DIRECT REGULATION OF GNRH TRANSCRIPTION BY CRF-LIKE PEPTIDES IN AN IMMORTALIZED NEURONAL CELL-LINE

THE existence of a CRF-dependent inhibition of GnRH transcription was investigated using a neuronal GnRH-expressing cell line (Gn11) stably transfected with mouse (-611 bp) or chicken (-3000 bp) GnRH promoter/l uciferase reporter constructs. The presence of the CRF-R1 receptor was established using a specific CRF-R1 antiserum. After 7h of incubation , urotensin-I and sauvagine increased the mouse GnRH-reporter biolumin escence by 1.3- and 1.2-fold, respectively, compared with control cell s. Subsequently, CRF, urotensin-I and sauvagine decreased luciferase r eporter activity to about 60% of the control values after 14 h. Simila r trends occurred with the chicken GnRH promoter with UI increasing re porter gene activity 2.4-fold over the controls after 14 h incubation. These data provide additional evidence for the direct regulation of G nRH transcription by CRF-like peptides. (C) 1998 Lippincott Williams & Wilkins.