Abstract: Objective To investigate the effect of α-synuclein(α-syn) on the neurite outgrowth of MES 23.5 dopaminergic cells. Methods The neurite length of MES 23.5 cells were measured at different time points after addition of recombinant human α-syn to the culture medium. Double immunofluorescent labeling was used to examine the co-localization of α-syn and β-tubulin in the cells. ELISA was applied to analyze the β-tubulin levels in the cells. Results The mean neurite length of the α-syn-treated cells was significantly longer than that of control neurons at 1 h, 4 h and 24 h after addition of α-syn. The effect of α-syn on neurite outgrowth was reversed by β-tubulin inhibitor, colchicine. α-Syn and β-tubulin were shown to colocalize in the cells, and the levels of β-tubulin was higher in the α-syn-treated cells than in control cells. Conclusion α-Syn can promote neurite outgrowth of MES23.5 dopaminergic cells possibly by its effect on tubulin synthesis and microtubule assembly.

Key words: α-synuclein, neurite, outgrowth, β-tubulin