A new primary culture system representative of the human gastric epithelium

The gastric pit-gland unit is a highly dynamic and compartimentalized struc ture which assumes important key functions such as acid secretion, digestio n of dietary proteins and triglycerides, protection, and epithelial restitu tion following injury. However, in vitro models representative of the intac t gastric epithelium are still lacking. The current study was undertaken to investigate the possibility of generating such primary cultures from human fetal stomach. The use of Matrisperse, a nonenzymatic solution, allowed co mplete dissociation of the epithelial layer and the maintenance for at leas t 7 days of all gastric epithelial cell types in primary culture on plastic . Indirect immunofluorescence and Western blot analyses confirmed the purit y of epithelial cultures, composed of 60% mucus-secreting cells, 25% zymoge nic chief cells, 5% parietal cells, and a small proportion of mitotic precu rsors. Their functionality was demonstrated by the presence of zonulae occl udens and adherens at cell to cell contacts, [H-3]thymidine incorporation, Periodic acid Schiff staining, and expression of growth factor receptors (E GF/TGF alpha, IGF1, HGF, KGF), gastric H+/K+-ATPase, pepsinogen (Pg5), and human gastric lipase (HGL). Chief cells were able to produce and secrete bo th Pg5 and HGL and to respond to EGF treatment. In conclusion, we developed a new primary culture system of human gastric epithelium characterized for the first time by the absence of added matrix and the maintenance of funct ional chief cells. It represents an experimental breakthrough that will ser ve applications in investigating the actions of hormones, mesenchymal growt h factors, and basement membrane proteins on human gastric functions in vit ro. (C) 1999 Academic Press.