Growth Factor Signal Transduction in Human Intestinal Cells

Abstract

One of the basic biological problems in the area of developmental gastroenterology is to understand the factors and mechanisms controlling the intestinal epithelial cell growth and differentiation. Enterocytes are the type of cells undergoing a rapid turnover during development and mature life. Cells in the crypt are rapidly dividing and less differentiated, whereas cells at the villus tip are terminally differentiated. Furthermore, there is a differential gene expression in both crypt cells and villus cells between the neonatal and adult intestine. Increasing evidence indicates that the control of enterocyte proliferation and differentiation appears to be mediated not only by endocrine or paracrine but also by autocrine mechanisms^1,2. Table 1 lists several growth factors that may potentially target at the human intestinal cells. No matter how the production of growth factors are regulated, they must interact with their specific cell-surface receptors. Ligand-receptor interaction on the cell surface is then translated into activation of intracellular signaling pathways, triggering a sequence of events that eventually leads to cell division or differentiation.