Defining the contribution of astrocytes to genetic MS susceptibility

科学抽象 全基因组关联研究已经提供了与多种遗传易感性相关的230多个遗传变异。 硬化症（MS）。从这些研究中出现的主题是MS风险变异扰乱了基因调控， 活化的淋巴细胞，支持MS是通过淋巴细胞失调介导的观点。缺席 尽管有大量证据表明这些细胞在MS中起着关键作用， 损伤形成。在这个提议中，我们挑战了以淋巴细胞为中心的遗传MS易感性观点。 我们假设遗传变异介导MS风险的一部分，通过失调星形胶质细胞功能。由于NF-κB 信号传导是MS病理学的中心通路，我们将确定两种常见NF-κB相关风险的影响 rs 1800693 G（TNFRSF 1A的内含子）和rs7665090 G（NFKB 1的近端）对炎症反应的影响 在星形胶质细胞中。这将在人类星形胶质细胞培养物中进行检查，这些培养物来源于基因组编辑的诱导多能干细胞。 干细胞（目的1）和活动性MS病变内的反应性星形胶质细胞（目的2）具有风险和保护性 基因型此外，我们将量化病变环境中的变异驱动的变化，如淋巴细胞 浸润、病变大小、细胞表型和表型相互作用。在目标3中，我们将系统地识别 在星形胶质细胞中活跃的多发性硬化症风险变体及其干扰的基因。为此，我们将生成 从MS病变中分离的星形胶质细胞的染色质可及性谱，我们将与MS风险变体相交。 由此产生的变体和变体依赖基因的列表将提供星形胶质细胞通路的路线图， MS风险变体的失调，从而可能导致星形胶质细胞介导的MS易感性。 我们的研究结果将有助于确定星形胶质细胞在遗传介导的MS风险中的作用。这将提供一个更 遗传变异如何赋予MS易感性的完整图片。此外， 星形胶质细胞将成为星形胶质细胞研究的重要资源，并可用于研究遗传 在其他复杂的遗传疾病如阿尔茨海默病中星形胶质细胞的失调。

Scientific abstract Genome-wide association studies have provided >230 genetic variants associated with susceptibility to multiple sclerosis (MS). The theme emerging from these studies is that MS risk variants perturb gene regulation in activated lymphocytes, supporting the view that MS is mediated through dysregulation of lymphocytes. Absent from this picture is a role for glial cells, despite substantial evidence that these cells are critical players in MS lesion formation. In this proposal, we are challenging the lymphocyte-centric view of genetic MS susceptibility. We hypothesize that genetic variants mediate MS risk in part by dysregulating astrocyte function. Since NF-κB signaling is a central pathway in MS pathology, we will determine the impact of two common NF-κB relevant risk variants, rs1800693G (intronic to TNFRSF1A) and rs7665090G (proximal to NFKB1), on inflammatory response in astrocytes. This will be examined in human astrocyte cultures, derived from genome-edited induced pluripotent stem cells (aim 1), and in reactive astrocytes within active MS lesions (aim 2) with the risk and protective genotypes. In addition, we will quantify variant-driven changes in the lesion environment such as lymphocyte infiltration, lesion size, cellular phenotypes and phenotype interactions. In aim 3, we will systematically identify the MS risk variants that are active in astrocytes and the genes that they perturb. For this, we will generate chromatin accessibility profiles of astrocytes isolated from MS lesions that we will intersect with MS risk variants. The resulting list of variants and variant-dependent genes will provide a roadmap of astroglial pathways that are dysregulated by MS risk variants and thereby are likely to contribute to astrocyte-mediated MS susceptibility. Our results will help to define the role of astrocytes in genetically mediated MS risk. This will provide a more complete picture of how genetic variants confer susceptibility to MS. Moreover, the epigenomic profiles of astrocytes will be an important resource for research in astrocytes and can be used to investigate genetic dysregulation of astrocytes in other complex genetic disease such as Alzheimer’s disease.