Fig. 3. FKBP12 potentiates the resilience of neurons to stress response.

(A) Representative blot image showed the elevation of FKBP12 in neurons transduced with FKBP12 AAV9. (B) Quantification of FKBP12 in neuronal lysate overexpressed with AAV9 vector. Data are expressed as means ± SEM. N = 3. Statistics by unpaired t test, ****P < 0.001. (C) Representative fluorescence-labeled images showed that overexpression of FKBP12 (green) preserved the integrity of neurons (labeled by MAP-2, magenta) and reduced the granular intensity of tau (labeled by CP13, red). Neurons were fixed at 24 hours after oTau stimulation. Scale bars, 20 μm. (D) Quantification of CP13 granular intensity as shown in (C). *P < 0.05, ***P < 0.005, and ****P < 0.001. ctrl, control. (E) Quantification of neuronal dendritic length labeled by MAP-2 as shown in (C). Data were collected from five independent experiments, expressed as means ± SEM. *P < 0.05, ***P < 0.005, ****P < 0.001. (F) Representative blot image showed the expression level of FKBP12, phosphorylated tau detected by CP13 (Tau phos Ser²⁰²) and cleaved caspase 3 in neurons transduced with FKBP12 AAV9 and/or stressed by tau oligomers. GAPDH is examined as the internal control. (G and H) Quantification of CP13 and cleaved caspase 3 band intensity. Data were normalized by GAPDH, shown as % of basal condition without FKBP12 overexpression and oTau stress, and expressed as means ± SEM. N = 3. **P < 0.01and ****P < 0.001. (I) Representative fluorescence colabeling images showed that FKBP12 knock down by small interfering RNA (siRNA) accelerated and potentiated the neuronal apoptosis (by cleaved caspase 3, magenta) induced by tau oligomers. (J and K) Quantification of MC1 (red) and cleaved caspase 3 fluorescence intensity as shown in (F), respectively. Data were collected from five independent experiments, expressed as means ± SEM. Statistics by two-way ANOVA, and post hoc multiple comparisons test by Fisher’s LSD. ***P < 0.005 and ****P < 0.001.