APOPTOSIS IN GASTRIC EPITHELIAL-CELLS IS INDUCED BY HELICOBACTER-PYLORI AND ACCOMPANIED BY INCREASED EXPRESSION OF BAK

Carriage of the bacterium H. pylori in the human stomach is associated with evidence of increased epithelial cell apoptosis. This may be of significance in the etiology of gastritis, peptic ulcers, and neoplasi a. The ability of H. pylori to directly induce epithelial apoptosis wa s examined in vitro by fluorescence and electron microscopy, flow cyto metry, and DNA fragmentation ELISA. The induction of apoptosis by H. p ylori was time and concentration-dependent and inhibited by preventing direct bacterial-epithelial cell contact. Apoptosis was accompanied b y increased expression of Bak, With little change in expression of oth er Bcl-2 family proteins, The expression of Bak was also increased in gastric biopsies from patients colonized by H. pylori. Thus, H. pylori induces gastric epithelial cell apoptosis, by a Bak-dependent pathway . (C) 1997 Academic Press.