Mei Jia-Ming, Niu Chao-Shi
Shandong University, Jinan, Shandong Province, China.
Department of Neurosurgery, Anhui Provincial Hospital, Hefei, Anhui Province, China.
Neural Regen Res. 2017 Jul;12(7):1145-1151. doi: 10.4103/1673-5374.211195.
Conserved dopamine neurotrophic factor protects and rescues dopaminergic neurodegeneration induced by 6-hydroxydopamine , but its potential value in treating Parkinson's disease remains controversial. Here, we used the proteasome inhibitors lactacystin and MG132 to induce neurodegeneration of PC12 cells. Afterwards, conserved dopamine neurotrophic factor was administrated as a therapeutic factor, both pretreatment and posttreatment. Our results showed that (1) conserved dopamine neurotrophic factor enhanced lactacystin/MG132-induced cell viability and morphology, and attenuated alpha-synuclein accumulation in differentiated PC12 cells. (2) Enzyme linked immunosorbent assay showed up-regulated 26S proteasomal activity in MG132-induced PC12 cells after pre- and posttreatment with conserved dopamine neurotrophic factor. Similarly, 26S proteasome activity was upregulated in lactacystin-induced PC12 cells pretreated with conserved dopamine neurotrophic factor. (3) With regard proteolytic enzymes (specifically, glutamyl peptide hydrolase, chymotrypsin, and trypsin), glutamyl peptide hydrolase activity was up-regulated in lactacystin/MG132-administered PC12 cells after pre- and posttreatment with conserved dopamine neurotrophic factor. However, upregulation of chymotrypsin activity was only observed in MG132-administered PC12 cells pretreated with conserved dopamine neurotrophic factor. There was no change in trypsin expression. We conclude that conserved dopamine neurotrophic factor develops its neurotrophic effects by modulating proteasomal activities, and thereby protects and rescues PC12 cells against neurodegeneration.
保守性多巴胺神经营养因子可保护并挽救由6-羟基多巴胺诱导的多巴胺能神经元变性，但其在治疗帕金森病中的潜在价值仍存在争议。在此，我们使用蛋白酶体抑制剂乳胞素和MG132诱导PC12细胞发生神经变性。随后，将保守性多巴胺神经营养因子作为治疗因子进行预处理和后处理。我们的结果表明：（1）保守性多巴胺神经营养因子增强了乳胞素/MG132诱导的细胞活力和形态，并减少了分化的PC12细胞中α-突触核蛋白的积累。（2）酶联免疫吸附测定显示，在保守性多巴胺神经营养因子预处理和后处理后，MG132诱导的PC12细胞中26S蛋白酶体活性上调。同样，在保守性多巴胺神经营养因子预处理的乳胞素诱导的PC12细胞中，26S蛋白酶体活性也上调。（3）关于蛋白水解酶（具体而言，谷氨酰肽水解酶、胰凝乳蛋白酶和胰蛋白酶），在保守性多巴胺神经营养因子预处理和后处理后，乳胞素/MG132处理的PC12细胞中谷氨酰肽水解酶活性上调。然而，仅在保守性多巴胺神经营养因子预处理的MG132处理的PC12细胞中观察到胰凝乳蛋白酶活性上调。胰蛋白酶表达没有变化。我们得出结论，保守性多巴胺神经营养因子通过调节蛋白酶体活性发挥其神经营养作用，从而保护并挽救PC12细胞免受神经变性。
