title: Beta-synuclein regulates Akt activity in neuronal cells. A possible mechanism for neuroprotection in Parkinson's disease.
abstract: Recent studies have shown that the neurodegenerative process in disorders with Lewy body formation, such as Parkinson's disease and dementia with Lewy bodies, is associated with alpha-synuclein accumulation and that beta-synuclein might protect the central nervous system from the neurotoxic effects of alpha-synuclein. However, the mechanisms are unclear. The main objective of the present study was to investigate the potential involvement of the serine threonine kinase Akt (also known as protein kinase B) signaling pathway in the mechanisms of beta-synuclein neuroprotection. For this purpose, Akt activity and cell survival were analyzed in synuclein-transfected B103 neuroblastoma cells and primary cortical neurons. Beta-synuclein transfection resulted in increased Akt activity and conferred protection from the neurotoxic effects of rotenone. Down-regulation of Akt expression resulted in an increased susceptibility to rotenone toxicity, whereas transfection with a lentiviral vector encoding for beta-synuclein was protective. The effects of beta-synuclein on the Akt pathway appear to be by direct interaction between these molecules and were independent of upstream signaling molecules. Taken together, these results indicate that the mechanisms of beta-synuclein neuroprotection might involve direct interactions between beta-synuclein and Akt and suggest that this signaling pathway could be a potential therapeutic target for neurological conditions associated with parkinsonism and alpha-synuclein aggregation.
authors.affiliation: Department of Neurosciences and Pathology, University of California at San Diego, La Jolla, California 92093-0624, USA.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Pazit
authors.initials: P
authors.lastname: Bar-On
authors.forename: Gilbert
authors.initials: G
authors.lastname: Ho
authors.forename: Takato
authors.initials: T
authors.lastname: Takenouchi
authors.forename: Edward
authors.initials: E
authors.lastname: Rockenstein
authors.forename: Leslie
authors.initials: L
authors.lastname: Crews
authors.forename: Eliezer
authors.initials: E
authors.lastname: Masliah
mesh_terms: D002460:Cell Line; D006801:Humans; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D010300:Parkinson Disease / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction; D051843:Synucleins; D051844:alpha-Synuclein; D051846:beta-Synuclein
chemical_list: D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; C497604:SNCA protein, human; C497607:SNCB protein, human; D051843:Synucleins; D051844:alpha-Synuclein; D051846:beta-Synuclein; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt