Genetic Mechanisms of Oligodendrogenesis and Remyelination

描述(申请人提供)：一组不同的成人和儿童中枢神经系统疾病，如多发性硬化症和脑室周围白质软化，脑性瘫痪的主要原因，有一个共同的特征，侮辱产生髓鞘的少突胶质细胞。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，以期在白质病理学的背景下如何通过治疗增强再髓鞘形成。这项拟议的研究侧重于在出生后啮齿动物大脑中调节这些过程的分子机制。成人室下带(SVZ)最近被认为是正在进行的少突胶质细胞形成的部位。为了研究出生后少突胶质细胞发育所涉及的祖细胞群体和遗传因素，我将结合免疫组织化学技术和共聚焦显微镜技术研究成年SVZ细胞的分子表达谱。我将确定在局灶性脱髓鞘损伤后，SVZ前体细胞增殖和表达的变化，并将其与少突胶质细胞的产生、在损伤部位的募集和重新髓鞘形成的变化相关联。我以前的工作表明，DLX同源框转录因子在胚胎发育过程中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，我将通过在出生后SVZ祖细胞中产生Dlx2功能缺失的条件性Dlx2基因敲除小鼠，以及通过病毒转导异位表达Dlx2，来研究Dlx在出生后少突胶质细胞发生中的作用。少突胶质前体细胞移植已被认为是后天性和先天性髓鞘形成障碍的一种潜在的修复策略。由于Dlx1和Dlx2缺失小鼠的OPC表现出加速成熟，我将研究在先天性脑白质营养不良小鼠模型中异时移植这些细胞(与野生型OPC相比)是否会导致更强大的髓鞘形成和提高存活率。综上所述，该项目将首次详细分析DLX在出生后少突胶质细胞发育和脱髓鞘损伤的内源性反应中的作用，并提供关于在基因工程细胞中操纵DLX是否可以增强其髓鞘形成潜力的洞察。LAY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鞘的少突胶质细胞丢失或功能障碍而对脑白质造成损害。这项研究项目调查了成年啮齿动物大脑中可作为少突胶质细胞内源性来源的干细胞，这些细胞在白质损伤动物模型中的反应，以及细胞移植范例治疗先天性髓鞘形成障碍或脑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.