Fate mapping reveals that microglia and recruited monocyte-derived macrophages are definitively distinguishable by phenotype in the retina.
Fate mapping reveals that microglia and recruited monocyte-derived macrophages are definitively distinguishable by phenotype in the retina.
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DOI：
10.1038/srep20636
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发表时间：
2016-02-09
影响因子：
4.6
通讯作者：
Saban DR
中科院分区：
文献类型：
--
作者：
O'Koren EG;Mathew R;Saban DR
最近的范式转变，即小胶质细胞是卵黄囊衍生的，而不是造血衍生的，正在重塑我们对小胶质细胞在中枢神经系统疾病（包括视网膜退行性疾病）中的孤立作用的认识。然而，解开小胶质细胞特异性功能已受到阻碍的小胶质细胞与单核细胞衍生的巨噬细胞的表型重叠。后者从神经炎症（包括视网膜）中募集的单核细胞分化而来。在这里，我们证明了使用命运映射，其中小胶质细胞和单核细胞衍生的细胞内源性标记不同的荧光报告。结合这种方法与12色流式细胞术，我们表明，这两个群体是明确区分的视网膜表型。我们证明视网膜小胶质细胞具有独特的CD 45 lo CD 11 clo F4/80 lo I-A/I-E−特征，在稳态和视网膜损伤期间保持不变。后者在广泛使用的光诱导视网膜变性模型中观察到，并在其他模型中得到证实，包括全身照射/骨髓移植。关于小胶质细胞（包括视网膜中的小胶质细胞）是否增加这些标志物在神经炎症中的表达，文献包含相互矛盾的观察结果。我们发现，单核细胞衍生的巨噬细胞具有这些表面标志物的表达升高，而不是小胶质细胞。我们的决议，这种表型差异可能作为一个强大的方式来帮助表征孤立的角色，这些细胞在视网膜神经炎症，并可能在中枢神经系统的其他地方。
The recent paradigm shift that microglia are yolk sac-derived, not hematopoietic-derived, is reshaping our knowledge about the isolated role of microglia in CNS diseases, including degenerative conditions of the retina. However, unraveling microglial-specific functions has been hindered by phenotypic overlap of microglia with monocyte-derived macrophages. The latter are differentiated from recruited monocytes in neuroinflammation, including retina. Here we demonstrate the use of fate mapping wherein microglia and monocyte-derived cells are endogenously labeled with different fluorescent reporters. Combining this method with 12-color flow cytometry, we show that these two populations are definitively distinguishable by phenotype in retina. We prove that retinal microglia have a unique CD45lo CD11clo F4/80lo I-A/I-E− signature, conserved in the steady state and during retinal injury. The latter was observed in the widely used light-induced retinal degeneration model and corroborated in other models, including whole-body irradiation/bone-marrow transplantation. The literature contains conflicting observations about whether microglia, including in the retina, increase expression of these markers in neuroinflammation. We show that monocyte-derived macrophages have elevated expression of these surface markers, not microglia. Our resolution of such phenotypic differences may serve as a robust way to help characterize isolated roles of these cells in retinal neuroinflammation and possibly elsewhere in CNS.