title: Enhancement of superoxide production and protection against heat shock by HSP27 in fibroblasts.
abstract: Extracellular superoxide production in the Chinese hamster CCL39 fibroblast cell line was detected by direct counting of luminol-enhanced chemiluminescence in the presence of horseradish peroxidase (HRP). This superoxide production, which is directly related to cell density, can be inhibited by diphenylene iodonium, a specific inhibitor of NADPH-oxidase. The O2- generation is transiently inhibited following exposure of the cells to elevated temperatures. To study the possible relationship between HSP27 and its modulation of NADPH-oxidase activity we measured the generation of O2- activity in CCL39 cells containing either the gene coding for human HSP27 or a mutant form of this gene leading to HSP27 unable to be phosphorylated. Cells with the enhanced expression of normal human HSP27 as well as the non-phosphorylatable protein exhibited a 20-fold higher superoxide production than control CCL39 cells. Furthermore, we demonstrate that accumulation of normal HSP27 appears to play a role in prevention of NADPH-oxidase inhibition by heat.
authors.affiliation: Department of Molecular Cell Biology, Utrecht University, The Netherlands.
authors.forename: J E
authors.initials: JE
authors.lastname: Souren
authors.forename: H
authors.initials: H
authors.lastname: Van Aken
authors.forename: R
authors.initials: R
authors.lastname: Van Wijk
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D005347:Fibroblasts / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D008163:Luminescent Measurements; D008165:Luminol; D013481:Superoxides / Q000378:metabolism*
chemical_list: D006360:Heat-Shock Proteins; D013481:Superoxides; D008165:Luminol