title: Alpha-synuclein knockdown attenuates MPP+ induced mitochondrial dysfunction of SH-SY5Y cells.
abstract: Alpha-synuclein is one of the main constituents of Lewy bodies and plays an important role in the pathology of Parkinson's disease. Mutation or overexpression of alpha-synuclein causes Parkinson's disease, and downregulation of alpha-synuclein resists MPP(+)-induced cell death, but the mechanism remains elusive. In this study, we attempted to explore the effect of alpha-synuclein knockdown on mitochondrial function in MPP(+)-treated SH-SY5Y cells. We reconstructed the short hairpin RNA expression vector, pGenesil-2, specially targeting alpha-synuclein mRNA, and it was stably transfected into SH-SY5Y cells. Cell viability, nuclear morphology, and mitochondrial membrane potential were then detected, and the expression of alpha-synuclein, cytochrome c, Bcl-2 and Bax were analyzed by Western blotting. The results showed that after exposure to 500 microM MPP(+) for 24 h, about 41.0+/-1.5% control cells showed low mitochondrial membrane potential. However, the percentage was 13.6+/-1.2% in MPP(+) treated alpha-synuclein knockdown cells. MPP(+) induced cytochrome c release significantly, which was about 3.1-fold compared with that of control. However, in alpha-synuclein knockdown cells, the release of cytochrome c was blocked, which was about 1.4-fold compared with that of control. The Bcl-2/Bax ratio of SH-SY5Y cells reduced to 35.5+/-3.8% after MPP(+) treatment, and this ratio was 85.2+/-3.0% in MPP(+) treated alpha-synuclein knockdown cells. These data suggest that knockdown of alpha- synuclein might be an effective means in rescuing MPP(+)-induced mitochondrial dysfunction of SH-SY5Y cells.
authors: Department of Anatomy, Shandong University School of Medicine, 44 Wen-hua Xi Road, Jinan, Shandong Province 250012, PR China.
authors: Fengxia
authors: F
authors: Wu
authors: Wai Sang
authors: WS
authors: Poon
authors: Gang
authors: G
authors: Lu
authors: Ancong
authors: A
authors: Wang
authors: Haiwei
authors: H
authors: Meng
authors: Lei
authors: L
authors: Feng
authors: Zhenping
authors: Z
authors: Li
authors: Shuwei
authors: S
authors: Liu
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000494:pharmacology; D045744:Cell Line, Tumor; D053144:Cell Nucleus Shape / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D002491:Central Nervous System Agents / Q000494:pharmacology; D045304:Cytochromes c / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006801:Humans; D055029:Inverted Repeat Sequences; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000502:physiology*; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology*; D028361:Mitochondrial Diseases / Q000139:chemically induced / Q000503:physiopathology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051844:alpha-Synuclein / Q000235:genetics* / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494826:BAX protein, human; D002491:Central Nervous System Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051844:alpha-Synuclein; D051028:bcl-2-Associated X Protein; D045304:Cytochromes c; D015655:1-Methyl-4-phenylpyridinium