title: Permeability transition pore-mediated mitochondrial superoxide flashes mediate an early inhibitory effect of amyloid beta1-42 on neural progenitor cell proliferation.
abstract: Cellular damage by reactive oxygen species and altered neurogenesis are implicated in the etiology of AD and the pathogenic actions of amyloid β-peptide (Aβ); the underlying mechanisms and the early oxidative intracellular events triggered by Aβ are not established. In the present study, we found that mouse embryonic cortical neural progenitor cells exhibit intermittent spontaneous mitochondrial superoxide (SO) flashes that require transient opening of mitochondrial permeability transition pores (mPTPs). The incidence of mitochondria SO flash activity in neural progenitor cells (NPCs) increased during the first 6-24 hours of exposure to aggregating amyloid β-peptide (Aβ1-42), indicating an increase in transient mPTP opening. Subsequently, the SO flash frequency progressively decreased and ceased between 48 and 72 hours of exposure to Aβ1-42, during which time global cellular reactive oxygen species increased, mitochondrial membrane potential decreased, cytochrome C was released from mitochondria and the cells degenerated. Inhibition of mPTPs and selective reduction in mitochondrial SO flashes significantly ameliorated the negative effects of Aβ1-42 on NPC proliferation and survival. Our findings suggest that mPTP-mediated bursts of mitochondrial SO production is a relatively early and pivotal event in the adverse effects of Aβ1-42 on NPCs. If Aβ inhibits NPC proliferation in the brains of AD patients by a similar mechanism, then interventions that inhibit mPTP-mediated superoxide flashes would be expected to protect NPCs against the adverse effects of Aβ.
authors: Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA.
authors: Yan
authors: Y
authors: Hou
authors: Laboratory of Immunology, National Institute on Aging Intramural Research Program, Baltimore, MD, USA.
authors: Paritosh
authors: P
authors: Ghosh
authors: Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA.
authors: Ruiqian
authors: R
authors: Wan
authors: Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA.
authors: Xin
authors: X
authors: Ouyang
authors: Institute of Molecular Medicine and National Laboratory of Biomembrane and Membrane Biotechnology, Peking University, Beijing, China.
authors: Heping
authors: H
authors: Cheng
authors: Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address: mattsonm@grc.nia.nih.gov.
authors: Mark P
authors: MP
authors: Mattson
authors: Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA. Electronic address: chengai@mail.nih.gov.
authors: Aiwu
authors: A
authors: Cheng
mesh_terms: D000544:Alzheimer Disease / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000009:adverse effects*; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D009474:Neurons / Q000166:cytology*; D022022:Nuclear Pore / Q000378:metabolism*; D010446:Peptide Fragments / Q000009:adverse effects*; D010539:Permeability; D017382:Reactive Oxygen Species / Q000009:adverse effects / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology*; D013481:Superoxides / Q000009:adverse effects* / Q000378:metabolism*
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D017382:Reactive Oxygen Species; C075222:amyloid beta-protein (1-42); D013481:Superoxides; D045304:Cytochromes c
keywords: Alzheimer's disease; Amyloid β-peptide; ERK; Mitochondrial permeability transition pore; Neurogenesis; SOD