Figure 5.

Pharmacologically Inhibiting LRRK2 Kinase Activity Partially Rescues Morphological Abnormalities

(A) LRRK2-IN-1, CZC25146, and GSK2578215A treatment reduced phosphorylation of S935 in LRRK2 G2019S sensory neurons as shown by western blot and densitometry. GAPDH was used as a protein loading control. For reference, longer exposure times allowed for the detection of S935 in control and SNCA (3×) samples.

(B and C) Representative peripherin (red) and βIII tubulin (green) images are shown for untreated and inhibitor treated conditions, with no significant impact on sensory neuron development or survival by one-way ANOVA. Nuclei are labeled in blue.

(D) LRRK2-IN-1, CZC25146, and GSK2578215A treatment significantly reduced the number of aggregates in sensory neurons derived from LRRK2 G2019S 1 and 2 compared to their respective untreated condition by one-way ANOVA. LRRK2-IN-1 and GSK2578215A treatment reduced neurite aggregation in LRRK2 G2019S het compared to its untreated condition by one-way ANOVA. CZC25146 treatment induced significant aggregate formation in control cells compared to its untreated condition by one-way ANOVA.

(E) LRRK2-IN-1, CZC25146, and GSK2578215A treatment of LRRK2 G2019S 2 resulted in a significant decrease in neurite aggregate area, whereas only CZC25146 and GSK2578215A significantly rescued neurite aggregate area in LRRK2 G2019S 1. Only LRRK2-IN-1 significantly decreased aggregate area in LRRK2 G2019S het. All three inhibitors increased aggregate area in control cells by Kruskal-Wallis test.

n.s., not significant within each cell line. ^∗p < 0.01 compared to untreated control and #p < 0.01 comparing treatment to the respective untreated condition. The scale bar represents 50 μm. n = 3 independent experiments totaling ≥50 neurons for each iPSC line.