Role of Pacs2 in central nervous system myelination

项目摘要 少突胶质细胞（Olds）对中枢神经系统（CNS）的髓鞘化对于发育是必不可少的。 和CNS的功能。当OL前体细胞（OPC）分化成OL时，髓鞘在CNS中发育， 强调OL分化是CNS髓鞘形成的关键事件。Myrf是OL的主要转录因子 分化和CNS髓鞘形成。OL谱系细胞中Myrf的条件性敲除（cKO）导致完全的 抑制OL成熟和致死性髓鞘形成障碍。显然，Myrf不可或缺的作用反映了 髓鞘形成过程中的Myrf靶基因。寻找可能在OL中发挥关键作用的新Myrf靶点 在开发中，我们进行了RNA-seq实验，其中我们在分化OL中急性敲除Myrf。 正如预期的那样，许多对OL分化和CNS髓鞘形成至关重要的基因的表达， 在急性Myrf敲除后显著下降。然而，出乎意料的是，基因本体分析显示， MYRF特异性激活与细胞投射、突触和细胞内 在髓鞘形成前的OL中的转运。此外，这表明参与轴突延伸的分子机制 可以促进接触轴突并最终形成髓鞘的OL过程的生长。研究 属于这些类别的基因可以提供对OL分化和CNS髓鞘形成的新见解。 在这方面，我们决定将重点放在Pacs 2（磷酸弗林酸性簇分选蛋白2）上， 在急性Myrf敲除后显著下调。Pacs 2是一种多功能蛋白质， 在多种过程中发挥重要作用，如内质网-线粒体接触和货物分选， 运输PACS 2突变与人类神经发育障碍有关，包括一种综合征， 自闭症的一种形式。值得注意的是，Pacs 2主要由CNS中的OL表达。与RNA-seq发现一起， Pacs 2是一个假定的Myrf靶点，这些观察结果表明，Pacs 2可能是OL所必需的 OL谱系细胞中的PACS 2功能障碍可能有助于中枢神经系统的髓鞘形成。 自闭症的发病机制为了支持这些假设，我们的初步研究发现，Pacs 2是必需的， 小鼠OPCs的体外分化，Pacs 2的表达在几个 观察到髓鞘缺乏的自闭症小鼠模型。此外，Pacs 2全身敲除小鼠 表现出神经系统的表型。目前，关于Pacs 2在体内OL发育中的作用知之甚少 和CNS髓鞘形成。该项目旨在通过Cre-删除OL谱系细胞中的Pacs 2来解决这个问题。 loxP方法。

Project Summary Myelination of the central nervous system (CNS) by oligodendrocytes (OLs) is essential for the development and function of the CNS. Myelin develops in the CNS as OL precursor cells (OPCs) differentiate into OLs, highlighting OL differentiation as a key event for CNS myelination. Myrf is a master transcription factor of OL differentiation and CNS myelination. Conditional knockout (cKO) of Myrf in OL lineage cells leads to complete arrest of OL maturation and lethal dysmyelination. Apparently, the indispensable role of Myrf reflects that of Myrf target genes in the myelination process. To find novel Myrf targets that may play a critical role in OL development, we performed an RNA-seq experiment where we acutely knocked out Myrf in differentiating OLs. As expected, the expression of many genes that are crucial for OL differentiation and CNS myelination went down significantly upon acute Myrf knockout. Unexpectedly, however, a gene ontology analysis revealed that Myrf specifically activates the expression of genes related to cell projection, synapse, and intracellular transport in pre-myelinating OLs. Further, it suggested that molecular machineries involved in axon elongation may propel the growth of OL processes, which contact axons and eventually form myelin sheaths. Studying genes that belong to these categories may provide a novel insight into OL differentiation and CNS myelination. In this regard, we decided to focus on Pacs2 (phosphofurin acidic cluster sorting protein 2), which was significantly down-regulated upon acute Myrf knockout. Pacs2 is a multifunctional protein that plays an important role in diverse processes such as endoplasmic reticulum-mitochondria contact and cargo sorting and transport. PACS2 mutations have been linked to human neurodevelopmental disorders, including a syndromic form of autism. Remarkably, Pacs2 is mainly expressed by OLs in the CNS. Together with the RNA-seq finding that Pacs2 is a putative Myrf target, these observations suggest that Pacs2 may be required for OL development and CNS myelination and that PACS2 dysfunction in OL lineage cells may contribute to the pathogenesis of autism. In support of these hypotheses, our preliminary study found that Pacs2 is required for the in vitro differentiation of mouse OPCs, and Pacs2 expression was significantly downregulated in several autism mouse models where myelin deficiency was observed. Moreover, Pacs2 whole-body knockout mice exhibited neurological phenotypes. Currently, little is known about the role of Pacs2 in in vivo OL development and CNS myelination. This project intends to address it by deleting Pacs2 in OL lineage cells through the Cre- loxP approach.