Genetic Mechanisms of Oligodendrogenesis and Remyelination

描述（由申请人提供）：多种成人和儿童中枢神经系统疾病，如多发性硬化症和脑瘫的主要原因脑室周围白质软化症，都有一个共同的特征，即产生髓磷脂的少突胶质细胞受到损伤。我研究的长期目标是了解少突胶质细胞产生和成熟的生物学，以期在白质病理的背景下如何通过治疗增强髓鞘再生。本研究的重点是在啮齿动物出生后的大脑中调节这些过程的分子机制。成人室下区（SVZ）最近被确定为一个正在进行的少突胶质发生的地点。为了描述出生后少突发生的祖细胞群和遗传因素，我将结合免疫组织化学技术和共聚焦显微镜研究成人SVZ细胞的分子表达谱。我将确定SVZ祖细胞在胼胝体局灶性脱髓鞘损伤时增殖和表达的变化，并将这些变化与少突胶质细胞生成、损伤部位的募集和髓鞘再生的变化联系起来。我之前的工作表明，在胚胎发生过程中，Dlx同源盒转录因子作为少突胶质细胞形成和成熟的抑制因子。在拟议的项目中，我将通过产生在出生后SVZ祖细胞中丧失Dlx2功能的条件Dlx2敲除小鼠，以及使用病毒转导异位表达Dlx2，来研究Dlx在出生后少突细胞发生中的作用。少突胶质细胞前体（OPCs）的细胞移植已被认为是一种潜在的修复策略，在获得性和先天性髓鞘疾病。由于dlx1和2缺失小鼠的OPCs表现出加速成熟，我将研究这些细胞（与野生型OPCs相比）在先天性白质营养不良小鼠模型中的异慢性移植是否会导致更强健的髓鞘形成和更高的存活率。总之，该项目将首次详细分析Dlx在出生后少突胶质发生和内源性脱髓鞘损伤反应中的功能，并为基因工程细胞中操纵Dlx是否可以增强其髓鞘形成潜力提供见解。摘要：常见的儿童和成人神经系统疾病，如脑瘫和多发性硬化症，其特征是由于产生髓磷脂的少突胶质细胞的丢失或功能障碍而导致脑白质损伤。本研究项目研究成年啮齿动物大脑内的干细胞，这些干细胞可以作为少突胶质细胞的内源性来源，这些细胞在白质损伤动物模型中的反应，以及细胞移植范式治疗先天性髓磷脂形成障碍或白质营养不良的有效性。

DESCRIPTION (provided by applicant): A diverse group of adult and pediatric CNS disorders, such as multiple sclerosis and periventricular leukomalacia, the leading cause of cerebral palsy, share a common feature of insult to myelin-producing oligodendrocytes. The long-term goal of my research is to understand the biology of oligodendrocyte production and maturation with a view towards how remyelination could be therapeutically enhanced in the setting of white matter pathology. The proposed research focuses on the molecular mechanisms regulating these processes within the postnatal rodent brain. The adult subventricular zone (SVZ) recently has been identified as a site of ongoing oligodendrogenesis. To characterize the progenitor populations and genetic factors involved in postnatal oligodendrogenesis, I will study the molecular expression profile of cells in the adult SVZ using a combination of immunohistochemical techniques and confocal microscopy. I will determine changes in proliferation and expression of SVZ progenitors in response to focal demyelinating lesion in the corpus callosum, and correlate these with changes in oligodendrocyte production, recruitment to the site of injury, and remyelination. My prior work indicates that Dlx homeobox transcription factors act as repressors of oligodendrocyte formation and maturation during embryogenesis. In the proposed project, I will examine the role of Dlx in postnatal oligodendrogenesis by generating conditional Dlx2 knockout mice with loss of Dlx2 function in postnatal SVZ progenitors, as well as ectopically expressing Dlx2 using viral transduction. Cell transplantation of oligodendrocyte precursors (OPCs) has been suggested as a potential repair strategy in both acquired and congenital disorders of myelination. Since OPCs from Dlx1&2 null mice show accelerated maturation, I will investigate whether heterochronic grafting of these cells (versus wild type OPCs) in a mouse model of congenital leukodystrophy leads to more robust myelination and improved survival. In summary, this project will be the first detailed analysis of Dlx function in postnatal oligodendrogenesis and in endogenous responses to demyelinating injury, and offer insight into whether manipulation of Dlx in genetically engineered cells could enhance their myelinating potential. Lay Summary: Common pediatric and adult neurological disorders, such as cerebral palsy and multiple sclerosis, are characterized by damage to the brain's white matter due to loss or dysfunction of myelin producing oligodendrocytes. This research project investigates stem cells within the adult rodent brain that could serve as endogenous sources of oligodendrocytes, the response of these cells in animal models of white matter injury, and the effectiveness of cell-transplantation paradigms to treat a congenital disorder of myelin formation or leukodystrophy.