Fig. 5

Felodipine clears mutant A53T a-synuclein in iPSC-derived human neurons and in vivo. a Representative western blots for α-synuclein in iPSC-derived human neurons homozygous for A53T α-synuclein mutation treated with 100 nM felodpine for 5 days. Densitometry data mean +/− SEM (α-synuclein vs. actin loading control; n = 3 independent experiments in triplicate; one-tailed, one sample t-test). Data normalised to control, set at 100. All nine data points are shown for the control and felodipine-treated samples. The data were also significant (p = 0.008) when each of the nine data points for control and treated samples were compared by t test. b–e Male and female SNCA mice (6.5 months-old; n = 20 felodipine; n = 19 vehicle) were implanted with subcutaneous felodipine-loaded osmotic minipumps (ALZET Model 2002) for 28 days, which were replaced once at day 14. At day 27, 17 felodipine and 18 vehicle control mice were available for analysis—some mice were culled for health reasons other than drug side effects. Behaviour was tested once before implanting and 14 days and 27 days after treatment (7 and 7.5 months-old, respectively). At the end of the study, 11 mice per group were used for biochemistry (b, c) and the remainder (9 felodipine; 8 vehicle) were used for histology. b Soluble and insoluble α-synuclein fractions of brain lysates from cerebral cortex and brain stem of SNCA mice. c Quantification of densitometry insoluble α-synuclein/GAPDH. Soluble α-synuclein was not significantly different between drug and vehicle (not shown). Data are mean α-synuclein vs. GAPDH ratio +/− SEM; two-tailed unpaired t-test. d Grip strength data are means +/− SEM; two-tailed, unpaired t-test. e Unbiased estimates of the number of TH-positive neurons in SN region of felodipine-treated and vehicle-treated SNCA mice. Data are means +/− SEM; two-tailed unpaired t-test. If the data are restricted to mice that survived until the end of the study, then the p values are: c (cerebral cortex): 0.057; (Brain stem): 0.025; e: 0.015