Effect of pulmonary vascular endothelial cells on the development of acute lung injury in rats

AIM: Effect of endothelial cell on the development of acute lung injury and the prevention of dexamethasone in acute lung injury were observed.METHODS:Rats were divided into three groups:1.Control group.2.LPS group:Venous injection with LPS(5mg/kg body weight),execute respectively at 1 h,2 h,6 h and 24 h after LPS injection. 3.dexamethasone group:intraperitoneal injection with dexamethasone ,1 h before LPS injection,execute after 2 hours after LPS injection.RESULTS: Serum NO,TNF-α levels,lung iNOS activity and lung ICAM-1mRNA expression were increased( P <0.05, P <0.01, vs control group),but serum ACE was decreased( P <0.01).Dexamethasone could improve all the changes above mentioned.CONCLUSION:Endothelial cell played a vital role in the development of acute lung injury and dexamethasone could prevent acute lung injury.     

Colquhounia root tablet inhibits the expression of adhesion molecule in acute lung injury of rats

AIM: To study the effects of colquhounia root tablet on the expression of adhesion molecule in acute lung injury of rats.METHODS: The rats were divided into 3 groups: ALI group,colquhounia root tablet＋ALI group and control group .ALI animal model was performed by treatment with oleic acid.The positive expression rates of CD11a,CD11b and CD18 in polymorphonuclear neutrophils and monocytes were analyzed by flow cytometry.ICAM-1 expression in lung tissue was determined by immunohistochemistry,histopathological examination and biological markers were measured from lung specimens.RESULTS: Colquhounia root tablet decreased the expression of CD11a,CD11b and CD18 in polymorphonuclear neutrophils and monocytes,and ICAM-1 in lung tissue (P<0.01),pathologic changes and the biological markers of ALI significantly ameliorated.CONCLUSION: The increase in the expression of CD11a/CD18 and CD11b/CD18 in polymorphonuclear neutrophils and monocytes,and expression of ICAM-1 in lung tissues of ALI may be involved in the formation of ALI.Colquhounia root tablet effectively ameliorates the lung damage,mechanism of which may be related to inhibition of adhesion molecule expression.     

Vinpocetine injection attenuates lipopolysaccharide-induced acute lung injury in rats

AIM:To observe the inhibitory effects of vinpocetine injection on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in the rats and to explore the underlying mechanisms.METHODS:Male Wistar rats (n=50) were randomly divided into 5 groups:control group,ALI model group,and low,medium and high doses of vinpocetine treatment groups.The rats in control group were injected with 0.9% NaCl at 5 mL/kg through femoral vein.The rats in ALI model group received LPS at 10 mg/kg through femoral vein.After injected with LPS,the rats in vinpocetine treatment groups received vinpocetine at 0.2 mg/kg,0.7 mg/kg or 1.2 mg/kg via intraperitoneal injection.The pathological changes of the lung tissues were observed under microscope with HE staining.The cell apoptosis in the lung tissues was detected by TUNEL staining.Myeloperoxidase (MPO) activity was measured by the method of spectrophotometry.The protein expression of NF-κB,ICAM-1,VCAM-1,Bax and Bcl-2 was determined by Western blot.RESULTS:Compared with ALI group,administration of vinpocetine significantly attenuated the structural injury of the lung and the infiltration of inflammatory cells.Moreover,vinpocetine decreased cell apoptosis and MPO activity in the lung tissues of ALI rats.In addition,the protein expression of NF-κB,ICAM-1,VCAM-1 and Bax was inhibited after vinpocetin treatment,whereas Bcl-2 expression was increased.CONCLUSION:Vinpocetine attenuates LPS-lung injury by reducing MPO activity and regulating NF-κB,ICAM-1,VCAM-1,Bax and Bcl-2 protein expression.     

Effects of dexamethasone on acute lung injury by inhibiting renin-angiotensin system in rats

AIM:To explore the relationship between renin-angiotensin system (RAS) and acute lung injury (ALI) in rats, and the effect of dexamethasone (DEX) on RAS was observed.METHODS: The rat model of ALI was induced by hemorrhagic shock and LPS administered intraperitoneally. The changes of MAP and the effects of DEX on MAP were observed. The mRNA expressions of ACE, AGT, AT1 and AT2 in lung tissue were assayed by RT-PCR. The changes of Ang I and Ang II in the serum and the effects of DEX on them were observed.RESULTS: The increasing of MAP was statistically obvious. MAP in hemorrhagic shock+LPS (HL) group recovered more slowly than that in HL+DEX(HLD) group. ACE, AGT, AT1 and AT2 mRNA expressions in HL group were increased, and higher than those in HLD group. The change of Ang II in serum in HL group was obviously higher than that in HLD group, while that of Ang I was not obvious.CONCLUSION:ALI activates RAS in rat lung, and promotes the production of Ang II then aggravates the injury of lung through increasing the expression of ACE and AGT. DEX decreases expression of Ang II.     

Role of macrophage and intercellular adhesion molecule-1 in the pathogenesis of oleic-acid-induced rat acute lung injury

AIM: To investigate the role of infiltration of macrophages and expression of intracellular adhesion molecule-1 in the pathogenesis of oleic-acid-induced acute lung injury rats. METHODS:The rats were subjected to injection of oleic acid (oleic acid group) or saline solution (control). After injecting oleic acid or saline for 4 hours, the PaO₂ of the left heart, lung permeability index(LPI), the number of macrophage and the levels of soluble intercellular molecule-1 (sICAM-1) in the bronchial alveolar lavage fluid (BALF) were measured. The levels of expression of ICAM-1 mRNA were evaluated by in situ hybridization and the degree of macrophage infiltration and the expression of ICAM-1 were evaluated by double staining immunocytochemistry. RESULTS:The PaO₂ of the oleic acid group was significantly lower than that of the control group (P＜0.01) and the LPI of the oleic acid group was significantly higher than that of the control group (P＜0.01). The cell number of macrophage and sICAM-1 level were significantly higher in the oleic acid group than those of the control group (P＜0.01). There were marked upregulation of ICAM-1 mRNA expression in injuried lung tissue compared with the normal lung tissue. Furthermore, the infiltrated number of macrophage and the level of ICAM-1 expression showed strong positive correlation with the lung injury parameters, PaO₂ and LPI.CONCLUSION:The infiltration of macrophage may play a pivotal role in the pathogenesis of progressive lung injuries induced by intravenous oleic acid injection,ICAM-1 may mediate the infiltrat ion and adhesion of macrophage in the injuried lung t issue and contribute to the development of acute lung injury.     

Effects of ambroxol combined with low-dose heparin on production of ICAM-1 and E,P-selectin in acute lung injury

AIM: To study the production of intercellular adhesion molecule-1(ICAM-1), E-selectin and P-selectin in serum, lung tissues and bronchoalveolar lavage fluid(BALF)of acute lung injury(ALI) model and to observe the effects of ambroxol combined with low-dose heparin on the changes of the 3 factors above.METHODS: Twenty-four healthy rabbits were randomly divided into 3 groups: normal saline control group (NC), oleic acid injury group (OA), ambroxol+ heparin treatment group (AH). The rabbit ALI model was induced by oleic acid injection through auricular vein. Partial pressure of O₂ in artery(PaO₂) was analyzed.The concentrations of ICAM-1 and E-selectin were detected by ELISA.The apoptosis index(AI) was measured by TUNEL method.The expression of P-selectin was determined by immunohistochemical method.The ultrastructural changes of the lung tissues were observed under electron microscope, and the lung wet/dry ratio(W/D) was calculated.RESULTS: PaO₂ in AH group and OA group was significantly lower (P<0.01) than that in NC group, and PaO₂ in AH group was significantly higher than that in OA group (P<0.01). The concentrations of ICAM-1 and E-selectin in serum, lung tissues and BALF, and AI and W/D in lung tissues in AH group were higher (P<0.05 or P<0.01) than those in NC group, and was lower than those in OA group (P<0.05 or P<0.01). In NC group, no significant change of the above parameters at all time points was observed (P>0.05). In OA group, PaO₂ was significantly decreased (P<0.01) with the pathological process developed, and the concentrations of ICAM-1 and E-selectin were significantly increased. In AH group, PaO₂ was decreased (P<0.05),and the concentrations of ICAM-1 and E-selectin were increased with the process of ALI developed. The P-selectin expression in lung tissues of OA group was distributed mainly in inflammatory cells, capillary endothelial cells and plasma. From low to high levels, the order was NC group < AH group < OA group in the expression of P-selectin. The most obvious apoptosis was observed in OA group. No apoptosis or occasional positive cells were found in NC group. The apoptotic rate in AH group was significantly reduced compared with that in OA group.CONCLUSION: In ALI induced by OA, ICAM-1, E-selectin and P-selectin are significantly increased and are involved in the occurrence and development of ALI. Ambroxol combined with low-dose heparin reduces the levels of ICAM-1, E-selectin and P-selectin, the pulmonary edema and the lung injury, improves pulmonary functions, and plays an important role in the prevention and treatment of acute lung injury.     

Protective role of endogenous hydrogen sulfide in cholecystokinin octapeptid against acute lung injury induced by lipopolysaccharide

AIM: To explore the role of endogenous hydrogen sulfide (H₂S) in the mechanism of cholecystokinin octapeptide (CCK-8) to alleviate acute lung injury (ALI) induced by lipopolysaccharide (LPS). METHODS: Eighty-four Sprague-Dawley rats were randomly divided into seven groups: control, LPS (instilled intratracheally to reproduce the model of ALI), NaHS (H₂S donor) +LPS, propargylglycine ［inhibitor of cysathionine-γ-lyase (CSE), PPG］+LPS, CCK-8+LPS, PPG+CCK-8+LPS and CCK-8 group. Animals were sacrificed at 4 h and 8 h after agent instillation. The wet and dry ratio (W/D) of the lung weight was measured and calculated. Morphological changes of lung tissues were observed. H₂S concentration in plasma, malondialdehyde (MDA) content, myeloperoxidase (MPO) and CSE activities in the lung were determined. Furthermore, the level of P-selectin of lung tissue was measured by radioimmunoassay, the CSE mRNA expression in the lung was detected by RT-PCR, and the protein content in bronchoalveolar lavage fluid (BALF) was detected. RESULTS: Compared with control, severe injury of lung tissues and increase in W/D, protein content in BALF, MDA content, MPO activity and P-selectin level in the lung were observed in rats treated with LPS. LPS also lead to a drop in plasma H₂S concentration, lung CSE activity and CSE mRNA expression. Administration of NaHS before LPS could attenuate the changes induced by LPS, while H₂S concentration, CSE activity and CSE mRNA expression were higher than those in LPS group. However, pre-treatment with PPG exacerbated the lung injury induced by LPS, H₂S concentration, CSE activity and CSE mRNA expression were lower than those in LPS and CCK-8 +LPS group, respectively. CONCLUSION: CCK-8 attenuates LPS-induced acute lung injury by means of anti-oxidation and inhibition of PMN adhesion and aggregation, both of which are mediated by endogenous H₂S.     

Role of heme oxygenase in cholecystokinin octopeptide ameliorating acute lung injury induced by lipopolysaccharide

AIM: To study the role of heme oxygenase (HO)-1 in the mechanism of cholecystokinin-octapeptide (CCK-8) for attenuation of acute lung injury (ALI) induced by lipopolysaccharide (LPS).METHODS: Adult male rats were randomly divided into five groups: control group,LPS group,CCK-8+LPS group,LPS+ Hm (hemin,HO-1 donor) group and LPS+ZnPP (zinc protoporphyrin,specific inhibitor of HO-1) group.PMN number in bronchoalveolar lavage fluid (BALF),the structure of the lung,MDA content,HO-1 activity,the expressions of HO-1 mRNA and protein in the lung were detected respectively.RESULTS: The lung injury in LPS group was observed,at the same time the numbers of PMN,the content of MDA,the activity and the expression of HO-1 were all higher than those in control group (all P<0.05).The degree of lung injury,PMN numbers and MDA content were lower,while the activity and the expression of HO-1 in CCK-8+LPS and LPS+Hm group were higher than those in LPS group (all P<0.05).However,the degree of lung injury,PMN numbers and MDA content were higher,the activity and the expression of HO-1 were lower in LPS+ZnPP than those in LPS group respectively (all P<0.05).CONCLUSION: CCK-8 attenuates the LPS-induced ALI by means of anti-oxidation and inhibits PMN aggregation,which are both mediated by HO-1 partly.     

Changes of pulmonary apoptosis and NOS mRNA in the lipopolysaccharide-induced acute lung injury

AIM: To observe the chronological changes of pulmonary apoptosis and the expression of iNOS mRNA,nNOS mRNA and eNOS mRNA in lipopolysaccharide (LPS)-induced acute lung injury (ALI) and to investigate the mechanisms of ALI.METHODS: Rats were randomly divided into 2 groups: control group and LPS treated group.The rats were injected with either saline or LPS and killed at 1,3,6,9 and 12 h after LPS injection.The expressions of iNOS mRNA,nNOS mRNA and eNOS mRNA in the lung tissue were respectively measured with RT-PCR methods.Apoptosis and expressions of Bcl-2 and Bax were respectively determined by flow cytometry (FCM) and immunohistochemistry (IHC).The pathological changes of lung tissue were observed under light and electron microscope.RESULTS: Compared with that in control group,the expression of iNOS mRNA was significantly increased at 3,6,9 and 12 h after administration of LPS (P<0.05).The eNOS mRNA was significantly decreased at 3,6,9 and 12 h after administration of LPS (P<0.05).The nNOS mRNA had no significant change during the 12 h in LPS group.Degree of ALI was gradually worsened after administration of LPS.Apoptosis of pulmonary cells was significantly increased,and reached the top level at 9 h after administration of LPS (P<0.01).The expression of Bcl-2 was markedly decreased and the expression of Bax was significantly enhanced in alveolar and airway epithelial cells in LPS treated group.CONCLUSION: The expressions of iNOS mRNA,eNOS mRNA and nNOS mRNA are not identical in LPS-induced acute lung injury.NOS regulates the apoptosis of pulmonary cells through affecting the balance of Bcl-2 and Bax.     

The protective effect of anti-macrophage migration inhibitory factor monoclonal antibody on oleic-acid-induced acute lung injury

AIM: To investigate the protective effect of anti-macrophage migration factor monoclonal antibody (anti-MIF MAb) on oleic-acid-induced acute lung injury (ALI) rats and its influence on the expression level of MIF and intercellular adhesion molecule-1(ICAM-1). METHODS: The rats were subjected to injection of oleic acid (oleic acid group) or saline solution (control group). One hours before administration of oleic acid, the rats were intraperitoneally injected with anti-MIF antibody (5 mg/kg) as the treatment group. After injecting oleic acid or saline for 4 hours, the PaO₂, lung permeability index (LPI), the number of macrophage and the level of soluble ICAM-1 (sICAM-1) in the bronchial alveolar lavage fluid (BALF) were measured. The expression level of MIF mRNA and ICAM-1 mRNA in the lung were detected by in situ hybridization, and the degree of macrophage infiltration and the expression of MIF were evaluated by double staining immunocytochemistry. RESULTS: The PaO₂ of the oleic acid group was far lower than those of the control and treatment group (P<0.01). The LPI of the oleic acid group was significantly higher than those of the control and treatment group (P<0.01). The sICAM-1 level in BALF were significantly higher than those of the control and treatment groups (P<0.01). There were marked up-regulation of MIF mRNA and ICAM-1 mRNA expression in ALI lung compared with the normal lung tissue. After pretreatment with anti-MIF antibody, the MIF expression was down-regulation in association with a marked reduction of macrophage infiltration. However, pretreatment with anti-MIF antibody did not interfere the expression level of ICAM-1. CONCLUSION: MIF and ICAM-1 may mediate the infiltration and adhesion of macrophage in injuried lung tissue, which play a pivotal role in the pathogenesis of progressive lung injuries induced by intravenous oleic acid. Pretreatment with anti-MIF antibody showed lung protective effect by blockage of MIF expression in association with reduction of macrophage infiltration and improvement in histological damage.     

Influence of glycine on LBP mRNA expression induced by LPS in the liver of rats

AIM:To study the influence of glycine(GLY) on lipopolysaccharide-binding protein(LBP) mRNA expression induced by LPS.METHODS:The level of LBP mRNA expression in liver tissues of rats was examined by RT-PCR, and the effects of glycine on LBP mRNA expression in liver tissues of rats induced by LPS were investigated.RESULTS: The level of LBP mRNA expression in hepatic tissue of rats in the LPS group was significantly higher than that in the control group(P＜0.01), the level of LBP mRNA expression in the hepatic tissue of rats in the LPS+GLY group was lower than that in the LPS group(P＜0.01).CONCLUSION:LPS can induce LBP mRNA expression in the hepatic tissue of rats, glycine can inhibit LBP mRNA expression in the hepatic tissue of rats treated by LPS.     

Effects of caveolin-1 scaffolding domain peptide on LPS-induced acute lung injury in mice

AIM: To investigate the effects of caveolin-1 (Cav-1) scaffolding domain peptide, cavtratin, on lipopolysaccharide (LPS)-induced mouse acute lung injury and heme oxygenase-1 (HO-1) activity. METHODS: Adult male BALB/c mice were randomly divided into 6 groups (n=8 to 10):control, Antennapedia internalization sequence (AP), LPS, LPS+hemin, LPS+ hemin+cavtratin and LPS+hemin+cavtratin+zinc protoporphyrin IX (ZnPP) groups. After LPS administration for 24 h, the lung pathological changes, the wet/dry weight (W/D) ratio of lung tissues, total cell number in bronchoalveolar lavage fluid and serum lactate dehydrogenase activity were measured. The co-localization of HO-1 and Cav-1 was displayed by immunofluorescence, and the HO-1 activity were detected. The mRNA expression of pro-inflammatory cytokines IL-1β, IL-6, TNF-α, MCP-1 and iNOS was detected by real-time PCR. RESULTS: The mice in LPS+hemin+cavtratin group had the decreased interaction between HO-1 and Cav-1, and the increased HO-1 activity compare with LPS group (P<0.05). Compared with LPS group, the pulmonary damage was attenuated in LPS+hemin+cavtratin group, and the injury indexes, including W/D ratio, total cell number in bronchoalveolar lavage fluid and lactate dehydrogenase activity in the serum, and the mRNA expression of inflammatory cytokines all decreased (P<0.05). HO-1 activity inhibitor ZnPP abolished the above protective effect of cavtratin on the lung tissues with LPS-induced acute lung injury. CONCLUSION: Cavtratin has beneficial effects on the lung with LPS-induced acute injury by restoring the HO-1 activity.     

Inhibitory effects of Angelicae sinensis and sodium ferulate on acute inflammatory liver injury and expression of ICAM-1 and E-selectin in mice

AIM: To explore the effects of Angelicae sinensis preparation and sodium ferulate on inflammatory liver injury induced by lipopolysaccharide (LPS) and their molecule mechanism. METHODS: ICR mice were divided into five groups: Angelicae sinensis group, sodium ferulate group, dexamethasone group, inflammation control group and normal group. The model of inflammatory injury in mice was set up by tail vein injection with the bacillus calmette-guerin (BCG) and LPS respectively prior and posterior to administration of those tested drugs. The tested drugs (the preparations of Angelica sinensis, sodium ferulate and dexamethasone) and normal saline were given respectively to the corresponding group. The pathological observation of the liver tissues in mice was made for the intensity of inflammatory liver injuries. The immunohistochemical detection and comparison were performed for the expression of ICAM-1 and E-selectin proteins in the liver tissues in those mice. RESULTS: The intensities of liver inflammatory injuries in mice from drug-treated groups were obviously lighter than that from the inflammation control group (P<0.01). The expressions of ICAM-1 and E-selectin proteins in the liver tissues of mice from the inflammation control group were not only significantly higher than that in normal control, but also obviously higher than that from drug-treated groups (P<0.01). CONCLUSIONS: Angelica sinensis and sodium ferulate alleviate inflammatory liver injury induced by injection of LPS. Their suppressive effects on inflammatory liver injury may be associated with the decrease in the expression of ICAM-1 and E-selectin proteins.     

Protective effect of Auricularia auricular-judae polysaccharide on pulmonary tissues of rats with LPS-induced acute lung injury

AIM: To investigate the effects of Auricularia auricular-judae polysaccharide(AAP) on pulmonary tissues of rats with LPS-induced acute lung injury(ALI) and its mechanisms.METHODS: Adult Sprague-Dawley rats were randomly divided into control group, LPS group,low-dose AAP group, middle-dose AAP group, high-dose APP group, and dexamethasone group. The rats were injected with LPS(8 mg/kg, ip) to induce ALI. The rats in the AAP groups were treated with AAP for 7 d before the induction of ALI. The protein concentration in the bronchoalveolar lavage fluid(BALF) was measured. The lung edema degree was measured by detecting the wet/dry weight ratio. The myeloper-oxidase(MPO), total antioxidant capacity(T-AOC), total superoxide dismutase(T-SOD), nitric oxide synthase(NOS) and malondialdehyde(MDA) levels were determined. The pathological changes of the lung tissues were evaluated by HE staining.RESULTS: Treatment with AAP significantly improved LPS-induced lung pathological changes, attenuated the protein concentration in the BALF and wet/dry weight ratio, inhibited the activities of MPO and NOS, reduced MDA level and increased the activities of T-AOC and T-SOD.CONCLUSION: AAP protects against LPS-induced acute lung injury in rats.     

会讯

AIM:To investigate the pulmonary expresson of macrophage migration inhibitory factor(MIF) in acute lung injury (ALI) rats induced by intravenous injection of oleic acid and its correlation with blood gas change, pulmonary weight index (PWI) and pulmonary pathological injuries.METHODS: ALI rats model were made by injecting oleic acid as the oleic acid group while rats injection with saline solution as control. After injecting oleic acid or saline for six hours, the PaO₂ and PaCO₂ of the left heart and pulmonary weight index were measured. At the same time, by using a microwave-base double immunohistochemistry labeling, the number of MIF^＋, ED₁⁺ (anti-CD68 antibody), ED₁⁺/MIF^＋cell in pulmonary tissue of different groups and their correlation with blood gas and pulmonary weight index were examined. RESULTS: The blood gas parameters of the oleic acid group were far worse than that of the control group (P＜0.01). The PWI of the oleic acid group was significantly higher than that of the control group (P＜0.01). There was marked upregulation of MIF expression on injured lung tissue. The number of cell expressed MIF^＋ , ED₁⁺ and MIF with ED₁ showed a strong positive correlation with PaO₂, PWI and histological changes. CONCLUSION: MIF may play a pivotal role in mediation of progressive lung injuries induced by intravenous oleic acid injection. In addition, the number of cells expressed MIF, especially macrophage, may reflect the severity of lung injury.     

Effects of neutrophil extracellular traps on acute lung injury in neonatal rats

AIMTo investigate the role of neutrophil extracellular traps (NETs) in neonatal rats with acute lung injury (ALI). METHODSThirty 7-day-old SD rats were randomly divided into normal saline control group, ALI group and ALI+deoxyribonuclease (Dnase) group (each n=10). The rats in ALI group were intraperitoneally injected with lipopolysaccharides (LPS) at 20 mg/kg, and the rats in ALI+Dnase group were intraperitoneally injected with Dnase at 5 mg/kg after LPS injection. After 6 h, the rats were anesthetized with chloral hydrate, bronchial alveolar lavage fluid (BALF) was collected, and the content of cell-free DNA (cf-DNA) in BALF was detected by fluorescence microarray. The right lung tissues were fixed in 4% paraformaldehyde, and the morphological structure of the lung tissues were observed by HE staining. The content of interleukin-6 (IL-6) and tumor necrosis factor-α （TNF-α） in the left lung homogenate was measured by ELISA. Immunofluorescence and Western blot were used to detect the production of citrullinated histone H3 (CitH3) and myeloperoxidase (MPO) in the rat lung tissues. RESULTSCompared with control group, the levels of cf-DNA, CitH3, MPO, IL-6 and TNF-α in lung tissues of neonatal rats in ALI group and ALI+Dnase group were all increased (P<0.05), and severe inflammatory infiltration in the lung tissues was observed. Compared with ALI group, the levels of cf-DNA, CitH3, MPO, IL-6 and TNF-α in ALI+Dnase group were decreased (P<0.05), and the inflammatory infiltration was attenuated. CONCLUSION In neonatal rats with ALI, the level of NETs is an important indicator of lung tissue injury, and NETs may be a new target for the treatment of neonatal ALI.     

Glucocorticoid attenuates LPS-induced acute lung injury by inhibiting p38MAP kinase in rats

AIM: To examine the role of glucocorticoid receptor (GR) in regulation of lipopolysaccharide (LPS)-induced lung injury. METHODS:Male Sprague-Dawley rats were divided into six groups randomly: control group (n=6), LPS group (n=6 each), Dex+LPS group (n=6 each), RU486 group (n=6), RU486+LPS group (n=6 each) and RU486+Dex+LPS group (n=6 each). All groups were subjected into 1 h, 3 h, 6 h and 12 h time point subgroups after LPS administration, except of control group and RU486 group. The concentrations of TNF-α and IL-6 in bronchoalveolar lavage fluids (BALF) were detected by ELISA. The histopathologic changes of lung tissues, the activation of p38MAPK and the expression of MKP-1 in lung tissue were also observed. Further, to confirm the role of GR in this model, the mortality of rats in LPS group vs RU486+LPS group and in Dex+LPS group vs RU486+Des+LPS group was compared. RESULTS: LPS induced lung injury and the secretions of TNF-α and IL-6 in BALF, which were significantly enhanced by pretreatment of RU486 (P<0.05). RU486 pretreatment also significantly increased the LPS-induced lethality (P<0.05). Dexamethasone attenuated LPS-induced lung damage, cytokine release and mortality rates, and the protective effects might be mediated by GR. Western blotting analysis showed dexamethasone inhibited the phosphorylation of p38MAPK in lung tissues by induction of MKP-1, and these actions were also GR dependent. CONCLUSION: GR plays an essential role in regulation of LPS-induced acute lung injury. Anti-inflammatory effects of hormone-activated GR may be mediated by inhibition of p38MAPK phosphorylation/activation, which is associated with the induction of MKP-1.     

Protective effect of HSF1 on mice with LPS-induced acute lung injury and screening of relevant differentially-expressed genes

AIM: To study the protective effect of heat shock factor1 (HSF1) on the mice with lipopolysaccharide (LPS)-induced acute lung injury (ALI), and to screen the relevant differentially-expressed genes. METHODS: ALI mouse model was established by LPS intracheal instillation. The macroscopic and pathological changes of the lung tissue were observed, and the concentrations of total protein, TNF-α, IL-β, IL-6 and VEGF in the bronchoalveolar lavage fluid (BALF) were analyzed. Differentially-expressed genes in the lung tissues of HSF1^+/+ mice and HSF1^-/- mice with ALI induced by LPS were screened by gene chips. The key gene was verified by real-time qPCR. RESULTS: The macroscopic and pathological changes of the lung injury in HSF1^-/-+LPS mice were more serious than those in HSF1^+/++LPS mice. The concentrations of total protein, VEGF, TNF-α, IL-1β and IL-6 in the BALF of HSF1^-/-+LPS mice were significantly higher than those of HSF1^+/++LPS mice (P<0.05). Compared with the HSF1^+/+ mice, a total of 918 differentially-expressed genes were indentified in the HSF1^-/- mice, among which the expression levels of 65 genes had obvious diffe-rence, with 28 genes up-regulated, including Atg7, ccr1, cxcr2, Tbl1xr1, Mmp9, Pparg, Plcb2, Arrb2, Cntn1, Col4a6, etc, and 37 genes down-regulated, including Fgfr1, Fgfr2, Map4k4, Ddx58, Tfg, Stat3, Smad4, Lamc1, Sdc3, etc. The results of real-time qPCR showed that the mRNA level of CXCR2 in HSF1^-/-+ LPS mice was significantly higher than that in HSF1^+/++ LPS mice, which was consistent with the results of gene chips. CONCLUSION: HSF1 has protective effect on the mice with LPS-induced ALI. CXCR2 may be involved in the protective effect of HSF1 on this process.     

Sphingosine-1-phosphate receptor-2 attenuates lipopolysaccharide-induced acute lung injury

AIM: To investigate the effects and mechanisms of sphingosine-1-phosphate receptor-2 (S1P2R)on lipopolysaccharide (LPS)-induced acute lung injury (ALI). METHODS: ALI model was induced by intratracheal administration of LPS in both wild-type mice and S1P2R -deficient mice. The pathological changes in the lung tissues were observed, and the protein concentration, total cell number, neutrophil ratio, TNF-α level and IL-6 level were determined in the bronchoalveolar lavage fluid (BALF) 24 h after LPS injection. In order to investigate the mechanisms of S1P2R in LPS-induced ALI, 10 min before LPS injection, both wild-type mice and S1P2R -deficient mice were injected with nitric oxide synthase inhibitor by tail vein injection, the pathological changes of the lung tissues were observed, and the protein concentration and total cell number in BALF were determined 12 h after LPS injection. RESULTS: Compared with wild-type mice, S1P2R -deficient mice showed more severe LPS-induced ALI, and the protein concentration, neutrophils and inflammatory cytokines in BALF were significantly increased in S1P2R -deficient mice. Administration of nitric oxide synthase inhibitor N^ω-L-nitro-arginine methyl ester protected S1P2R -deficient mice from aggravation of ALI. CONCLUSION: S1P2R mediates the protection from LPS-induced ALI possibly through inhibiting nitric oxide synthase.