Pathological Role of Peptidyl-Prolyl Isomerase Pin1 in the Disruption of Synaptic Plasticity in Alzheimer’s Disease

Figure 5

Blocking of Pin1 activity leads to degradation of Shank3 proteins in PSD. Cultured cortical neurons at 21 DIV were prepared on coverslips for immunofluorescence detection and in 10 cm dishes for immunoblot assay. Panels (a)–(f) showed the cultured cortical neurons of C57/BL6 mice at 21 DIV treated with vehicle (a and d), 2 μM PiB (b and e), or 0.5 μM PiB (c and f) for 24 h; panels (d), (e), and (f) were the high-magnification images of selected fields. Panels (g)–(l) showed the cultured cortical neurons of Pin1^+/+ (g and j), Pin1^+/− (h and k), and Pin1^−/− (i and l) mice at 21 DIV; panels (j), (k), and (l) were the high-magnification images of selected fields. These neurons on coverslips were fixed, permeabilized, and labeled by Shank3 antibody for immunofluorescence detection by immunocytochemistry. (m) Immunofluorescence intensity demonstrated a large PiB-induced decrease in Shank3 proteins from seven independent experiments (~90 neurons for each experimental condition, ; ). (n) Western blots showed significant decrease in the levels of Shank3 proteins in PiB-treated or in Pin1^−/− neurons compared with vehicle-treated or Pin1^+/+ neuron extracts, respectively ( dishes for each experimental condition, ; ; ).

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