Mechanisms of oxysterol-induced oligodendrogenesis

摘要： 白色物质损伤是最常见的新生儿脑损伤，导致早产儿神经功能预后不良。 婴儿。这种损伤导致少突胶质细胞的局灶性和/或弥漫性损失，少突胶质细胞是脊髓中的髓鞘形成细胞。 个脑袋缺氧和炎症是这一脆弱人群中常见的重要风险因素， 没有可用的治疗方案。开发新治疗策略的重大挑战 对于新生儿脑损伤的治疗是安全性的适当考虑。降低创新治疗开发的风险 在这一领域，我们集中在鉴定存在于人母体中的内源性信号分子， 母乳，以进一步发展成为安全和有效的新生儿治疗。我们发现了多种氧化的 人母乳中促进少突胶质细胞命运特化的胆固醇（氧固醇） 出生后的神经干细胞群通过一个音刺猬依赖机制。新生儿流产后， 全身给予母乳相关的氧固醇逆转了室周少突胶质细胞的丢失 并挽救了我们的新生炎症小鼠模型中的相关运动缺陷。我们的长期目标 是开发安全有效的治疗方法，减轻新生儿神经功能缺损。的目标 该建议是在慢性缺氧模型中测试20 HC治疗的功效，并确定20 HC治疗的分子机制。 诱导少突发育的机制。我们的中心假设是，氧固醇治疗将改善 通过干细胞来源的少突神经元发生和诱导的缺氧诱导的新生儿髓鞘形成 少突胶质细胞前体细胞（OPC）成熟。基本原理是，确定氧固醇的功效 在缺氧动物模型中的治疗将导致治疗缺氧诱导的 新生儿脑损伤在Amis 1和2中，我们将在新生小鼠中测试20 HC治疗的功效 慢性缺氧模型。使用不同的遗传工具，我们可以确定两者的细胞行为， 内源性神经干细胞（Aim 1）以及OPCs（Aim 2）对治疗的反应。在最终目标3中，我们 将探索氧化甾醇诱导的翻译后蛋白修饰对Sox 10的影响。Sox 10是一个关键 调节少突胶质细胞成熟的转录因子。因为母乳中含有氧化固醇， 这种方法可以进一步发展成为一种新的和安全的治疗策略，以减轻髓鞘损伤，包括 新生儿时期的人。全面了解氧化甾醇诱导细胞凋亡的分子机制 OPC成熟可以支持在成人髓鞘疾病模型中的进一步测试，包括多发性硬化症 (MS)创伤性脑损伤和中风。

Abstract: White matter injury is the most common neonatal brain injury leading to poor neurologic outcomes in premature infants. This injury results in both focal and/or diffuse losses of oligodendrocytes, the myelinating cells in the brain. Hypoxia and inflammation are common and important risk factors within this vulnerable population and there are no treatment options available. A significant challenge to the development of novel treatment strategies for brain injury in neonates is the appropriate concern for safety. To de-risk innovative therapeutic development in this field, we focused on the identification of endogenous signaling molecules present in human maternal breast milk to further develop into safe and effective therapies for neonates. We identified multiple oxidized cholesterols (oxysterols) in human maternal breast milk that promote oligodendrocyte fate specification in postnatal neural stem cell populations via a sonic hedgehog-dependent mechanism. Following neonatal WMI, systemic administration of breast milk-associated oxysterol reversed the loss of periventricular oligodendrocytes and rescued associated motor deficits in our neonatal inflammatory WMI mouse model. Our long-term objective is to develop safe and effective therapy that mitigates the neurologic deficits of neonatal WMI. The objective of this proposal is to test the efficacy of 20HC therapy in a chronic hypoxia model and determine the molecular mechanism(s) of induced oligodendrogenesis. Our central hypothesis is that oxysterol therapy will improve myelination in hypoxia-induced neonatal WMI through stem cell-derived oligodendrogenesis and induced oligodendrocyte precursor cell (OPC) maturation. The rationale is that determining the efficacy of oxysterol therapy in animal models of hypoxia will lead to critical development of novel therapies to treat hypoxia-induced neonatal brain injuries. In Amis 1 & 2 this proposal we will test the efficacy of 20HC therapy in a neonatal mouse model of chronic hypoxia. Using separate genetic tools, we can determine the cellular behavior of both endogenous neural stem cells (Aim 1) as well as OPCs (Aim 2) in response to therapy. In our final Aim 3, we will explore the impact of oxysterol-induced posttranslational protein modifications on Sox10. Sox10 is a critical transcription factor that regulates oligodendrocyte maturation. Because oxysterols are found in breast milk, this approach may be further developed into a novel and safe therapeutic strategy to mitigate myelin injuries including those in the neonatal period. A comprehensive understanding of the molecular mechanisms of oxysterol-induced OPC maturation may support further testing in models of adult myelin disorders including, multiple sclerosis (MS), traumatic brain injury, and stroke.