lncRNA-miRNA调控DJ-1的表达在散发性帕金森病发病中作用的研究

It is well-known that oxidative stress is one of the major causes of Parkinson’s Disease (PD). DJ-1 is a protein which can protect cells from oxidative insult. In familial PD, mutations of DJ-1 gene always cause the structural defects or instability of the protein which makes DJ-1 easily degraded, leading to the decreased level of DJ-1, subsequent loss of anti-oxidative stress function and the development of PD. Reduced DJ-1 has also been reported in sporadic PD. Because there is no change in the gene sequence, the reduction may be caused by the abnormal regulation of protein expression. MicroRNAs (miRNAs) play important regulatory roles at the post-transcriptional level by targeting mRNAs for cleavage or translational repression. In recent years, a competitive RNA (ceRNA) hypothesis has been proposed and several studies have suggested the interaction between lncRNA and miRNA in neurodegeneration diseases. LncRNAs can act as “miRNA sponge” and sequester miRNAs to inactivate these small regulatory RNAs. The aim of our projectwe is to explore a lncRNA-miRNA regulation pathway in the regulation of DJ-1 expression and the pathogenesis of sporadic Parkinson's disease. Since sporadic PD accounts for 90% of cases of the disease, this project is considered to be of both great scientific importance and potential clinical application.

氧化应激与帕金森病（PD）的发生密切相关，DJ-1是细胞内一重要的抗氧化应激蛋白。家族性PD中DJ-1基因的突变可引起蛋白结构的缺失或增加蛋白的不稳定性而使其易被降解，导致DJ-1蛋白水平下降、抗氧化应激功能丧失和PD的发生。散发性PD中也存在着DJ-1蛋白水平的降低，但由于不存在DJ-1基因的异常，因此，散发性PD中DJ-1水平下降的主要原因可能是其表达调控的异常。miRNA是蛋白转录后修饰的重要机制，在控制蛋白表达水平上起到了重要作用。近年来，lncNRA与miRNA相互作用的研究（ceRNA hypothesis）更引起了广泛关注。LncRNA与miRNA结合，抑制了miRNA的作用，发挥对靶基因的调控作用。本项目拟探讨lncRNA-miRNA对DJ-1的表达调控机制在散发性PD发病中的作用。由于PD中90%为散发性，故本课题的开展具有重要的科学意义和临床应用价值。

帕金森病（PD）是最常见的中枢神经系统退行性疾病之一，严重影响着患者的生活质量。MicroRNA-203a-3p (miR-203a-3p)是一种肿瘤抑制因子。然而miR-203a-3p 在PD发病中的作用和机制尚不清楚。本研究旨在探讨miR-203a-3p 参与PD发病的作用和机制。首先，我们用MPP+处理SH-SY5Y细胞，建立PD细胞模型。我们发现，随着MPP+浓度的增加，细胞活力逐渐下降。基于此，我们选择2000μM MPP+浓度进行后续实验。qRT-PCR检测结果显示，经MPP+处理的SH-SY5Y细胞中miR-203a-3p表达下调。其次，TargetScan和荧光素酶报告基因检测显示，α-突触核蛋白(SNCA)是PD发病的一个重要遗传基因，也是miR-203a-3p的直接靶基因。随后，我们证实了miR-203a-3p可以下调SH-SY5Y细胞中α-突触核蛋白表达。最后，我们研究了miR-203a-3p对MPP+处理的SH-SY5Y细胞的影响。CCK-8检测结果表明，MPP+可抑制细胞增殖和诱导细胞凋亡，而miR-203a-3p的过表达可抑制这一过程。此外，我们发现MPP+可以上调α-synuclein、p53和caspase3蛋白的表达，而miR-203a-3p的过表达则降低了这些蛋白的水平。然而，SNCA基因的过表达可以逆转这些变化。因此，miR-203a-3p通过抑制α-突触核蛋白的表达调节了MPP+诱导的SH-SY5Y细胞凋亡。miR-203a-3p/α-synuclein通路可能成为PD治疗的潜在靶点。