Identification and quantitative analysis of hepatic protein and its relationship to prognosis in biliary atresia patients by quantitative proteomic technology

Abstract

Objective To identify and quantify total proteins in liver tissue of patients with biliary atresia (BA) by isobaric tags for relative and absolute quantification (iTRAQ) technology to decipher the relationship between significant protein and its prognosis.Methods According to the serum level of total bilirubin (TBIL) in 3 months and native liver survival time (NLST),the patients were divided into 2 groups of good prognosis (3M TBIL≤ 25 μmol/L,NLST＞2 years) and poor prognosis (3M TBIL＞25μmol/L,NLST＜ 1 year) (n =10 each).Liver tissues were collected during Kasai operation.And iTRAQ technique was used to identify and quantify the expression of differential proteins.Then differential proteins were classified by Panther classification system.The results were further validated by Western blot.Results A total of 5177 proteins were identified by mass spectrometry.Among them,323 differential proteins with expression folds of over 1.5 were identified.Among these proteins,as compared with poor prognosis group,131 proteins were up-regulated and 192 proteins down-regulated in good prognosis group.These differential proteins were related with 14 kinds of biological processes (e.g.metabolic and immune system).Conclusions The technique of iTRAQ is effective for comparative proteomic studies.Thus these identified differential proteins will provide further clues for studying the pathogenesis and prognosis of BA. Key words: Biliary atresia; Mifferential proteins; Prognosis