Early Involvement of Peripherally Derived Monocytes in Inflammation in an NMO-Like Mouse Model [microglia]

Neuromyelitis optica (NMO) is an autoimmune inflammatory disease that primarily affects the spinal cord and optic nerves in the central nervous system (CNS). It is characterized by the presence of immunoglobulin G (IgG) antibodies against aquaporin 4, a protein found in astrocytes (known as NMO-IgG). Monocytes/macrophages and microglia accumulate at the active injury sites and contribute to the disease process. However, it is unclear whether these active cells originate from circulating monocytes/macrophages or resident microglia. Recent studies have investigated the role of microglia/macrophages in multiple sclerosis (MS) using specific microglial markers, such as P2ry12 and Tmem119, and have shown that active cells are derived from microglia. In contrast, the function of monocyte/macrophages and microglia in NMO has not been extensively studied. Therefore, this study aims to analyze the functions of monocytes/macrophages and microglia using microglial markers (P2ry12 and Tmem119) in an NMO-like mouse model and evaluate their role in the pathophysiology of NMO. Overall design: Cells were labeled with CD45, CD11b, P2ry12, Ly6C and Ly6G, and sorted CD45+CD11b+P2ry12+ cells for microglia

视神经脊髓炎（Neuromyelitis optica, NMO）是一类主要累及中枢神经系统（central nervous system, CNS）脊髓与视神经的自身免疫性炎症疾病。该疾病的标志性特征为患者体内存在针对星形胶质细胞表达的水通道蛋白4的免疫球蛋白G（immunoglobulin G, IgG）抗体，即NMO-IgG。活动性损伤病灶处会聚集单核细胞/巨噬细胞与小胶质细胞，并参与疾病进展过程，但目前尚未明确这些活化细胞究竟起源于循环单核细胞/巨噬细胞，还是组织常驻的小胶质细胞。
既往已有研究通过P2ry12、Tmem119等特异性小胶质细胞标志物，探究了小胶质细胞/巨噬细胞在多发性硬化症（multiple sclerosis, MS）中的作用，并证实病灶内的活化细胞源自小胶质细胞。与之相对，目前针对NMO中单核细胞/巨噬细胞与小胶质细胞的功能尚未开展广泛深入的研究。因此，本研究计划在类视神经脊髓炎小鼠模型中，利用P2ry12、Tmem119等小胶质细胞标志物分析单核细胞/巨噬细胞与小胶质细胞的功能，并评估二者在NMO病理生理学过程中的作用。
实验整体设计：采用CD45、CD11b、P2ry12、Ly6C及Ly6G对细胞进行标记，并分选得到CD45+CD11b+P2ry12+的小胶质细胞。