title: Regulation of CD95 (Fas) expression and Fas-mediated apoptotic signaling in HLE B-3 cells by 4-hydroxynonenal.
abstract: The Fas (apo/CD95) receptor which belongs to the TNF-alpha family is a transmembrane protein involved in the signaling for apoptosis through the extrinsic pathway. During this study, we have examined a correlation between intracellular levels of 4-HNE and expression of Fas in human lens epithelial (HLE B-3) cells. Our results show that in HLE B-3 cells, Fas is induced by 4-HNE in a concentration- and time-dependent manner, and it is accompanied by the activation of JNK, caspase 3, and the onset of apoptosis. Fas induction and activation of JNK are also observed in various tissues of mGsta4 null mice which have elevated levels of 4-HNE. Conversely, when 4-HNE is depleted in HLE B-3 cells by a transient transfection with hGSTA4, Fas expression is suppressed. However, upon the cessation of hGSTA4 expression in these transiently transfected cells, Fas and 4-HNE return to their basal levels. Fas-deficient transformed HLE B-3 cells stably transfected with hGSTA4 show remarkable resistance to apoptosis. Also, the wild-type HLE B-3 cells in which Fas is partially depleted by siRNA acquire resistance to 4-HNE-induced apoptosis, suggesting an at least partial role of Fas in 4-HNE-induced apoptosis in HLE B-3 cells. We also demonstrate that during 4-HNE-induced apoptosis of HLE B-3 cells, Daxx is induced and it binds to Fas. Together, these results show an important role of 4-HNE in regulation of the expression and functions of Fas.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555-0647, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Rajendra
authors.initials: R
authors.lastname: Sharma
authors.forename: Brad
authors.initials: B
authors.lastname: Patrick
authors.forename: Abha
authors.initials: A
authors.lastname: Sharma
authors.forename: Prince V S
authors.initials: PV
authors.lastname: Jeyabal
authors.forename: Prasada M R V
authors.initials: PM
authors.lastname: Reddy
authors.forename: Manjit K
authors.initials: MK
authors.lastname: Saini
authors.forename: Seema
authors.initials: S
authors.lastname: Dwivedi
authors.forename: Shaheen
authors.initials: S
authors.lastname: Dhanani
authors.forename: Naseem H
authors.initials: NH
authors.lastname: Ansari
authors.forename: Piotr
authors.initials: P
authors.lastname: Zimniak
authors.forename: Sanjay
authors.initials: S
authors.lastname: Awasthi
authors.forename: Yogesh C
authors.initials: YC
authors.lastname: Awasthi
mesh_terms: D000447:Aldehydes / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D015536:Down-Regulation; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007908:Lens, Crystalline; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D051379:Mice; D015398:Signal Transduction / Q000502:physiology*; D019014:fas Receptor / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D000447:Aldehydes; D019014:fas Receptor; D048670:MAP Kinase Kinase 4; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; C027576:4-hydroxy-2-nonenal