Analysis Of Differential Protein Expression In Radiation-induced Intestinal Injury Model Based On Proteomics

Purpose The rat model of radiation-induced intestinal injury was established by a single dose of 10 Gy irradiation on the rat abdomen.The differential expression of rat intestinal proteins was screened by proteomics method,and the differential target proteins associated with acute radiation-induced intestinal injury were searched for as markers of injury for verification,which provided an important experimental basis for the preliminary analysis of the mechanism related to radiation-induced intestinal injury and a new idea for the exploration of potential markers of radiation-induced intestinal injury.Methods 1.Ten male SD rats were randomly divided into control group and 10 Gy irradiation group,with 5 rats in each group.The abdomen of rats in 10 Gy group was irradiated with a single high dose.2.The general state changes of rats were observed,including mental state,activity,body weight,diet,frequency of defecation and character,etc.The rats in both groups were sacrificed on the 4th day,and the changes of intestinal cavity were observed by naked eye after dissection and the pathological changes of intestinal tissue were observed under light microscope,which was used as the standard to verify the successful establishment of rat model of radiation-induced intestinal injury.3.The intestinal tissues of the control group and the irradiation group were selected for proteomics analysis,and the differentially expressed proteins were obtained through extraction,quantification,detection and other experimental steps.Four databases were used for functional annotation to understand the functional properties of proteins.Finally,biological functions of differential proteins in injury were further studied by GO enrichment,KEGG pathway,domain enrichment,subcellular localization of differential proteins and pathway analysis,and differential proteins were screened out.4.Western Blot was used to verify the expression levels of selected differential proteins.Results 1.General state of rats: The rats in the irradiation group showed poor mental state,decreased activity,decreased diet,decreased body weight,and increased mucus excretion and frequency.2.Pathological changes: The intestinal mucosa of rats in the control group had no damage changes,while the intestinal villi of rats in the irradiation group were short,thick and detached,the intestinal recess was deformed and disordered,and lymphocytes and plasma cells were infiltrated and even bleeding.3.Proteomic analysis showed that the differentially expressed proteins were mainly involved in metabolism,enzyme catalytic activity and organic matter metabolism by GO database analysis.KEGG database analysis showed that a total of 133 signaling pathways were annotated,and the related pathways were mainly enriched in Biosynthesis of amino acids,Carbohydrate digestion and absorption,Hematopoietic cell lineage,Renin angiotensin system and Asthma pathways,among which Renin angiotensin system had the highest degree of differential protein enrichment and the most statistically significant pathway.Domain enrichment analysis showed that the differential protein enrichment in the catalytic domain of glycosylhydrolase,family 13,was relatively high,and extracellular protein was relatively high in subcellular localization analysis.Compared with the control group,114 kinds of differentially expressed proteins were screened in the irradiation group,including 27 up-regulated proteins and 87 down-regulated proteins.We screened out a target protein,Aminopeptidase N,which was significant for radioactive intestinal injury and belonged to the up-regulated protein with the third difference factor.Biological functions mainly include metal peptidase activity,hydrolase activity,catalytic activity and ion binding,and the involved pathways include Metabolic pathways,Renin angiotensin system,Glutathione metabolism and Hematopoietic cell lineage.4.Western Blot results showed that: compared with the control group,the expression of aminopeptidase N protein in the intestinal tissues of the irradiation group increased,and the trend of expression change was consistent with the proteomics results.Conclusion In this study,a rat model of radiation-induced intestinal damage was successfully established,relevant differential proteins were obtained through proteomics studies,Aminopeptidase N was screened,and its significant enrichment pathway was analyzed,providing potential molecular biomarkers for clinical diagnosis,new directions for the study of the mechanism of radioactive intestinal injury,and targets for clinical drug research.