Protective effects of heat shock protein 70 induced by geranylgeranylacetone on oxidative injury in rat intestinal epithelial cells

OBJECTIVE: Geranylgeranylacetone (GGA), an anti-ulcer agent, has recently been demonstrated to protect a variety of cells and tissues via induction of heat shock protein (HSP)70 against numerous stresses. We investigated whether GGA induces HSP70 and protects against an oxidative stressor, monocrolamine (NH(2)Cl), in a rat intestinal epithelial cell line (IEC-18). MATERIAL AND METHODS: IEC-18 cells pretreated with GGA (0.1-10 microM) were subjected to injury induced by NH(2)Cl. Cell viability was assessed, and endogenous HSP70 levels were determined by enzyme-linked immunosorbent assay in IEC-18 cells. RESULTS: Treatment with GGA (0.1-10 microM) was found rapidly to elevate HSP70 levels and to protect against NH(2)Cl-induced injury in IEC-18 cells. Furthermore, quercetin, an inhibitor of HSP70 synthesis, diminished the protective effects of GGA in IEC-18 cells upon NH(2)Cl-caused injury. CONCLUSIONS: The results of this study suggest that GGA plays an important role in defense mechanisms against oxidative injury in the intestine, primarily via induction of HSP70.