Parkin介导的新型RNA结合蛋白FMO3调控脑缺血-再灌注损伤的作用与机制研究

脑缺血-再灌注（I/R）损伤的病理机制尚未完全明确。我们前期工作发现：上调FMO3表达水平对体外培养神经元OGD损伤具有保护作用，且与其自身酶的活性无关；同时FMO3通过提高其下游Parkin成熟mRNA的表达水平促进线粒体自噬、进而调控脑I/R损伤；另外脑缺血时神经元miR-543表达水平增高可直接抑制FMO3表达。因此推测FMO3可能是一种新型RNA结合蛋白，在脑I/R损伤时具有全新的调控机制。为明确这一假说，我们将利用已建立的原代神经元、模式动物、体内外脑I/R损伤模型，通过系列体内外实验，包括RNA结合蛋白功能研究、转录调控分析等，阐明FMO3作为一种兼具酶催化作用的新型RNA结合蛋白，可直接与Parkin mRNA结合、通过转录后调控影响其蛋白表达水平，进而调控脑I/R损伤的重要机制，并形成miR-543--FMO3--Parkin的新通路，为脑缺血损伤的治疗提供新的思路及靶点。

The specific pathophysiological mechanism of cerebral ischemia-reperfusion (I/R) injury still remains unclear. Our previously work found that upregulation of FMO3 had a protective effect on oxygen-glucose deprivation (OGD) injury of primary cultured neurons in vitro, which was independent of its enzyme activations. Moreover, FMO3 promoted mitochondrial autophagy of neurons by increasing the expression level of downstream Parkin mature mRNA, and then regulated cerebral I/R injury. In addition, the increased expression of miR-543 in neurons during cerebral ischemia can directly inhibit the expression of FMO3. Based on these findings, we hypothesize that FMO3 may be a novel RNA-binding protein with a new regulatory mechanism in cerebral I/R injury. In order to clarify this hypothesis, we plan to use the established primary culture neurons, transgenic animals, cerebral I/R injury models, through a series of in vivo and in vitro experiments, including RNA binding protein function experiment and transcriptional regulatory mechanism analysis, to elucidate the important mechanism that FMO3, as a novel RNA binding protein with enzymatic catalysis, can directly bind to Parkin mRNA, affect its protein expression level through post-transcriptional regulation, and then regulate cerebral I/R injury. We aim to propose a novel “miR-543--FMO3--Parkin” signal pathway, for furtherly finding out the new theories or potential therapeutic targets for cerebral I/R injury.