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）是一种以脑中少突胶质细胞丢失为特征的衰弱性疾病。一 MS的潜在治疗角度是通过增加少突胶质细胞祖细胞的分化 （OPCs）转化为少突胶质细胞。增加OPCs的分化是一种可行的治疗选择，因为它们 在成人大脑中发现的具有分化能力的干细胞群，尽管通常以较低的速度分化 不同的实验室已经进行了高通量筛选，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，我们发现了一种统一的 从这些屏幕上点击的机制。每个小分子都抑制胆固醇中的三个步骤之一 生物合成途径，然后我们确定了从这些步骤中积累的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固醇的积累和胆固醇 生物合成途径的其他新的目标。在这项建议中，我们计划阐明 胆固醇生物合成途径，并评估这些甾醇增强 少突胶质细胞形成。在目标1中，我们已经开发了以前针对的工具和小分子 胆固醇生物合成途径中被忽视的酶，SC 4 MOL，NSDHL和HSD 17 B7。潜在 这三种酶的抑制将类似地导致8，9-不饱和甾醇的积累。所以我们 假设这些酶提供了额外的治疗靶点。在目标2中，我们提出两个平行的 胆固醇生物合成途径中的途径对少突胶质细胞分化具有独特的作用。在 目的3，我们确定了8，9-不饱和甾醇促进OPC的两种可能的信号转导机制 分化转录组学和蛋白质组学分析已经完成，以确定不同的下游 这些8，9-不饱和固醇通过其起作用以促进OPC分化的信号传导途径。两 不同的信号通路已经被牵连，并且该提议评估它们是否是机制。 总的来说，本提案中概述的实验将为研究提供关键的新发现， 髓鞘再生疗法的发展。这两个新的目标（目标1和2）和这些甾醇的机制 (Aim 3）将提供更完整的图片和潜在的治疗策略，以靶向OPCs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.