Figure 3. CRH promoter activity was conservatively regulated by CREB and glucocorticoid receptor.

(A–D) CHO and Neuro-2a cells were transfected with luciferase vectors inserted with 800 bp or 2000 bp fragments from tree shrew or human CRH promoter region. Cells were treated with forskolin (10⁻⁵M) for 12 h before subjected to dual luciferase reporter assay. CRH promoter activity was much higher of 2 kb, not 800 bp tree shrew fragments than of human under native condition or treatment with forskolin (**P < 0.01, n = 3, Two way Anova). (E–M) CRH promoter activity was significantly enhanced under treatment with Forskolin (10⁻⁵M) and GR was required for Dexamethasone (10⁻⁵M) in counteracting the effect, under the overexpression of GR (J–M) or not (E–H) in CHO (E,F,J,K) and Neuro-2a (G,H,L,M) cells (**P < 0.01, ^##P < 0.01, ^###P < 0.001, n = 3, One Way Anova).