Abstract
AIM: To investigate the effect of N-acetylcysteine (NAC), a potent antioxidant, on neuron differentiation of cultured mouse embryonic stem cells (ESCs) induced by retinoic acid (RA) in vitro. Superior cervical ganglion (SCG) neurons were used to study the effect of NAC on neuritogenesis. METHODS: Immunoblotting was performed to detect the expression of microtubule-associated protein 2 (MAP2). MTT assays were used to determine cell viability. Cell death was estimated with trypan blue exclusion and Hoechst 33342 staining. Immunocytochemical analysis was carried out to identify neurons. RESULTS: We obtained a high percentage of MAP2-positive neurons derived from embryoid bodies (EBs) induced by RA by administering 1 mmol/L NAC at differentiation day 0. On differentiation day 8, the expression of MAP2 protein was strongly upregulated in the presence of NAC. NAC promoted neuron differentiation of ES cells in a dose- and time-dependent manner. Notably, NAC suppressed cell death caused by RA during neuron differentiation. In addition, neurite extension of SCG neurons was greatly stimulated in the presence of NAC. CONCLUSION: These results show that NAC enhanced both neuron differentiation and neuritogenesis, suggesting that it may be used in the development of novel therapeutic approaches targeting neuron loss and neurite dystrophy in neurodegenerative diseases.Acta Pharmacologica Sinica (2009) 30: 907-912; doi: 10.1038/aps.2009.72.