INDUCTION OF LACTASE BIOSYNTHESIS IN THE HUMAN INTESTINAL EPITHELIAL-CELL LINE CACO-2
INDUCTION OF LACTASE BIOSYNTHESIS IN THE HUMAN INTESTINAL EPITHELIAL-CELL LINE CACO-2
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DOI：
10.1111/j.1432-1033.1994.tb19969.x
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发表时间：
1994-01-15
期刊：
影响因子：
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通讯作者：
NAIM, H
中科院分区：
文献类型：
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作者：
HAURI, HP;SANDER, B;NAIM, H
人结肠腺癌细胞系Caco-2在可渗透支持物上培养时形成分化的肠细胞样细胞单层。融合后，Caco-2细胞表达许多刷状缘酶，包括乳糖酶-根皮苷水解酶，蔗糖酶-异麦芽糖酶和二肽基肽酶IV。我们已经研究了，特别强调乳糖酶根皮苷水解酶，这些酶的生物合成的调制刺激第二信使系统。毛喉素诱导乳糖酶根皮苷水解酶合成约4倍，在7小时内，抑制蔗糖酶异麦芽糖酶的合成，并对二肽基肽酶IV的影响不大。二丁酰cAMP，8-溴cAMP和血管活性肠肽也增加乳糖酶根皮苷水解酶的生物合成，表明cAMP依赖性调节。乳糖酶-根皮苷水解酶生物合成的诱导可被放线菌素D抑制，并且在此之前，乳糖酶-根皮苷水解酶mRNA水平增加了四倍，这表明转录控制。佛波醇12-肉豆蔻酸酯13-乙酸酯对刷状缘酶的合成有抑制作用，特别是对蔗糖酶-异麦芽糖酶的抑制作用，并阻断毛喉素诱导的乳糖酶-根皮苷水解酶的生物合成。乳糖酶根皮苷水解酶的合成也诱导氢化可的松，但最大的诱导需要至少3天，在此期间，蔗糖酶异麦芽糖酶的合成减少。结果表明，相反的调节乳糖酶根皮苷水解酶和蔗糖酶异麦芽糖酶通过cAMP和皮质类固醇，并建议Caco-2细胞系可以作为一个模型系统，以研究方面的体液调节人类肠道刷状缘酶在细胞培养。
The human colonic adenocarcinoma cell line Caco-2 forms monolayers of differentiated enterocyte-like cells when cultured on permeable supports. After confluency, Caco-2 cells express a number of brush-border enzymes including lactase-phlorizin hydrolase, sucrase-isomaltase and dipeptidylpeptidase IV. We have studied, with particular emphasis on lactase-phlorizin hydrolase, the modulation of biosynthesis of these enzymes by stimulating second messenger systems. Forskolin induced lactase-phlorizin hydrolase synthesis approximately fourfold within 7 h, suppressed sucrase-isomaltase synthesis, and had little effect on dipeptidylpeptidase IV. Dibutyryl-cAMP, 8-bromo-cAMP and vasoactive intestinal peptide also increased lactase-phlorizin hydrolase biosynthesis, indicating c-AMP dependent regulation. The induction of lactase-phlorizin hydrolase biosynthesis could be inhibited by actinomycin D and was preceded by a fourfold increase in lactase-phlorizin hydrolase mRNA levels, suggesting transcriptional control. Phorbol 12-myristate 13-acetate had an inhibitory effect on brush-border enzyme synthesis, in particular on sucrase-isomaltase, and blocked the forskolin-induced biosynthesis of lactase-phlorizin hydrolase. Lactase-phlorizin hydrolase synthesis was also inducible by hydrocortisone, but maximal induction required at least 3 days during which time sucrase-isomaltase synthesis diminished. The results indicate opposite regulation of lactase-phlorizin hydrolase and sucrase-isomaltase via cAMP and corticosteroids, and suggest that the Caco-2 cell line can serve as a model system to study aspects of the humoral regulation of human intestinal brush-border enzymes in cell culture.