FIGURE 6.
Bcl-XL effects on proneural and dopaminergic gene expression. Cell lines were analyzed under division (Div) or after 3 and 7 days (d3 and d7) of differentiation. A–C, proneural gene expression was determined from division to day 7 of differentiation by analyzing NGN2 (A), NEUROD1 (B), and MASH1 (C). D and E, expression of genes involved in DAn patterning. EN1 and LMX1B were analyzed in proliferating cells. In relation to EN1 gene expression, mRNA levels remained elevated in Bcl-XL overexpressing cells as compared with hVM1-ø cells during the whole differentiation period (not shown). The Western blot shows En1 protein levels in proliferating cells. β-actin was used as loading control. F and G, expression assay of genes involved in DAn maturation; quantitative expression of NURR1 and PITX3 genes in proliferating cells (Div) and 3-day (d3) or 7-day (d7) differentiated cells (results for VMAT2, DAT, and GIRK2 were shown in Fig. 5). NURR1 and PITX3 were analyzed and reported in proliferating and in early differentiated cells (d3) because these genes were also essential for postmitotic DAn. Data represent mean ± S.E. (n = 3 or 5) and were normalized to GAPDH gene expression. RQ was calibrated by referring all data to hVM1-ø cell under division conditions (p < 0.05, ANOVA, post hoc Fisher test; *, versus Div; †, versus hVM1-ø; $, versus hVM1-low Bcl-XL).