title: Geldanamycin increases 4-hydroxynonenal (HNE)-induced cell death in human retinal pigment epithelial cells.
abstract: Development of age-related macular degeneration (AMD) is associated with functional abnormalities and cell death in retinal pigment epithelial (RPE) cells attributable to oxidative stress. To minimize the adverse effects of oxidative stress, cells activate their defence systems, e.g., via increased expression of heat shock protein (Hsp), activation of stress sensitive AP-1 and NF-kappaB transcription factors. In this study, we examined the accumulation of Hsp70 protein, activation of AP-1 and NF-kappaB transcription factors in human ARPE-19 cells subjected to a 4-hydroxynonenal (HNE)-induced oxidative stress. In addition, the influence of Hsp90 inhibitor geldanamycin (GA) was studied in HNE-treated cells. Mitochondrial metabolic activity and apoptosis were determined to evaluate cell death in the ARPE-19 cells. The ARPE-19 cells showed increased accumulation of Hsp70 protein before of the cytotoxic hallmarks appearing in response to HNE. In contrast, increased DNA-binding activities of AP-1 or NF-kappaB transcription factors were not seen under HNE insults. Interestingly, GA significantly increased cell death in the HNE-treated cells, which was involved in caspase-3 independent apoptosis. This study reveals that the Hsps have an important role in the cytoprotection of RPE cells subjected to HNE-derived oxidative stress.
authors.affiliation: Department of Ophthalmology, University of Kuopio, 70211 Kuopio, Finland. kaarnira@messi.uku.fi
authors.forename: Kai
authors.initials: K
authors.lastname: Kaarniranta
authors.forename: Tuomas
authors.initials: T
authors.lastname: Ryhänen
authors.forename: Hannu M
authors.initials: HM
authors.lastname: Karjalainen
authors.forename: Mikko J
authors.initials: MJ
authors.lastname: Lammi
authors.forename: Tiina
authors.initials: T
authors.lastname: Suuronen
authors.forename: Anne
authors.initials: A
authors.lastname: Huhtala
authors.forename: Matti
authors.initials: M
authors.lastname: Kontkanen
authors.forename: Markku
authors.initials: M
authors.lastname: Teräsvirta
authors.forename: Hannu
authors.initials: H
authors.lastname: Uusitalo
authors.forename: Antero
authors.initials: A
authors.lastname: Salminen
mesh_terms: D000447:Aldehydes / Q000633:toxicity*; D016227:Benzoquinones; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000502:physiology; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D024202:Electrophoretic Mobility Shift Assay; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis; D018841:HSP90 Heat-Shock Proteins / Q000502:physiology; D006801:Humans; D047029:Lactams, Macrocyclic; D016328:NF-kappa B / Q000502:physiology; D018384:Oxidative Stress / Q000187:drug effects; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000187:drug effects*; D011809:Quinones / Q000494:pharmacology*; D013778:Tetrazolium Salts; D013844:Thiazoles; D018808:Transcription Factor AP-1 / Q000502:physiology
chemical_list: D000447:Aldehydes; D016227:Benzoquinones; D015853:Cysteine Proteinase Inhibitors; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D016328:NF-kappa B; D011809:Quinones; D013778:Tetrazolium Salts; D013844:Thiazoles; D018808:Transcription Factor AP-1; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; C022616:thiazolyl blue; C027576:4-hydroxy-2-nonenal; C001277:geldanamycin