Contribution of spermidine to stimulation by hepatocyte growth factor in repair after damage of rabbit gastric mucosal cells in primary culture

Abstract

Wound-healing of the gastric mucosa is suggested to be stimulated by hepatocyte growth factor (HGF). Polyamines are shown to contribute to repair after damage in the gastric mucosa. The present study was designed to elucidate whether HGF can stimulate wound-healing of the gastric mucosa via polyamine production, using rabbit gastric mucosal cells in primary culture. A wound was made as a round cell-free area in the cell sheet of confluent cultured cells. When HGF was added to the culture medium, such denuded area was significantly reduced in size compared with the control, but the reduction was inhibited by addition of d,l-α-difluoromethylornithine (DFMO), an inhibitor of a rate-limiting enzyme (ornithine decarboxylase) of polyamine biosynthesis, to the culture medium. However, the inhibitory effect by DFMO was reversed by pretreatment with spermidine, but not with putrescine. Intracellular levels of polyamines in the whole confluent cells including the cells around the denuded area were not changed by addition of HGF, but putrescine and spermidine levels were decreased by further addition of DFMO. We conclude that spermidine may be involved in stimulation by HGF in the repair after damage of gastric mucosal cells.