Expression of leptin in two‐layered culture of gastric mucous cells and fibroblasts: effect of Helicobacter pylori attachment

Summary Background : Our recent histochemical studies have revealed an increase in myofibroblasts and in leptin and its receptor in endothelial cells, and myofibroblasts in Helicobacter pylori‐infected human and Mongolian gerbil fundic mucosa. Aim : The present study was undertaken to clarify the H. pylori–induced interaction between leptin in cultured gastric surface mucous cells and fibroblasts. Methods : GSM06 cells were incubated with an air− liquid interface on a collagen gel layer containing mouse fibroblast cell line L929. Medium containing H. pylori bacilli (ATCC43504) at 10–100 times higher concentration than the GSM06 cells was added from the luminal side and the localization of leptin was observed by immunohistochemistry. The transformation of L929 cells to myofibroblasts was detected by electron microscopy and PR 2D3 immunoreactivity. Results : L929 cells in the control group showed a spindle shape with scarce cytoplasm. In the H. pylori‐treated group, L929 cells showed features characteristic of myofibroblasts, and most GSM06 and L929 cells showed leptin immunoreactivity. In contrast, L929 cells incubated with H. pylori alone did not undergo this differentiation. Conclusions : Attachment of H. pylori to surface epithelial cells caused conversion of fibroblasts to myofibroblasts. We suggest that leptin plays a role in this transformation.