Expression of synaptophysin protein in different dopaminergic cell lines.

Synaptophysin is a specific presynaptic marker for neurons. Loss of synaptophysin occurs in Parkinson's disease, dementia with Lewy bodies and other neurodegenerative diseases. In vitro studies on synaptophysin are important to understand both the function of the protein itself and its implication in the pathogenesis of neurological diseases. In this study, we determined synaptophysin protein expression by Western analysis in 6 different dopaminergic cell lines including one human (SH-SY5Y), two rat (PC12 and N27) and 3 mouse (MN9D, Cath.a and CAD) cell lines. We found that synaptophysin protein is richly expressed in PC12 cells, but much less in other cells we studied. The order of synaptophysin expression from high to low for the other 5 cell lines was CAD> SH-SY5Y> MN9D> Cath.a = N27 cells, with Cath.a and N27 cells expressing almost undetectable content of synaptophysin protein. These data may be useful to other researchers in choosing a dopaminergic cell line as a model system to study the pathophysiology of neuron terminal loss.