The Role Of Sema4D In RSV-induced Airway Inflammation And Airway Remodeling In Asthmatic Rats And The Intervention Mechanism Of Kechuanning

Objective:To study the expression of Sema4D and its receptor CD72 and plexin-B1 in RSV induced asthmatic rats,to observe the effect of Sema4D on Th 1/Th2,airway epithelium and PI3K/Akt signaling pathway,to elucidate the role of Sema4D in virus induced airway inflammation and airway remodeling in asthmatic rats,to explore the mechanism of Kechuanning in regulating Sema4D and improving airway inflammation and airway remodeling in asthmatic rats New targets and possible approaches for the prevention and treatment of asthmaMethods:(1)The RSV compound OVA model was constructed,and the rats were randomly divided into normal group,model group,Kechuanning low,medium and high dose group,and Sema4D antibody group,and were treated with corresponding drugs.HE staining was used to observe the pathological changes in the lung tissue of each group of rats;Masson staining was used to observe the collagen deposition in the lung tissue of each group of rats;ELISA was used to detect the contents of IL-4,IL-6,IL-8,TNF-?,IFN-?;immunity Hi stochemical,Western Blot and PCR were used to detect the expression of Sema4D,CD72,Plexin-B1 protein and mRNA in lung tissue of rats in each group.(2)Rat airway epithelial cells were isolated,and the effects on the cells and the regulating effect of Kechuanning were observed by intervention of Sema4D.CCK8 detects cell proliferation;Transwell and scratch tests detect cell migration;Western Blot detects intracellular expression of Sema4D,CD72,Plexin-B 1;immunofluorescence and PCR are used to detect intracellular CD72,Plexin-B1 protein,and mRNA expression.(3)The airway epithelial cells of asthmatic rats were isolated,and the effects of Sema4D and PI3K/Akt signal pathway on the cells and the intervention effect of Kechuanning were observed.Cell proliferation was observed by CCK8,cell migration was observed by Transwell and cell scratch testResults:(1)In vivo experiments showed that the expression of Sema4D and Plexin-B1 in the lung tissue of the model group was significantly higher than that in the normal group.The levels of IL-4,IL-6,IL-8,and TNF-? in the serum were significantly higher than those in the normal group,while IFN-? And the expression of CD72 were lower than those in the normal group;the expressions of Sema4D and Plexin-B1 in the lung tissue of rats and the serum levels of IL-4,IL-6,IL-8,TNF-? content decreased to varying degrees,of which the decrease was most significant in the high-dose Kechuanning group and the Sema4D antibody group,which was closer to the normal group,but the difference between the two groups was not large.(2)The results of in vitro experiment showed that the contents of Sema4D,Plexin-B1 in the airway epithelial cells of the model group were higher than those of the normal group,and the expression of CD72 decreased.After the intervention of Kechuanning drug-containing plasma,the expression of Sema4D and Plexin-B1 decreased,the expression of CD72 increased,and the number of cell proliferation and migration decreased compared with the model group.After the addition of Sema4D,the proliferation and migration rate of cells were significantly higher than those of the model group.After the intervention of Sema4D antibody,the number of cell proliferation and migration decreased significantly,the expression of Plexin-B 1 was lower than that of Sema4D group,and the expression of CD72 increased.There was no significant difference between SII group,III group and anti-Sema4D group,but the effect of Kechuanning high dose group was the most stable.(3)The proliferation and migration rate of cells in PI3K group increased significantly,but decreased after treatment with inhibitors,and there was no significant difference between PIII group and anti-PI3K group,while the number of cell proliferation and migration in combined activation group was significantly higher than that in Sema4D group,but there was no significant difference between inhibitory activation group and Sema4D group,anti-PI3K group and combined inhibition groupConclusion:Sema4D interacts with its receptors CD72 and Plexin-B1,regulates PI3K/Akt pathway,participates in airway inflammation and airway remodeling,and plays a positive role in the pathogenesis of asthma;Kechuanning can reduce the expression of Sema4D and inhibit PI3K/Akt pathway,thus affecting airway inflammation and airway remodeling,achieving therapeutic effect.