Pathophysiological mechanisms of peptides involved in the proliferation and differentiation of gastrointestinal mucosal epithelial cells.

肽参与胃肠粘膜上皮细胞增殖和分化的病理生理机制。

基本信息

批准号：
17590354
负责人：
ITOH Hiroshi
金额：
$ 2.24万
依托单位：
University of Fukui
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17590354/
关键词：
HGF HGFA HAI H2RSP Gastrointestinal tract

项目摘要

Hepatocyte growth factor (HGF) has an important role in the proliferation and differentiation of gastrointestinal epithelial cells and is activated by a specific serine proteinase, namely HGF activator (HGFA). Activity of HGFA is strictly regulated by its specific inhibitors, HGFA inhibitors type-1 and-2 (HAM and HAI-2). HAI-2-related small peptide (H2RSP) is a recently identified small nuclear peptide and the gene consists of four exons spanning approximately 1 kbp and is located in 11 kbp downstream of HAI-2 gene. In this study, we developed a specific antibody against H2RSP and investigated the expression and localization of H2RSP in normal, injured and neoplastic human intestinal tissues. In the normal intestine, H2RSP was observed in the nuclei of surface epithelial cells and this nuclear localization was impaired in regenerating epithelium. In vitro, the nuclear translocation of H2RSP was observed along with increasing cellular density, and an over-expression of H2RSP resulted in … More a reduced growth rate. In well-differentiated colorectal adenocarcinomas, H2RSP expression was down-regulated. However, a significant up-regulation of the cytoplasmic H2RSP immunoreactivity was observed in cancer cells at the invasive front. These cells showed low MIB-1 labeling, an enhanced p16 expression and nuclear β-catenin. The number of H2RSP-positive cells in the invasive front of well-differentiated adenocarcinomas was significantly higher in the cases with lymph node metastases than node-negative ones. With the pull-down assay, no apparently bound nuclear proteins were detectable. On the other hand, recombinant H2RSP specifically bound to poly (rG) beads, but not to other polynucleotides, single or double strand DNA. Among several deleted series of recombinant H2RSP, only constructs containing exon 4 region bound to poly (rG). From these results, in the normal intestine, the nuclear accumulation of H2RSP is thought to a marker of differentiated epithelial cells. Although H2RSP was down-regulated in colorectal adenocarcinomas, a paradoxical up-regulation was observed in actively invading carcinoma cells. These H2RSP positive cells at the invasive front were considered to be low proliferating and invasive subpopulation. H2RSP immunoreactivity at the invasive front may serve as a marker of invasive phenotype of well-differentiated colon cancers. In order to investigate the relationship between HGF activation and H2RSP function, we also made several constructs of functional recombinant HGF-related molecules Less

肝细胞生长因子（HGF）在胃肠道上皮细胞的增殖和分化中具有重要作用，并由特定的丝氨酸蛋白酶，即HGF激活剂（HGFA）激活，HGFA的活性受到其特定抑制剂（HGFA抑制剂型）的严格调节。 1和-2（HAM和HAI-2）是最近发现的一种小核肽，该基因由4个组成。外显子跨度约为 1 kbp，位于 HAI-2 基因下游 11 kbp。在本研究中，我们开发了一种针对 H2RSP 的特异性抗体，并研究了 H2RSP 在正常、损伤和肿瘤性人类肠道组织中的表达和定位。在肠道中，在表面上皮细胞的细胞核中观察到H2RSP，并且这种核定位在再生上皮细胞中受损。在体外，观察到H2RSP的核转位随着增加而增加。然而，细胞密度和 H2RSP 的过度表达导致生长速度降低。在分化良好的结直肠腺癌中，H2RSP 表达下调。在癌症中观察到细胞质 H2RSP 免疫反应性显着上调。这些细胞显示出低 MIB-1 标记、增强的 p16 表达和细胞核 β-连环蛋白。在有淋巴结转移的病例中，分化良好的腺癌明显高于淋巴结阴性的病例。通过 Pull-down 测定，没有检测到明显结合的核蛋白。另一方面，重组 H2RSP 与聚 (rG) 珠特异性结合。，但不与其他多核苷酸、单链或双链 DNA 在重组 H2RSP 的几个删除系列中，仅含有与聚 (rG) 结合的外显子 4 区域的构建体。在正常肠道中，H2RSP 的核积聚被认为是分化上皮细胞的标志，尽管 H2RSP 在结直肠腺癌中表达下调，但在积极侵袭的癌细胞中却观察到了相反的上调。前沿被认为是低增殖和侵袭性亚群，在侵袭性前沿的H2RSP免疫反应性可以作为分化良好的侵袭性表型的标志。为了研究HGF激活与H2RSP功能之间的关系，我们还构建了几种功能性重组HGF相关分子Less。