LncRNA调控CREB对抑郁症作用机理研究

The etiology of Major depressive disorder (MDD) remains unknown, which may lead to poor effect and prognosis. It is gradually recognized that the abnormal signal transduction pathway of neruon may block the neuroplasticity and is very likely to be involved in the pathophysiology of MDD. A growing body of studies has provided evidence that the abnormal expression regulation of CREB, the key node in neuron signal transduction pathway may participate in the pathogenesis of MDD by affecting the neuroplasticity. However the regulatory mechanism of CREB in MDD remains unclear. With the help of gene chip screening, bioinformatics analysis and qRT-PCR verification, our preliminary study found that lncRNA CREB1/2 can modulate the expression of CREB in MDD. According to this, we proposed the hypothesis that"lncRNA CREB1/2 impacts the neuroplasticity and participates in the pathogenesis of depression by regulating CREB". This study attempts to explore the following questions deeply on human body, animal and cellular levels.(1)The regulation of LncRNA CREB1/2 on CREB. (2) The CREB regulated by LncRNA CREB1/2 may impact the neuroplasticity and participate in the pathogenesis of MDD. These ?ndings may contribute to illuminating new influence factor of neuroplasticity in MDD, supplementing the hypothises of neuroplasticity in MDD and providing clues for new antidepressants development.

抑郁症病因不明是导致其治疗及预后差的主要原因，神经细胞信号转导通路异常造成的神经可塑性障碍为抑郁症最重要的病因之一。研究表明，神经细胞信号转导通路关键节点CREB表达异常影响神经可塑性并参与了抑郁症发病。然而，迄今为止，抑郁症中CREB表达调控机制仍不清楚，课题组前期通过芯片筛查、生物信息学分析和qRT-PCR验证，发现抑郁症中长链非编码RNA（lncRNA）CREB1/2可调控CREB表达。据此提出"lncRNA CREB1/2通过调控CREB影响神经可塑性参与抑郁症发病"的科学假说。本课题拟采用人体、动物、细胞水平研究，深入探讨：（1）lncRNA CREB1/2对CREB的调控作用；（2）lncRNA CREB1/2对CREB的调控作用影响神经可塑性参与抑郁症发病。本项目将发现抑郁症神经可塑性新的影响因素，补充完善抑郁症神经可塑性障碍假说的内容，也为抗抑郁药物的研发提供新线索。

抑郁症是最常见的精神障碍之一，但其病因及发病机理尚不明确。长链非编码 RNA（lncRNA），作为表观遗传学调控的重要机制之一，可能参与了抑郁症的发生及发展。课题组前期研究显示，抑郁症存在异常的lncRNAs 表达及调控，且与神经可塑性密切相关的CREB存在共表达关系。本研究拟在人群及细胞水平筛选及验证抑郁症CREB相关的lncRNAs。利用前期芯片筛选结果进行生物信息学分析，确定与CREB存在共表达关系的lncRNAs；利用UCSC基因组数据库，寻找CREB基因调控区的lncRNAs，筛选出抑郁症CREB相关的lncRNAs。收集抑郁症与正常对照各35例，抑郁症给予SSRIs类抗抑郁药物追踪8周，收集研究对象外周血，检测前述筛选出的lncRNAs，确定抑郁症CREB相关的关键lncRNAs。将抑郁症CREB相关的关键lncRNAs制备干扰慢病毒，转染至神经干细胞，检测细胞内关键lncRNAs及CREB表达，检测神经细胞增殖情况，明确lncRNAs对CREB的调控作用。确定抑郁症CREB相关的特异lncRNAs。结果显示1、初步筛选出2个lncRNA chr20:46277638-46277729和chr4:73971145-73971245与mRNA CREB存在共表达关系；通过UCSC基因组数据库查找，找到4个lncRNA在CREB调控区，分别是UCA1，DQ786243，AK091534和AK123952。2、MDD存在外周血CREB以及调控CREB的lncRNAs表达异常，UCA1和DQ786243与MDD发病相关；UCA1和DQ786243与MDD发病时的严重程度有相关关系，UCA1与MDD严重程度成正相关，DQ786243与MDD严重程度成负相关。3、UCA1和DQ786243可抑制神经干细胞的增殖，降低神经干细胞细胞CREB mRNA的表达，并进而降低pho-CREB蛋白质表达。本研究从lncRNA表观调控角度，探索了MDD的可能发病机制，并在人群、细胞两个层面，综合临床指标、mRNA及蛋白质多个指标，较为系统的阐述了调控CREB的lncRNAs参与MDD发生发展的可能机制，研究思路具有一定的创新性。本课题是首次在MDD中发现UCA1和DQ786243的作用，丰富了MDD病因学研究，为MDD研究提供了新的思路和理论基础。