Establishme Nt Of A Mouse Model Of Pulmonary Fibrosis Induced By Bleomycin And Screening Of Biomarkers

Pulmonary fibrosis is a kind of disease caused by abnormal repair of lung tissue,which has high mortality,poor prognosis and unclear pathogenesis.This study was used bleomycin(BLM)to establish a mouse model of pulmonary fibrosis that is the basis for further screening of pulmonary fibrosis biomarkers,provid ing scientific basis for further research on the pathogenesis of pulmonary fibrosis and pulmonary fibrosis animal clinical treatment and drug development.The 40 male C57BL/6 mice were randomly divided into two groups: negative control group and model group.The model group was divided into 2.0mg/kg,3.5mg/kg and 5.0mg/kg according to the concentration of BLM,and each group had only 10 rats.In addition to the control group with physiological saline instead,the rest of the model group was injected into the trachea with different concentrations of BLM to establish the model of pulmonary fibrosis.After 28 days,the dynamic distribution of the target in vivo was observed by a small animal imaging syste m,and the blood samples were collected for ELISA detection of MMP7,KL-6/MUC1,SP-A and SP-D in serum.Anaesthetized the left lung was fixed with 4% paraformaldehyde for HE and Masson staining;the right lung for the extraction of total RNA of lung tissue,the expression of lung tissue was detected by Real-time PC R method in MMP7,KL-6/MUC1,SP-A,SP-D,mRNA;the method of immunohistochemistry was used to observe MMP7 and KL-6/MUC1 protein in lung tissue expression and distribution the expression of KL-6/MUC1 protein,MMP7,detection of lung tissue was used Western Blotting method.The experimental results shown that: BLM after ingestion rate had effect on mice body condition,body weight,survival,BLM intake is directly related to the concentration and alveolitis and pulmonary fibrosis,the higher concentration of mortality is also higher,so the 3.5mg/kg concentration is the ideal dosage.Combined detection of four markers,MMP7,KL-6/MUC1,SP-A and SP-D,can improve sensitivity,and is an ideal biomarker for lung fibrosis.It is important for early diagnosis and prognosis of pulmonary fibrosis.The distribution of MMP7 in vitro was consistent with the results of in vivo detection.In vivo imaging technology can be used to observe the dynamic process of pulmonary fibrosis more directly,or to be the future research direction of pulmonary fibrosis.The experiment with BLM induced pulmonary fibrosis in mice to establish animal model,different concentrations of BLM rats lung tissue showed different pathologica l changes,MMP7,K L-6/MUC1,SP-A and SP-D expression in serum and lung tissue in mice was significant difference with control group,the joint detection and can be used as markers for early diagnosis of pulmonary fibrosis.MMP7,KL-6/MUC1,SP-A and SP-D may play an important role in the pathogenesis of pulmonary fibrosis.Biomarkers provide new ideas for future research on pulmonary fibrosis.