Expression of ciliary neurotrophic factor (CNTF) and its tripartite receptor complex by cells of the human optic nerve head

PURPOSE: Ciliary neurotrophic factor (CNTF) promotes gene expression, cell survival and differentiation in various types of peripheral and central neurons, glia and nonneural cells. The level of CNTF rises rapidly upon injury to neural tissue, suggesting that CNTF exerts its cytoprotective effects after release from cells via mechanisms induced by cell injury. The purpose of this study was to determine if cells in the optic nerve head express CNTF and its tripartite receptor complex. METHODS: Well-established optic nerve head astrocytes (ONHA) and lamina cribrosa (LC) cell cultures were derived from normal human donors. Total RNA was reverse transcribed and polymerase chain reaction (PCR) amplified for mRNA detection. Cytoplasmic protein expression was determined by immunocytochemistry and Western blot analysis of the cellular lysates. Serum free medium was concentrated and used for detecting extracellular proteins. CNTF complexed with CNTFR-α was assayed by immunoprecipitation. RESULTS: Cells isolated from the human optic nerve head express CNTF and its tripartite receptor complex members (CNTFR-α, gp130, LIFR-β). CONCLUSIONS: Taken together, these data suggest a possible neuroprotective role of CNTF in the optic nerve head.