Histone deacetylases - therapeutic targets for functional restoration after strok

描述（由申请人提供）：事实证明，寻找改善缺血性中风结果的干预措施具有挑战性，目前的治疗仅限于溶栓、阿司匹林和中风病房的管理。理想的中风治疗方法应最大限度地减少对成熟神经元和白质的损害，并最大限度地从内源性祖细胞中生成新神经元。我们自己和其他人最近在体外和中风动物模型中的发现表明，组蛋白脱乙酰酶 (HDAC) 抑制剂符合这些标准。药物给药可以保护分离的神经元免受诱导的细胞凋亡和白质免受氧-葡萄糖剥夺的影响，从而改善脑缺血后的组织学和功能结果，并且似乎可以驱动多能神经祖细胞的“神经元”分化。因此，我们假设 HDAC 抑制在中风中可能具有急性作用（改善白质兴奋性毒性），并且在中长期来看，通过减少细胞凋亡和促进再生而增加益处。由于许多 HDAC 抑制剂要么已获得 FDA 批准（伏立诺他），要么因其他原因在临床试验（MS-275）中取得进展，因此可以加快将这些药物中的一种或多种重新用于治疗中风。此外，新的特异性抑制剂的开发正在进行中，特别是针对 I 类 HDAC 的抑制剂，这是本文关注的焦点。目标 1 中描述的研究旨在使用体外和离体制剂来鉴定导致这些抑制剂有益作用的特定 HDAC，其中用 shRNA 敲低单个 HDAC，然后对转导的细胞/组织进行氧-葡萄糖剥夺。确定了特定的 HDAC 后，我们将在目标 2 中探索导致 HDAC 抑制的有益作用的潜在底物和机制。最后，在最后一个目标中，我们考虑用 I 类 HDAC 抑制剂 MS-275 治疗小鼠是否可以保留解剖完整性并促进短暂性脑缺血（大脑中动脉闭塞）的长期功能（运动、感觉、认知）恢复，以及功能恢复是否与“神经元发生”的程度相关。两个最近开发的转基因系，p53 / 和 p53 -/- mitoCFP 小鼠，将被用来监测 CFP 纤维束的缺血病理学，评估药物相关的神经元细胞体内线粒体频率和分布及其过程的变化，并确定 HDAC 抑制是否最终涉及神经元 p53 之外的靶点。

DESCRIPTION (provided by applicant): Finding interventions that improve outcome from ischemic stroke has proved to be challenging and current treatment is limited to thrombolysis, aspirin, and management in a stroke unit. An ideal stroke therapeutic would minimize damage to mature neurons and white matter, and also maximize the generation of new neurons from endogenous progenitors. Recent findings of our own and of others, both in vitro and in animal models of stroke, suggest that histone deacetylase (HDAC) inhibitors meet these criteria. Drug administration protects isolated neurons from induced apoptotic cell death and white matter from oxygen-glucose deprivation, results in improved histologic and functional outcomes following cerebral ischemia, and appears to drive 'neuronal' differentiation of multipotent neural progenitor cells. Therefore, we hypothesize that HDAC inhibition in stroke may have acute effects (to ameliorate white matter excitotoxicity), and in the intermediate and longer term, added benefit by reducing apoptosis and encouraging regeneration. As a number of HDAC inhibitors are either already approved by the FDA (vorinostat), or well-advanced in clinical trials (MS-275) for other reasons, then re- purposing one or more of these drugs for stroke could be expedited. In addition, development of new and specific inhibitors is ongoing, especially against the Class I HDACs which are the focus of interest here. Studies described in Aim 1 are designed to identify the specific HDACs which account for the beneficial actions of these inhibitors, using in vitro and ex vivo preparations in which individual HDACs are knocked down with shRNA and transduced cells/tissues then subjected to oxygen-glucose deprivation. Having identified specific HDACs, we shall explore in Aim 2 the potential substrates and mechanisms responsible for the beneficial actions of HDAC inhibition. Finally, in the last aim we consider whether treatment of mice with MS-275, a Class I HDAC inhibitor, preserves anatomic integrity and promotes long term functional (motor, sensory, cognitive) recovery from transient cerebral ischemia (middle cerebral artery occlusion), and whether restoration of function correlates with the extent of 'neuronogenesis'. Two recently developed transgenic lines, p53+/+ and p53 -/- mitoCFP mice, will be employed so that we can monitor ischemic pathology in CFP+ fiber tracts, assess drug-associated changes in mitochondrial frequency and distribution within neuronal cell bodies and their processes, and also determine whether HDAC inhibition ultimately involves targets in addition to neuronal p53.