is a lack of complete understanding of the underlying mechanisms,and by improving our knowledge,novel tools for prevention and intervention may be developed,thus contributing to improved outcome.

Review:Acute lung injury/acute respiratory distress syndrome (ALI/ARDS): the mechanism,present strategies and future perspectives of therapies

Acute lung injury/acute respiratory distress syndrome （ALI/ARDS）, which manifests as non-cardiogcnic pulmonary edema, respiratory distress and hypoxemia, could be resulted from various processes that directly or indirectly injure the lung. Extensive investigations in experimental models and humans with ALI/ARDS have revealed many molecular mechanisms that offer therapeutic opportunities for cell or gene therapy. Herein the present strategies and future perspectives of the treatment for ALI/ARDS, include the ventilatory, pharmacological, as well as cell therapies.

Therapeutic effects of Caspase-1 inhibitors on acute lung injury in experimental severe acute pancreatitis

AIM： To assess the therapeutic effect of Caspase-1 inhibitors （ICE-I） on acute lung injury （ALI） in experimental severe acute pancreatitis （SAP）. METHODS： Forty-two SD rats were randomly divided into 3 groups： healthy controls （HC, n = 6）; SAP-S group （n = 18）; SAP-ICE-i group （n = 18）. SAP was induced by retrograde infusion of 5% sodium taurocholate into the bile-pancreatic duct. HC rats underwent the same surgical procedures and duct cannulation without sodium taurocholate infusion, in SAP-S group, rats received the first intraperitoneal injection of isotonic saline 2 h after induction of acute pancreatitis and a repeated injection after 12 h. In SAP-ICE-I group, the rats were firstly given ICE inhibitors intraperitoneally 2 h after induction of pancreatitis. As in SAP-S group, the injection was repeated at 12 h. Serum 1L-1β was measured by EUSA. Intrapulmonary expression of Caspase-1, IL-1β and IL-18 mRNA were detected by semi-quantitative RT-PCR. The wet/dry weight ratios and histopathological changes of the lungs were also evaluated. RESULTS： Serum IL-1β levels in SAP-S group were 276.77 ± 44.92 pg/mL at 6 h, 308.99 ± 34.95 pg/mL at 12 h, and 311.60 ± 46.51 pg/mL at 18 h, which were increased significantly （P 〈 0.01, vs HC）. in SAP- ICE-I group, those values were decreased significantly （P 〈 0.01, vs SAP-S）. intrapulmonary expression of Caspase-1, IL-1β and IL-18 mRNA were observed in the HC group, while they were increased significantly in the SAP-S group （P 〈 0.01, vs HC）. The expression of IL-lβ and IL-18 mRNA were decreased significantly in the SAP- ICE-I group （P 〈 0.01, vs SAP-S）, whereas Caspase-1 mRNA expression had no significant difference （P 〉 0.05）. The wet/dry weight ratios of the lungs in the SAP-S group were increased significantly （P 〈 0.05 at 6 h, P 〈 0.01 at 12 h and 18 h, vs HC） and they were decreased significantly in the SAP-ICE-I group （P 〈 0.05, vs SAP-S）.Caspase-1 inhibitors ameliorated the severity of ALl in SAP.CONCLUSION： Caspase-1 activation, and overproduction of IL-1β and IL-18 play an important role in the course of ALI, and Caspase-1 inhibition is effective for the treatment of ALI in experimental SAP.

Dexmedetomidine Alleviates Pulmonary Edema by Upregulating AQP1 and AQP5 Expression in Rats with Acute Lung Injury Induced by Lipopolysaccharide

This study aims to elucidate the mechanisms by which dexmedetomidine alleviates pulmonary edema in rats with acute lung injury induced by lipopolysaccharide （LPS）. Male Wistar rats were randomly divided into five groups： normal saline control （NS） group, receiving intravenous 0.9% normal saline （5 mL/kg）; LPS group, receiving intravenous LPS （10 mg/kg）; small-dose dexmedetomidine （S） group, treated with a small dose of dexmedetomidine （0.5 μg·kg^-1·h^-1）; medium-dose dexmedetomidine （M） group, treated with a medium dose of dexmedetomidine （2.5 μg·kg^-1·h^-1）; high-dose dexmedetomidine （H） group, treated with a high dose of dexmedetomidine （5μg·kg^-1·h^-1）. The rats were sacrificed 6 h after intravenous injection of LPS or NS, and the hmgs were removed for evaluating histological characteristics and determining the lung wet/dry weight ratio （W/D）. The levels of tumor necrosis factor-alpha （TNF-α） and interleukin-1β （IL-1β） in the lung tissues were assessed by enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expression levels of aquaporin-1 （AQP1） and aquaporin-5 （AQP5） were detected by RT-PCR, immunohistochemistry, and Western blot- ting. The lung tissues from the LPS groups were significantly damaged, which were less pronounced in the H group but not in the small-dose dexmedetomidine group or medium-dose dexmedetomidine group. The W/D and the concentrations of TNF-α and IL-1β in the pulmonary tissues were increased in the LPS group as compared with those in NS group, which were reduced in the H group but not in S group or M group （P〈0.01）. The expression of AQP1 and AQP5 was lower in the LPS group than in the NS group, and significantly increased in the H group but not in the S group or M group （P〈0.01）. Our findings suggest that dexmedetomidine may alleviate pulmonary edema by increasing the expression of AQP-1 and AQP-5.

Circulating miRNAs as biomarkers for severe acute pancreatitis associated with acute lung injury

AIM To identify circulating micro(mi)RNAs as biological markers for prediction of severe acute pancreatitis(SAP) with acute lung injury(ALI).METHODS Twenty-four serum samples were respectively collected and classified as SAP associated with ALI and SAP without ALI, and the mi RNA expression profiles were determined by microarray analysis. These mi RNAs were validated by quantitative reverse transcriptionpolymerase chain reaction, and their putative targets were predicted by the online software Target Scan, mi Randa and Pic Tar database. Gene ontology(GO) and Kyoto encyclopedia of genes and genomes(commonly known as KEGG) were used to predict their possible functions and pathways involved.RESULTS We investigated 287 mi RNAs based on microarray data analysis. Twelve mi RNAs were differentially expressed in the patients with SAP with ALI and those with SAP without ALI. Hsa-mi R-1260 b, 762, 22-3 p, 23 b and 23 a were differently up-regulated and hsa-mi R-550 a*, 324-5 p, 484, 331-3 p, 140-3 p, 342-3 p and 150 were differently down-regulated in patients with SAP with ALI compared to those with SAP without ALI. In addition, 85 putative target genes of the significantly dysregulated mi RNAs were found by Target Scan, mi Randa and Pic Tar. Finally, GO and pathway network analysis showed that they were mainly enriched in signal transduction, metabolic processes, cytoplasm and cell membranes.CONCLUSION This is the first study to identify 12 circulating mi RNAs in patients with SAP with ALI, which may be biomarkers for prediction of ALI after SAP.

Pathogenesis of acute lung injury in rats with severe acute pancreatitis

BACKGROUND: Acute lung injury (ALI) is the most common and severe complication of severe acute pancreatitis (SAP). The elucidation of the mechanism of ALI contributes to the diagnosis and treatment of the illness. In this study, we studied the pathogenesis of ALI in rats with severe acute pancreatitis. METHODS: The rats were sacrificed at 1, 3, 5, 6, 9 and 12 hours after the establishment of the model of SAP. Pancreas and lung tissues were obtained for pathological study, and examination of microvascular permeability and myeloperoxidase (MPO) examination. The gene expressions of tumor necrosis factor-α (TNF-α) and intercellular adhesion molecule-1 (ICAM-1) in the pancreas and lung tissues were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: After the establishment of the SAP model, the degree of pancreatic and lung injury increased gradually along with the gradual increase of MPO activity and micro-vascular permeability. Gene expressions of TNF-α and ICAM-1 in the pancreas rose at 1 hour and peaked at 7 hours. In contrast, their gene expression in the lungs rose slightly at 1 hour and peaked at 9-12 hours. CONCLUSION: An obvious time window existed between SAP and lung injury, which is beneficial to the early prevention of the development of ALI.

Perioperative"remote"acute lung injury:recent update

Perioperative acute lung injury（ALI） is a syndrome characterised by hypoxia and chest radiograph changes.It is a serious post-operative complication,associated with considerable mortality and morbidity.In addition to mechanical ventilation,remote organ insult could also trigger systemic responses which induce ALI.Currently,there are limited treatment options available beyond conservative respiratory support.However,increasing understanding of the pathophysiology of ALI and the biochemical pathways involved will aid the development of novel treatments and help to improve patient outcome as well as to reduce cost to the health service.In this review we will discuss the epidemiology of peri-operative ALI;the cellular and molecular mechanisms involved on the pathological process;the clinical considerations in preventing and managing perioperative ALI and the potential future treatment options.

Acute lung injury and acute respiratory distress syndrome： experimental and clinical investigations

Acute lung injury （ALl） or acute respiratory distress syndrome （ARDS） can be associated with various disorders. Recent investigation has involved clinical studies in collaboration with clinical investigators and pathologists on the pathogenetic mechanisms of ALl or ARDS caused by various disorders. This literature review includes a brief historical retrospective of ALI/ARDS, the neurogenic pulmonary edema due to head injury, the long-term experimental studies and clinical investigations from our laboratory, the detrimental role of NO, the risk factors, and the possible pathogenetic mechanisms as well as therapeutic regimen for ALI/ARDS.

Calycosin attenuates severe acute pancreatitis-associated acute lung injury by curtailing high mobility group box 1-induced inflammation

BACKGROUND Acute lung injury(ALI)is a common and life-threatening complication of severe acute pancreatitis(SAP).There are currently limited effective treatment options for SAP and associated ALI.Calycosin(Cal),a bioactive constituent extracted from the medicinal herb Radix Astragali exhibits potent anti-inflammatory properties,but its effect on SAP and associated ALI has yet to be determined.AIM To identify the roles of Cal in SAP-ALI and the underlying mechanism.METHODS SAP was induced via two intraperitoneal injections of L-arg(4 g/kg)and Cal(25 or 50 mg/kg)were injected 1 h prior to the first L-arg challenge.Mice were sacrificed 72 h after the induction of SAP and associated ALI was examined histologically and biochemically.An in vitro model of lipopolysaccharide(LPS)-induced ALI was established using A549 cells.Immunofluorescence analysis and western blot were evaluated in cells.Molecular docking analyses were conducted to examine the interaction of Cal with HMGB1.RESULTS Cal treatment substantially reduced the serum amylase levels and alleviated histopathological injury associated with SAP and ALI.Neutrophil infiltration and lung tissue levels of neutrophil mediator myeloperoxidase were reduced in line with protective effects of Cal against ALI in SAP.Cal treatment also attenuated the serum levels and mRNA expression of pro-inflammatory cytokines tumor necrosis factor-α,interleukin-6,IL-1β,HMGB1 and chemokine(CXC motif)ligand 1 in lung tissue.Immunofluorescence and western blot analyses showed that Cal treatment markedly suppressed the expression of HMGB1 and phosphorylated nuclear factor-kappa B(NF-κB)p65 in lung tissues and an in vitro model of LPSinduced ALI in A549 cells suggesting a role for HGMB1 in the pathogenesis of ALI.Furthermore,molecular docking analysis provided evidence for the direct interaction of Cal with HGMB1.CONCLUSION Cal protects mice against L-arg-induced SAP and associated ALI by attenuating local and systemic neutrophil infiltration and inflammatory response via inhibition of HGMB1 and the NF-κB signaling pathway.

Drug repurposing of histone deacetylase inhibitors that alleviate neutrophilic inflammation in acute lung injury and idiopathic pulmonary fibrosis via inhibiting leukotriene a4 hydrolase and blocking LTB4 biosynthesis

OBJECTIVE Leukotriene B4(LTB4)biosynthesis and subsequently neutrophilic inflammation may provide a potential strategy for the treatment of acute lung injury(ALI)or idiopathic pulmonary fibrosis(IPF).To provide a potential strategy for the treatment of ALI or IPF,we identified potent inhibitors of Leukotriene A4 hydrolase(LTA4H),a key enzyme in the biosynthesis of LTB4.METHODS In this study,we identified two known histone deacetylase(HDAC)inhibitors,suberanilohydroxamic acid(SAHA)and its analogue 4-(dimethylamino)-N-[7-(hydroxyamino)-7-oxoheptyl]benzamide(M344),as effective inhibitors of LTA4H using enzymatic assay,thermofluor assay,and X-ray crystallographic investigation.We next tested the effect of SAHA and M344 on endogenous LTB4 biosynthesis in neutrophils by ELISA and neutrophil migration by transwell migration assay.A murine experimental model of ALI was induced by lipopolysaccharide(LPS)inhalation.Histopathological analysis of lung tissue using H&E staining revealed the serious pulmonary damage caused by LPS treatment and the effect of the SAHA.We next examined m RNA and protein levels of pro-inflammatory cytokines in lung tissue and bronchoalveolar lavage fluid using q RT-PCR and ELISA to further investigate the underlying mechanisms of anti-inflammatory activities by SAHA.We also investigated the effects of SAHA and M344 on a murine experimental model of bleomycin(BLM)-induced IPF model.RESULTS The results of enzymatic assay and X-ray crystallography showed that both SAHA and M344 bind to LTA4H,significantly decrease LTB4 levels in neutrophil,and markedly diminish early neutrophilic inflammation in mouse models of ALI and IPF under a clinical safety dose.CONCLUSION Collectively,SAHA and M344 would provide promising agents with well-known clinical safety for potential treatment in patients with ALI and IPF via pharmacologically inhibiting LAT4H and blocking LTB4 biosynthesis.

Protective Effect of Curcumin on Endotoxin-induced Acute Lung Injury in Rats

To investigate the protective effect of curcumin on endotoxin-induced acute lung injury in rats, and explore the underlying mechanisms, 24 male Wistar rats were randomly divided into 4 experimental groups： sham-vehicle （S）, sham-curcumin （C）, lipopolysaccharide （LPS）-vehicle （L）, and curcumin-lipopolysaccharide （C-L） groups. The wet/dry （W/D） weight ratio of the lung and bronchoalveolar lavage （BAL） fluid protein content were used as measures of lung injury. Neutrophil recruitment and activation were evaluated by BAL fluid cellularity and myeloperoxidase （MPO） activity in cell-free BAL and lung tissue. The levels of cytokine-induced neutrophil chemoattractant-1 （CINC-1） in lung tissues were measured by ELISA. were observed by using the HE staining. Our results the wet/dry weight ratio and protein content in BALE The histopathological changes of lung tissues showed that lung injury parameters, including were significantly higher in the L group than in the S group （P〈0.01）. In the L group, higher numbers of neutrophils and greater MPO activity in cell-free BAL and lung homogenates were observed when compared with the S group （P〈0.01）. There was a marked increase in CINC-1 levels in lung tissues in response to LPS challenge （P〈0.01, L group vs S group）. Curcumin pretreatment significantly attenuated LPS-induced changes in these indices. LPS caused extensive morphological lung damage, which was also lessened after curcumin pretreatment. All the above-mentioned parameters in the C group were not significantly different from those of the S group. It is concluded that curcumin pretreatment attenuates LPS-induced lung injury in rats. This beneficial effect of curcumin may involves, in part, inhibition of neutrophilic recruitment and activity, possibly through inhibition of lung CINC-1 expression.

Expression of phosphatidylinositol-3 kinase and effects of inhibitor Wortmannin on expression of tumor necrosis factor-α in severe acute pancreatitis associated with acute lung injury

BACKGROUND: Acute lung injury(ALI) is a common and serious complication of severe acute pancreatitis(SAP). The study aimed to investigate the protective effect and mechanism of phosphatidylinositol-3 kinase(PI3K) inhibitor Wortmannin in SAP associated with ALI.METHODS: Ninety rats were randomly divided into three groups: sham operation(SO) group(n=30), SAP group(n=30), and SAP+Wortmannin(SAP+W) group(n=30). SAP model was induced by retrograde injection of 4% sodium taurocholate into the biliopancreatic duct of rats. The rate of lung water content, myeloperoxidase(MPO), matrix metalloproteinase 9(MMP-9), protein kinase B(PKB), abdphosphorylation of protein kinase B(P-PKB) activity in the lung tissue were evaluated.RESULTS: In the SAP group, the p-PKB expression in the lung tissue began to rise at 3 hours after modeling, and peaked at 12 hours(P<0.05); the rate of lung water content, MPO and TNF-α activity were also gradually increased, and the degree of lung lesion gradually increased(P<0.05). In the SAP+Wortmannin group, the p-PKB expression in the lung tissue began to rise at 3 hours after modeling, and peaked at 12 hours; it was higher than that in the SO group(P<0.05), but significantly lower than that in the SAP group(P<0.05). The rest indicators in the SAP+Wortmannin group were also significantly decreased as compared with the SAP group(P<0.05).CONCLUSIONS: The expression of phosphatidylinositol-3 kinase/protein kinase B was elevated in severe pancreatitis rats with lung injury. This suggested that PI3 K signal transduction pathway is involved in the control and release of proinfl ammatory cytokines TNF-α, which may play an important role in the pathogenesis of severe acute pancreatitis associated with lung injury. This finding indicated that Wortmannin can block the PI3 K signal transduction pathway, and inhibit the release of infl ammatory factor TNF-α.

Crotalaria ferruginea extract attenuates lipopolysaccharide-induced acute lung injury in mice by inhibiting MAPK/NF-κB signaling pathways

Objective:To evaluate the anti-inflammatory activity of Crotalaria ferruginea extract(CFE)and its mechanism.Methods:An intratracheal lipopolysaccharide(LPS)instillationinduced acute lung injury(ALI)model was used to study the antiinflammatory activity of CFE in vivo.The LPS-induced shock model was used to analyze the effect of CFE on survival.LPS-stimulated RAW264.7 cell model was used to investigate the anti-inflammatory activity of CFE in vitro and the effects on mitogen-activated protein kinase(MAPK)or nuclear factor-κB(NF-κB)signaling pathways.Results:CFE administration decreased the number of inflammatory cells,reduced the levels of tumor necrosis factor-α(TNF-α),monocyte chemotactic protein-1(MCP-1),interleukin-6(IL-6),and interferon-γ,and diminished protein content in the bronchoalveolar lavage fluid of mice.CFE also reduced lung wet-to-dry weight ratio,myeloperoxidase,and lung tissue pathological injury.CFE preadministration improved the survival rate of mice challenged with a lethal dose of LPS.CFE reduced LPS-activated RAW264.7 cells to produce nitric oxide,TNF-α,MCP-1,and IL-6.Furthermore,CFE inhibited nuclear translocation and phosphorylation of NF-κB P65,extracellular signal-regulated kinase,c-Jun N-terminal kinases,and P38 MAPKs.Conclusions:CFE exhibits potent anti-inflammatory activity in LPS-induced ALI mice,LPS-shock mice,and RAW264.7 cells,and its mechanism may be associated with the inhibition of NF-κB and MAPK signaling pathways.Crotalaria ferruginea may be a useful therapeutic drug for the treatment of ALI and other respiratory inflammations.

Lipocalin-2 Test in Distinguishing Acute Lung Injury Cases from Septic Mice Without Acute Lung Injury

Objective To explore whether the amount of lipocalin-2 in the biofluid could reflect the onset of sepsis-induced acute lung injury(ALI) in mice. Methods Lipopolysaccharide(LPS, 10 mg/kg) injection or cecal ligation and puncture(CLP) was performed to induce severe sepsis and ALI in C57 BL/6 male mice randomly divided into 5 groups(n=10 in each group): group A(intraperitoneal LPS injection), group B(intravenous LPS injection via tail vein), group C(CLP with 25% of the cecum ligated), group D(CLP with 75% of the cecum ligated), and the control group(6 sham-operation controls plus 4 saline controls). All the mice received volume resuscitation. Measurements of pulmonary morphological and functional alterations were used to identify the presence of experimental ALI. The expressions of lipocalin-2 and interleukin(IL)-6 in serum, bronchoalveolar lavage fluid(BALF), and lung tissue were quantified at both protein and mRNA levels. The overall abilities of lipocalin-2 and IL-6 tests to diagnose sepsis-induced ALI were evaluated by generating receiver operator characteristic curves(ROC) and computing area under curve(AUC). Results In both group B and group D, most of the "main features" of experimental ALI were reproduced in mice, while group A and group C showed septic syndrome without definite evidence for the presence of ALI. Compared with septic mice without ALI(group A+group C), lipocalin-2 protein expression in septic mice with ALI(group B+group D) was significantly up-regulated in BALF(P<0.01) and in serum(P<0.01), and mRNA expression boosted in lung tissues(all P<0.05). Lipocalin-2 tests performed better than IL-6 tests in recognizing sepsis-induced ALI cases, evidenced by the larger AUC of the former(BALF tests, 0.8800 versus 0.6625; serum tests, 0.8500 versus 0.7000). Using a dual cutoff system to diagnose sepsis-induced ALI, BALF lipocalin-2 test exhibited the highest positive likelihood ratio(13.000) and the lowest negative likelihood ratio(0.077) among the tests of lipocalin-2 and IL-6 in blood and BALF. A statistically significant correlation was found between lipocalin-2 concentration in BALF and that in serum(Spearman r=0.8803,P<0.0001). Conclusions Lipocalin-2 expression is significantly up-regulated in septic ALI mice compared with those without ALI. Lipocalin-2 tests with a dual cutoff system could be an effective tool in distinguishing experimental ALI cases.