Iwakiri D, Podolsky D K
Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
Gastroenterology. 2001 May;120(6):1372-80. doi: 10.1053/gast.2001.24029.
BACKGROUND & AIMS: Keratinocyte growth factor (KGF) is an epithelial cell-specific growth factor. Previous reports demonstrated that KGF induces differentiation of epithelial cells of gastrointestinal tract in vivo, especially goblet cell-specific lineage stimulation. Intestinal trefoil factor (ITF) is selectively expressed in intestinal goblet cells and its expression correlates with intestinal goblet cell differentiation. In this study, we analyzed the mechanism of KGF modulation of goblet cell differentiation through characterization of its effects on ITF gene expression.
Subclone H2 of the human colonic epithelial cell line HT-29, which can be induced to intestinal goblet cells, was treated with KGF and characterized by Northern and Western blot analyses, transient transfection assays, and electrophoretic mobility shift assays (EMSAs).
KGF promoted differentiation of H2 cells to goblet cells as reflected by induced ITF expression. Transient transfection assays revealed that KGF regulates mouse ITF transcription through the goblet cell silencer inhibitor (GCSI) element, which is essential for goblet cell-specific expression of ITF. EMSAs showed that KGF induces GCSI binding protein (GCSI-BP).
KGF promotes goblet cell differentiation through the induction of GCSI-BP, a goblet cell-specific transcription factor. GCSI-BP may play a central role in intestinal goblet cell differentiation.
角质形成细胞生长因子（KGF）是一种上皮细胞特异性生长因子。先前的报道表明，KGF在体内可诱导胃肠道上皮细胞分化，尤其是对杯状细胞特异性谱系的刺激。肠三叶因子（ITF）在肠道杯状细胞中选择性表达，其表达与肠道杯状细胞分化相关。在本研究中，我们通过表征KGF对ITF基因表达的影响，分析了KGF调节杯状细胞分化的机制。
人结肠上皮细胞系HT-29的亚克隆H2可被诱导分化为肠道杯状细胞，用KGF处理该细胞，并通过Northern和Western印迹分析、瞬时转染试验及电泳迁移率变动分析（EMSA）进行表征。
KGF通过诱导ITF表达促进H2细胞向杯状细胞分化。瞬时转染试验表明，KGF通过杯状细胞沉默子抑制剂（GCSI）元件调节小鼠ITF转录，该元件对ITF的杯状细胞特异性表达至关重要。EMSA显示KGF诱导GCSI结合蛋白（GCSI-BP）。
KGF通过诱导杯状细胞特异性转录因子GCSI-BP促进杯状细胞分化。GCSI-BP可能在肠道杯状细胞分化中起核心作用。
