Effects of mesalamine on the hsp72 stress response in rat IEC-18 intestinal epithelial cells.

Abstract

Mesalamine has many effects and is commonly used for the treatment of inflammatory bowel diseases. Because sodium salicylate, a related compound, modulates the heat shock protein (hsp72) response in nonepithelial cells, the possibility that mesalamine confers cell protection by increasing intestinal epithelial hsp72 expression was examined. Rat intestinal IEC-18 cells were treated with 0.3-3 mmol/L mesalamine and thermally stressed (39 degrees C-42 degrees C) for 23 minutes. The effects of mesalamine on basal expression and the threshold and time course of hsp72 thermal induction were determined. Although mesalamine had no effects on the basal hsp72 expression or its thermal activation threshold in IEC-18 cells, it accelerated and augmented thermal induction of hsp72 within the first 2 hours of exposure. This was associated with a transient increase in heat shock factor-heat shock element binding and enhanced cellular protection against oxidant-induced injury. In contrast, both mesalamine and sodium salicylate have been shown to lower the thermal induction threshold but not to enhance the hsp72 response in HeLa cells. Mesalamine augments thermal induction of the intestinal epithelial hsp72 expression in a manner that differs from that in nonintestinal epithelial cells. This effect is accompanied by increased cellular protection against oxidant injury.