Effect of lithium treatment on the expression of GSK-3β isoforms and pAkt(Ser473) in the 3-month-old TgCRND8 mouse brain.

Abstract

<p>A–D: representative photomicrographs of p-GSK-3β(Ser9) immunoreactivity in the cortex and hippocampus of saline (A,C)- and lithium (B,D)-treated TgCRND8 mice showing an increased p-GSK-3β(Ser9) immunoreactivity in the deep layers of the parietal neocortex (B) and in the hippocampus (D) of the lithium group compared to the saline group. Arrows in D indicate the p-GSK-3β(Ser9) immunoreactivity in the CA3 and dentate gyrus of the hippocampus. Scale bar: 100 µm (A–D). E and F: qualitative Western blotting and densitometric analysis of p-GSK-3β(Ser9) and total GSK-3β bands, respectively. β-actin serves as a protein loading control. Statistics indicate a significant increase of p-GSK-3β (Ser9) levels in the neocortex and hippocampus of lithium-treated 3-month-old Tg mice compared with the age-matched controls and no differences in the total GSK-3β expression among the groups. *P<0.05, vs saline-treated Tg. Two-way ANOVA plus Bonferroni's post hoc test. G–J: representative photomicrographs of active GSK-3β immunoreactivity in the cortex and dentate gyrus of the hippocampus of saline (G,I)- and lithium (H,J)-treated TgCRND8 mice. Note fewer active GSK-3β positive cells in the parietal neocortex (H) and hippocampus (J) of the lithium group compared to the saline group. Arrows in I and J indicate the GSK-3β immunoreactivity in the dentate gyrus. Scale bar:100 µm (G–J). K: qualitative Western blotting and densitometric analysis of p-GSK-3β(Tyr216) protein levels in the cortex and hippocampus of saline- and lithium-treated TgCRND8 mice. Statistics indicate a significant reduction of p-GSK-3β(Tyr216) levels in the cortex and hippocampus of lithium-treated 3-month-old Tg mice compared with the age-matched controls. Student's t test: *P<0.05, lithium-treated Tg vs saline-treated Tg mice. (L) qualitative Western blotting and densitometric analysis of pAkt(Ser473) in the cortex and hippocampus of saline- and lithium-treated wt and Tg mice. Statistics indicate a slight but significant increase in the levels of this kinase by lithium treatment in the Tg mice. Two-way ANOVA plus Bonferroni's post hoc test: *P<0.05, saline-treated Tg vs lithium-treated Tg mice. Data are presented as mean ± S.E.M. β-actin serves as a protein loading control. Ctx: Cortex; Hippo: hippocampus, S = saline, L = lithium, Tg: TgCRND8.</p