Hepatocyte growth factor regulates the development of highly pure cultured chief cells from rat stomach by stimulating chief cell proliferation in vitro

Abstract

The physiology of gastric epithelial cells is often studied by using cancer cell lines, which may or may not provide information relevant to normal cells. Because few models exist to study chief cell physiology in vitro, our purpose was to develop primary cultured chief cells from rodent species that are structurally and functionally similar to native chief cells. For this, isolated chief cells from the rat stomach, purified by counterflow elutriation and density gradient centrifugation, were grown in media with growth factors. Purity and the continuity of tight junctions were determined, and permeability, viability, transepithelial resistance (TER), cell number and proliferation, and pepsinogen secretion in response to carbachol were measured. When plated in media alone or with basic fibroblast growth factor, the isolated chief cells attached by 2 days and were confluent by 4 days after seeding. However, tight junctions were discontinuous, TER was less than 300 Ω·cm2, and permeability was high. In contrast, chief cells incubated with hepatocyte growth factor (HGF) were confluent in 3 days and had a TER greater than 2,000 Ω·cm2, continuous tight junctions, and low permeability. EGF was intermediate. HGF facilitated monolayer development by increasing cell number, which occurred by the proliferation of chief cells. Chief cell cultures, grown with HGF, consisted of more than 99% gastric intrinsic factor-expressing cells and showed robust pepsinogen secretion. Coexpression studies for neck and chief cell markers suggest that the cultures are a mixture of mature, immature, and transitional zone cells. This model will be useful for investigating mechanisms that regulate chief cell physiology in health and disease.