Figure 6.

Genetic reduction of senescent cells in aged p16-3MR mice enhances hippocampal precursor proliferation and numbers

(A) qPCR for mRfp mRNA in total mRNA from the DG of 22 month old P16-3MR mice 5 days after intraperitoneal (i.p.) injection with ABT-263 or vehicle. Values are normalized to Gapdh mRNA in the same samples and expressed as a fold change relative to vehicle-injected mice.

(B–I) Twelve month old P16-3MR mice were infused ICV for 7 days with PBS or ganciclovir (GCV), and DG sections were analyzed. In (H) mice were also injected with BrdU after 6 days of infusion.

(B and C) DG sections were stained for SA-β-Gal (B, black, arrows), and total SA-β-Gal-positive SGZ cells were quantified (C). Dashed lines indicate the SGZ/hilus border.

(D and E) DG sections were immunostained for SOX2 (D, green, arrows), and total positive SGZ cells were quantified (E).

(F) Quantification of immunostained DG sections for total GFAP-positive, SOX2-positive SGZ cells.

(G and H) DG sections from mice injected with BrdU during GCV or PBS infusion were immunostained 24 h post-BrdU to identify (G, green, arrows) and quantify (H) total BrdU-positive SGZ cells.

(I) Quantification of immunostained DG sections for GFAP-positive, KI67-positive SGZ cells, expressed as a percentage of total GFAP-positive, SOX2-positive SGZ cells as determined in (F). In all cases, error bars indicate SEM and n ≥ 3 mice/condition. In (D and G) sections were counterstained with Hoechst 33258 (blue). Scale bars: 20 μm (B) and 50 μm (D and G). ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001.