利用转录物组数据挖掘致脑膜炎大肠杆菌候选非编码RNA  

Transcriptome Profiling of Potential Non-coding RNAs in Meningitis-causing Escherichia coli K1

作　　者：孙昊 宋雅君 郑杨洋 刘郁涛 任薇 万雪花 SUN Hao;SONG Ya-Jun;ZHENG Yang-Yang;LIU Yu-Tao;REN Wei;WAN Xue-Hua(Collge of Life Sciences,Nankai Universily,Tianjin 300071,China;TEDA Institute of Biological Sctences and Biotechnology,Nankai University,Tianjin 300457,Chuna)

机构地区：[1]南开大学生命科学学院,天津300071 [2]南开大学泰达生物技术研究院,天津300457

出　　处：《中国生物化学与分子生物学报》2021年第1期118-126,共9页Chinese Journal of Biochemistry and Molecular Biology

基　　金：南开大学中央高校基本科研基金(No.63191440)资助。

摘　　要：细菌非编码RNA(ncRNAs)是细菌生长和感染过程中至关重要的转录调控因子,对致病菌快速响应环境变化,调整自身基因表达抵御环境胁迫尤为重要。本研究通过对新生儿脑膜炎大肠杆菌K1 RS218的高通量转录物组测序,发现新生儿脑膜炎大肠杆菌K1 RS218(NMEC)表达丰富的ncRNAs。经生物信息学分析,在新生儿脑膜炎大肠杆菌K1 RS218中,共发现45个潜在的ncRNAs。通过与非致病性大肠杆菌K-12基因组比对,发现新生儿脑膜炎大肠杆菌K1 RS218基因组有300个大于100 bp的特异性序列。结合分析获得的非编码RNA,发现共有9个ncRNAs是新生儿脑膜炎大肠杆菌K1 RS218特异的。随机选择Nsr21,用小鼠尾静脉注射模型验证其作用,发现与野生型RS218对照组相比,注射Δnsr21的小鼠血液中的含菌量显著增加(P<0.01)。说明缺失Nsr21后,更有利于新生儿脑膜炎大肠杆菌K1 RS218在小鼠血液内生存和繁殖。通过qRT-PCR检测Nsr21表达发现,与体外培养环境相比,小鼠血液环境中Nsr21的表达显著下调(P<0.001)。说明新生儿脑膜炎大肠杆菌K1 RS218,是通过下调Nsr21的表达使其更有利于在血液中生存和繁殖。本研究提示,新生儿脑膜炎大肠杆菌K1 RS218基因组中包含大量的ncRNA,这些ncRNA可能与调控NMEC致病性相关。NMEC在感染血液过程中,通过下调Nsr21的表达使NMEC在血液中的繁殖能力增加。Bacterial non-coding RNAs(ncRNAs) are pivotal transcriptional regulators during bacterial proliferation and infection processes. Bacterial ncRNAs play important roles in responding to environmental changes and regulating bacterial gene expression to resist environmental stress. Transcriptome profiling of neonatal meningitis-causing Escherichia coli K1 RS218(NMEC) reveals abundant ncRNAs. Bioinformatic analyses identified 45 potential ncRNAs. Comparative genome analyses of non-pathogenic E. coli K12 and NMEC identified 300 NMEC-specific sequences(above 100 bp), which contain 9 NMEC-specific ncRNAs(Nsr). Moreover, deletion of one ncRNA, Nsr21, enhanced NMEC survival and proliferation in mouse blood(P< 0.01), compared to the wild-type RS218 control, in a mouse tail vein injection model. qRT-PCR analysis further revealed expression of Nsr21 decreased in NMEC collected from mouse blood compared to that in NMEC collected from in vitro medium(P< 0.001), indicating that NMEC downregulates Nsr21 expression to benefit its survival and proliferation in blood. This study suggests that the NMEC genome contains a number of ncRNAs, which may be involved in regulating NMEC pathogenicity. During infection process in the blood, NMEC enhances its proliferation ability in blood by downregulating the expression of Nsr21.

关 键 词：非编码RNA 新生儿脑膜炎大肠杆菌K1 RS218(NMEC) 转录物组 

分 类 号：Q93-3[生物学—微生物学]