Figure 10

AICAR promotes PC-12 cell neurite extension following stimulation with NGF in the presence of glial conditioned medium. Figure A shows the scheme of treatment using glial cell-conditioned medium (see Methods) either in the presence or absence of AICAR (1 mM). Figures B shows phase contrast micrographs of PC-12 cells of control untreated cells and NGF differentiated PC-12 cells. Where figure B(i) shows control untreated cells (40× magnification) and treated with NGF (50 ng/ml) form neurites reminiscent of axonal network in neurons as shown in figure B (ii) at 40× magnification. AICAR protection against glial conditioned medium is demonstrated in figure 10C where figure (i) is vehicle (control) NGF + 1 mM AICAR treatment. Inhibition of NGF-induced neurite outgrowth observed on treatment with glia-conditioned medium (from LPS, Aβ treatment) showing aggregation of cells (ii) and its reversal in AICAR pre-treated and NGF- and conditioned medium-challenged cells (iii), (all at 20× magnification). Aβ (25–35) (1 μM) treatment was performed as one of the controls (iv) 20× magnification. Experiments were carried out in triplicate. Figure D shows a histogram plot of neurite lengths greater than or equal to 100 μm in the above experiment in vehicle-treated, condition medium-treated, AICAR-treated or Aβ- (25–35) treated PC-12 cells. Data shown are mean ± SEM. # p < 0.5 was considered significant. Figure E shows the effects of different concentrations of AICAR in the presence of fixed amount of conditioned medium on neurite outgrowth. AICAR was tried at three different concentrations against condition medium challenged cells. Values shown are relative percentage values. The neurite outgrowth was recorded after 96 h of NGF stimulation. Quantitative analysis of neurite outgrowth is from ~300 cells. The data was plotted as mean ± SD from three experiments. *p < 0.5 was considered significant. P values for Conditioned medium/AICAR treated samples * and ** significant.