Ciliary neurotrophic factor and its receptors are differentially expressed in the optic nerve transected adult rat retina.

Ciliary neurotrophic factor (CNTF) has been implicated in the survival and regeneration of adult rat retinal ganglion cells (RGCs). Expression of CNTF and its receptors, ciliary neurotrophic factor receptor alpha (CNTFRalpha) and leukemia inhibitory factor receptor (LIFR) was studied in normal, 6-h, 1-, and 3-day optic nerve transected retinas. Optic nerve transection was performed on the right eye in one group. In the other group, it was performed 5 days after intratectal Fluorogold injection. Retinas were studied using immunohistochemical labeling and Western blot analysis. Astrocytes were labeled with GFAP and Müller cells with glutamine synthetase. CNTF was observed in identifiable astrocytes and Müller cells, and its intensity increased in the experimental retinas. CNTFRalpha was localized on RGCs in experimental retinas. LIFR was localized on RGCs and Müller cells in normal and experimental retinas. CNTF and its receptors are differentially expressed after optic nerve transection and could help delay RGC death in such a stressful environment.