Cells from ZS patients show defects in cholesterol enrichment in the ciliary membrane and Shh signal transduction (A) Primary skin fibroblasts from a normal individual, SLOS patient, ZS patients, X-ALD patient, and NPC patient incubated for 24 h without serum were immunostained with anti-pericentrin (red) and anti-acetylated tubulin (blue) antibodies.Figure 1Primary skin fibroblasts from a normal individual, SLOS patient, ZS patients, X-ALD patient, and NPC patient incubated for 24 h without serum were immunostained with anti-pericentrin (red) and anti-acetylated tubulin (blue) antibodies. Cholesterol was stained with Filipin III (green). Arrows indicate primary cilia. Scale bar, 5 μm. The intensity of Filipin III signal at primary cilia from (a) was remarkably reduced in SLOS and ZS patient cells (**p<0.01: one-way ANOVA with Tukey's HSD, n=3: 45-50 cells per experiment). In the boxplot, medians, 25th/75th percentile and min/max were represented by the central lines, the box limits, and the whiskers/error bars, representatively. Immunofluorescent staining of primary skin fibroblasts in quiescent G0 phase treated with 50 nM Shh-N for 24 h using anti-Smo (green), anti-acetylated-tubulin (blue), and anti-γ-tubulin (red) antibodies. Arrows indicate primary cilia. Scale bar, 2.5 μm. Quantification of proportion of Smo-positive ciliated cells upon Shh-N stimulation from (C). The populations of Smo-positive ciliated fibroblasts from the SLOS and ZS patients were significantly reduced (mean ± s.d.: ***p<0.001: one-way ANOVA with Tukey's HSD, n=3: 100 cells per experiment). The Smo intensity at primary cilia in the fibroblasts from (C). The ciliary localization of Smo upon Shh-N stimulation was significantly impaired in fibroblasts from the SLOS and ZS patients (***p<0.001: one-way ANOVA with Tukey's HSD, n=3: 90-100 cells per experiment). In the boxplot, medians, 25th/75th percentile and min/max were represented by the central lines, the box limits, and the whiskers/error bars, representatively. Primary fibroblasts from a normal individual, and SLOS and ZS patients were treated with 1.5% methyl-β-cyclodextrin for 45 min to remove cellular cholesterol, and then incubated with or without cholesterol (cholesterol/methyl-β-cyclodextrin complex) for 1 h. After washing out the exogenous cholesterol, the fibroblasts were stimulated with 50 nM Shh-N for 24 h in the presence of pravastatin, and then immunostained with anti-Smo (green), anti-acetylated-tubulin (blue), and anti-pericentrin (red) antibodies. For the alternative cholesterol complementation, LDL (0.06 mg/ml) was co-incubated with Shh-N and pravastatin for 24 h after methyl-β-cyclodextrin-mediated cholesterol depletion. Scale bar, 2.5 μm. Quantification of the Smo intensity at primary cilia in the fibroblasts from (F). The ciliary accumulation of Smo upon the Shh-N stimulation of fibroblasts from an SLO patient was restored by the complementation of both exogenous cholesterol/methyl-β-cyclodextrin complex and LDL, while that of cells from ZS patients was efficiently rescued by not LDL but cholesterol/methyl-β-cyclodextrin complex (*p<0.05, **p<0.01, ***p<0.001: one-way ANOVA with Tukey's HSD, n=3: 90-100 cells per experiment). In the boxplot, medians, 25th/75th percentile and min/max were represented by the central lines, the box limits, and the whiskers/error bars, representatively.