C-fos gene expression in rat retinal cells after focal retinal injury.

PURPOSE: To examine the expression of c-fos proto-oncogene in the rat retina after focal retinal injury. METHODS: A penetrating wound was made by pushing a 22-gauge hypodermic needle through the retina into the vitreous. The retinas were analyzed by in situ hybridization using single-stranded RNA probes for c-fos transcripts and by immunocytochemistry using anti-S100 protein antibody. RESULTS: Thirty minutes after the penetrating wound, c-fos mRNA was expressed in the inner nuclear layer (INL) and the ganglion cell layer (GCL) of the retina. Immunocytochemistry before in situ hybridization demonstrated c-fos mRNA surrounding the S-100 protein immunoreactive cytoplasm in the middle layer of the INL. CONCLUSIONS: Focal retinal injury of the rat retina induced the expression of c-fos mRNA in retinal cells. In the INL, it is suggested that the major cells that express c-fos mRNA after focal retinal injury were the Müller cells. These results suggest that c-fos may be involved in the transcription in the Müller cells after injury to the retina.