Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, 113-8657, Tokyo, Bunkyo-ku, Japan,
Cytotechnology. 2005 Jan;47(1-3):79-88. doi: 10.1007/s10616-005-3753-8.
A system for assessing intestinal dioxin absorption was established by applying a Caco-2 cell monolayer and stable dioxin-responsive cell line. The stable dioxin-responsive cell line was established by introducing a plasmid incorporating the human CYP1A1 promoter into human hepatic HepG2 genomic DNA upstream of the luciferase gene. 2,3,7,8-Tetrachlorodibenzodioxin (TCDD) was added to the apical side of differentiated human intestinal epithelial Caco-2 cell monolayers that had been cultured on a semipermeable membrane. The basal medium was taken after an appropriate incubation time and added to the dioxin-responsive cells, the TCDD content then being analyzed by a luciferase assay. The amount of TCDD in the basal medium increased in a dose- and time-dependent manner, the results being sufficiently sensitive and reproducible. The inhibition of TCDD permeability to the Caco-2 cell monolayer by such food substances as chlorophyll, insoluble corn fiber and tea dregs were observed by this in vitro assessment system. The system will therefore be useful to identify food substances having a preventive effect on the intestinal absorption of dioxins.
建立了一种通过应用 Caco-2 细胞单层和稳定的二恶英反应细胞系来评估肠道二恶英吸收的系统。该稳定的二恶英反应细胞系是通过将包含人 CYP1A1 启动子的质粒引入人肝 HepG2 基因组 DNA 中，位于荧光素酶基因的上游而建立的。将 2,3,7,8-四氯二苯并二恶英（TCDD）添加到已在半透膜上培养的分化的人肠上皮 Caco-2 细胞单层的顶侧。在适当的孵育时间后，从基底培养基中取出并添加到二恶英反应细胞中，然后通过荧光素酶测定法分析 TCDD 含量。结果表明，TCDD 在基底培养基中的量呈剂量和时间依赖性增加，结果足够灵敏且可重复。通过该体外评估系统观察到叶绿素、不溶性玉米纤维和茶渣等食物物质对 Caco-2 细胞单层中 TCDD 通透性的抑制作用。因此，该系统将有助于鉴定对二恶英肠道吸收具有预防作用的食物物质。
