Differential protein profile of PC12 cells exposed to proteasomal inhibitor lactacystin

•We induce PD cellular model with lactacystin in PC12 cells.•Proteomic study reveals 46 differentially expressed protein spots.•Six proteins are identified, with SERPINB6 linking to PD for the first time.•The data provide clues on biological basis for PD and potential treatment targets.

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide and recent studies implicate a central role for ubiquitin–proteasome system (UPS) impairment in the etiopathogenesis of PD. To explore the possible role of UPS dysfunction in PD and the proteins involved, PC12 cells were treated with 10 μM lactacystin, a 20S proteasome inhibitor, for 24 h. Lactacystin induced cell death and α-synuclein-positive inclusions in cytoplasm. Following two-dimensional difference in-gel electrophoresis (2-D DIGE) which was used to separate the cellular proteins, the proteins that were significantly altered were analyzed and identified. Proteomic study identified 6 differentially expressed proteins between lactacystin-treated and control cells in this study. Four proteins (heat shock 70 kDa protein 8, 78 kDa glucose-regulated protein, serine proteinase inhibitor clade B member 6 and aldehyde reductase) were increased and 2 proteins (peripherin and tyrosine hydroxylase) were decreased following proteasomal inhibition. The results revealed that PC12 cells treated with 10 μM lactacystin for 24 h could be used as a cellular model of PD. The proteins identified in the present indicate not only the damage of proteasomal inhibition to the cells but also the possible responses of the cells. These data show that proteomic study may provide information relevant to biological basis for PD and potential new treatment targets.