Changes in transcription factor expression in long-term administration of salicylate. (A) Immunofluorescent labeling of OHCs for c-fos, egr-1 and PPARγ. The transcription factors of c-fos and egr-1 had intensive labeling in OHC nuclei but PPARγ had no detectable protein expression in the OHC nucleus (indicated by a white arrow). However, the positive labeling for PPARγ in a supporting cell nucleus is visible in the same field. (B) Increases in expressions of c-fos, egr-1, IκB, and PPARγ in long-term administration of salicylate by real-time RT-PCR recording.