Effects of testosterone on differentiation and oxidative stress resistance in C1300 neuroblastoma cells.

OBJECTIVES: Using undifferentiated mouse neuroblastoma cells (C1300), we have previously observed that testosterone (T) exerts a neuroprotective action against oxidative stress. Nitrogen intermediates induce the production of 3-nitro-L-tyrosine (3NT), an amino acid analogue involved in many neurodegenerative disorders. The aim of our work is to investigate T capability on C1300 cell differentiation. It is also evaluated whether differentiation could mitigate the nitrosative effects of 3NT.

METHODS: The effects of both T and 3NT were studied on an undifferentiated cell line of neural origin (C1300). For this purpose, cell cultures underwent morphometric investigation, blot analyses and catalase activity assay. All data obtained were expressed as mean+/-SD and tested by one-way ANOVA or Student's t test.

RESULTS: The results were compared with those gathered by means of N6,2'-O-dibutyryl-adenosine-3',5'-cyclic-mono-phosphate (db-cAMP), a well-known differentiating agent. T-exposed cells showed an irregular shape and exhibited long branching cytoplasmic extensions, which were longer than in db-cAMP cells. Moreover, T-exposure induced an increase in the expression of tyrosinated and acetylated alpha-tubulin while 3NT-incorporation into tubulin was markedly reduced. The action of antioxidant defence systems, namely catalase activity, was enhanced in cells exposed to T.

CONCLUSION: This work highlighted the effects of db-cAMP on differentiation and neuroprotection, but even indicated that T exposure induced differentiation in C1300 cells and this process matches a significant neuroprotective effect. This action seemed to be more effective than in db-cAMP-treated cells. T is suggested, like other substances having antioxidant properties, to be of potential interest in the experimental therapy of neuropathological conditions.