原花青素对尿路致病性大肠杆菌黏附、侵袭膀胱上皮细胞的影响及其机制

摘要

目的 探讨原花青素对尿路致病性大肠杆菌(UPEC)黏附、侵袭膀胱上皮细胞的影响,并探讨其作用机制.方法 体外培养人膀胱上皮细胞T24,随机分为空白对照组、阴性对照组和原花青素组,阴性对照组和原花青素组分别加入等量DMSO和亚抑菌浓度的原花青素溶液.采用平板菌落计数法检测各组UPEC J96对膀胱上皮细胞T24的相对黏附率和相对侵袭率;采用RT-PCR法检测各组细胞表面整合素受体α3和β1 mRNA表达;采用流式细胞术检测各组纤维状肌动蛋白(F-Actin)相对荧光强度.结果 与空白对照组和阴性对照组比较,原花青素组UPEC J96的相对黏附率和相对侵袭率均明显降低(P均＜0.01),T24细胞表面整合素受体α3、β1 mRNA相对表达量均明显下降(P均＜0.01).与空白对照组和阴性对照组比较,原花青素组无论是UPEC J96未感染细胞还是UPEC J96感染细胞,F-Actin相对荧光强度均明显降低(P均＜0.01).空白对照组与阴性对照组上述指标比较P均>0.05.结论 原花青素可抑制UPEC黏附、侵袭膀胱上皮细胞,其机制可能通过抑制膀胱上皮细胞表面整合素受体及F-Actin表达实现.%Objective To investigate the effect and mechanism of procyanidin on the adhesion and invasion of uropathogenic Escherichia coli (UPEC) to bladder epithelial cells.Methods Human bladder epithelial cells T24 were cultured in vitro and randomly divided into the blank control group, negative control group, and procyanidin group.The cells in the negative control group and the procyanidin group were respectively added with equal volume of DMSO and procyanidin solution with antibacterial concentration.The relative adhesion and invasion rates of UPEC J96 were detected by plate colony counting method.RT-PCR was used to detect the mRNA expression of integrinα3 andβ1 on the cell surface of each group.The relative fluorescence intensity of fibrin F-Actin of each group was observed by flow cytometry.Results Compared with the blank control group, the adhesion rate and invasion rate of J96 in the procyanidin group decreased, with statistically significant difference (both P＜0.01).The mRNA expression levels of integrinα3 andβ1 on the cell surface of T24 cells decreased, with statistically significant differences (P＜0.01).Compared with the blank control group, the relative fluorescence intensity of F-Actin decreased in the proanthocyanidin group, whether they were UPEC J96 uninfected cells or UPEC J96 infected cells and the difference was statistically significant (P＜0.01).Conclusion Procyanidin can inhibit the adhesion and invasion of UPEC to bladder epithelial cells by inhibiting the expression of integrin receptor and F-Actin on the surface of bladder epithelial cells.