Novel Approach to Visualize Microglia Death and Proliferation After Intracerebral Hemorrhage in Mice.
Novel Approach to Visualize Microglia Death and Proliferation After Intracerebral Hemorrhage in Mice.
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可视化小鼠脑出血后小胶质细胞死亡与增殖的新方法
DOI：
10.1161/strokeaha.122.040302
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发表时间：
2022-11
期刊：
影响因子：
8.3
通讯作者：
Xi, Guohua
中科院分区：
文献类型：
--
作者：
Ye, Fenghui;Yang, Jinting;Hua, Ya;Keep, Richard F.;Xi, Guohua
小胶质细胞是重要的脑免疫细胞。然而，很难区分小胶质细胞和单核细胞来源的巨噬细胞。为了可视化脑出血 (ICH) 后小胶质细胞的变化，我们利用了基因敲入小鼠系 Tmem119 增强的绿色荧光蛋白 (EGFP)，它在小胶质细胞中特异性表达 EGFP。这项研究分为两个部分。首先，将自体血液注射到右侧基底神经节中，以建立 Tmem119-EGFP 小鼠的 ICH 模型。 ICH后4小时、第1天、第3天和第7天对小鼠实施安乐死。使用假动物作为对照。其次，对 Tmem119-EGFP 小鼠注射铁或凝血酶（参与 ICH 诱导损伤的因子），并在 4 小时后处死。幼稚小鼠作为对照。收获大脑用于组织学分析。 ICH后1天，血肿周围小胶质细胞的数量显着减少，但第3天和第7天显着增加。脑内注射铁剂也可诱导小胶质细胞死亡，而脑内注射凝血酶则发现小胶质细胞增殖。使用 Tmem119-EGFP 转基因小鼠系在体内观察 ICH 后血肿周围小胶质细胞的死亡和增殖。铁和凝血酶可能分别导致 ICH 诱导的小胶质细胞死亡和增殖。
Microglia are important brain immune cells. However, it is difficult to differentiate microglia from monocyte-derived macrophages. To visualize microglia changes following intracerebral hemorrhage (ICH), we utilized a genetic knock-in mouse line, Tmem119-enhanced green fluorescent protein (EGFP), which expresses EGFP specifically in microglia. There were two parts in this study. First, autologous blood was injected into the right basal ganglia to model ICH in Tmem119-EGFP mice. Mice were euthanized at 4 hours, days 1, 3, and 7 after ICH. Sham animals were used as controls. Second, Tmem119-EGFP mice were injected with iron or thrombin, factors involved in ICH-induced injury, and were euthanized at 4 hours. Naïve mice were controls. Brains were harvested for histology. The number of perihematomal microglia significantly decreased 1 day after ICH, but markedly increased by days 3 and 7. Microglia death was also induced by intracerebral iron injection while microglia proliferation was found with intracerebral thrombin injection. Perihematomal microglia death and proliferation after ICH are visualized in vivo with a Tmem119-EGFP transgenic mouse line. Iron and thrombin may contribute to ICH-induced microglia death and proliferation, respectively.