Dissecting the roles of glia-specific Sigma-1 receptors in chronic inflammatory CNS disease

在中枢神经系统（CNS）中，神经胶质细胞的活化伴随促炎性细胞因子和趋化因子的表达增加是对多种神经病理学（如多发性硬化症（MS））的炎症反应期间的指示性标志。我们的中国合作伙伴和我们的结果表明，Sigma-1受体（Sig-1 R）可能介导星形胶质细胞的活化，小胶质细胞的存活和少突胶质细胞系细胞的命运承诺。然而，由于缺乏选择性Sig-1 R失活动物模型，我们仍然无法阐明Sig-1 R在不同胶质细胞类型中的精确体内功能。因此，在本项目中，我们将首先通过产生floxed Sig-1 R小鼠和体内CRISPR/Cas9基因缺失系统来建立体内选择性表达Sig-1 R的方法。其次，我们将利用建立的条件性Sig-1 R基因敲除小鼠和CRISPR/Cas9基因缺失系统研究胶质细胞特异性Sig-1 R在MS模型中的功能。第三，我们将应用包括新一代测序在内的先进技术来剖析MS模型中神经炎症过程中胶质细胞特异性Sig-1 R功能的分子机制。第四，我们将通过活体双光子激光扫描显微镜（2-P LSM）成像技术研究胶质细胞特异性Sig-1 R介导的Ca ~（2+）信号转导，这将有助于理解Sig-1 R下游信号转导的潜在Ca ~（2+）依赖机制，如MAPK和PI 3 K/Akt。该项目将整合德国团队（转基因小鼠模型和2-P LSM活体成像）和中国团队（分子生物学和神经炎症研究）的专业知识，从机制上研究胶质细胞特异性Sig-1 R在MS中的功能，这将通过关注Sig-1 R作为抗炎靶点为MS的治疗提供新的概念。

In the central nervous system (CNS), activation of glia cells with increased expression of proinflammatory cytokines and chemokines are indicative hallmarks during the inflammatory response to a variety of neuropathologies such as multiply sclerosis (MS). Results of our Chinese partners and us suggest that Sigma-1 receptors (Sig-1R) may mediate activation of astrocyte, survival of microglia and fate commitment of oligodendrocyte lineage cells. However, due to the lack of selective Sig-1R inactivation animal models, we are still not able to elucidate the precise in vivo functions of Sig-1Rs in different glial cell types. Therefore, in this project, we will firstly establish the methods to selectively inactivate Sig-1Rs in vivo by generating floxed Sig-1R mice and in vivo CRISPR/Cas9 gene-deleting system. Secondly, we will study the functions of glia-specific Sig-1Rs in the MS models with the established conditional Sig-1R knockout mice and CRISPR/Cas9 gene-deleting system. Thirdly, we will apply advanced techniques including next-generation sequencing to dissect the molecular mechanisms involved in glia-specific Sig-1R functions during neuroinflammation in the MS models. Fourthly, we will study the glia-specific Sig-1R mediated Ca2+ signaling by in vivo two-photon laser-scanning microscopy (2-P LSM) live imaging, which will help to understand the potential Ca2+-dependent mechanisms modulating the downstream signaling of Sig-1Rs such as MAPK and PI3K/Akt. The proposed project will integrate the expertise of the German group (transgenic mouse models and 2-P LSM live imaging) and the Chinese group (molecular biology and neuroinflammation study) to mechanistically study the functions of glia-specific Sig-1Rs in MS, which will provide novel concept to the treatment of MS by focusing on the Sig-1R as an anti-inflammatory target.