Neurotoxicity of ubiquitin C-terminal hydrolase L1 inhibitor in dopaminergic neurons
10.3760/cma.j.issn.1671-8925.2009.06.001
- VernacularTitle:泛素羧基末端水解酶-1抑制剂对多巴胺能神经元的神经毒性作用
- Author:
Yu-Yan TAN
1
;
Zhi-Quan WANG
;
Hai-Yan ZHOU
;
Sheng-Di CHEN
Author Information
1. 上海交通大学医学院附属瑞金医院
- Keywords:
Ubiquitin C-terminal hydrolase L1;
Parkinson's disease;
Ubiquitin proteasome pathway;
Polyubiquitinated proteins;
Apoptosis
- From:
Chinese Journal of Neuromedicine
2009;8(6):541-545
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the neurotoxic effects ofLDN-57444, a specific ubiquitin C-termiual hydrolase L1 (UCH-L1) inhibitor, on dopaminergic neurons and the possible mechanism. Methods The viability of SK-N-SH cells exposed to 5, 10, 25, 50, 75 or 100 μmol/L LDN-57444 for 24 h was assessed using MTT assay, and the cell apoptosis was detected with Hoechst staining. Western blot was performed to identify the expressions of UCH-L1 protein, ubiquitin monomer and polyubiquitinated proteins, and the activity of the ubiquitin-proteasome system (UPS) was evaluated with fluorometry. Results After exposure to UCH-LI inhibitor for 24 h, the cell process-like structures of SK-N-SH cells diminished, and the cell body shrank and became spherical. Exposure to LDN-57444 resulted in concentration-dependent reduction of the cell viability, and the reduction became statistically significant following the exposure to 50 μmol/L LDN-57444, as compared with that in the control group (P<0.05). The exposure also resulted in obvious cell apoptosis as shown by nuclear fragmentation and presence of the apoptotie bodies. Western blot detected no obvious changes in UCH-L1 protein expression but identified reduced ubiquitin monomer and increased polyubiquitinated protein expression in the cells. Fluorometry showed reduced activity of UPS in the exposed cells. Conclusion UCH-L1 inhibitor produces neurotoxicity to dopaminergie neurons and induces cell apoptosis possibly as the result of impaired UPS activity and intracellular accumulation of polyubiquitinated proteins following the exposure.
