Effects of membrane fatty acids on thermal and oxidative injury in the human premonocytic line U937

Abstract

Heat shock (HS) proteins (HSP) function as molecular chaperones and protect cells from thermal and oxidative injury. The signals leading to HSP synthesis, i.e. the “cellular thermometer(s),” are still a matter of debate. In the human premonocytic line U937, we investigated the effects of specific modification of membrane fatty acid (FA) composition by incubation with various saturated and unsaturated fatty acids (UFA) on the HS response and on hydrogen peroxide (H 2O 2)-induced cell death. FA readily incorporated into U937 cell membranes. UFA did not modulate the HS response but potentiated H 2O 2-mediated damage, while pre-exposure to HS protected the UFA-treated cells from this increased H 2O 2 toxicity.