Fig. 6.

ATF3 regulates Agrp transcription by interacting with FoxO1 on the Agrp promoter. (a) mRNA levels of Agrp, Npy, Pomc and Hcrt in the hypothalamus after 24 h of fasting at 8 months of age (n = 4 for each group). (b) mRNA levels of Atf3 and Agrp in N-41 cells treated with low glucose (LG) or high glucose (HG). (c) mRNA levels of Atf3 and Agrp in the hypothalamus of wild-type mice after fasting for the periods indicated. (d) Hypothalamic ATF3 protein levels in wild-type mice after fasting or refeeding for the periods indicated. (e) Agrp promoter (−401 to +16)-driven luciferase (Luc) activities in HEK293 or N-41 cells transfected with ATF3 at the indicated amount of DNA. (f) Co-IP of ATF3 and FoxO1 in HEK293 cells cotransfected with ATF3 and FoxO1. HA-FoxO1 or HA-ATF3 was detected in the IP with Flag-ATF3 or Flag-FoxO1, respectively; TCL, total cell lysate. (g) The promoter region of the mouse Agrp gene. The square indicates the forkhead response element. Arrows indicate the primers used for PCR. Chromatin immunoprecipitation assays using indicated antibodies in N-41 cells cotransfected with ATF3 and FoxO1. (h) mRNA levels of Atf3 and Agrp in N-41 cells transfected with shAtf3 or FoxO1 siRNA. Data are mean ± SEM. *p < 0.05, **p < 0.01. IB, immunoblot; IP, immunoprecipitation