The impact of Paeoniflorin on α-synuclein degradation pathway

ZHANG Yong-jin; WANG Min; XU Jing; ZHANG Xin-zhi; LI Xiu-ming; CAI Zeng-lin

doi:10.3969/j.issn.1006-5725.2015.19.006

Abstract：Objective To study the impact of Paeoniflorin (PF) on α-synuclein degradation pathway. Methods PC12 cells were treated with or without MPP+ (0.5mM) for 24 h, then treated with Paeoniflorin (50 uM) or Rapamycin (0.2 μg/ml) for 24 h. The proliferative activity of cells was detected with the MTT method , and then the protein expression levels of α-synuclein, microtubule-associated protein light chain 3 (LC3-II) and E1 were detected by Western Blot. The expressions of α-synuclein and LC3 were detected by confocal microscopy. Results (1) CAT and SOD activity were significantly decreased after PF and RAPA treatment compared with MPP+ (P < 0.001). (2)MPP+ activated both LC3-Ⅱand E1. MPP+ promoted the increase ofLC3-Ⅱ but inhibited E1. PF significantly upregulated both LC3-Ⅱ (autophagy) and E1 expression (ubiquitin-proteasome pathway) (P < 0.001), promoted degradation of α-synuclein, and reduced cell damage. (3) MPP+enhanced immunofluorescence signal of intracellular α-synuclein and LC3. Fluorescence intensity of α-synuclein decreasedafter PF treatment. Conclusion PF may significantly upregulate both autophagy and ubiquitin proteasome pathways, promote the degradation of α-synuclein and reduce cell damage. These findings suggest Paeoniflorin may be a potential therapy for neurodegenerative diseases.