| Objective: Acute lung injury(ALI)is one of the most common and serious complications in the early stage of severe acute pancreatitis(SAP).In this experiment,a rat model of SAP was prepared to explore the role of the "Wnt/β-catenin" signaling pathway in the pathogenesis of acute pancreatitis-associated lung injury(APALI),and observing the intervention effect of Qingyi decoction(QYD)will provide a reliable experimental and theoretical basis for the pathogenesis and treatment of SAP and its related lung injury.Methods:1.Ten male SD(Sprague Dawley)rats were randomly divided into 2 groups(n=5)by random number table method: sham operation(Sham)group and SAP group.Among them,the Sham group opened the abdomen and only turned the pancreas several times before closing the abdomen.In the SAP group,the SAP model was established by retrograde injection of 3.5% sodium taurocholate(35mg/kg)through the pancreaticobiliary duct.48 hours after the operation,laparotomy was performed under anesthesia,and materials were collected.Part of the lung and pancreas tissues were taken for hematoxylin-eosin(HE)staining and the degree of histopathological damage was evaluated.The expression of alveolar type Ⅱ epithelial cells(AEC Ⅱ)marker SFTPC in different tissues was analyzed by immunohistochemical(IHC)method.The levels of Amylase(AMY)in the serum of rats in each group were detected by ELISA to reflect the index of pancreatitis.2.Using the random number table method,40 male SD rats were randomly divided into 4 groups(n=10): Sham group,sham operation administration(Sham+QYD)group,SAP group,QYD treatment(SAP+QYD)group.Among them,the operation of Sham group and Sham+QYD group is the same as that of Sham group in method 1.The operation of SAP group and SAP+QYD group is the same as that of SAP group in method1.Sham+QYD group and SAP+QYD group were intragastric administration of QYD at4 h after operation,and then were treated with QYD every 12 hours(5.265ml/kg).Blood and tissues were collected from rats in each group under anesthesia 48 hours after operation.Some lung and pancreas tissues were taken for HE staining and pathological scoring.Vacuum drying method was used to detect lung wet/dry weight ratio(W/D),and ELISA method was used to detect the level of pro-inflammatory factor interleukin-6(IL-6)in serum.TUNEL kit and Western blot(WB)method were used to detect the changes of apoptosis in lung tissue of rats in each group.The expression of SFTPC in lung tissue of rats in each group and the double staining of Cyclin D1 and SFTPC,β-catenin and SFTPC were detected by immunofluorescence method.The expressions of Wnt3 a,β-catenin and downstream factors Cyclin D1 and SFTPC in the Wnt/β-catenin signaling pathway in lung tissues were detected by WB method.Results:1.The SAP model was successfully established.The HE films of the rats in the SAP group showed severe lesions of the pancreas and lungs(p<0.0001);ELISA showed that the content of serum AMY,a key indicator of pancreatitis,increased significantly(p<0.01);Immunohistochemical results of lung tissue showed that the expression of SFTPC decreased.2.Compared with the Sham group and the Sham+QYD group,the pathological scores of the pancreas and lung tissues of the rats in the SAP group were increased(p<0.0001),and the W/D weight ratio of the lung tissue was significantly increased(p<0.0001),the content of IL-6 in arterial serum was obviously increased(p<0.0001),the TUNEL results of lung tissues in SAP group and the changes of Bax and Bcl-2 protein expression levels(p<0.001)showed that the apoptosis increased.The protein expression levels of Cyclin D1 and SFTPC in rat lung tissue decreased(p<0.01),and the immunofluorescence of SFTPC and double staining of Cyclin D1 and SFTPC also had similar results.The protein expression levels of Wnt3a(p<0.05)and β-catenin(p<0.0001)in the lung tissues of rats in the SAP group decreased,and immunofluorescent double staining also confirmed same results.Compared with the rats in the SAP group,the pathological scores of pancreas and lung tissues(p<0.0001),the ratio of W/D weight of lung tissues(p<0.01)and other disease indicators of the rats treated by intragastric administration of QYD had different degrees.And the production and release of proinflammatory factor IL-6 in lung tissues decreased(p<0.0001).The protein expressions of Wnt3a(p<0.001),β-catenin(p<0.001),Bcl-2(p<0.05),Cyclin D1(p<0.01),SFTPC(p<0.05)were significantly increased,and the protein expression level of Bax(p<0.01)was significantly decreased,all of which indicated that QYD can control inflammation and resist apoptosis by promoting Wnt/β-catenin signaling pathway,promote repair,reduce lung damage.The double staining results of Cyclin D1 and SFTPC,β-catenin and SFTPC also showed that the fluorescence expression of the SAP+QYD group was significantly increased compared with the SAP group.More double-stained cells appeared,which proved that the effect of QYD on reducing lung injury was indeed accomplished by activating the Wnt/β-catenin signaling pathway to promote the repair of AEC Ⅱ.Conclusions:1.Severe acute pancreatitis is a serious disease involving the whole body.Among them,lung injury,especially the lung air-blood barrier,which is mainly composed of AECⅡ,is seriously affected.2.QYD can significantly reduce pancreatic injury in severe acute pancreatitis,and promote the repair of related lung injury by reducing apoptosis and reducing inflammation.3.Wnt/β-catenin signaling pathway plays a key role in QYD promoting the repair of acute pancreatitis-related lung injury. |
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