定量蛋白质组学研究揭示知母可缓解2型糖尿病模型大鼠肝脏代谢异常

Quantitative proteomics reveals the abnormal liver metabolism-relieving effect of Anemarrhenae rhizoma in type 2 diabetes mellitus rats

摘要:

2型糖尿病（type 2 diabetes mellitus，T2DM）是一种在全球范围内广泛存在的代谢性疾病，不及时治疗可能会引发众多危及生命的并发症。肝脏代谢在糖尿病发生发展的过程中扮演着至关重要的角色。目前已有报道中药知母用于缓解胰岛素抵抗及糖尿病，但其能否缓解糖尿病中肝脏代谢的异常仍有待深入研究。因此，提取了高脂饮食和化学药物链脲佐菌素（streptozotocin，STZ）诱导的2型糖尿病大鼠模型、知母提取物处理的2型糖尿病大鼠模型、高脂饮食大鼠模型以及正常饮食大鼠对照组的肝脏蛋白，通过基于质谱的定量蛋白质组学串联质量标签（tandem mass tag，TMT）标记技术获得定量蛋白质组数据。利用生物信息学软件对各组数据进行层次聚类分析及主成分分析，并以P<0.05，差异倍数（fold change）>1.5作为阈值标准进行火山图分析，发现知母提取物治疗组相较未治疗组与正常对照组更接近，表明肝脏组织定量蛋白质组数据能够反映知母提取物对2型糖尿病大鼠模型的治疗效果。筛选获得了表达水平与知母提取物治疗密切相关的关键蛋白簇。利用在线网站分析蛋白簇的GO功能与KEGG通路，发现知母缓解2型糖尿病模型大鼠肝脏脂肪酸代谢异常可能与关键蛋白Ndufa6和Prkar2b的表达水平回调有关。

Abstract:

Type 2 diabetes mellitus (T2DM) is a global metabolic disease with potentially life- threatening complications. Liver metabolism plays a vital role in the occurrence and development of diabetes mellitus. It has been reported that the Chinese medicinal Anemarrhenae rhizoma (AR) can relieve insulin resistance and diabetes mellitus. However, the effect on abnormal liver metabolism in diabetes mellitus is still unclear. Therefore, we extracted liver proteins of T2DM rats induced by high-fat diet (HFD) and streptozotocin (STZ), T2DM rats treated with AR extract (ARE), obesity rats (fed with HFD), and normal control rats (fed with normal diet). Then, through tandem mass tag (TMT) labeling combined with mass spectrometry (MS), we obtained the quantitative proteomic data. Bioinformatics software was used for hierarchical cluster analysis and principal component analysis of the data in each group. The volcano map for differentially expressed proteins (P < 0.05, fold change > 1.5) was plotted. It was found that the treatment group was closer to the normal control group, indicating that the quantitative proteomic data of liver tissue can reflect the therapeutic effect of ARE on T2DM rats. Key protein clusters closely related to the treatment of ARE were screened out. The Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the protein clusters were analyzed by David, and the result showed that AR's alleviation of abnormal fatty acid metabolism in livers of T2DM rats may be related to the regulation of the expression of key proteins Ndufa6 and Prkar2b.