Figure 4. Neuroprotection by CPE-ΔN is mediated by FGF2.

A. Bar graph shows the quantification by qRT-PCR of FGF2 mRNA in primary cultured rat cortical neurons after transduction with CPE-ΔN or LacZ (control) viral vectors. Data are normalized against 18S RNA and presented as a % compared to control (LacZ) cells. Values are the mean ± SEM (n = 5), t test, ** p<0.01. At least three independent experiments were done. Data shown represent all the experiments combined. B. Bar graph shows the levels of secreted FGF2 by ELISA in primary cultured rat cortical neurons after transduction with CPE-ΔN or LacZ (control) viral vectors. Values are the mean ± SEM (n = 4), t test, * p<0.05. Two independent experiments were done. Data shown represent one experiment. C. Top panel: Western blot analysis of FGF2 protein in primary cortical neurons, transduced with CPE-ΔN or LacZ viral vectors and subsequently challenged with or without glutamate for 24 h. Actin was also analyzed and served as an internal control for protein load; Bottom panel: Bar graphs show the quantification of FGF2 protein normalized to actin and expressed as a % compared to vehicle treated control cells. Note that CPE-ΔN significantly inhibited the glutamate-induced decrease in FGF2 protein in primary cultured cortical neurons. At least three independent experiments were done. Data shown represent all the experiments combined. D. Bar graphs show WST activity, indicative of cell viability of rat cortical neurons with and without transduction of CPE-ΔN construct and treated with and without glutamate in the continued presence or absence of FGF receptor inhibitor, PD166285. Note the neuroprotective effect of CPE-ΔN was blocked by PD166285 in primary cultured cortical neurons, indicating that FGF2 mediates the neuroprotective effect of CPE-ΔN. Two independent experiments were done. Data shown represent one experiment. n = 6/group (C); 5/group (D). Values are mean ± SEM, one-way ANOVA followed by Tukey test, *p<0.05.