RNA测序研究抗菌肽KT2治疗溃疡性结肠炎的作用机制

Study on therapeutic mechanism of antimicrobial peptides KT2 on ulcerative colitis based on RNA sequencing

目的通过RNA测序(RNA-seq)研究抗菌肽KT2治疗溃疡性结肠炎(UC)小鼠的分子机制。方法用葡聚糖硫酸钠(DSS)构造小鼠UC模型,将60只小鼠随机分为对照组、DSS组、KT2组、mCRAMP组和美沙拉嗪组5组,每组12只。评估小鼠结肠炎症程度。从对照组、DSS组和KT2组中每组随机选4只小鼠的结肠组织进行测序,鉴定差异表达基因(DEGs)并进行基因富集分析,随后用定量逆转录聚合酶链反应(qRT-PCR)进行验证。结果KT2组小鼠炎症程度比mCRAMP组和美沙拉嗪组更低;KT2组与DSS组相比,共得到113个DEGs,其中下调DEGs71个,上调DEGs42个。基因富集分析显示下调DEGs主要与胶原代谢有关,上调DEGs主要与生物氧化有关,筛选出差异较大且研究甚少的DEGs进行qRT-PCR验证,发现Foxp3、FUT4、IFRD1、VEGF在DSS干预后表达下调,经抗菌肽KT2治疗后表达上调;Arg2、FXR在DSS干预后表达上调,经抗菌肽KT2治疗后表达下调。结论抗菌肽KT2治疗UC小鼠效果优于mCRAMP和美沙拉嗪;抗菌肽KT2可能通过上调Foxp3、FUT4、IFRD1、VEGF以及下调Arg2、FXR的表达治疗UC小鼠,提示上述基因可能参与抗菌肽KT2治疗UC的分子机制。

ObjectiveTo investigate the molecular mechanism of antimicrobial peptide KT2 in the treatment of ulcerative colitis (UC) mice using RNA sequencing (RNA-seq).MethodsUC mice models were constructed with dextran sulfate sodium (DSS) and sixty mice were randomly divided into control group, DSS group, KT2 group, mCRAMP group and mesalazine group, with 12 mice in each group. The inflammation severity of mouse colon tissues was evaluated. Colon tissues of four mice from each group of control group, DSS group and KT2 group were randomly selected for RNA-seq, identification of differential genes (DEGs) and gene enrichment analysis, and then verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR).ResultsThe inflammation severity of mouse colon tissues of KT2 group was lower than that of mCRAMP group and mesalazine group;Compared with DSS group, 113 DEGs was identified including 71 down-regulated genes and 42 up-regulated in the KT2 group. Gene set enrichment analysis suggested the down-regulated and up-regulated DEGs were mainly related to collagen metabolism and biological oxidation separately. DEGs with significant difference and few studies were screened for qRT-PCR verification. The expressions of Foxp3, FUT4, IFRD1 and VEGF were down-regulated after DSS intervention and up-regulated after treatment of antimicrobial peptide KT2. The expressions of Arg2 and FXR were up-regulated after DSS intervention, and down-regulated after antimicrobial peptide KT2 treatment.ConclusionThe therapeutic efficacy of antimicrobial peptide KT2 in UC mice is better than mCRAMP and mesalazine;Antimicrobial peptide KT2 may treat UC mice by up-regulating the expressions of Foxp3, FUT4, IFRD1, VEGF and down-regulating the expressions of Arg2 and FXR, indicating that the above-mentioned DEGs may involve in the molecular mechanism of antimicrobial peptide KT2 in UC treatment.