RESUMO
BACKGROUND: Acute respiratory distress syndrome (ARDS) is a serious life threatening clinical critical illness. ARDS-related pulmonary fibrosis is a common complication of ARDS. The occurrence of early pulmonary fibrosis indicates a higher incidence and mortality of multiple organ failure. LPS-induced ARDS-related pulmonary fibrosis model in mice was established in this study. And we have explored the anti-pulmonary fibrosis effects and molecular mechanisms of the Citrus Alkaline Extracts (CAE) in vivo and in vitro. METHODS: Pulmonary fibrosis mouse model and lung epithelial cell injury model were established in this study. H&E, Masson and Sirius Red staining were used to estimate lung tissue damage. Immunohistochemistry and western blotting were used to analyze proteins expression. Protein-protein interaction was observed by Co-Immunoprecipitation. Systemic impact of CAE on signaling pathway was examined by RNA-seq. RESULTS: Through H&E, Masson and Sirius Red staining, it was convincingly indicated that therapeutic administration of CAE alleviated lung injury and fibrosis, while pretreated administration of CAE showed weak improvement. In vitro experiments showed that CAE had dual regulation to E-cadherin and N-cadherin, the important indicators of epithelial-mesenchymal transition (EMT). And it was further demonstrated that CAE reversed TGF-ß1-induced EMT mainly through Wnt/ß-catenin, Stat3/6 and COX2/PGE2 signals. Through RNA-Seq, we discovered important mechanisms by which CAE exerts its therapeutic effect. And network pharmacology analysis demonstrated core potential targets of CAE in EMT. CONCLUSION: Thus, this study provides new therapeutic effects of CAE in anti-fibrosis, and offers potential mechanisms for CAE in LPS-induced pulmonary fibrosis.
RESUMO
OBJECTIVE: To investigate the effect of monophosphoryl lipid A (MLA) on ischemia/reperfusion (I/R) injury in rabbit heart and its signal transduction pathway. METHODS: Eighteen rabbits were randomly assigned to three groups: (1) MLA-group: Six rabbits received injection of MLA (35 &mgr;g/kg, iv) 24 h prior to 45 min of ischemia followed by 60 min of reperfusion. (2) Control group: Six rabbits received an intravenous bolus injection of the same volume of vehicle. (3) SB group: Six rabbits intravenously received 2 &mgr;mol/l SB 203580 30-min prior to MLA administration. At the end of reperfusion, myocardial infarct size and serum nitrite/nitrate were detected. Myocardium p38 mitogen-activated protein kinase (p38 MAPK) was detected using a Western blotting method. RESULTS: MLA pretreatment caused a significant reduction of infarct size as percent of area at risk as compared to vehicle-pretreated controls (36+/-3 vs. 65+/-4%, P<0.001). Total nitrite in serum increased in MLA pretreated animals (P<0.05). The protective effects of MLA were completely abolished by selective p38 MAPK inhibitor SB 203580. Western blot analysis showed significant accumulations of p38 MAPK proteins in the myocardium of MLA pretreated animals. CONCLUSIONS: MLA can protect the heart by reducing myocardial infarct size in rabbits. This cardioprotective effect might be attributed to upregulation of nitric oxide (NO) through the activation of p38 MAPK.
