OBJECTIVE: To explore the protective effect of noninvasive limb ischemic preconditioning (N-LIP) on acute lung injury (ALT) induced by lipopolysaccharide (LPS) in rats. METHODS: Fifteen female SD rats were randomly divided into a control group, an acute lung injury group (ALI group), an acute lung injury and noninvasive limb ischemic preconditioning group (ALI+N-LIP group). After ALI rats were treated with N-LIP, the changes of airway resistance (AR) and dynamic compliance (Cdyn) were tested by invasive pulmonary function system and recorded. Blood samples and bronchoalveolar lavage fluid (BALF) were collected, the amounts of white blood cell (WBC) in BALF were counted by cytometry, and the level of lactate dehydrogenase (LDH) in BALF was also examined by automatic biochemistry analyzer. The level of serum superoxide dismutase (SOD) and malondialdehyd (MDA) was examined by chromatometry. The lung tissues were acquired to observe the expression of pulmonary surfactant-associated protein-A (SP-A) and pathological changes. RESULTS: After being stimulated by methacholine (Mch), the increasing rate of AR and decreasing rate of Cdyn in the ALI+N-LIP group were less than those in the ALI group (P<0.01). The levels of WBC and LDH in BALF in the ALI+N-LIP group were much lower than those in the ALI group (P<0.05). Meanwhile, the activity of serum SOD in the ALI+N-LIP group was higher, and the level of serum MDA was lower than that in the ALI group (P<0.05). The expression of SP-A in the lung tissue in the ALI+N-LIP group was the highest in the 3 groups, while that in the ALI group was the weakest (P<0.01). Injury of the lung tissue in the ALI+N-LIP group was less than that in the ALI group, but more severe than that in the control group. CONCLUSION N-LIP has protective effect on acute lung injury induced by LPS in rats. The possible mechanism is related to improving the secretion of SP-A and antioxidation.
Acute Lung Injury ; chemically induced ; complications ; prevention & control ; Animals ; Female ; Ischemia ; complications ; physiopathology ; Ischemic Preconditioning ; methods ; Lipopolysaccharides ; Lower Extremity ; blood supply ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo explore the protective mechanism of Nervilia fordii (NF) by observing the effect of its pretreatment on lung aquaporin 1 and 5 (AQP-1, AQP-5) expression in rats with endotoxin-induced acute lung injury (ALI).

METHODSTwenty-four SD rats were randomly divided into 3 groups, the normal group (A), the NF pre-intervention group (B) and the endotoxin model group (C). Rats in Group B and C were made into ALI by endotoxin (5 mg/kg) injection via sublingual vein, and NF pretreatment was applied to Group B. Animals were sacrificed at the 8 h after modeling, their lung were taken for observing the water permeability change by wet/dry weight ratio (W/D) measuring, pathological feature by HE staining, and the expression of AQP-1, AQP-5 was detected by immunohistochemistry and RT-PCR.

RESULTSThe W/D ratio of lung was higher in model rats than in normal rats, but as compared with Group C, it was significantly lower (P < 0.05) in Group B. The pulmonary edematous change was significantly mild and the AQP-1 and AQP-5 protein expressions were significantly higher in Group B than in Group C (P < 0.05).

CONCLUSIONNF pretreatment can promote lung AQP-1 and AQP-5 expression up-regulation, increase lung water clearance and transportation to improve the water balance and eliminate pulmonary edema, so as to effectively protect lung from acute injury.

Acute Lung Injury ; chemically induced ; drug therapy ; prevention & control ; Animals ; Aquaporin 1 ; metabolism ; Aquaporin 5 ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Endotoxins ; Female ; Lung ; metabolism ; Male ; Phytotherapy ; Rats ; Rats, Sprague-Dawley ; Up-Regulation

OBJECTIVETo investigate the effects and the mechanisms of L-Arginine (L-Arg), the critical substrate for nitric oxide (NO) production, on pulmonary inflammatory cytokine expression and Nuclear Factor-kappa B signal pathway in a model of lipopolysaccharide (LPS) induced acute lung injury (ALI).

METHODSModel of ALI was induced by injection (iv) with LPS 5 mg/kg in male SD rats. L-Arg (500 mg/kg ip) was administrated at 3 h or 6 h after LPS injection respectively for 3 h, and the rats were killed at 6 h or 9 h after saline (control) or LPS injection. The expression and the translocation of NF-kappa B P65 in lung tissue were detected with immunohistochemisty (IHC). The gene expression of intercellular adhesion molecule-1 (ICAM-1) was examined by RT-PCR. The concentrations of TNF-alpha and IL-6 in lung tissue were respectively evaluated by radioimmunoassay. The pathological changes of lung tissue were observed by light microscope.

RESULTSCompared with LPS group, treatment with L-Arg at 3 h after LPS significantly decreased the expression of NF-kappa B protein. The concentrations of TNF-alpha and IL-6 in lung tissue were significantly decreased and the lung damage was inproved respectively compared with that of the LPS (3 h + 3 h) group. The lung damage was alleviated in L-Arg (3 h + 3 h) group.

CONCLUSIONRelatively early administration of L-Arg might protect lung from LPS-induced injury by inhibiting NF-kappa B activation and subsequently inhibiting the NF-kappa B-mediated release of inflammatory factors.

Acute Lung Injury ; chemically induced ; physiopathology ; prevention & control ; Animals ; Arginine ; pharmacology ; therapeutic use ; Inflammation ; physiopathology ; Interleukin-6 ; metabolism ; Lipopolysaccharides ; Male ; NF-kappa B ; metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects ; Tumor Necrosis Factor-alpha ; metabolism

BACKGROUNDPyroptosis is the term for caspase-1-dependent cell death associated with pro-inflammatory cytokines. The role of alveolar macrophage (AM) pyroptosis in the pathogenesis of the acute lung injury and acute respiratory distress syndrome (ALI/ARDS) remains unclear.

METHODSC57BL/6 wild-type mice were assigned to sham, lipopolysaccharide (LPS) + vehicle, LPS + acetyl-tyrosyl-valyl- alanyl-aspartyl-chloromethylketone (Ac-YVAD-CMK) and LPS + Z-Asp-Glu-Val-Asp-fluoromethylketone groups. Mice were given intraperitoneal (IP) injections of LPS. Drugs were IP injected 1 h before LPS administration. Mice were sacrificed 16 h after LPS administration, and AMs were isolated. Western blot analysis for active caspase-1 and cleaved caspase-3, evaluation of lung injury and a cytokine release analysis were performed. AMs were treated with LPS and adenosine triphosphate (ATP); caspase-1-dependent cell death was evaluated using flow cytometry; the apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) pyroptosomes were examined by immunofluorescence.

RESULTSThe expression of activated caspase-1 in AMs was enhanced following LPS challenge compared with the sham group. In the ex vivo study, the caspase-1/propidium iodide-positive cells, caspase-1 specks and ASC pyroptosomes were up-regulated in AMs following LPS/ATP stimulation. The specific caspase-1 inhibitor Ac-YVAD-CMK inhibited the activation of caspase-1 and pyroptotic cell death. Ac-YVAD-CMK also reduced the lung injury, pulmonary edema and total protein in bronchoalveolar lavage fluid (BALF). In addition, Ac-YVAD-CMK significantly inhibited interleukin-α2 (IL-1α2) release both in serum and BALF and reduced the levels of IL-18, tumor necrosis factor-α± (TNF-α±), High Mobility Group Box 1 (HMGB1) in BALF during LPS-induced ALI/ARDS.

CONCLUSIONSThis study reported AM pyroptosis during LPS-induced ALI/ARDS in mice and has demonstrated that Ac-YVAD-CMK can prevent AM-induced pyroptosis and lung injury. These preliminary findings may form the basis for further studies to evaluate this pathway as a target for prevention or reduction of ALI/ARDS.

Acute Lung Injury ; chemically induced ; prevention & control ; Amino Acid Chloromethyl Ketones ; pharmacology ; Animals ; Lipopolysaccharides ; toxicity ; Macrophages, Alveolar ; drug effects ; Male ; Mice ; Mice, Inbred C57BL ; Oligopeptides ; pharmacology ; Pyroptosis ; drug effects

OBJECTIVETo investigate the effect of mitochondrial permeability transition pore inhibitor cyclosporine A (CsA) on lipopolysaccharide (LPS)-induced acute lung injury in mice.

METHODSAll male ICR mice were randomly divided into five groups (n = 24): control group, LPS group, dexamethasone group, cyclosporine A(CsA) group and CsA + atractyloside(Atr) group. Six hours after treatment with LPS, the activity of lactate dehydrogenlase (LDH) in bronchoalveolar lavage fluid (BALF) and level of tumor necrosis factor-alpha (TNF-alpha) in lung tissue were detected. The lung wet weight/dry weight ratio and the pulmonary capillary permeability index were also detected.

RESULTSIn contrast to LPS group, the mitochondrial permeability transition pore inhibitor CsA induced a decrease in LDH activity in the BALF and TNF-alpha level in lung tissue, lung wet weight/dry weight ratio and the pulmonary capillary permeability index were declined. Atractyloside, the activator of mitochondrial permeability transition pore, almost abolished the role of CsA on LPS-induced lung injury.

CONCLUSIONThese results suggested that CsA plays the protective effect on LPS-induced lung injury in mice, it is likely through inhibiting the opening of mitochondrial permeability transition pore.

Acute Lung Injury ; chemically induced ; physiopathology ; prevention & control ; Animals ; Cyclosporine ; pharmacology ; L-Lactate Dehydrogenase ; metabolism ; Lipopolysaccharides ; Male ; Mice ; Mice, Inbred ICR ; Mitochondrial Membrane Transport Proteins ; antagonists & inhibitors ; Protective Agents ; pharmacology ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo study the early effects of ulinastatin (UTI) by aerosol inhalation on rabbits with acute lung injury induced by LPS, and to observe the early diagnostic value of 320-slice CT.

METHODSAccording to the random number table, 18 specific pathogen free New Zealand white rabbits were divided into normal control group, group LPS, and group UTI, with 6 rabbits in each group. Rabbits in group LPS and group UTI were given 15 mL lipopolysaccharide (0.16 mg/mL, in the dose of 0.8 mg/kg) to reproduce acute lung injury model. Rabbits in normal control group were given equal volume of normal saline. Rabbits in UTI group were treated with UTI by aerosol inhalation for 10 min from 30 min after injury, while those in the other two groups received normal saline by aerosol inhalation. Rabbits in group LPS and group UTI were scanned by 320-slice CT at post injury hour (PIH) 6 and 24. After anesthesia, heart blood of rabbits in group LPS and group UTI was collected for determination of serum levels of TNF-α, IL-1β, and IL-6 by ELISA at PBH 24. At PBH 24, lung tissue samples were harvested for gross observation and histomorphological observation, measurement of wet to dry weight ratio, and detection of mRNA expressions of TNF-α, IL-1β, and IL-6 with RT-PCR. Above-mentioned indexes were detected in rabbits of normal control group at the same time point. Data were processed with one-way analysis of variance and LSD test.

RESULTS(1) CT perfusion (CTP) image. The difference in CTP image of rabbits in group LPS between PBH 6 and PBH 24 was obvious, while that of rabbits in group UTI and normal control group was slight and not obvious respectively. (2) There were statistically significant differences in the serum levels of TNF-α, IL-1β, and IL-6 of rabbits among the three groups (with F values from 843.896 to 2 564.336, P values below 0.001). The serum levels of TNF-α, IL-1β, and IL-6 in group UTI were respectively (225 ± 9), (190 ± 8), (227 ± 6) pg/mL, and they were significantly lower than those in group LPS [(710 ± 25), (306 ± 16), (422 ± 16) pg/mL, with P values below 0.001]. (3) Gross observation. In group UTI, the degrees of pulmonary edema and pneumorrhagia of rabbits were lower than those in group LSP. (4) Histological observation. The damage to alveolar wall in group UTI was milder, and alveolar space hemorrhage and inflammatory cell infiltration were significantly less intense as compared with those in group LPS. (5) Compared with that in normal control group, the wet to dry weight ratio of lung tissue was increased in group LPS (P < 0.001). The wet to dry weight ratio of lung tissue in group UTI was significantly higher than that in normal control group but lower than that in group LPS (P values below 0.001). (6) There were statistically significant differences in mRNA levels of TNF-α, IL-1β, and IL-6 in lung tissue of rabbits among three groups (with F values from 24.700 to 69.538, P values below 0.001). The mRNA levels of TNF-α, IL-1β, and IL-6 in lung tissue of rabbits in group UTI were respectively (31.4 ± 2.7), (21.2 ± 3.3), (13.9 ± 2.4) pg/mL, which were significantly lower than those in group LPS [ (58.5 ± 10.0) , (35.1 ± 5.1), (20.7 ± 3.2) pg/mL, P values below 0.001].

CONCLUSIONSUTI by aerosol inhalation can mitigate pulmonary edema and hemorrhage and inhibit inflammatory response. 320-slice CT may be used for detection of early lung injury.

Acute Lung Injury ; chemically induced ; drug therapy ; pathology ; physiopathology ; Aerosols ; therapeutic use ; Animals ; Glycoproteins ; therapeutic use ; Interleukin-1beta ; blood ; Interleukin-6 ; blood ; Lipopolysaccharides ; blood ; Lung ; physiopathology ; Lung Injury ; Multidetector Computed Tomography ; Multiple Organ Failure ; blood ; prevention & control ; RNA, Messenger ; genetics ; Rabbits ; Reverse Transcriptase Polymerase Chain Reaction ; Trypsin Inhibitors ; therapeutic use ; Tumor Necrosis Factor-alpha ; blood

To explore the role of heme oxygenase (HO)-1 experimental system in dachengqitang (DD) ameliorating ALI induced by lipopolysaccharide (LPS) in mice. Seventy-five male Kunming mice were randomly divided into control group (normal saline was instilled intratracheally(50 microL/per mouse), LPS group (LPS was instilled intratracheally to replicate ALI model), DD + LPS group, DD + LPS + ZnPP (ZnPP, HO-1 specific inhibitor) group and the DD group. Mice were killed at 6 h after administration. Lung indexes were tested; lung histomorphological changes were observed under microscope, and neutrophils (PMN) number and protein content of bronchoalveolar lavage fluid (BALF) were measured; HO-1 mRNA and protein expression in lung tissue were detected by RT-PCR and Western blot. The results showed that intratracheal instillation of LPS in mice can cause significant morphological changes in lung tissue. Both PMN numbers and protein content in BALF were increased. meanwhile the expressions of HO-1 mRNA and protein in lung tissue were increased. Pretreated with DD and then intratracheally instillated LPS coulde ameliorat lung tissue injury, reduced PMN BALF number and protein content, but increase HO-1 mRNA and protein expression in the lung tissue when compared with LPS. HO-1 inhibitor ZnPP coulde inhibite the ameliorative effect of DD. The results suggest that the ameliorative effect of DD on ALI induced by LPS in mice were related with upregulation HO-1 mRNA and protein.
Acute Lung Injury ; chemically induced ; prevention & control ; Animals ; Blotting, Western ; Bronchoalveolar Lavage Fluid ; chemistry ; cytology ; Gene Expression Regulation, Enzymologic ; drug effects ; Heme Oxygenase-1 ; antagonists & inhibitors ; genetics ; metabolism ; Leukocyte Count ; Lipopolysaccharides ; Lung ; drug effects ; enzymology ; pathology ; Male ; Mice ; Neutrophils ; cytology ; drug effects ; Phytotherapy ; methods ; Plant Extracts ; pharmacology ; Proteins ; metabolism ; Protoporphyrins ; pharmacology ; Random Allocation ; Reverse Transcriptase Polymerase Chain Reaction ; Treatment Outcome

This study is to determine the preventive effect and mechanism of targeting IL-17A on pulmonary inflammation and fibrosis after acute lung injury. Mice were treated with anti-IL-17A antibody on the day 7 and sacrificed on the day 14 after bleomycin lung injury. The pulmonary inflammatory status and the deposition of collagen were measured by HE and Sirius stains staining. The contents of hydroxyproline and collagen were measured by using commercial kits. The survival rate of mice was calculated by Kaplan-Meier methods. The inflammatory cytokines in bronchoalveolar lavage fluid were measured by ELISA and the expressions of inflammation-related molecules were detected by Western blotting assay. Targeting of IL-17A could prevent the development of lung inflammation, decrease collagen deposition and the contents of hydroxyproline, and protect against the development of pulmonary fibrosis, which together led to an increase in the animal survival. Moreover, blocking IL-17A decreased the expression ofpro-fibrotic cytokines such as IL-17A, TGF-beta1 and IL-13; increased the expression of anti-fibrotic or anti-inflammatory factors such as IFN-gamma, COX-2, 5-LOX, 15-LOX. Indeed, IL-17A antagonism suppressed the activation of pro-inflammatory p65NF-kappaB but enhanced the activation of pro-resolving p50NF-kappaB. In conclusion, that blockade of IL-17A prevents the development of pulmonary fibrosis from acute lung injury, is because blocking IL-17A may prevent acute inflammation converting to chronic inflammation.
Acute Lung Injury ; chemically induced ; complications ; Animals ; Bleomycin ; Collagen ; metabolism ; Hydroxyproline ; metabolism ; Interleukin-13 ; metabolism ; Interleukin-17 ; antagonists & inhibitors ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; NF-kappa B p50 Subunit ; metabolism ; Pneumonia ; etiology ; metabolism ; Pulmonary Fibrosis ; etiology ; metabolism ; prevention & control ; Random Allocation ; Transcription Factor RelA ; metabolism ; Transforming Growth Factor beta1 ; metabolism ; Up-Regulation

OBJECTIVETo investigate the antioxidant effect of melatonin (MT) in the rats with phosgene-induced lung injury and its possible mechanism.

METHODSFifty male SD rats were equally randomized into phosgene exposure group, air control group, MT treatment group, dexamethasone (DX) treatment group, and negative control group. All groups except the air control group were exposed to 8.33 mg/L phosgene for 5 min, and the MT treatment group, DX treatment group, and negative control group were injected with MT (10 mg/kg), DX (2.5 mg/kg), and 1% ethanol saline (1 ml/kg), respectively, via the caudal vein 1 hour after exposure. The rats were sacrificed 6h later. Then, the wet/dry ratio of the lung, the total protein content and neutrophil count in bronchoalveolar lavage fluid (BALF), and the malonaldehyde (MDA) content and superoxide dismutase (SOD) and myeloperoxidase (MPO) activities in lung homogenate were measured; pathological observation was made on the lung tissue under an optical microscope; the protein expression of inducible nitric oxide synthase (iNOS) and NF-κB in the lung tissue was measured by Western blot.

RESULTSCompared with the air control group, the phosgene exposure group showed significantly increased wet/dry ratio of the lung and total protein content and neutrophil count in BALF (P < 0.01) as well as significantly increased MDA content and MPO activity in the lung tissue (P < 0.05). Compared with the phosgene exposure group, the MT treatment group showed significantly decreased MDA content and MPO activity and significantly increased SOD activity (P < 0.01), and the MT treatment group and DX treatment group showed significantly decreased protein expression of iNOS and NF-κB (P < 0.01).

CONCLUSIONMT has protective effect in phosgene-induced lung injury, and its protective mechanism may be associated with scavenging free radicals and inhibiting expression of iNOS and NF-κB.

Acute Lung Injury ; chemically induced ; metabolism ; prevention & control ; Animals ; Disease Models, Animal ; Male ; Malondialdehyde ; metabolism ; Melatonin ; pharmacology ; therapeutic use ; NF-kappa B ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Peroxidase ; metabolism ; Phosgene ; toxicity ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism

Although 4,4'-diaminodiphenylsulfone (DDS, dapsone) has been used to treat several dermatologic conditions, including Hansen disease, for the past several decades, its mode of action has remained a topic of debate. We recently reported that DDS treatment significantly extends the lifespan of the nematode C. elegans by decreasing the generation of reactive oxygen species. Additionally, in in vitro experiments using non-phagocytic human fibroblasts, we found that DDS effectively counteracted the toxicity of paraquat (PQ). In the present study, we extended our work to test the protective effect of DDS against PQ in vivo using a mouse lung injury model. Oral administration of DDS to mice significantly attenuated the lung tissue damage caused by subsequent administration of PQ. Moreover, DDS reduced the local expression of mRNA transcripts encoding inflammation-related molecules, including endothelin-1 (ET-1), macrophage inflammatory protein-1alpha (MIP-1alpha), and transforming growth factor-beta (TGF-beta). In addition, DDS decreased the PQ-induced expression of NADPH oxidase mRNA and activation of protein kinase Cmicro (PKCmicro). DDS treatment also decreased the PQ-induced generation of superoxide anions in mouse lung fibroblasts. Taken together, these data suggest the novel efficacy of DDS as an effective protective agent against oxidative stress-induced tissue damages.
Animals ; Cells, Cultured ; Chemokine CCL3/drug effects/metabolism ; Dapsone/*administration & dosage ; Endothelin-1/drug effects/metabolism ; Fibroblasts/drug effects ; Herbicides/*antagonists & inhibitors/toxicity ; Lung Injury/chemically induced/*prevention & control ; Male ; Mice ; Mice, Inbred BALB C ; Oxidative Stress ; Paraquat/*antagonists & inhibitors/toxicity ; Protective Agents/*administration & dosage ; Protein Kinase C/genetics/metabolism ; Superoxides/analysis ; Transforming Growth Factor beta/drug effects/metabolism