Fig. 7
From: Alzheimer risk gene product Pyk2 suppresses tau phosphorylation and phenotypic effects of tauopathy
Pyk2 expression protects against Tau-mediated C1q deposition. A–D, Crude hippocampal, synaptosomal fractions were obtained from 9.5–10.5-month-old WT, Pyk2−/−, PS190/+ and PS190/+;Pyk2−/− animals. Lysates were separated by SDS-PAGE and immunoblotted with the antibodies indicated. A, Representative immunoblot images of hippocampal, synaptosomal fractions. B–D, Quantification of A. A significant decrease in synaptic PSD-95 expression (normalized to β-Actin) was observed in synaptosomal fractions from PS190/+;Pyk2−/− hippocampi compared to those from Pyk2−/− animals (B). When normalized to PSD-95, a significant increase in synaptic C1q expression was observed in PS190/+;Pyk2−/− hippocampi compared to those from WT and Pyk2−/− animals (C). When normalized to β-Actin, an increase in synaptic C1q expression in PS190/+;Pyk2−/− hippocampi was significant compared to those from WT, Pyk2−/− and PS190/+ animals (D). Data are graphed as mean ± SEM, one-way ANOVA with Tukey’s multiple comparisons test, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, n = 10–13 mice. E–H, Crude cortical, synaptosomal lysates were obtained from 9.5–10.5-month-old WT, Pyk2−/−, PS190/+ and PS190/+;Pyk2−/− animals and immunoblots prepared as described above. E, Representative immunoblot images of cortical, synaptosomal fractions. F–H, Quantification of E. No significant changes in cortical, synaptic PSD-95 (normalized to β-Actin) were observed in synaptosomal fractions across genotypes (F). When normalized to β-Actin, synaptic PSD-95 expression was significantly higher in Pyk2−/−, PS190/+ cortices compared to those from WT and Pyk2−/− animals (G). When normalized to β-Actin, PS190/+;Pyk2−/− cortices demonstrated significantly higher synaptic C1q expression compared to cortices from WT and PS190/+ animals (H). Data are graphed as mean ± SEM, one-way ANOVA with Tukey’s multiple comparisons test, *p < 0.05, n = 10–13 mice. I, Representative immunofluorescent images of PSD-95 immunoreactivity in dentate gyrus of 9.5–10.5-month-old WT, Pyk2−/−, PS190/+ and PS190/+;Pyk2−/− animals. Scale bar, 10 μm. J, Quantification of I. In the dentate gyrus, both PS190/+ and PS190/+;Pyk2−/− animals demonstrated significant reductions in the area occupied by PSD-95-positive puncta compare to WT and Pyk2−/− animals (I). Data are graphed as mean ± SEM, one-way ANOVA with Tukey’s multiple comparisons test, ****p < 0.0001, n = 11–13 mice. K, Representative immunofluorescent images of C1q immunoreactivity in CA3 of 9.5–10.5-month-old WT, Pyk2−/−, PS190/+ and PS190/+;Pyk2−/− animals. Scale bar, 10 μm. L, Quantification of K. PS190/+ and PS190/+;Pyk2−/− animals showed significantly higher C1q immunoreactivity (mean image intensity) in the CA3 region of the hippocampus compared WT and Pyk2−/− animals (L). Data are graphed as mean ± SEM, one-way ANOVA with Tukey’s multiple comparisons test, *p < 0.05, **p < 0.01, n = 17–19 mice. M, Representative immunofluorescent images of C1q immunoreactivity in the dentate gyrus of 9.5–10.5-month-old WT, Pyk2−/−, PS190/+ and PS190/+;Pyk2−/− animals. Scale bar, 10 μm. N, Quantification of M. Only PS190/+;Pyk2−/− animals showed significantly higher C1q immunoreactivity in the dentate gyrus compared to WT animals. Data are graphed as mean ± SEM, one-way ANOVA with Tukey’s multiple comparisons test, *p < 0.05, n = 17–19 mice