Identifying novel targets and mechanistic role of 8,9 unsaturated sterol accumulation on enhancement of oligodendrocyte formation

项目摘要 多发性硬化症(MS)是一种以脑内少突胶质细胞丢失为特征的衰弱疾病。一个 多发性硬化症的潜在治疗角度是通过增加少突胶质前体细胞的分化 (OPC)转化为少突胶质细胞。增加OPC的分化是一个可行的治疗选择，因为它们 一种在成人大脑中发现的具有分化能力的干细胞群体，尽管分化速度通常较低 不同的实验室已经进行了高通量的筛查，以确定 导致OPC分化增加的新型小分子。在我们实验室的工作中，我们发现了一个统一的 从这些屏幕点击的机制。每个小分子都抑制胆固醇中的三个步骤中的一个 生物合成途径，然后我们确定了在这些步骤中积累的8，9不饱和甾醇 作为行动的机制。我们的实验室已经评估了不同的类固醇和胆固醇的积累 其他新靶点的生物合成途径。在这项建议中，我们计划澄清 胆固醇的生物合成途径及其促进胆固醇合成的潜在机制 少突胶质细胞形成。在目标1中，我们已经开发了以前针对目标的工具和小分子 忽略了胆固醇生物合成途径中的酶，SC4MOL，NSDHL和HSD17B7。潜力 抑制这三种酶同样会导致8，9-不饱和甾醇的积累。因此，我们 假设这些酶提供了额外的治疗靶点。在目标2中，我们提出了两个平行 胆固醇生物合成途径对少突胶质细胞的分化有独特的影响。在……里面 目的3，我们已经确定了8，9-不饱和甾醇促进OPC的两种潜在的信号机制 差异化。进行了转录和蛋白质组学分析以确定不同的下游 这些8，9-不饱和甾醇促进OPC分化的信号通路。二 不同的信号通路已经被牵连，这项建议评估它们是否是机制。 综上所述，这项提案中概述的实验将提供搜索和 髓鞘再生疗法的发展。新靶点(目标1和目标2)和这些甾醇的作用机制 (AIM 3)将提供更全面的情况和潜在的治疗策略，以针对门诊诊所重新填充 大脑中的少突胶质细胞。

Project Summary Multiple Sclerosis (MS) is a debilitating disease that is characterized by loss of oligodendrocytes in the brain. A potential therapeutic angle for MS is through the increased differentiation of oligodendrocyte progenitor cells (OPCs) into oligodendrocytes. Increasing differentiation of OPCs is a viable therapeutic option because they are a stem cell population that is found in the adult brain with the ability to differentiate, albeit typically at lower rates than needed to alleviate the symptoms of MS. Different labs have conducted high throughput screens to identify novel small molecules that lead to increased OPC differentiation. In work from our lab, we identified a unifying mechanism of the hits from these screens. Each small molecule inhibited one of three steps within the cholesterol biosynthesis pathway, which we then identified the accumulation of the 8,9 unsaturated sterols from these steps as being the mechanism of action. Our lab has evaluated the accumulation of different sterols and the cholesterol biosynthesis pathway for other novel targets. In this proposal, we plan to elucidate different targets within the cholesterol biosynthesis pathway and evaluate potential mechanisms by which these sterols enhance oligodendrocyte formation. In Aim 1, we have developed tools and small molecules to target previously overlooked enzymes within the cholesterol biosynthesis pathway, SC4MOL, NSDHL, and HSD17B7. Potential inhibition of these three enzymes would similarly lead to accumulation of 8,9-unsaturated sterols. Therefore, we hypothesize that these enzymes provide additional therapeutic targets. In Aim 2, we propose that two parallel pathways within the cholesterol biosynthesis pathway have unique effects on oligodendrocyte differentiation. In Aim 3, we have identified two potential signaling mechanisms in which 8,9-unsaturated sterols promote OPC differentiation. Transcriptomic and proteomic analyses have been done to determine different downstream signaling pathways by which these 8,9-unsaturated sterols act through to promote OPC differentiation. Two different signaling pathways have been implicated, and this proposal evaluates whether they are the mechanism. Taken together, the experiments outlined in this proposal will provide key new findings in the search and development of remyelinating therapeutics. Both new targets (Aim 1 and 2) and the mechanism of these sterols (Aim 3) will provide a more complete picture and potential therapeutic strategies to target OPCs to repopulate oligodendrocytes in the brain.