Moesin is a member of the ezrin, radixin and moesin (ERM) proteins that are involved in the formation and/or maintenance of cortical actin organization through their cross-linking activity between actin filaments and proteins located on the plasma membranes as well as through regulation of small GTPase activities. Microglia, immune cells in the central nervous system, show dynamic reorganization of the actin cytoskeleton in their process elongation and retraction as well as phagocytosis and migration. In microglia, moesin is the predominant ERM protein. Here, we show that microglial activation after systemic lipopolysaccharide application is partly inhibited in moesin knockout (Msn-KO) mice. We prepared primary microglia from wild-type and Msn-KO mice, and studied them to compare their phenotypes accompanying morphological changes and reorganization of the actin cytoskeleton induced by UDP-stimulated phagocytosis and ADP-stimulated migration. The Msn-KO microglia showed higher phagocytotic activity in the absence of UDP, which was not further increased by the treatment with UDP. They also exhibited decreased ADP-stimulated migration activities compared with the wild-type microglia. However, the Msn-KO microglia retained their ability to secrete tumor necrosis factor α and nitric oxide in response to lipopolysaccharide.

中文翻译：

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Moesin 参与小胶质细胞的激活以及肌动蛋白细胞骨架的形态变化和重组


Moesin 是埃兹蛋白 (ezrin)、根蛋白 (radixin) 和 moesin (ERM) 蛋白的成员，这些蛋白通过肌动蛋白丝和位于质膜上的蛋白质之间的交联活性以及通过调节参与皮质肌动蛋白组织的形成和/或维持小 GTP 酶活性。小胶质细胞是中枢神经系统中的免疫细胞，在伸长和收缩以及吞噬和迁移过程中表现出肌动蛋白细胞骨架的动态重组。在小胶质细胞中，moesin 是主要的 ERM 蛋白。在这里，我们发现，在moesin敲除（Msn-KO​​）小鼠中，全身脂多糖应用后小胶质细胞的激活受到部分抑制。我们从野生型和 Msn-KO​​ 小鼠中制备了原代小胶质细胞，并对它们进行了研究，以比较它们伴随着 UDP 刺激的吞噬作用和 ADP 刺激的迁移诱导的肌动蛋白细胞骨架的形态变化和重组的表型。 Msn-KO​​ 小胶质细胞在不存在 UDP 的情况下表现出较高的吞噬活性，而用 UDP 处理后该活性并未进一步增加。与野生型小胶质细胞相比，它们还表现出 ADP 刺激的迁移活性降低。然而，Msn-KO​​ 小胶质细胞保留了响应脂多糖而分泌肿瘤坏死因子 α 和一氧化氮的能力。