The possible role of heat shock factor-1 in the negative regulation of heme oxygenase-1

We examined a possible role for heat shock factor- 1 (HSF-1) in the negative regulation of HO-1 gene expression in human Hep3Bhepatomacel Is responding to stimulation with 15-deoxy- Delta(12,14) -prostaglandin J(2) (15d-PGJ(2)) and arsenite. Overexpression of HSF- 1 and heat-shock experiments indicated that HSF- I repressed the 15d-PGJ(2)-and arsenite-induced HO- 1 gene expression through directly binding to the consensus heat shock element (HSE) of the HO-1 gene promoter. In addition, point mutations at specific HSE sequences of the HO-1 promoter-driven luciferase plasmid (pGL2/hHO3.2-Luc) abolished the heat shock- and HSF- I -mediated repression of reporter activity. Overall, it is possible that HSF- I negatively regulates HO- 1 gene expression, and that the HSE present in the -389 to -362 region mediates HSF- I -induced repression of human HO- I gene expression. (C) 2004 Elsevier Ltd. All rights reserved.