ABSTRACT
Abstract Purpose: To investigate whether modulating GSK-3β could attenuate myocardial ischemia reperfusion injury (MIRI) induced acute lung injury (ALI) and analyze the underlying mechanism. Methods: Male SD rats were subjected to MIRI with or without myocardial ischemic post-conditioning in the presence or absence of GSK-3β inhibitor. GSK-3β inhibitor was injected peritoneally 10min before MIRI. Lung W/D weight ratio, MPO, PMNs, histopathological changes, TUNEL, Bax, Bcl-2, IL-6, IL-8, IL-10, GSK-3β, and caspase-3 were evaluated in the lung tissues of all rats. Results: After MIRI, lung injury was significantly increased manifested as significant morphological changes and increased leukocytes in the interstitial capillaries, Lung W/D ratio, MPO, and PMN in BALF, which was associated with enhanced inflammation evidenced by increased expressions of IL-6, IL-8 and reduced expression of IL-10. MIRI significantly increased cell apoptosis in the lung as increased levels of apoptotosis, Bax, cleaved caspase-3, and reduced expression of Bcl-2 was observed, which was concomitant with reduced p-GSK-3β. All these changes were reversed/prevented by ischemic post-conditioning, while these beneficial effects of ischemic post-conditioning were abolished by GSK-3β inhibition. Conclusion: Myocardial ischemia reperfusion injury induces acute lung injury by induction of inflammation and cell apoptosis. Ischemic post-conditioning protects the lung from ALI following MIRI by increasing p-GSK-3β.
Subject(s)
Animals , Male , Myocardial Reperfusion Injury/prevention & control , Protective Agents/metabolism , Acute Lung Injury/prevention & control , Ischemic Postconditioning/methods , Glycogen Synthase Kinase 3 beta/metabolism , Random Allocation , Down-Regulation , Interleukins/metabolism , Rats, Sprague-Dawley , Apoptosis/drug effects , Peroxidase/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Protective Agents/pharmacology , In Situ Nick-End Labeling , Models, Animal , Enzyme Activation , bcl-2-Associated X Protein/metabolism , Caspase 3/metabolism , Acute Lung Injury/enzymology , Glycogen Synthase Kinase 3 beta/antagonists & inhibitors , Glycogen Synthase Kinase 3 beta/pharmacology , Inflammation/metabolism , Myocardial Infarction/pathology , Neutrophils/enzymologyABSTRACT
ABSTRACT PURPOSE: To investigate the regulatory roles of neutrophil elastase (NE) and matrix metalloproteinase-9 (MMP-9) in lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. METHODS: To construct LPS-induced ALI mouse models, wild-type C57BL/6 mice were administered 5.0 mg/kg of LPS through endotracheal, and/or 1.0 mg/kg of ONO-5046, and/or 20.0 mg/kg of chemically modified tetracycline-3 (CMT-3) by gavage. The levels of MMP-9, tissue inhibitor of metalloprotease-1, interleukin (IL)-6 were detected by real time RT-PCR at 6 h, 24 h and 48 h, and tumor necrosis factor (TNF), lung wet-dry weight ratio, white blood cell (WBC) count and polymorphonuclear (PMN) count in bronchoalveolar lavage fluid (BALF) were tested at 48 h after administration. The 5-day survival analysis of the ALI mice was also performed. RESULTS: Both ONO-5046 and CMT-3, regardless of being used individually or combined, significantly reduced the levels of MMP-9, IL-6, and TNF in lung tissue as well as in BALF, and the WBC and PMN count in BALF. Combined treatment with ONO-5046 and CMT-3 remarkably improved the survival rate of ALI mice. CONCLUSION: Neutrophil elastase synergizes with matrix metalloproteinase-9 to promote and regulate the release of inflammatory mediators and the infiltration of inflammatory cells, consequently affecting the survival of lipopolysaccharide-induced acute lung injury mice.
Subject(s)
Animals , Sulfonamides/administration & dosage , Tetracyclines/administration & dosage , Leukocyte Elastase/metabolism , Matrix Metalloproteinase 9/metabolism , Acute Lung Injury/enzymology , Glycine/analogs & derivatives , Time Factors , Bronchoalveolar Lavage Fluid/cytology , Survival Analysis , Lipopolysaccharides , Interleukin-6/metabolism , Inflammation Mediators/metabolism , Leukocyte Elastase/drug effects , Tissue Inhibitor of Metalloproteinase-1/metabolism , Matrix Metalloproteinase 9/analysis , Matrix Metalloproteinase 9/drug effects , Tumor Necrosis Factors/metabolism , Disease Models, Animal , Acute Lung Injury/chemically induced , Acute Lung Injury/blood , Glycine/administration & dosage , Leukocyte Count , Mice, Inbred C57BL , NeutrophilsABSTRACT
The aim of this study was to investigate the effect of propofol pretreatment on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and the role of the phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) pathway in this procedure. Survival was determined 48 h after LPS injection. At 1 h after LPS challenge, the lung wet- to dry-weight ratio was examined, and concentrations of protein, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in bronchoalveolar lavage fluid (BALF) were determined using the bicinchoninic acid method or ELISA. Lung injury was assayed via lung histological examination. PI3K and p-Akt expression levels in the lung tissue were determined by Western blotting. Propofol pretreatment prolonged survival, decreased the concentrations of protein, TNF-α, and IL-6 in BALF, attenuated ALI, and increased PI3K and p-Akt expression in the lung tissue of LPS-challenged rats, whereas treatment with wortmannin, a PI3K/Akt pathway specific inhibitor, blunted this effect. Our study indicates that propofol pretreatment attenuated LPS-induced ALI, partly by activation of the PI3K/Akt pathway.
Subject(s)
Animals , Male , Acute Lung Injury/drug therapy , /metabolism , Propofol/therapeutic use , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects , Acute Lung Injury/chemically induced , Acute Lung Injury/enzymology , Acute Lung Injury/metabolism , Blotting, Western , Bronchoalveolar Lavage Fluid/chemistry , Enzyme-Linked Immunosorbent Assay , Indicators and Reagents , /analysis , Kaplan-Meier Estimate , Lipopolysaccharides , Lung/drug effects , Lung/metabolism , Propofol/metabolism , Quinolines , Rats, Sprague-Dawley , Tumor Necrosis Factor-alpha/metabolismABSTRACT
PURPOSE: To investigate if the ethyl-pyruvate solution could reduce mortality in AP and/or diminish the acute lung injury. METHODS: Forty male rats, weighing between 270 to 330 grams were operated. An experimental model of severe AP by injection of 0.1ml/100g of 2.5% sodium taurocholate into the bilio-pancreatic duct was utilized. The rats were divided into two groups of ten animals each: CT - control (treatment with 50ml/kg of Ringer's solution, intraperitoneal) and EP (treatment with 50ml/kg of Ringer ethyl- pyruvate solution, intra-peritoneal), three hours following AP induction. After six hours, a new infusion of the treatment solution was performed in each group. Two hours later, the animals were killed and the pulmonary parenchyma was resected for biomolecular analysis, consisting of: interleukin, myeloperoxidase, MDA, nitric oxide, metalloproteinases and heat shock protein. In the second part of the experiment, another, 20 rats were randomly divided into EP and CT groups, in order to evaluate a survival comparison between the two groups. RESULTS: There were no significant differences in IL-1B,IL-10, MMP-9, HSP70, nitric oxide, MPO, MDA (lipidic peroxidation) concerning both groups. The levels of IL-6 were significantly diminished in the EP group. Furthermore, the MMP-2 levels were also reduced in the EP group (p<0.05). The animals from the EP treatment groups had improved survival, when compared to control group (p<0.05). CONCLUSION: The ethyl-pyruvate diminishes acute lung injury inflammatory response in acute pancreatitis and ameliorates survival when compared to control group, in the experimental model of necrotizing acute pancreatitis.