title: Glucuronic acid is a novel inducer of heat shock response.
abstract: The elevated expression of 70 kDa heat shock protein (Hsp70) induces resistance to stress-induced apoptosis. We have screened a variety of natural products for their ability to enhance Hsp70 expression as anti-apoptotic agent. We found that glucuronic acid (GA) induced the synthesis of Hsp70 and that cells pretreated with GA were significantly tolerant to stress including heat shock and hydrogen peroxide. We also found that GA induces the production of reactive oxygen species (ROS), a process inhibited by NADPH oxidase inhibitor, diphenyleneiodonium chloride (DPI) and antioxidant N-acetylcysteine (NAC). GA-induced ROS production was also inhibited in RacN17 cell line overexpressing a dominant negative mutant of Rac1. Furthermore, GA treatment induces MAPKs activation (SAPK/JNK and p38) and Hsp70 expression in ROS dependent manner, suggesting that GA turns on the signaling pathway by generation of ROS through Rac1. We analyzed the profiles of newly synthesized proteins by GA with 2-dimensional gel electrophoresis and MALDI-TOF MS and found that two families of proteins were expressed by GA. One was similar to the protein family synthesized by heat shock (Hsp70, Hsp73, Hsp65, Hsp90, vimentin, tubulin, Ras homolog); and the other was a family of protein specific to GA (calreticulin, annexin III, thioredoxin peroxidase). These results suggest that GA-induced stress responses are mediated by ROS generation and are similar, in part, to heat shock-induced responses and GA can be possibly adopted for the protecting agent from cell death.
authors.affiliation: Center for Cell Signaling Research, Division of Molecular Life Sciences and College of Pharmacy, Ewha Womans University, Seoul, Korea.
authors.forename: Young Mee
authors.initials: YM
authors.lastname: Kim
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Song
authors.forename: Kong-Joo
authors.initials: KJ
authors.lastname: Lee
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D017318:Annexin A3 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D037282:Calreticulin / Q000378:metabolism; D002460:Cell Line; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D020723:Glucuronic Acid / Q000494:pharmacology*; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D051379:Mice; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009861:Onium Compounds / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013879:Thioredoxins / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: D037282:Calreticulin; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D009861:Onium Compounds; D017382:Reactive Oxygen Species; D014404:Tubulin; D014746:Vimentin; D013879:Thioredoxins; C007517:diphenyleneiodonium; D020723:Glucuronic Acid; D006861:Hydrogen Peroxide; D019255:NADPH Oxidases; D048049:Extracellular Signal-Regulated MAP Kinases; D017318:Annexin A3; D020830:rac1 GTP-Binding Protein; D000111:Acetylcysteine