Fate of DNA from retinal cells dying during development: Uptake by microglia and macroglia (Muller cells)
Fate of DNA from retinal cells dying during development: Uptake by microglia and macroglia (Muller cells)
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DOI：
10.1016/s0165-3806(96)00119-8
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发表时间：
1996-11-22
期刊：
影响因子：
--
通讯作者：
Stone, J
中科院分区：
文献类型：
--
作者：
Egensperger, R;Maslim, J;Stone, J
TUNEL技术的标记片段化DNA被用来检查细胞死亡的发育中的视网膜的兔，大鼠和猫。TUNEL标记的结构包括仍然完整的视网膜细胞核和较小的，强烈标记的机构解释为碎片的解体核（凋亡或固缩体）。用共聚焦显微镜，观察到标记的细胞核周围的细胞质被标记，表明DNA片段扩散到垂死细胞的细胞质中。还观察到细胞核为TUNEL（-）但细胞质为TUNEL（+）的细胞，从而可以辨别它们的形态。有证据表明，这些是吞噬细胞，其细胞质标签从一个垂死的邻居的DNA片段的摄入。结果表明，在发育中的视网膜碎片DNA主要由小胶质细胞和Muller细胞吞噬，少数神经元和星形胶质细胞作为吞噬细胞活跃。在所研究的出生后材料中，小胶质细胞是神经节细胞和内核层中死亡细胞的主要吞噬细胞。米勒细胞似乎能够吞噬任何视网膜层中死亡的细胞，并且由于小胶质细胞通常不进入外核层，因此对于吞噬垂死的光感受器可能是重要的。
The TUNEL technique of labelling fragmenting DNA was used to examine cell death in the developing retina of the rabbit, rat and cat. TUNEL-labelled structures included the still-intact nuclei of retinal cells and smaller, strongly labelled bodies interpreted as fragments of disintegrating nuclei (apoptotic or pyknotic bodies). With confocal microscopy, the cytoplasm around labelled nuclei was observed to be labelled, suggesting that DNA fragments spread into the cytoplasm of the dying cell. Also observed were cells whose nuclei were TUNEL(-) but whose cytoplasm was TUNEL(+), so that their morphology could be discerned. Evidence is presented that these are phagocytes, their cytoplasmic labelling resulting from the ingestion of the fragmenting DNA of a dying neighbour. Results suggest that in developing retina fragmenting DNA is phagocytosed principally by microglia and Muller cells, with a few neurones and no astrocytes active as phagocytes. in the postnatal material studied, microglia are the predominant phagocytes for cells dying in the ganglion cell and inner nuclear layers. Muller cells appear able to phagocytose cells dying in any retinal layer and, since microglia do not normally enter the outer nuclear layer, may be important for the phagocytosis of dying photoreceptors.