Protective and reversal effects of conserved dopamine neurotrophic factor on PC12 cells following 6-hydroxydopamine administration.

Conserved dopamine neurotrophic factor (CDNF), a member of the mammalian mesencephalic astrocyte-derived neurotrophic factor family of conserved secreted factors, has been reported to protect and rescue dopaminergic neurons in vivo. PC12 pheochromocytoma cells are widely used as a cell model for Parkinson's disease (PD) for experimental studies. In the present study, PC12 cells were induced using 6-hydroxydopamine (6-OHDA) to mimic PD, which was used to investigate the protective and reversal effects of CDNF against PD in vitro. Cell growth was assessed using an MTT assay, the rate of cell apoptosis was detected using flow cytometry and the apoptotic morphology of cells was observed using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) staining. Pre-treatment of PC12 cells with CDNF (50, 100 and 200 nM) prior to exposure to 100 µM 6-OHDA for 24 h, resulted in a significant increase in cell viability compared with that of 6-OHDA only-treated cells, with cell survival rates of 46.6, 54.7 and 69.6%, respectively. In addition, PC12 cells were treated with CDNF (50, 100 and 200 nM) following 6-OHDA administration, which resulted in cell survival rates of 47.7, 57.6 and 57.5%, respectively. Flow cytometric and TUNEL staining analyses revealed that CDNF exhibited significant dose-dependent protective and reversal effects on the apoptotic rate of PC12 cells following 6-OHDA treatment. In conclusion, the results of the present study showed that CDNF exhibited neuroprotective and reversal effects on the 6-OHDA-induced apoptosis of PC12 cells in a dose-dependent manner.