Regulation of the survival motor neuron gene

描述(申请人提供)：脊髓性肌萎缩症(SMA)是导致婴儿死亡的最常见的遗传性原因。这种疾病是由存活运动神经元1(SMN1)基因突变引起的。所有患者都保留了该基因的第二个拷贝(SMN2)，该基因产生的SMN蛋白数量不足以完全弥补SMN1的丢失。SMA的一个有希望的治疗策略是通过增加SMN2基因的表达来提高SMN蛋白水平。我们实验室和其他研究小组所做的初步工作表明，组蛋白脱乙酰酶抑制剂在体外可以增加SMN的水平。然而，这些化合物的具体作用机制和调控SMN2基因表达的基本机制目前尚不清楚。我们的目标是了解调节SMN2基因表达的机制，以推进SMA的治疗。我们假设SMN2基因的部分调控因素是组蛋白的乙酰化状态和DNA的甲基化状态，这些状态与SMN2启动子内的顺式和反式作用因子协同作用，并且这些决定因素的操作可以导致人类细胞中SMN水平的增加。我们计划通过追求以下三个特定目标来验证我们的假设：特定目标1：表征组蛋白乙酰化和DNA甲基化在SMN基因表达调控中的作用。特定目的2：确定与表观遗传决定因素协同作用的转录因子和SMN启动子元件，以调控SMN基因的表达。具体目的3：确定SMA患者外周血细胞中SMN蛋白的基线水平，并在体外测试调节SMN基因表达的药物化合物提高这些细胞中SMN蛋白水平的能力。

DESCRIPTION (provided by applicant): Spinal muscular atrophy (SMA) is the most common inherited cause of infant mortality. The disease is caused by mutations in the survival motor neuron 1 (SMN1) gene. All patients retain a second copy of the gene (SMN2) that produces insufficient quantities of SMN protein to fully compensate for the loss of SMN1. One promising therapeutic strategy for SMA is to augment SMN protein levels by increasing SMN2 gene expression. Preliminary work done in our laboratory and by other groups indicates that histone deacetylase inhibitors can increase SMN levels in vitro. However, the specific mechanism of action of these compounds and the fundamental mechanisms that regulate SMN2 gene expression are currently unknown. Our goal is to understand the mechanisms that regulate SMN2 gene expression in order to advance therapy for SMA. We hypothesize that the SMN2 gene is regulated, in part, by the acetylation state of histones and the methylation state of DNA acting in concert with cis- and trans-acting factors within the SMN2 promoter and that manipulation of these determinants can lead to increased SMN levels in human cells. We plan to test our hypothesis by pursuing the following three Specific Aims: Specific Aim 1: To characterize the role of histone acetylation and DNA methylation in SMN gene expression regulation. Specific Aim 2: To identify transcription factors and SMN promoter elements that act in concert with epigenetic determinants to regulate SMN gene expression. Specific Aim 3: To characterize baseline SMN protein levels in peripheral blood cells of SMA patients and to test the ability of pharmacological compounds that modulate SMN gene expression to increase SMN protein levels in these cells in vitro.