Escherichia coli alpha-hemolysin HlyA induces host cell polarity changes, epithelial barrier dysfunction and cell detachment in human colon carcinoma Caco-2 cell model via PTEN-dependent dysregulation of cell junctions

Escherichia coli of the B2 phylotype reside in human and animal intestines. We addressed the questions which host cell processes were dysregulated by E. coli HlyA that can potentiate intestinal diseases. The colon carcinoma cell line Caco-2 was infected by HlyA+ E. coli. Cell polarity regulation was analyzed by live cell imaging for the localization of phosphatidylinositol-4,5-bisphosphate (PIP2) abundance in the plasma membrane. In Caco-2 monolayers, transepithelial electrical resistance was measured to determine barrier function. Cell morphologyproliferation and dissemination was assessed microscopically. Cell signaling and polarity regulation was analyzed by RNA-Seq. mRNA profiles from infected Caco-2 cells and controls were generated by paired-end sequencing using Illumina NovaSeq 6000

属于B2系统型的大肠杆菌（Escherichia coli）寄居在人类与动物的肠道内。本研究针对可加重肠道疾病的大肠杆菌溶血素A（Hemolysin A，HlyA）所失调调控的宿主细胞进程相关问题展开探究。研究采用携带HlyA的大肠杆菌感染结肠癌细胞系Caco-2（Caco-2）。通过活细胞成像技术，分析磷脂酰肌醇-4,5-二磷酸（phosphatidylinositol-4,5-bisphosphate，PIP2）在质膜中的丰度定位情况，以此探究细胞极性调控机制。在Caco-2单层细胞模型中，通过检测跨上皮电阻值以评估细胞屏障功能。通过显微镜观察评估细胞形态、增殖与扩散能力。采用RNA测序（RNA-Seq）技术分析细胞信号通路与极性调控相关的分子特征。本研究通过Illumina NovaSeq 6000平台的双端测序技术，获取了感染组与对照组Caco-2细胞的mRNA表达谱数据。