Journal: Acta Neuropathologica
Article Title: Transcriptional mutagenesis of α-synuclein caused by DNA oxidation in Parkinson’s disease pathogenesis
doi: 10.1007/s00401-023-02632-7
Figure Lengend Snippet: S42Y α-SYN exhibits stronger aggregation over WT and accelerates aggregation of WT α-SYN protein. a Western blot showing increased aggregation of S42Y α-SYN over WT. Triton X-100-soluble supernatant or –insoluble pellet prepared from SNCA KO HEK293 cells transiently transfected with either backbone vector (Empty), WT or S42Y α-SYN were analyzed using anti-α-SYN antibody. The insoluble fraction was further analyzed using anti-pS129 α-SYN antibody, confirming stronger aggregation of S42Y. β-actin in the soluble fraction was used as an internal control. b Overexpression of S42Y in SNCA KO HEK293 cells showed significant increases in cells containing PK-resistant aggregates compared to the WT overexpression. White arrow heads, perinuclear punctate α-SYN aggregates detected with α-SYN immunofluorescence staining. Data represent mean ± SEM. ‡ p < 0.001 (Non-parametric t-test with Mann–Whitney post-hoc corrections, two-tailed p-values). c Western blot showing that overexpression of S42Y accelerates WT α-SYN aggregation. SNCA KO HEK293 cells were transfected with WT and S42Y α-SYN plasmids with various ratios, and Triton X-100 insoluble fractions were analyzed using anti-α-SYN or anti-S42Y antibodies. β-actin in the soluble fraction was used as an internal control. d Split luciferase complementation assay exhibits a small amount of S42Y accelerates WT α-SYN aggregation. SNCA KO HEK293 cells were transfected with split luciferase tagged with WT-α-SYN (S1, S2) together with various α-SYN constructs including WT, S42Y, A53T and A53E for 24, 48, and 72 h. α-SYN aggregations were assessed by luciferase activity. Data represent mean ± SEM. * p < 0.05, † p < 0.01, ‡ p < 0.001, § p < 0.0001 (One-way ANOVA with Tukey’s multiple comparison test for each time point). e ThT fluorescence traces for α-SYN fibril formation for WT, S42Y, 1:99 S42Y:WT and 10:90 S42Y:WT. The mixed monomer sample ratios represent molar equivalents. For clarity, the inset plot shows the early ThT fluorescence traces up to 20 h. The total protein concentration for each experiment was 70 μM and was conducted at a pH = 7.4 at 37 °C with shaking. Traces shown are representative of at least 3 replicates each, and error bars represent the standard error of the mean (SEM). f BCA assay results showing the amount of monomer remaining at the endpoint of the 70 μM ThT assay. Residual monomer concentrations are shown as the percentage of the starting monomer concentration (14.99% for WT; 9.63% for S42Y). Error bars represent standard deviation
Article Snippet: The antibodies used for the western blot analysis were mouse anti- α-SYN antibody (BD transduction lab #610,786), rabbit polyclonal anti-S42Y α-SYN antibody (developed from Abcam), rabbit anti-pS129 α-SYN antibody (Santa Cruz # sc135638), and mouse anti-β-actin (Sigma # A2228).
Techniques: Western Blot, Transfection, Plasmid Preparation, Control, Over Expression, Immunofluorescence, Staining, MANN-WHITNEY, Two Tailed Test, Luciferase, Construct, Activity Assay, Comparison, Fluorescence, Protein Concentration, BIA-KA, ThT Assay, Concentration Assay, Standard Deviation