Proteomic study of the rat model on intervention of leeches against IgA nephropathy based on iTRAQ technology

Objective To detect the fingering map of urinary proteins from the rat model of IgA nephropathy (IgAN) with iTRAQ technology combined with mass spectrometry,to screen those proteins with differential expression,and to investigate the mechanism of treatment of IgAN of blood stasis syndrome.Methods A total of 140 Wistar male rats aged 6 weeks were used to establish the experimental IgAN model with the method of lipopolysaccharide-bovine serum albumin+lipopolysaccharide+carbon tetrachloride.After the model was successfully established,the rats were randomly divided into six groups,including the model-controlled group, saline-controlled group,high-dose leech-treated group,middle-dose leech-treated group,low-dose leech-treated group and prednisone-controlled group.Another blank control group was set and 20 animals were assigned to each of these seven groups.Urine samples were collected from rats of each group,and was labeled with iTRAQ technology after SDS-PAGE electrophoresis.The labeled urine samples were then separated and dot-targeted by off-line two-dimensional liquid chromatography,and analyzed by mass spectrometry.With database retrieval relative quantitative analysis was done for samples in each group.Informatic analysis was performed with bioinformatics software.Results Using p-value<0.05 and fold change <0.83 or fold change > 1.2 as the screening criteria for differential proteins,sixteen differential proteins in total were screened out from urine samples.There were six proteins,which were upregulated in the model-controlled and the blank control group,and downregulated in the leech-treated groups;and,ten proteins,which were downregulated in the model-controlled and the blank control group and upregulated in the leech-treated groups.By adopting KEGG accumulation analysis ten molecular signaling pathways were screened out to have close association with development and progression of IgAN,and the major pathways were complement and coagulation cascade reactions.Conclusions The differentially expressed proteins and the molecular signaling pathways closely associated with development and progression of IgAN have been screened out from the urine samples from the IgAN rat model after leech treatment,which lays basis for study pathogenesis of IgAN of blood stasis syndrome and therapeutic mechanism of leech treatment of IgAN.