The role of the transcelluIar route and paracelluIar route in bacterial translocation

【背景】：本研究旨在阐明细菌易位中跨细胞和细胞旁途径可能参与的功能。【方法与结果】：1)经细胞途径：将10只wister大鼠分为两组，5只给予伊立替康治疗，5只不给予伊立替康治疗为对照组。伊立替康处理大鼠于第0、1天腹腔注射伊立替康250 mg/kg，给药后48 h处死，收集组织分析。对照组用生理盐水处理。BT组细胞凋亡增加，炎症因子升高。降低了大鼠的大肠阻力。2)细胞旁通路：细胞旁通路研究采用相同模型。伊立替康组大鼠小肠和大肠Claudin-1蛋白表达降低（P<0.05），小肠occludin蛋白表达降低（P<0.05），大肠occludin蛋白表达有降低趋势（P=0.07）。伊立替康组大鼠小肠claudin-1 mRNA表达降低（P<0.05），大肠claudin-1 mRNA表达有降低趋势（P=0.05），小肠和大肠occludin mRNA表达均降低（P<0.05）。3)自噬：我们使用Atg敲除小鼠（缺乏自噬功能）。小鼠给予伊立替康治疗。现在我们研究自噬功能与细菌易位之间的关系。【结论】：这些结果提示细菌易位与胞外途径和胞外途径有一定的关系。可能是这些机制阻止了细菌的易位。

【Background】 : This aim of this study was conducted to clarify the possible functional involvement of transcellular and paracellular route in bacterial translocation.【Methods and Results】 : 1) Transcellular route : Ten wister rats were divided into two groups : Five were treated with irinotecan and five were not treated with irinotecan, the control group. Irinotecan treated rats were administrated irinotecan 250 mg/kg intraperitoneally on days designated 0 and 1, were then killed at 48 h after treatment, and tissues were collected for analysis. Controls were treated with a saline solution. Apoptosis in the BT group was increased and inflammatory cytokine was also increased. Large intestinal resistance of the rats was decreased. 2) Paracellular route : Same model was adopted in paracellular route study. Claudin-1 protein expression of both the small and large intestine decreased (P<0.05), occludin protein expression of the small intestine decreased (P<0.05), and occludin protein expression of the large intestine had decreasing tendency (P=0.07) in irinotecan treated rats. In irinotecan treated rats, claudin-1 mRNA of the small intestine decreased (P<0.05), claudin-1 mRNA of large intestine had a tendency to decrease (P=0.05), occludin mRNA of both small and large intestine decreased (P<0.05). 3) Autophagy : We use the Atg knock out mouse (lacked the autophagy function). Mouse was treated with irinotecan. Now we investigate the relationship between the autophagy function and bacterial translocation.【Conclusions】 : Those findings indicated some relationship between the transcellular and paracellular route and bacterial translocation. It is possible that these mechanism prevent the bacterial translocation.