title: An endoplasmic-reticulum-specific apoptotic pathway is involved in prion and amyloid-beta peptides neurotoxicity.
abstract: Prion (PrP) and amyloid-beta (Abeta) peptides are involved in the neuronal loss that occurs in Prion disorders (PrD) and Alzheimer's disease (AD), respectively, partially due to Ca(2+) dysregulation. Besides, the endoplasmic reticulum (ER) stress has an active role in the neurotoxic mechanisms that lead to these pathologies. Here, we analyzed whether the ER-mediated apoptotic pathway is involved in the toxic effect of synthetic PrP and Abeta peptides. In PrP106-126- and Abeta1-40-treated cortical neurons, the release of Ca(2+) through ER ryanodine (RyR) and inositol 1,4,5-trisphosphate (IP(3)R) receptors induces ER stress and leads to increased cytosolic Ca(2+) and reactive oxygen species (ROS) levels and subsequently to apoptotic death involving mitochondrial cytochrome c release and caspases activation. These results demonstrate that the early PrP- and Abeta-induced perturbation of ER Ca(2+) homeostasis is a death message that leads to neuronal loss, suggesting that the regulation of ER Ca(2+) levels may be a potential therapeutical target for PrD and AD.
authors.affiliation: Center for Neuroscience and Cell Biology of Coimbra, Institute of Biochemistry, Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal.
authors.forename: Elisabete
authors.initials: E
authors.lastname: Ferreiro
authors.forename: Rosa
authors.initials: R
authors.lastname: Resende
authors.forename: Rui
authors.initials: R
authors.lastname: Costa
authors.forename: Catarina R
authors.initials: CR
authors.lastname: Oliveira
authors.forename: Cláudia M F
authors.initials: CM
authors.lastname: Pereira
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism* / Q000503:physiopathology; D016229:Amyloid beta-Peptides / Q000378:metabolism / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D003576:Electron Transport Complex IV / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D006706:Homeostasis / Q000187:drug effects / Q000502:physiology; D053496:Inositol 1,4,5-Trisphosphate Receptors; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D009498:Neurotoxins / Q000378:metabolism / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000378:metabolism / Q000633:toxicity; D010455:Peptides / Q000378:metabolism / Q000633:toxicity; D017096:Prion Diseases / Q000378:metabolism* / Q000503:physiopathology; D011328:Prions / Q000378:metabolism / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000187:drug effects / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000187:drug effects / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D009498:Neurotoxins; D010446:Peptide Fragments; D010455:Peptides; D011328:Prions; D017382:Reactive Oxygen Species; D018160:Receptors, Cytoplasmic and Nuclear; D019837:Ryanodine Receptor Calcium Release Channel; C078592:amyloid beta-protein (1-40); D003576:Electron Transport Complex IV; D020169:Caspases; D002118:Calcium