FIGURE 4.

The Ptch1-mediated Shh pathway inhibition impairs neuronogenesis and reduces neurite length but not astrogliogenesis in NPCs from Ts65Dn mice. A, shown are the percentages of β-tubulin III- and GFAP-positive cells in 6-day-differentiated NPC cultures from euploid (EU; n = 8) and Ts65Dn (TS; n = 8) mice. NPCs were treated with SAG (250 nm), cyclopamine (CYC; 10 μg/ml), or Ptch1 antisense oligonucleotide (AS-Ptch1; 10 μm) throughout the entire differentiation period. Data are given as a percentage of the euploid untreated condition (dashed line). Values represent the mean ± S.E. *, p < 0.05; **, p < 0.01; ***, p < 0.001 (Bonferroni test after ANOVA). B, quantification of neurite outgrowth of β-tubulin III-positive cells from differentiated NPC cultures from euploid (n = 8) and Ts65Dn (n = 8) mice is shown. NPC cultures were treated as specified in A. Values represent the mean ± S.E. ***, p < 0.001 as compared with euploid condition; ##, p < 0.01 as compared with untreated trisomic samples (Bonferroni test after ANOVA). C, the diagram shows the Shh pathway, the inhibition exerted by Ptch1 on Smo, and the negative and positive effect exerted by cyclopamine and SAG, respectively, on Smo.