miRNA-103a-3p 靶向Parkin/Ambra1调控线粒体自噬在帕金森病中的作用及机制

Parkinson's disease (PD) is a common neurodegenerative disease. The pathogenesis of PD is complex. Mitophagy dysfunction plays an important role in PD. Parkin/Ambra1 is involved in the regulation of mitophagy, but the specific regulatory mechanism in PD is unknown. Our preliminary experimental results showed that in the PD model: 1) The expressions of Parkin and Ambra1 were decreased. 2) miR-103a-3p was significantly up-regulated and negatively correlated with Parkin expression. Bioinformatics result found for the first time that miR-103a-3p has a potential binding sequence with Parkin which has species conservation. 3) Inhibited miR-103a-3p significantly increased the mitochondrial membrane potential and alleviated mitochondrial damage in the model of PD in vitro. Accordingly, we hypothesized that miR-103a-3p can target Parkin expression and further regulate Ambra1-mediated mitophagy. Regulating this pathway could be an important control strategy for PD. In this study, advanced molecular biology methods will be used to investigate the mechanism of miR-103a-3p/Parkin-Ambra1-mediated mitophagy in the model of PD in vitro and in vivo. The study may provide new targets for the treatment of PD and drug development.

帕金森病（PD）是中老年常见的神经系统退行性疾病，发病机制复杂，线粒体自噬功能紊乱起重要作用。Parkin/Ambra1参与线粒体自噬的调节，但其在PD发病中的具体调控机制未明。我们预实验结果发现：在PD模型中1）Parkin和Ambra1表达降低；2）miR-103a-3p显著上调，与Parkin呈负相关，且生物信息学首次发现miR-103a-3p与Parkin存在潜在结合序列并具有物种保守性；3）体外抑制miR-103a-3p可明显提高PD线粒体膜电位，减轻线粒体损伤。据此，提出科学假说：miR-103a-3p可靶向调控Parkin表达，影响Ambra1介导的线粒体自噬，调控该通路可作为PD的重要防治策略。本研究利用体内外模型及先进的分子生物学技术，探讨miR-103a-3p调控Parkin/Ambra1介导的线粒体自噬在PD发病中的作用及分子机制，为PD防治及药物研发提供新的靶标。

parkin突变导致常染色体隐性遗传帕金森病(AR-PD)。然而，Parkin介导的线粒体自噬在PD中的确切调控机制仍不清楚。在本研究中，分别通过1-甲基-4-苯基吡啶离子（MPP+，1.5 mM，24小时）诱导SH-SY5Y细胞和腹膜注射1-甲基-4-苯基-1,2,3,6四氢吡啶（MPTP，30 mg/kg，连续 5 天）制备PD细胞和小鼠动物模型。采用生物信息学数据库验证Parkin靶向microRNA(miRNAs)。在体外和体内使用miR-103a-3p agomir、miR-103a-3p antagomir和Parkin siRNA来检测miR-103a-3p/Parkin/Ambra1通路介导的线粒体自噬对PD的影响。结果显示：Parkin和Ambra1的蛋白水平显著降低。人脑中高表达的miR-103a-3p在PD小鼠和SH-SY5Y细胞模型中明显升高。此外，miR-103a-3p通过靶向Parkin mRNA的3'非翻译区(UTR)中的保守结合位点来抑制Parkin表达。抑制miR-103a-3p可通过改善线粒体自噬产生神经保护作用，而干扰Parkin后此保护作用消失。这些研究结果表明，抑制miR-103a-3p在PD中具有显著的神经保护作用，其与Parkin/Ambra1介导的线粒体自噬调节密切相关。调控miR-103a-3p有望成为治疗PD的新策略。