Overexpression of alpha-synuclein decreased viability and enhanced sensitivity to prostaglandin E(2), hydrogen peroxide, and a nitric oxide donor in differentiated neuroblastoma cells.
Increased accumulation of alpha-synuclein is associated with certain neurodegenerative diseases including Parkinson's disease (PD) and Alzheimer's disease (AD). One mechanism of alpha-synuclein-induced toxicity involves increased oxidative stress. It was unknown whether neurons overexpressing alpha-synuclein would exhibit increased sensitivity to hydrogen peroxide (H(2)O(2)) or 3-morpholinosydnonimine (SIN-1; a nitrous oxide donor). To study this, we developed a murine neuroblastoma (NB) cell line that overexpresses wild-type human alpha-synuclein (NBP2-PN54) under the control of the cytomegalovirus (CMV) promoter using a retroviral vector. Human alpha-synuclein mRNA and protein were readily detectable in NBP2-PN54 cells. Results showed that differentiated NBP2-PN54 cells exhibited decreased viability in comparison to differentiated vector (NBP2-PN1) and parent (NBP2) control cells. These cells also exhibited increased sensitivity to PGE(2), H(2)O(2) and SIN-1. Because of involvement of proteasome inhibition in neurodegeneration, we also investigated whether treatment of differentiated NBP2-PN54 cells with PGE(2), H(2)O(2) or SIN-1 inhibits proteasome activity. Results showed that H(2)O(2) and SIN-1 inhibited proteasome activity, but PGE(2) did not. These results suggest that overexpression of alpha-synuclein not only participates directly in degeneration of neurons, but it also increases the vulnerability of neurons to other potential neurotoxins.
Prasad
Judith E
JE
Center for Vitamins and Cancer Research, Department of Radiology, School of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.
Kumar
Bipin
B
Andreatta
Cynthia
C
Nahreini
Piruz
P
Hanson
Amy J
AJ
Yan
Xiang Dong
XD
Prasad
Kedar N
KN
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D015232:Dinoprostone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D051379:Mice; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000187:drug effects / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D051843:Synucleins; D014162:Transfection; D014407:Tumor Cells, Cultured; D051844:alpha-Synuclein
D009419:Nerve Tissue Proteins; D020030:Nitric Oxide Donors; C497604:SNCA protein, human; C497605:Snca protein, mouse; D051843:Synucleins; D051844:alpha-Synuclein; C002385:linsidomine; D006861:Hydrogen Peroxide; D008981:Molsidomine; D015232:Dinoprostone