Figure 4
cAMP–pCREB signal activation promotes differentiation, survival and exogenous expression maintenance of midbrain-type DA neuron. The cAMP–pCREB signal was activated in Nurr1(Lenti-pUb)+Foxa2(Retro-pLTR)-transduced NPCs by treatment of cAMP (0.5 mM) or co-transduction with ca-PKA (using lenti-pUb vector). (a, b) Effect of cAMP–pCREB signal activation on Nurr1+Foxa2-induced DA neuronal yield. Shown in a are representative images for TH+ cells at D5 in the indicated cultures. Scale bar, 20 μm. DA cell yields estimated by %TH+ cells (b). *Significantly different from the untreated control at P<0.05. (c) Effect of cAMP–pCREB signal activation on maintenance of exogenous Retro-pLTR-Foxa2 expression during late differentiation period (D5–D14). Significantly different from D5* and from cAMP-untreated# at P<0.05. (d) TH+ DA neurons treated with cAMP showed higher cell viability in the presence of H2O2-mediated toxic stimuli. TH+ cell generated by Nurr1+Foxa2 expression (at D13) were treated with various doses of H2O2 in the absence or presence of cAMP. Statistical analyses were used to compare cAMP-treated and untreated control values at each H2O2 dose. *P<0.05 (n=5). cAMP, cyclic AMP; DA, dopamine; NPCs, neural stem/precursor cells; TH, tyrosine hydroxylase.
