Fig. 2

Lrrk2 knockout cells display increased canonical Wnt activity. a-d Wild-type and Lrrk2 knockout cells were co-transfected with TOPflash or FOPflash and TK-renilla. a In the absence of canonical Wnt pathway activation, TOPflash activity 24-h post-transfection was significantly higher in Lrrk2 knockout cells than wild-type controls (n = 36; T-test, p < 0.001). No difference was detected in FOPflash values (n = 30). b Overnight transfection followed by 6-h treatment with 50 ng/ml recombinant Wnt3a elicited a further increase in TOPflash activity in Lrrk2 knockout cells relative to wild-type (1-way ANOVA: n = 9; F = 19.143, p < 0.001; Bonferroni post-hoc analysis: p < 0.001 versus all other conditions). No significant changes in FOPflash values were detected (n = 6, F = 0.40, p = 0.989). c Overnight transfection followed by incubation for 6 h in the presence of 30 mM NaCl or LiCl. 1-way ANOVA (n = 9; F = 93.414, p < 0.001) followed by Bonferroni post-hoc analysis revealed increased LiCl-driven TOPflash activity in Lrrk2 knockout cells (p < 0.001 relative to all other conditions). No significant changes in FOPflash values were detected (n = 6; F = 2.391, p = 0.1). d Co-transfection with FLAG-β-catenin or empty vector revealed a marked activation of TOPflash by β-catenin in Lrrk2 knockout cells relative to wild-type cells (n = 9; 1-way ANOVA (F = 128.490, p < 0.001; Bonferroni post-hoc analysis, p < 0.001 versus all other conditions). No significant changes in FOPflash values were detected (n = 9, F = 0.165, p = 0.919)