Epigenetic regulation of adult neurogenesis

描述（由申请人提供）：癫痫发作活动诱导干细胞增殖和神经发生的深刻变化，但在理解癫痫发作诱导的神经发生机制及其与癫痫的关系方面存在根本性差距。长期的目标是更好地了解表观遗传/转录电路重要的神经元细胞的命运，在生理和病理的情况下。这项资助计划的目的是阐明成年海马神经干细胞中神经发生的主要调节因子NRSF的作用。中心假设是癫痫发作活动触发NRSF的失调，并选择NRSF靶基因介导异常神经发生和癫痫发生。这项研究的基本原理是，了解病理刺激（如癫痫发作）后神经发生的机制，有可能了解脑损伤后潜在的修复反应和神经可塑性变化，并评估干细胞对神经再生医学的适用性。因此，拟议的研究与NIH的使命的一部分有关，该使命涉及获得可能有助于治疗神经系统疾病（如癫痫）的基础知识。在强有力的初步数据的指导下，该假设将通过追求三个特定目标进行测试：1）确定负责NRSF调节神经元细胞命运的表观遗传/转录机制; 2）使用单细胞遗传方法确定NRSF如何介导癫痫发作后的异常神经发生; 3）使用NRSF条件性基因敲除小鼠确定NRSF有助于癫痫诱导的神经发生和癫痫发生。目标1和2将集中在NRSF在神经发生中的作用，使用功能获得和功能丧失的逆转录病毒构建体在体外和体内神经诱导的神经发生过程中操纵NRSF，这与Hsieh实验室的技能和经验直接相关。具体目标3将与Christopher辛顿博士合作进行，重点是使用NRSF条件性敲除小鼠，以确定NRSF在癫痫诱导的神经发生中的作用，并检查异常神经发生对癫痫发生的贡献。这种方法是创新的，因为它有潜力探索成体神经干细胞的生物学，并挖掘它们在脑损伤后细胞替代策略中的潜力。拟议的工作是重要的，因为它有望推进和扩大我们的基本理解的表观遗传/转录调控机制控制神经元细胞的命运后，广泛的病理刺激，而不仅仅是癫痫发作。神经系统的疾病、变性或创伤性损伤是美国最大的公共卫生问题之一，通常被认为是不可修复的，通常会对个人的功能造成灾难性的损害。然而，现在，神经干细胞的特征驻留在特定的大脑的生发中心和细胞培养提出了希望，神经组织的功能再生可能是可行的，如果我们学会利用成人神经发生的临床效益。这项研究提案将导致对神经干细胞生物学的更好理解，可能导致神经系统修复和再生新药的开发。

DESCRIPTION (provided by applicant): Seizure activity induces profound changes in stem cell proliferation and neurogenesis, yet there is a fundamental gap in understanding the mechanism of seizure-induced neurogenesis and the relationship to epilepsy. The long-term goal is to better understand the epigenetic/transcriptional circuitry important for neuronal cell fate, in both physiological and pathological contexts. The objective of this grant proposal is to elucidate the role of the master regulator of neurogenesis NRSF, in adult hippocampal neural stem cells. The central hypothesis is that seizure activity triggers the dysregulation of NRSF and selects NRSF target genes that mediate aberrant neurogenesis and epileptogenesis. The rationale for the proposed research is that understanding the mechanisms of neurogenesis after pathologic stimuli, such as seizures, has the potential to understand the underlying repair response and neuroplasticity changes after brain injury, and evaluate the suitability of stem cells for neuro-regenerative medicine. Thus, the proposed study is relevant to that part of NIH's mission that relates to gaining fundamental knowledge that will potentially help treat neurological disorders, such as epilepsy. Guided by strong preliminary data, this hypothesis will be tested by pursuing three specific aims: 1) Identify the epigenetic/transcriptional mechanism that is responsible for NRSF regulation of neuronal cell fate; 2) Determine how NRSF mediates aberrant neurogenesis after seizures using a single-cell genetic approach, and 3) Establish that NRSF contributes to seizure-induced neurogenesis and epileptogenesis using NRSF conditional knockout mice. Aims 1 and 2 will focus on the role of NRSF in neurogenesis, using gain-of-function and loss-of-function retroviral constructs to manipulate NRSF in vitro and during seizure-induced neurogenesis in vivo, which directly relate to the skills and experience in the Hsieh lab. Specific Aim 3 will be performed in collaboration with Dr. Christopher Sinton, and focus on the use of the NRSF conditional knockout mouse, to determine the role of NRSF in seizure-induced neurogenesis, and examine the contribution of aberrant neurogenesis to epileptogenesis. The approach is innovative, because it has the potential to explore the biology of adult neural stem cells and tap into their potential for cell replacement strategies after brain injury. The proposed work is significant, because it is expected to advance and expand our basic understanding of epigenetic/transcriptional regulatory mechanisms controlling neuronal cell fate after a wide range of pathologic stimuli, not just seizures. PUBLIC HEALTH RELEVANCE Disease, degeneration or traumatic injury of the nervous system are among the greatest public health concerns in the United States and are generally considered irreparable, often causing catastrophic damage to the functional capacity of the individual. Now, however, characterization of neural stem cells residing within specific germinal centers of the brain and in cell culture raises hope that functional regeneration of nervous tissue may be feasible, if we learn to exploit adult neurogenesis for clinical benefit. The research proposal will lead to improved understanding of neural stem cell biology, possibly leading to the development of new drugs for repair and regeneration of the nervous system.