Figure 5

IL-6 regulates the balance between SP-1 transciptional activity and R1 repressor. The relative amount of SP-1 transcription factor bound to the MAOA promoter was assessed in Mz-Neo neg and Mz-IL-6 shRNA cells by chromatin immunoprecipitation (a) using a specific SP-1 antibody to precipitate the complex followed by real-time PCR using specific primers for the MAOA promoter region. The subcellular localization of SP-1 and R1 repressor in these cell lines was determined by immunofluorescence. SP-1- or R1-repressor immunoreactivity is shown in red, nuclei were counterstained with 4′,6-diamidino-2-phenylindole (blue; scale=20 μm; b). A stable transfected cell line expressing R1-repressor shRNA (Mz-R1 shRNA) was used to assess the effects of R1 repressor on MAOA expression by real-time PCR (c) and immunoblotting (d). Real-time PCR data are expressed as average±s.d. (n=4; *P<0.05). Representative MAOA immunoblots are shown; β-Actin was used as the loading control.