Abstract

Our laboratory has shown previously [1] that activity of surface P-glycoprotein (P-gp) was inversely associated with bacterial adhesion to the human gastrointestinal cell lines, Caco-2 and LS174T. To attempt a detailed analysis of the rationale for our observations, filtered conditioned medium, that contained only low molecular weight proteins, was taken from these human cell lines with or without treatment with rifampicin, a P-gp inducer. The conditioned medium samples were tested against pathogenic microflora and screened for antimicrobial factors with and without exposure to lipopolysaccharides of E. coli 0111:B4. Human β-defensin-1 mRNA expression increased with the pregnane X receptor (PXR) inducing rifampicin suggesting a positive association with PXR stimulation. In conclusion, antimicrobial activity was detected in the conditioned medium of the gastrointestinal cells, however, a single antimicrobial peptide responsive to PXR-mediated regulation and acting as a substrate for P-gp, was not conclusive.

中文翻译：

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检测表达P-糖蛋白的人胃肠道细胞系及其分泌物中的β-防御素和其他抗菌肽

摘要

我们的实验室先前已经证明[1]，表面P-糖蛋白（P-gp）的活性与细菌粘附于人胃肠道细胞系Caco-2和LS174T呈负相关。为了对我们的观察结果进行详细分析，我们从这些人细胞系中提取了仅含有低分子量蛋白质的过滤条件培养基，无论是否经过利福平（一种P-gp诱导剂）处理。测试条件培养基样品的病原微生物群，并筛选暴露于或不暴露于大肠杆菌脂多糖的抗微生物因子0111：B4。人β-防御素-1 mRNA表达随孕烷X受体（PXR）诱导利福平的增加而增加，表明与PXR刺激呈正相关。总之，在胃肠道细胞的条件培养基中检测到抗菌活性，但是，对PXR介导的调节有反应并充当P-gp底物的单个抗菌肽尚无定论。