title: Tauroursodeoxycholic acid modulates p53-mediated apoptosis in Alzheimer's disease mutant neuroblastoma cells.
abstract: Early onset familial Alzheimer's disease (FAD) is linked to autosomal dominant mutations in the amyloid precursor protein (APP) and presenilin 1 and 2 (PS1 and PS2) genes. These are critical mediators of total amyloid beta-peptide (Abeta) production, inducing cell death through uncertain mechanisms. Tauroursodeoxycholic acid (TUDCA) modulates exogenous Abeta-induced apoptosis by interfering with E2F-1/p53/Bax. Here, we used mouse neuroblastoma cells that express either wild-type APP, APP with the Swedish mutation (APPswe), or double-mutated human APP and PS1 (APPswe/DeltaE9), all exhibiting increased Abeta production and aggregation. Cell viability was decreased in APPswe and APPswe/DeltaE9 but was partially reversed by z-VAD.fmk. Nuclear fragmentation and caspase 2, 6 and 8 activation were also readily detected. TUDCA reduced nuclear fragmentation as well as caspase 2 and 6, but not caspase 8 activities. p53 activity, and Bcl-2 and Bax changes, were also modulated by TUDCA. Overexpression of p53, but not mutant p53, in wild-type and mutant neuroblastoma cells was sufficient to induce apoptosis, which, in turn, was reduced by TUDCA. In addition, inhibition of the phosphatidylinositide 3'-OH kinase pathway reduced TUDCA protection against p53-induced apoptosis. In conclusion, FAD mutations are associated with the activation of classical apoptotic pathways. TUDCA reduces p53-induced apoptosis and modulates expression of Bcl-2 family.
authors.affiliation: Centro de Patogénese Molecular, Faculty of Pharmacy, University of Lisbon, Portugal.
authors.forename: Rita M
authors.initials: RM
authors.lastname: Ramalho
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Borralho
authors.forename: Rui E
authors.initials: RE
authors.lastname: Castro
authors.forename: Susana
authors.initials: S
authors.lastname: Solá
authors.forename: Clifford J
authors.initials: CJ
authors.lastname: Steer
authors.forename: Cecília M P
authors.initials: CM
authors.lastname: Rodrigues
mesh_terms: D000544:Alzheimer Disease / Q000235:genetics*; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D016564:Amyloid beta-Protein Precursor / Q000235:genetics; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D020287:In Situ Nick-End Labeling / Q000379:methods; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D009154:Mutation; D009447:Neuroblastoma; D053764:Presenilin-1; D053766:Presenilin-2; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D013655:Taurochenodeoxycholic Acid / Q000494:pharmacology*; D014162:Transfection / Q000379:methods; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D016564:Amyloid beta-Protein Precursor; D000998:Antiviral Agents; D015853:Cysteine Proteinase Inhibitors; D008565:Membrane Proteins; C508853:PSEN1 protein, human; C508861:PSEN2 protein, human; D053764:Presenilin-1; D053766:Presenilin-2; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D013655:Taurochenodeoxycholic Acid; C031655:ursodoxicoltaurine; D020169:Caspases