LRRK2 involvement in dopaminergic differentiation of hmNPCs. (A) Representative samples of expanded hmNPCs quantified for LRRK2 or nestin mRNA level as determined 72 h upon nucleofection with either non-specific siRNA (scrambled control siRNA) or LRRK2-specific siRNA, both relative to HMBS mRNA expression. (B) Immunoblot demonstrating knockdown of LRRK2 protein expression in hmNPCs, observed 72 h after siRNA delivery. (C) Densitometric analysis of Western blots exhibiting relative band intensities of unaffected neuronal (Tuj1) and glial (GFAP) markers but reduced TH expression, all normalized to control samples. β-actin served as loading control (D). Quantification of TH+ and TH/caspase-3 double-positive cells expressed as number of immunoreactive cells per visual field (n = 6). Data are means of 3 independent experiments ± S.E.M. *P < 0.05 vs. scrambled siRNA sample.