137Cs γ射线累积照射大鼠后血清蛋白质组分析

摘要

目的 探讨137Csγ射线累积照射对SD大鼠血清蛋白质的影响.方法 将30只SD大鼠按随机数字表法分为3个剂量组:0.2 Gy累积照射组、2 Gy累积照射组和健康对照组.采用137Cs γ射线累积照射SD大鼠,剂量率为0.336 mGy/min.利用同位素标记的相对和绝对定量技术(iTRAQ)分析累积受照大鼠的血清蛋白质表达,筛选出差异蛋白质.对差异表达的蛋白质进行GO注释分析及相互作用网络分析.结果 在3组样品中共鉴定到363种蛋白;与健康对照组相比,0.2 Gy照射组差异蛋白质有50种,16种蛋白质上调,34种下调;2 Gy照射组有64种差异蛋白质,31种上调,33种下调;两组共同表达差异的蛋白质有29种,其中,10种蛋白表达上调,19种下调.根据细胞组成注释,多数蛋白为胞质蛋白、膜蛋白;根据分子功能注释,差异蛋白以蛋白质结合和酶活性调节等为主.两个剂量组共同差异表达的蛋白质构成相互作用网络.GSTP1、PGK1、P4HB、CAPZA1是蛋白质相互作用网络的关键性节点,这几个蛋白质直接或间接地与其他差异蛋白存在相互作用.结论 不同剂量累积照射可诱导大鼠血清蛋白质组的改变,GSTP1、PGK1、P4HB、CAPZA1蛋白可能在累积照射的损伤机制中发挥作用.%Objective To investigate the changes of proteomics in serum of Sprague-Dawley(SD) rats after accumulated irradiation with 137Cs γ-rays.Methods A total of thirty mature SD rats were randomly divided into three groups:0.2 Gy group,2 Gy group and healthy control group.Rats were irradiated at a dose rate of 0.336 mGy/min for 10 d and 20 d continuously.Isobaric tags for relative and absolute quantitation (iTRAQ) was used to analyze the different protein expression in serum of irradiated rats.Gene Ontology,KEGG pathway and protein-protein interaction network analysis were conducted using softwares.Results In total,363 protein spots were identified.Twenty nine proteins were differentially expressed in both groups compared with control,of which 10 proteins were up-regulated and 19 proteins were down-regulated.Based on the information of GO categories,these differentially expressed proteins were mainly located in the cytoplasm and membrane concerning the function of binding and catalytic activity.Analysis with the PAJEK software demonstrated that 16 differentially expressed proteins could form a complicated interaction network where glutathione S-transferase P1 (GSTP1),phosphoglycerate kinase 1 (PGK1) and protein disulfide-isomerase (PDI) might be key nodes.Conclusions Accumulated irradiation can induce differentially expressed proteins in serum of irradiated rats.Analysis on functional roles of the screened proteins GSTP1,PGK1 and PDI may provide insight into further mechanistic investigations and underlying molecular biomarkers induced by accumulated irradiation.