Based On Proteomics And Phosphorylation Analysis The Related Proteins And Phosphorylation Modifications Characteristics Of IgA Nephropathy

BackgroundIgA nephropathy(IgA nephropathy,IgAN)is a common primary glomerulonephritis disease,which accounts for 30% to 45% of renal biopsy patients.It is characterized by the deposition of immune complexes dominated by IgA in the mesangial region of the glomerulus.The clinical manifestations are diverse,mainly hematuria,which may be accompanied by varying degrees of proteinuria,hypertension,and impaired renal function.The pathogenic mechanism of IgAN is related to many factors,but the specific pathogenic mechanism has not been elucidated.Quantitative proteomics has discovered a variety of potential protein markers,but there are still no IgAN-specific protein markers.At present,there are few studies on phosphorylation of IgAN protein.In this study,quantitative proteomics and phosphoproteomics were used to analyze IgAN renal tissues to reveal the characteristics of IgAN-related proteins and phosphorylation modification of IgAN.ObjectiveScreening the proteins related to the pathogenesis of IgAN at the proteomic level.We analyzed the phosphorylation sites of IgA renal tissue proteins,predicted the upstream kinases of the modification sites and constructed the kinase-protein network diagram.In order to reveal the phosphorylation characteristics of IgAN,it provides a new basis for the study of IgAN molecular diagnostic markers and pathogenesis.MethodIn this study,the disease group was diagnosed IgAN patients(n=7),and the control group was diagnosed minor glomerular abnormalities(MGA)(n=10).First,extract the protein from the renal tissues of the disease group and the control group,and the BCA kit detects the protein concentration.Secondly,trypsin was used to digest the proteolytic enzymes of the disease group and the control group into peptides,and the peptides were used for quantitative proteomics and protein phosphorylation analysis.Analyze differentially expressed proteins with modern biological information methods,including protein annotation,GO,KEGG and domains.MCODE and Cyto Hubba screen for differential proteins and differentially phosphorylated proteins related to IgAN.IGPS1.0 software was used to predict the upstream phosphokinases at the phosphorylation sites and to screen the differentially expressed kinases in the disease group and the control group.Results1 Proteomics(1)A total of 4360 proteins were identified,of which 2894 had quantitative information.There were 227 upregulated proteins(>2)and 263 downregulated proteins(<1/2).(2)Annotation protein found that a total of 146 differential proteins were found to be mainly distributed in the cytoplasm.(3)The function enrichment analysis of protein.GO analysis found that proteins are mainly enriched in the extracellular matrix,immune system development and ion transport.KEGG analysis found that the proteins are mainly enriched in primary immunodeficiency and amino acid metabolism.Domain enrichment found that the proteins are mainly enriched in C-type lectin folding and metallothionein structure area.(4)Six ribosomal proteins that may be related to IgAN were screened by MCODE and Cyto Hubba: RPL23,RPL11,RPS15 A,RPL32,RPS13 and RPS8.2 Phosphoproteomics(1)A total of 279 differentially phosphorylated proteins were identified,including 99 were upregulated(>2)and 180 were downregulated(<1/2).(2)Phosphorylated protein annotation shows that a total of 126 phosphorylated modified proteins are mainly distributed in the nucleus.(3)The function enrichment analysis of phosphorylated proteins.GO enrichment analysis found that the phosphorylated proteins are mainly enriched in anchoring junctions,actin binding other functions.KEGG enrichment analysis found that phosphorylated proteins are mainly enriched in HIF-1 signaling pathway and PI3K-Akt signaling pathway.Domain analysis found that the phosphorylated proteins are mainly enriched in zinc fingers and LIM-type domains.(4)We predicted the kinases upstream of the phosphorylation site and identified 225 kinases,of which the activity of 65 kinases tends to be activated,and the activity of 160 kinases tends to be inhibited.(5)The kinases(CDK2,CDK5,CK2A1,CK2A2,ERK1 and ERK2)were screened to construct a kinase-phosphorylation site network diagram.Combining MCODE and Cyto Hubba analysis to screen six phosphorylated proteins related to IgAN,such as PXN,RPS3,RPS27,VCL,TLN and HSP90AA1.Conclusion(1)Quantitative proteomics screened 227 upregulated proteins and 263 downregulated proteins.The proteins(RPL23,RPL11,RPS15 A,RPL32,RPS13 and RPS8)may be related to the pathogenesis of IgAN.(2)Phosphoproteomics screened 99 upregulated proteins and 180 downregulated proteins.(3)Phosphorylated proteins such as PXN,RPS3,RPS27,VCL,TLN and HSP90AA1 may be related to the mechanism of IgAN.(4)The proteins and phosphorylated proteins screened out in this study can be used as potential molecular markers of IgAN,providing new ideas for elucidating the pathogenic mechanism of IgAN.