Figure 5. Stasimon-Dependent p53^S18 Phosphorylation Is Mediated by p38α MAPK.

(A) Immunofluorescence analysis of total p53 (green) in NIH 3T3-Stas_RNAi cells treated with either vehicle or MW150 and the indicated MOs. Nuclei were counterstained with DAPI (blue). Scale bar: 25 μm.

(B) Percentage of p53⁺ NIH 3T3-Stas_RNAi cells from the same treatment groups as in (A). Data represent means and SEM (n = 3). Statistics were performed with two-tailed unpaired Student’s t test. ns, not significant.

(C) Immunofluorescence analysis of p-p53^S18 (green) in NIH 3T3-Stas_RNAi cells treated with either vehicle or MW150 and the indicated MOs. Nuclei were counterstained with DAPI (blue). Scale bar: 25 μm.

(D) Percentage of p-p53^S18+ NIH 3T3-Stas_RNAi cells from the same treatment groups as in (C). Data represent means and SEM (n = 3). Statistics were performed with two-tailed unpaired Student’s t test. ***p < 0.001; ns, not significant.

(E) ChAT (red) and p53 (green) immunostaining of P11 L5 spinal cords from uninjected WT mice and SMA mice treated daily with either saline or MW150 (5 mg/kg). L5 MMC motor neurons are indicated by dotted circles and magnified in the insets. Scale bar: 100 μm.

(F) Percentage of p53⁺ L5 MMC motor neurons in the same groups as in (E). Data represent means and SEM from WT (n = 4), SMA+Vehicle (n = 4), and SMA+MW150 (n = 4). Statistics were performed with one-way ANOVA with Tukey’s post hoc test. ***p < 0.001; ns, not significant.

(G) ChAT (red) and p-p53^S18 (green) immunostaining of P11 L5 spinal cords from uninjected WT mice and SMA mice treated daily with either saline or MW150 (5 mg/kg). L5 MMC motor neurons are indicated by dotted circles and magnified in the insets. Scale bar: 100 μm.

(H) Percentage of p-p53^S18+ L5 MMC motor neurons in the same groups as in (G). Data represent means and SEM from WT (n = 4), SMA+Vehicle (n = 4), and SMA+MW150 (n = 4). Statistics were performed with one-way ANOVA with Tukey’s post hoc test. **p < 0.01, ***p < 0.001.

See also Figure S4.