The Role Of Cathepsin L In The Rotenone Induced Cell Cycle Abnormal Of SH-SY5Y Cells

Aim: To study the role of Cathepsin L and cell cycle abnormal in rotenone-induced death of SH-SY5Y cells in PD models, and to investigate the effects of Cathepsin L on inhibition of apoptosis.Methods: In this study, SH-SY5Y cells were exposed to rotenone to establish the in vitro model of PD. The treated group was exposed to Cathepsin L inhibitor Z-FY-DMK(10μM/L)before rotenone administration. WST-1 was determined to study the SH-SY5Y cells viability. Hoechst 33258 dye was employed to detect apoptotic morphology. Propidium iodide (PI) staining was used to analyze DNA content. Immunocytochemistry and Western blot analysis were conducted to study the mechanisms of Cathepsin L involved in death and cell cycle related protein.Results: WST-1 analysis proved Z-FY-DMK could protect SH-SY5Y cells from rotenone induced cell death. Hoechst 33258 dye and PI staining demonstrated rotenone induced SH-SY5Y cells death belonged to apotosis, and Z-FY-DMK could protect cells from apotosis. Cell cycle analysis revealed that rotenone induced G2/M and S-phase arrest, and Z-FY-DMK decreased S-phase arrest and sub-G1. Immunocytochemistry and western blot analysis showed Cathepsin L increased after rotenone treatment, some of which even translocate into nucler. Z-FY-DMK could inhibit Cathepsin L increased expression and nuclear translocation. Western blotting analysis showed that the level of cyclin A decreased after rotenone treatment, which was parallel with the transient S-phase arrest.Z-FY-DMK could influenced the level of cyclin AConclusions: 1. Rotenone-induced SH-SY5Y cells apoptosis. It couldn induce Cathepsin L increased expression, nuclear translocation and S-phase arrest. 2. Cathepsin L inhibitor Z-FY-DMK protected SH-SY5Y cells from apoptosis. It could inhibit Cathepsin L expression, nuclear translocation, and S-phase arrest. 3. Furthermore, Z-FY-DMK could influenced the cell cycle protein, cyclin A. In conclusion, our results demonstrate significant involvement of Cathepsin L and cell cycle abnormal in rotenone-induced cytotoxicity.