Search for novel peptide hormones, which act on gastrointestinal stemcells, and its role on the regeneration of gastrointestinal epithelium

点击翻译按钮获取中文摘要

An orphan GPCR LGR5 receptor is a marker for gastrointestinal stem cells. However,the endogenous ligand for LGR5 has not been discovered. We established a cell line, whichstably expressed LGR5, and used it for a systematic assay on brain and gastrointestinaltissue peptide extracts to search for the ligands. We detected a positive signal in thebrain samples and purified it to a single peptide. By amino acid sequence analysis, wefound that the purified peptide is CGRP, a neuropeptide. We thought that CGRP should havereacted to endogenous CGRP receptors on CHO cells. The real endogenous ligands for LGR5and its relative receptors, LGR4 and LGR6, are still controversial.