title: Selenomethionine prevents degeneration induced by overexpression of wild-type human alpha-synuclein during differentiation of neuroblastoma cells.
abstract: OBJECTIVE
  High levels of wild-type alpha-synuclein are found in autopsied brain samples of idiopathic Parkinson's disease (PD), some familial PD, some Alzheimer's disease (AD) and Down's syndrome with dementia. Therefore, we have investigated whether overexpression of wild-type alpha-synuclein causes degeneration during adenosine, 3',5'-cyclic monophosphate (cAMP)-induced differentiation of murine neuroblastoma (NB) cells in culture. We have also studied whether selenomethionine can modify the effect of overexpression of alpha-synuclein during differentiation of NB cells.
  
  
  METHODS
  To study these issues, we established a murine neuroblastoma (NB) clone (NBP2-PN54-C20) that expressed high levels of wild-type human alpha-synuclein as determined by real time PCR and Western blot. We have utilized RO20-1724, an inhibitor of cyclic nucleotide phosphodiesterase, and prostaglandin A1 (PGA1), a stimulator of adenylate cyclase, or RO20-1724 and dibutyryl cAMP to induce terminal differentiation in over 95% of the cell population by elevating the intracellular levels of cAMP in NB cells. The viability of cells was determined by MTT assay and LDH leakage assay, and the degeneration was documented by photomicrographs.
  
  
  RESULTS
  The results showed that overexpression of human wild-type alpha-synuclein decreased viability and increased degenerative changes in comparison to those observed in vector control cells, when differentiation was induced by treatment with RO20-1724 and PGA1, but not with RO20-1724 and dibutyryl cAMP. When selenomethionine was added to NB cells overexpressing alpha-synuclein immediately after the addition of RO20-1724 and PGA1, the viability and degenerative changes were markedly reduced, suggesting the involvement of increased oxidative stress in the mechanism of action of alpha-synuclein. This protective effect was not observed after treatment with sodium selenite or methionine.
  
  
  CONCLUSIONS
  Data suggested that Overexpression of wild-type human alpha-synuclein-decreased viability and increased the levels of degenerative changes during differentiation of NB cells were reduced by selenomethionine treatment. This suggest that one of mechanisms of action alpha-synuclein may involve increased oxidative stress.
authors.affiliation: Center for Vitamins and Cancer Research, Department of Radiology, School of Medicine, University of Colorado Health Sciences Center, Denver 80262, USA.
authors.forename: Bipin
authors.initials: B
authors.lastname: Kumar
authors.forename: Piruz
authors.initials: P
authors.lastname: Nahreini
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Hanson
authors.forename: Cynthia
authors.initials: C
authors.lastname: Andreatta
authors.forename: Judith E
authors.initials: JE
authors.lastname: Prasad
authors.forename: Kedar N
authors.initials: KN
authors.lastname: Prasad
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D051379:Mice; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D018384:Oxidative Stress; D012645:Selenomethionine / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D051844:alpha-Synuclein / Q000187:drug effects* / Q000378:metabolism
chemical_list: D051844:alpha-Synuclein; D012645:Selenomethionine