Figure 2.
Gadd45b overexpression leads to heterochromatin destructuration in mDA neurons
(A–E) H3K9me3 heterochromatin staining is perturbed as early as 14d after the injection of AAV8-mGadd45b. TH + neurons in the SNpc of AAV8-mGadd45b injected mice (A) display at 14d p.i. a 1.13-fold increase in the number (3.64 ± 0.12; 4.10 ± 0.12, data represented as a frequency distribution histogramm in (B) and a 1.24-fold increase in the volume (4.78 ± 0.15; 5.91 ± 0.22 μm3, (C) of H3K9me3 foci. The diffuse nucleoplasmic staining intensity (2.37 × 107 ± 557961; 1.96 × 107 ± 441292) is decreased by 1.21-fold (D) while the foci intensity (1.32 × 106 ± 54,236; 1.41 × 106 ± 64,942) remains unchanged (E).
(F–J) H3K9me3 heterochromatin staining remains perturbed up until 90d after the injection of AAV8-mGadd45b. A similar pattern as in A-E was observed at 90d p.i. with a 1.18-fold increase in the number (4.07 ± 0.17; 4.82 ± 0.20, data represented as a frequency distribution histogramm in (G) and a 1.15-fold increase in the volume (5.51 ± 0.18; 6.35 ± 0.24 μm3, (H) of H3K9me3 foci shown in (F). The diffuse nucleoplasmic staining intensity (5.66 × 107±5 × 106; 1.97 × 107 ± 573406) is decreased by 2.87-fold while the foci intensity (1.22 × 106 ± 56,943; 1.26 × 106 ± 74,064) remains unchanged (I; J). Scale bar in A and F represents 5 μm. ∗∗p < 0.01; ∗∗∗p < 0.001; ∗∗∗∗p < 0.0001; 3 mice per condition; between 510 and 534 neurons from at least nine different images were quantified per condition at 14d p.i. and 428 neurons from at least nine different images were quantified per condition at 90d p.i.. Error bars represent SEM.