Figure 5. IKKα promotes expression of markers of mature neurons and BDNF.

(A) Elevated IKKα+ enhances neuronal maturation. Cell lysates from various time points (days after inducing differentiation) were examined by western blotting for the levels MeCP2, SCG10, syntaxin, and PSD-95. A lentivirus encoding an shRNA targeting MeCP2 was used to knockdown the expression of MeCP2 in IKKα+ NPCs (labeled as MeCP2KD) (lanes 9–12). IKKγ was used as a loading control. A non-specific band (N.S., below the authentic band) is recognized by the anti-PSD95 antibody. (B) Knockdown of MeCP2 expression does not influence IKKα-induced neuronal differentiation. NPCs were differentiated and examined as described in Fig. 2A. Representative confocal micrographs of 4^th day differentiating cultures are shown. (C) IKKα promotes MeCP2-dependent BDNF expression. A time course (days) for BDNF expression during the differentiation of NPCs is shown. Taqman probes were used to quantify mRNA generated from the exon-IV of the BDNF promoter. GAPDH was used for normalization. The data are shown relative to the level in proliferating control (day 0) NPCs. (D) IKKα also promotes MeCP2-dependent BDNF expression following depolarization. Data are shown for cultures after 8^th days of differentiation and depolarization with 50 mM KCl for 6 hr immediately preceding harvest. The data are shown relative to the level in non-depolarized control cells. Assays were done in triplicate and P values were obtained using student's t-test.