Genetic analysis of a microRNA pathway regulating neural tube closure

 描述（由申请人提供）：本提案的总体目标是建立microRNA（miRNA）miR-302/367调节神经管闭合（NTC）的新机制。NTC的破坏导致神经管缺陷（NTD），这是人类第二大常见的出生缺陷，影响1至1，000名新生儿。然而，在转录后基因调控水平上控制NTC的调控因子和机制在很大程度上仍然未知。 我们已经建立了第一个NTD的miRNA小鼠模型。我们发现miR-302/367的缺失导致NTD和胚胎致死。神经前体细胞（NPC）表现出减少的增殖，过早分化，并降低突变胚胎的存活率。重要的是，我们已经确定了在突变胚胎中受影响的特定细胞行为中具有有效作用的单个miRNA靶标。此外，我们发现miR-302/367与RNA结合蛋白Lin 41相关以调节基因表达; Lin 41的缺失也导致NTD。这些初步数据导致了一个新的假设，即miR-302/367与Lin 41相互作用，通过调节神经管闭合（NTC）过程中不同的miRNA靶标来协调控制多种神经前体细胞（NPC）行为。 在本项目中，我们将确定miR-302/367在神经管关闭过程中的功能及其作用机制。本研究的三个具体目标是：1）确定miR-302/367突变小鼠神经管缺陷（NTD）的发育和细胞基础; 2）检测我们已经确定为miR-302靶点的单个基因是否在神经管闭合期间介导特定的细胞行为; 3）验证miR-302与Lin 41共同调控神经管闭合过程中基因表达和NPC行为的假设。总之，这些研究将提高我们对与NTD相关的遗传因素的理解，并为神经管闭合和神经管缺陷（NTD）的潜在机制提供新的见解。

 DESCRIPTION (provided by applicant): The overall goal of this proposal is to establish a novel mechanism whereby microRNA (miRNA) miR-302/367 regulates neural tube closure (NTC). Disruption of NTC leads to neural tube defect (NTD), which is the second most common birth defect in humans affecting 1 to 1,000 births. However, the regulators and mechanisms that control NTC at post-transcriptional gene regulation levels remain largely unknown. We have created the first miRNA mouse model of NTD. We found that depletion of miR-302/367 leads to NTD and embryonic lethality. Neural precursor cells (NPCs) exhibit reduced proliferation, premature differentiation, and decreased survival in the mutant embryos. Importantly, we have identified individual miRNA targets with potent roles in specific cellular behaviors that are affected in mutant embryos. In addition, we found that miR-302/367 is associated with an RNA binding protein Lin41 to regulate gene expression; depletion of Lin41 also leads to NTD. These preliminary data lead to a novel hypothesis that miR-302/367 interacts with Lin41 to coordinately control multiple neural precursor cell (NPC) behaviors by regulating different miRNA targets during neural tube closure (NTC). In this project, we will determine miR-302/367 functions and their action mechanisms during neural tube closure. Three specific aims will be pursued: 1) Determine the developmental and cellular basis of neural tube defect (NTD) in miR-302/367 mutant mice; 2) Test whether individual genes that we have identified as targets of miR-302 mediate specific cellular behaviors during neural tube closure; 3) Test the hypothesis that miR-302 functions together with Lin41 to regulate gene expression and NPC behaviors during neural tube closure. Together, these studies will improve our understanding of genetic factors associated with NTD and provide novel insights into mechanisms underlying neural tube closure and neural tube defect (NTD).