Overexpression of VP16-CREB and NPAS4 + ARNT2 induces reporter expression in 1A4s2 and 3E2s rBDNF-hRluc-EGFP cell lines. (A, B) 1A4s2 (A) and 3E2s (B) cells were transfected with constructs expressing VP16-CREB, NPAS4 and ARNT2 (at 1:1 ratio) transcription factors or empty vector control pRC. Renilla luciferase luminescence was assayed 24 hours after transfection and fold luciferase activity relative to empty vector control (pRC) was calculated. Error bars indicate SD. (n – number of independent experiments, * p < 0.01, relative to empty vector control).