Abstract:

Objective To study the  growth-promoting effect of α-Synuclein (α-Syn) function fragment on neurites of primary cultured neurons of rats and to clarify its physiological function fragment  and to explore its mechanism.Methods The neurons in neocortex of newborn SD rats were cultured in various groups.The α-syn (adding α-Syn group) and its function segments such as  N segment(adding N segment group),C segment (adding C  segment group) and NAC segment (adding NAC segment group)  were added into the neural cells,and no protein was added  into  control group.The lengths of neurites of neurons were observed with inverted phase contrast microscope.Western blotting  and immunofluorescence staining assay were used to confirm the expression levels of proteins in various groups.Results 1 and 2 h after culture,the average lengths of neurites in  adding C segment group and adding α-Syn group were longer than that in control group (P<0.05);the average lengths of neuites in  adding NAC and N segment groups had no significant differences compared with control group(P>0.05). 4 h after culture,the average length of neurites in  adding C segment group was  significantly higher than that in control group (P<0.01);the average lengths of neuites in adding NAC and N segment groups had no significant difference compared with control group(P>0.05).The results of Western blotting and immunofluorescence staining assay showed  that N segment and C segment could enter into the neuron,but NAC could not enter into the neuron.Conclusion α-Syn can enhance the outgrowth of neurite  of primarily cultured neuron.The C segment of α-Syn has the potential to enhance neurite outgrowth,and its possible mechanism may be that C segment of α-Syn  can enter into the neuron,and  polymerize tubulin into microtubule,and accelerate the formation of cytoskeleton and axoplasmic transporting.

Key words: α-Synuclein, neuron;neurite outgrowth, cell culture;Parkinson’s disease