BACKGROUND: In various retinal neurodegenerative animal models, ciliary neurotrophic factor (CNTF) exhibits prominent neuroprotective effects on retinal nerve cells Bcl-2 is an anti-apoptotic protein c-Jun is upregulated and phosphorylated in the activated c-Jun N-terminal kinase pathway, which subsequently mediates apoptosis However, the effect of CNTF on Bcl-2 and c-Jun expression in retinal nerve cells remains unclear OBJECTIVE: To determine the dynamic changes in retinal nerve cell apoptosis, as well as bcl-2 and c-jun gene and protein expression, following a single dose of CNTF in a short period of time DESIGN, TIME AND SETTING: A single-blind, randomized, controlled, in vitro experiment was performed at the Central Laboratory of Beijing Tongren Hospital from May 2008 to April 2009 MATERIALS: Neonatal bovine retinal nerve cells (Chinese Holstein), recombinant human CNTF (PeproTech, Rocky Hill, NJ, USA), rabbit polyclonal anti-Bcl-2 and c-Jun antibodies (Abcam, Cambridge, UK), fluorescein isothiocyanate-conjugated annexin V/propidium iodide kit (Bio Vision, Mountain View, CA, USA), real time polymerase chain reaction instrument (ABI, Foster City, CA, USA), and flow cytometer (BD FACSCalibur, Franklin Lakes, NJ, USA) METHODS: Neonatal bovine retinal cells from passage 2 were cultured for 3 days and incubated with, or without, 50 ng/mL CNTF (control) MAIN OUTCOME MEASURES: Cell apoptosis was detected via Annexin V-FITC/PI double-staining and flow cytometry bcl-2 and c-jun mRNA and protein expression were detected by quantitative real time polymerase chain reaction and western blot analysis RESULTS: The proportion of late-stage apoptotic cells was significantly decreased at 2, 4, and 6 days after CNTF treatment compared with the control group (P < 0 01) CNTF did not alter bcl-2 mRNA expression at the three time points, but significantly increased Bcl-2 protein expression at 2 and 4 days (P < 0 01) c-jun mRNA expression was significantly decreased 4 days after CNTF treatment (P < 0 01) In addition, c-Jun protein expression was slightly increased at 4 days (P < 0 01), but decreased at 6 days, compared with the control group (P < 0 05) CONCLUSION: A single dose of CNTF (50 ng/mL) upregulated Bcl-2 protein and downregulated c-jun mRNA expression, followed by a parallel, but lagged, change in c-Jun protein production in cultured neonatal bovine retinal nerve cells These results suggested that CNTF reduces retinal nerve cell apoptosis by modifying Bcl-2 and c-Jun expression