Regulation of iron uptake and transport by transferrin in Caco-2 cells, an intestinal cell line.
Regulation of iron uptake and transport by transferrin in Caco-2 cells, an intestinal cell line.
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DOI：
10.1016/0005-2736(94)90121-x
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发表时间：
1994-06
期刊：
影响因子：
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通讯作者：
X. Alvarez-Hernandez;Margaret Smith;Jonathan Glass
中科院分区：
文献类型：
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作者：
X. Alvarez-Hernandez;Margaret Smith;Jonathan Glass
在双室室中生长的 Caco-2 细胞是肠上皮铁转运模型 (Biochim. Biophys. Acta (1991) 1070, 205–208)，用于研究基底室中载脂铁转铁蛋白 (apo-Tf) 对顶端表面 59 Fe 吸收、细胞内 59 Fe 分布和 59 Fe 转运到基底室的影响。 Caco-2 细胞在不同量的铁中生长，以获得缺铁 (FeD)、正常铁状态 (FeN) 或铁负载 (FeH) 的细胞。 apo-Tf 的作用在 FeD 细胞中最为显着，在存在 apo-Tf 的情况下，将 59 Fe 从顶端侧的 1 μM 59 Fe-抗坏血酸盐转运至基底室，测量为 (22.2±3.0)·10 4、(8.2±0.6)·10 4 和 (2.7±0.4)·10 4 原子 59 Fe/细胞/分钟分别为 apo-Tf、BSA 和不添加蛋白质。出乎意料的是，在FeD细胞中，基底外侧apo-Tf使总59 Fe摄取（即细胞内的59 Fe和转运到基底室的59 Fe）减少，apo-Tf的总摄取量为(2.6±0.3)·10 5、(4.8±0.6)·10 5和(4.8±0.7)·10 5 原子/细胞/分钟， BSA 和无添加物分别。通过在聚丙烯酰胺凝胶中等电聚焦对细胞内 59 Fe 进行分析表明，FeD 细胞中 59 Fe 与碱性 p I 和铁蛋白 (Ft) 的 p I 值一起迁移，比例为 200:1（碱性 p I 部分：铁蛋白）。 Tf的存在进一步减少了Ft中少量的59 Fe。这些研究表明，基底外侧 Tf 影响 59 Fe 的顶端摄取、 59 Fe 的细胞内分布以及 59 Fe 穿过肠上皮的转运，即使细胞内铁蛋白含量较高，后一种效应也会发生。
Caco-2 cells grown in bicameral chambers, a model of intestinal epithelial iron transport (Biochim. Biophys. Acta (1991) 1070, 205–208), were used to study the effect of apo-transferrin (apo-Tf) in the basal chamber on 59 Fe uptake from the apical surface, intracellular 59 Fe distribution, and 59 Fe transport into the basal chamber. Caco-2 cells were grown with varying amounts of iron to achieve cells that were either iron-deficient (FeD), of normal iron status (FeN), or iron-loaded (FeH). The effect of apo-Tf was most marked in FeD cells with the transport of 59 Fe from 1 μM 59 Fe-ascorbate on the apical side to the basal chamber measured as (22.2±3.0)· 10 4,(8.2±0.6)· 10 4, and (2.7±0.4)· 10 4 atoms 59 Fe/cell/min in the presence of apo-Tf, BSA, and no added protein, respectively. Unexpectedly in FeD cells total 59 Fe uptake (ie, both 59 Fe in the cells and that transported into the basal chamber) was decreased by basolateral apo-Tf with total uptake of (2.6±0.3)· 10 5,(4.8±0.6)· 10 5, and (4.8±0.7)· 10 5 atoms/cell/min with apo-Tf, BSA, and no additions, respectively. Analysis of intracellular 59 Fe by isoelectrofocusing in polyacrylamide gels demonstrated 59 Fe migrating both with a basic p I and with the p I values of ferritin (Ft) at a ratio of 200: 1 (basic p I moiety: ferritin) in FeD cells. The presence of Tf further decreased the small amount of 59 Fe in Ft. These studies demonstrate that basolateral Tf affects the apical uptake of 59 Fe, the intracellular distribution of 59 Fe, and the transport of 59 Fe across intestinal epithelium, the latter effect occurring even when cellular content of ferritin is high.