The Expressions And Roles Of MiR-146B And MiR-503in The Bleomycin-induced Pulmonary Fibrosis

Objective:We explored the expressions and potential roles of microRNA-146b and microRNA-503in the bleomycin-induced pulmonary fibrosis.Methods:①Divided50C57BL/6mice into3groups randomly:control group,bleomycin-induced pulmonary fibrosis group(model group), boriezomib intervention group(intervention group);The control group was treated with normal saline through intratracheal instillation,the model group was treated with bleomycin solution(3.5mg/kg),and one week after model building,the model group received intraperitoneal injection of normal saline(0.1ml);while the intervention group was treated with bleomycin solution in the same way as model group,and one week after model building,the model group received intraperitoneal injection of boriezomib solution(120μg/kg,0.1ml);The mice were sacrificed separately at3and4weeks after building model.②Verified whether the pulmonary fibrosis was successful by hematoxylin-eosin staining,Masson staining and testing the expression of fibrosis-related genes.③Extracted the total ribonucleic acid(RNA) to test the expression of miR-146b and miR-503.④Predicted the fibrosis-related target genes of miR-146b and miR-503throgh the website TargetScan,PicTar,MiRand Pubmed.⑤Utilized the Real-time Polymerase Chain Reaction and western-blot to verify whether those predicted genes were changed. Results:①The hematoxylin-eosin staining and Masson staining showed that the lung were changed as pulmonary fibrosis in the model group and intervention group;The fibrosis-related genes are also elevated in the model group and intervention group(P<0.05).②Compared with the control group,miR-146was elevated in the model group,and miR-503was downregulated in the model group(P<0.01).③We got6fibrosis-related genes targeted by miR-146b through the method of bioinformatics:irak, siah2, klf4, mmp16,notch1and foxO3,and the foxO3,siah2were downregulated (P<0.01) which was negative correlated with miR-146b in the model group.④We predicted the fibrosis-related gene smad7as the target of miR-503by bioinformation methods,howerer,we did not find any changes in the level of miR-503mRNA.Conclusions:①miR-146b is elevated,while miR-503is downregulated in the bleomycin-induced pulmonary fibrosis.②foxO3, siah2are downregulated in the bleomycin-induced pulmonary fibrosis, while they are also the predicted target gene of miR-146b.③boriezomib (120ug/kg) is not found to influence the development of bleomycin-induced pulmonary fibrosis...