Background Parkinson's disease (PD) is a neurodegenerative pathology whose molecular etiopathogenesis is not known. Novel contributions have come from familial forms of PD caused by alterations in genes with apparently unrelated physiological functions. The gene coding for alpha-synuclein (α-syn) (PARK1) has been investigated as α-syn is located in Lewy bodies (LB), intraneuronal inclusions in the substantia nigra (SN) of PD patients. A-syn has neuroprotective chaperone-like and antioxidant functions and is involved in dopamine storage and release. DJ-1 (PARK7), another family-PD-linked gene causing an autosomal recessive form of the pathology, shows antioxidant and chaperone-like activities too. Methodology/Principal Findings The present study addressed the question whether α-syn and DJ-1 interact functionally, with a view to finding some mechanism linking DJ-1 inactivation and α-syn aggregation and toxicity. We developed an in vitro model of α-syn toxicity in the human neuroblastoma cell line SK-N-BE, influencing DJ-1 and α-syn intracellular concentrations by exogenous addition of the fusion proteins TAT-α-syn and TAT-DJ-1; DJ-1 was inactivated by the siRNA method. On a micromolar scale TAT-α-syn aggregated and triggered neurotoxicity, while on the nanomolar scale it was neuroprotective against oxidative stress (induced by H2O2 or 6-hydroxydopamine). TAT-DJ-1 increased the expression of HSP70, while DJ-1 silencing made SK-N-BE cells more susceptible to oxidative challenge, rendering TAT-α-syn neurotoxic at nanomolar scale, with the appearance of TAT-α-syn aggregates. Conclusion/Significance DJ-1 inactivation may thus promote α-syn aggregation and the related toxicity, and in this model HSP70 is involved in the antioxidant response and in the regulation of α-syn fibril formation.
References
[1]
Di Monte DA (2003) The environment and Parkinson's disease: is the nigrostriatal system preferentially targeted by neurotoxins? Lancet Neurol 2: 531–538.
[2]
Fahn S (2003) Description of Parkinson's disease as a clinical syndrome. Ann N Y Acad Sci 991: 1–14.
[3]
Hardy J, Cookson MR, Singleton A (2003) Genes and parkinsonism. Lancet Neurol 2: 221–228.
[4]
Gosal D, Ross OA, Toft M (2006) Parkinson's disease: the genetics of a heterogeneous disorder. Eur J Neurol 13: 616–627.
[5]
Klein C, Schlossmacher MG (2006) The genetics of Parkinson disease: Implications for neurological care. Nat Clin Pract Neurol. 2: 136–146.
[6]
Polymeropoulos MH, Lavedan C, Leroy E, Ide SE, Dehejia A, et al. (1997) Mutation in the alpha-synuclein gene identified in families with Parkinson's disease. Science 276: 2045–2047.
[7]
Kruger R, Kuhn W, Muller T, Woitalla D, Graeber M, et al. (1998) Ala30-to-pro mutation in the gene encoding alpha-synuclein in Parkinson's disease. Nat Genet 18: 106–108.
[8]
Abeliovich A, Flint Beal M (2006) Parkinsonism genes: culprits and clues. J Neurochem 99: 1062–1072.
[9]
Tang B, Xiong H, Sun P, Zhang Y, Wang D, et al. (2006) Association of PINK1 and DJ-1 confers digenic inheritance of early-onset Parkinson's disease. Hum Mol Genet 15: 1816–1825.
[10]
Jellinger KA (2006) The morphological basis of mental dysfunction in Parkinson's disease. J Neurol Sci [Epub ahead of print].
[11]
Volles MJ, Lansbury PT Jr (2003) Zeroing in on the pathogenic form of alpha-synuclein and its mechanism of neurotoxicity in Parkinson's disease. Biochemistry 42: 7871–7878.
[12]
Klucken J, Outeiro TF, Nguyen P, McLean PJ, Hyman BT (2006) Detection of novel intracellular alpha-synuclein oligomeric species by fluorescence lifetime imaging. FASEB J 20: 2050–2057.
[13]
Hashimoto M, Rockenstein E, Masliah E (2003) Transgenic models of alpha-synuclein pathology: past, present, and future. Ann N Y Acad Sci 991: 171–188.
[14]
Fleming SM, Fernagut PO, Chesselet MF (2005) Genetic mouse models of parkinsonism: strengths and limitations NeuroRx 2: 495–503.
[15]
Singleton AB, Farrer M, Johnson J, Singleton A, Hague S, et al. (2003) alpha-Synuclein locus triplication causes Parkinson's disease. Science 302: 841.
[16]
Nishioka K, Hayashi S, Farrer MJ, Singleton AB, Yoshino H, et al. (2006) Clinical heterogeneity of alpha-synuclein gene duplication in Parkinson's disease. Ann Neurol 59: 298–309.
[17]
Lykkebo S, Jensen PH (2002) Alpha-synuclein and presynaptic function: implications for Parkinson's disease. Neuromolecular Med 2: 115–129.
[18]
Wersinger C, Prou D, Vernier P, Niznik HB, Sidhu A (2003) Mutations in the lipid-binding domain of alpha-synuclein confer overlapping, yet distinct, functional properties in the regulation of dopamine transporter activity. Mol Cell Neurosci 24: 91–105.
[19]
Ahn M, Kim S, Kang M, Ryu Y, Kim TD (2006) Chaperone-like activities of alpha-synuclein: alpha-synuclein assists enzyme activities of esterases. Biochem Biophys Res Commun 346: 1142–1149.
[20]
Chandra S, Fornai F, Kwon HB, Yazdani U, Atasoy D, et al. (2004) Double-knockout mice for alpha- and beta-synucleins: effect on synaptic functions. Proc Natl Acad Sci U S A 101: 14966–14971.
[21]
Bonifati V, Oostra BA, Heutink P (2004) Linking DJ-1 to neurodegeneration offers novel insights for understanding the pathogenesis of Parkinson's disease. J Mol Med 82: 163–174.
[22]
Hedrich K, Djarmati A, Schafer N, Hering R, Wellenbrock C, et al. (2004) DJ-1 (PARK7) mutations are less frequent than Parkin (PARK2) mutations in early-onset Parkinson disease. Neurology 62: 389–394.
[23]
Eerola J, Hernandez D, Launes J, Hellstrom O, Hague S, et al. (2003) Assessment of a DJ-1 (PARK7) polymorphism in Finnish PD Neurology 61: 1000–1002.
[24]
Choi J, Sullards MC, Olzmann JA, Rees HD, Weintraub ST, et al. (2006) Oxidative damage of DJ-1 is linked to sporadic Parkinson and Alzheimer diseases. J Biol Chem 281: 10816–10824.
[25]
Menzies FM, Yenisetti SC, Min KT (2005) Roles of Drosophila DJ-1 in survival of dopaminergic neurons and oxidative stress. Curr Biol 15: 1578–1582.
[26]
Yang Y, Gehrke S, Haque ME, Imai Y, Kosek J, et al. (2005) Inactivation of Drosophila DJ-1 leads to impairments of oxidative stress response and phosphatidylinositol 3-kinase/Akt signaling. Proc Natl Acad Sci U S A 102: 13670–13675.
[27]
Shendelman S, Jonason A, Martinat C, Leete T, Abeliovich A (2004) DJ-1 is a redox-dependent molecular chaperone that inhibits alpha-synuclein aggregate formation. PLoS Biol 2: e362.
[28]
Zhou W, Zhu M, Wilson MA, Petsko GA, Fink AL (2006) The oxidation state of DJ-1 regulates its chaperone activity toward alpha-synuclein. J Mol Biol 356: 1036–1048.
[29]
Ved R, Saha S, Westlund B, Perier C, Burnam L, et al. (2005) Similar patterns of mitochondrial vulnerability and rescue induced by genetic modification of alpha-synuclein, parkin, and DJ-1 in Caenorhabditis elegans. J Biol Chem 280: 42655–42668.
[30]
Zhang L, Shimoji M, Thomas B, Moore DJ, Yu SW, et al. (2005) Mitochondrial localization of the Parkinson's disease related protein DJ-1: implications for pathogenesis. Hum Mol Genet 14: 2063–2073.
[31]
Goldberg MS, Pisani A, Haburcak M, Vortherms TA, Kitada T, et al. (2005) Nigrostriatal dopaminergic deficits and hypokinesia caused by inactivation of the familial Parkinsonism-linked gene DJ-1. Neuron 45: 489–496.
[32]
Zhong N, Kim CY, Rizzu P, Geula C, Porter DR, et al. (2006) DJ-1 transcriptionally up-regulates the human tyrosine hydroxylase by inhibiting the sumoylation of pyrimidine tract-binding protein-associated splicing factor. J Biol Chem 281: 20940–20948.
Huang C, Cheng H, Hao S, Zhou H, Zhang X, et al. (2006) Heat Shock Protein 70 Inhibits alpha-Synuclein Fibril Formation via Interactions with Diverse Intermediates. J Mol Biol [Epub ahead of print].
[35]
Klucken J, Shin Y, Masliah E, Hyman BT, McLean PJ (2004) Hsp70 Reduces alpha-Synuclein Aggregation and Toxicity. J Biol Chem 279: 25497–25502.
[36]
Albani D, Peverelli E, Rametta R, Batelli S, Veschini L, et al. (2004) Protective effect of TAT-delivered alpha-synuclein: relevance of the C-terminal domain and involvement of HSP70. FASEB J 18: 1713–1715.
[37]
Dietz GP, Bahr M (2004) Delivery of bioactive molecules into the cell: the Trojan horse approach. Mol Cell Neurosci 27: 85–131.
[38]
Zhou W, Freed CR (2004) Tyrosine-to-cysteine modification of human alpha-synuclein enhances protein aggregation and cellular toxicity. J Biol Chem 279: 10128–10135.
