Screening Differential Protein Pathways in Insulin Resistance Complicated with PCOS Using iTRAQ Combined with LC-MS/MS Technology

XIE Fang; LI Ping; CHEN Yang

摘要：Objective:To screen potential serum differential proteins in insulin re-sistance(IR)complicated with polycystic ovary syndrome(PCOS)using isobaric tags for relative and absolute quantitation(iTRAQ)combined with ultra-high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS).Methods:A total of 20 pa-tients diagnosed with PCOS in our hospital were selected,including 10 cases of simple PCOS and 10 cases of PCOS+IR.iTRAQ combined with LC-MS/MS was used for pro-teomic analysis to identify serum differential proteins.Bioinformatics analyses,including gene ontology(GO),Kyoto encyclopedia of genes and genomes(KEGG),and pro-tein-protein interaction(PPI)analysis,were conducted to understand the biological pro-cesses,cellular components,and molecular functions of the differentially expressed pro-teins detected by the two methods.Results:A total of 454,675 secondary spectra were detected by iTRAQ,with 14,376 matched spectra.Combined with LC-MS/MS,74,386 peptides,47,542 unique peptide sequences,and 54,675 proteins were identified.A total of 249 differentially expressed proteins with a fold change≥1.30 or≤0.83 were found,among which 9 had a P-value<0.05.There were 5 up-regulated and 4 down-regulated proteins,namely RPAP3,ALDH6A1,COX20,RASSF3,ALPK2,NANOS1,FAM210A,CHGA,and CGA.These differential proteins were imported into the STRING database for PPI network analysis,which revealed 21 nodes and 69 edges with a PPI enrichment P-value<0.001.KEGG enrichment results included hsa04913(Ovarian steroidogene-sis),hsa04024(cAMP signaling pathway),and hsa04080(Neuroactive ligand-receptor interaction).Conclusion:The combination of iTRAQ and LC-MS/MS technologies i-dentified nine differential proteins including CHGA and CGA,which are mainly en-riched in pathways related to ovarian steroidogenesis,cAMP signaling,and neuroactive ligand-receptor interaction.This combination provides a powerful platform for exploring the pathogenesis of IR complicated with PCOS and discovering new biomarkers.