Figure 10: PK2 overexpression protects against MPTP-induced neurotoxicity in mice. | Nature Communications

Figure 10: PK2 overexpression protects against MPTP-induced neurotoxicity in mice.

From: Prokineticin-2 upregulation during neuronal injury mediates a compensatory protective response against dopaminergic neuronal degeneration

Figure 10

Mice were stereotaxically injected into the striatum with either GFP-AAV or GFP-tagged PK2-AAV and allowed to reach maximal viral expression for 4 weeks. The mice were then intraperitoneally injected with 20 mg kg−1 MPTP or equal volumes of saline (vehicle), once daily for four consecutive days and euthanized 24 h after the last injection. (a) Expression of PK2 virus in the striatum by immunofluorescence microscopy. Brain sections were probed with anti-GFP (green) and anti-PK2 (red) antibodies and imaged to show that the two proteins co-localize together (× 2 and × 20 images). Scale bar, 200 μm (× 2 images); 40 μm (× 20 images). (b) PK2 overexpression levels by western blotting. Striatal protein lysates probed for either GFP or PK2 show that the PK2 virus was able to overexpress PK2 in the striatum. Since GFP was directly fused to PK2, we observed only one band corresponding to the tagged PK2-GFP fusion protein and did not detect a separate 25-kDa GFP band in the GFP-tagged PK2-AAV samples. (c–f) Mice were tested for motor activities 1 day after the last dose of MPTP. (c) Representative VersaPlot movement tracks of mice are shown. Behavioural data showing horizontal activity (d), number of movements (e) and rotarod activity (f). Data represented by group mean±s.e.m. using one-way ANOVA with Bonferroni post-test comparison and n=12–24 mice per group (**P<0.01 and ***P<0.001, relative to relevant control or MPTP-treated groups; NS, non-significant, P=0.0912 (d), 0.1048 (e), 0.55 (f) and 0.054 (h)). (g–j) PK2 AAV protects against MPTP-induced loss of dopaminergic neurons. (g) TH-DAB immunostaining in the striatum (× 2 magnification). Scale bar, 200 μm. (h) Integrated density quantification of DAB immunostaining in the striatum (one-way ANOVA with Bonferroni post-test comparison and n=12–16). (i) TH-DAB immunostaining (× 2 magnification) in the substantia nigra (SN). Scale bar, 100 μm. (j–k) Stereological counts of TH-positive (j) and Nissl-positive (k) neurons in the SN of the ventral midbrain. Data represented by group mean±s.e.m. using one-way ANOVA with Bonferroni post-test comparison and n=3 mice per group (***P<0.001, relative to relevant control or MPTP-treated groups).

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