Identification Of Differentially Expressed Proteins In Lung Injury Caused By Paraquat Poisoning With Label-free Quantitative Proteomics Technique

Objective Differentially expressed proteins in lung tissues of paraquat(PQ)poisoned mice and serum of PQ poisoned patients were identified by non-label quantitative proteomics,and the role of differentially expressed proteins in the mechanism of PQ poisoning injury was analyzed,so as to explore potential the pathological damage markers and therapeutic targets of PQ poisoning.Methods 1.Six SPF grade normal male BALB/C mice were selected and divided into the experimental group(n=3)and the control group(n=3).The experimental group was intraperitoneally injected with 50ml/kg paraquat solution to establish a PQ poisoning mouse model.The control group was intraperitoneally injected with 50ml/kg normal saline.The mice were sacrificed and lung tissue samples were collected after 48 h.The protein components of samples were analyzed by unlabeled quantitative proteomics,differentially expressed proteins were screened by mass spectrometry database and MaxQuant software,and significant differentially expressed proteins were analyzed by bioinformatics method.2.Six serum of PQ poisoning patients and healthy volunteers respectively were collected,and the differentially expressed proteins were analyzed and screened by using unlabeled quantitative proteomics technology,and the protein clustering,GO and KEGG pathway and other bioinformatics analysis were performed on the significantly differentially expressed proteins.Results 1.Thirty-three differentially expressed proteins were identified in mouse lung tissue,of which 18 were up-regulated and 15 were down-regulated.Protein analysis showed that most of the differentially expressed proteins had high enrichment in extracellular(vesicles,etc.)and were mainly involved in the regulation of metabolism and stress response.Among them,KEGG pathway enrichment analysis suggested that complement and coagulation cascade pathways were important in the disease process.2.Fifty-six differentially expressed proteins were identified in human serum samples,of which 46 were up-regulated and 10 were down-regulated.According to the different protein analysis,protein basic role in cellular vesicle,external,by adjusting the enzyme,the activity of receptors which involved in the body protein metabolism,material transport and immune stress process,involving the proteasome,carbon metabolism,amino acid biosynthesis,glycolysis and sugar dysplasia,antigen processing and rendering,porphyrins,and multiple pathways including chlorophyll metabolism.3.According to the results of mass spectrometry and bioinformatics analysis,complement C3,proteasome(20S)and heat shock protein(HSP70)may be the molecular markers related to lung injury caused by PQ poisoning.Conclusion 1.Functional analysis of differential proteins in mouse lung tissues showed that oxidative stress,complement activation and coagulation cascade may be the main mechanisms of acute PQ lung injury resulting in thrombosis.2.Through the functional analysis of human serum differentially expressed proteins,the differentially expressed proteins are mainly involved in the functions of proteasome,glycolysis,gluconeogenesis,antigen processing and presentation,etc.The proteasome pathway may be a key pathway in the pathogenesis of PQ poisoning.3.According to mass spectrometry results,the two groups of differentially expressed proteins were analyzed by combining bioinformatics methods such as protein clustering analysis,GO enrichment analysis,KEGG enrichment pathway and protein interaction network to screen out proteins related to the mechanism of PQ poisoning induced lung injury.Among them,Complement C3 and 20 S proteasome are potential molecular markers of assessing lung injury score caused by PQ poisoning,while HSP70 is a protective protein molecule in the process of PQ poisoning,which could be as potential therapeutic targets of PQ poisoning lung injury.