Apoptosis and Gastrointestinal Disease

Kim, Dae Ghon

Abstract

Apoptosis (programmed cell death) is essential for the normal development and homeostasis of most multi-cellular organism. The morphological and biochemical characteristics of apoptosis are highly conserved during the evolution. This form of cell death can be induced by a wide range of cellular signals, which leads to activation of cell death machinery within the cell. It is generally believed that apoptosis can be divided into at least two functionally distinct pathway, i.e. extrinsic (receptor-mediated) and intrinsic (mitochondrial) pathways. Apoptosis is especially relevant in the gastrointestinal tract as the intestinal mucosa undergoes a process of continual cell turnover that is essential for maintenance of normal function. Cell proliferation is confined to the crypts, while differentiation occurs during a rapid, orderly migration up to the villus. The differentiated enterocytes, which make up the majority of the cells, then undergo a process of programmed cell death. Although apoptosis is essential for the maintenance of normal gut epithelial function, dysregulated apoptosis is seen in a number of pathological conditions. in the gastrointestinal tract and hepatobiliary system. The cellular mechanism regulating this tightly regimented process have not been clearly defined and this topic represents an area of active investigation as delineation of this process will lead to a better understanding of normal gut and hepatobiliary system.