激光共聚焦显微技术在细菌粘附肾小管上皮细胞研究中的应用

Application of laser scanning confocal microscopy(LSCM)in primary renal tubular epithelial cells adhered to uropathogenic Escherichia coli

目的:观察尿路致病大肠杆菌和甘露糖在肾小管上皮细胞(PTEC)内的共定位,探讨细菌粘附PTEC的可能机制。方法:在C5a刺激和C5aR拮抗剂(PMX53)作用下,利用激光共聚焦扫描显微镜观察荧光标记的大肠杆菌和甘露糖在原代培养的肾小管上皮细胞中的表达位置。结果:在无任何刺激情况下,PTEC本身表达的甘露糖主要分布在细胞核周围;加入细菌后,甘露糖表达明显升高,并观察到少数细菌与甘露糖共定位;在C5a刺激和等量细菌刺激情况下,PTEC表面粘附的细菌明显增多,且甘露糖的表达明显增多,另外细菌与甘露糖共定位也明显增多;而在PMX53和等量细菌作用下,PTEC粘附的细菌量和甘露糖表达均明显减少。结论:C5a-C5aR信号改变了细胞表面甘露糖的表达,从而影响了细菌在PTEC上的定殖。

Objective： To investigate the mechanism of bacterial adhesion to renal tubular epithelial cells（ PTEC）,we observed the colonization of pathogenic Escherichia coli and mannose in PTEC. Methods： Under the stimulation of anaphylatoxin C5 a and C5 aR antagonist（ PMX53）,the expression of mannose on PTEC and adhesion of PTEC to bacteria was observed by laser scanning confocal microscopy（ LSCM）. Results： The mannose expression was mainly distributed around the nucleus in normal PTEC; after bacterial stimulation,the expression of mannose was significantly increased,and the co-localization of bacteria with cell surface mannosyl residues on PTEC was also observed; after stimulated with C5 a or bacteria,the adhesion of bacteria to PTEC and the expression of mannose were up-regulated significantly,and co-localization of bacteria with mannose was enhanced notably; however,under the stimulation of PMX53 and bacteria, the adhesion of PTEC to bacteria and mannose expression were significantly decreased.Conclusion： C5 a changes the expression of mannose on the cell surface,which maybe affect the adhesion of bacteria to PTEC.