Microglia and macrophages are increased in response to ischemia-induced retinopathy in the mouse retina.
Microglia and macrophages are increased in response to ischemia-induced retinopathy in the mouse retina.
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发表时间：
2006-05
期刊：
影响因子：
2.2
通讯作者：
M. H. Davies;J. Eubanks;M. R. Powers
中科院分区：
文献类型：
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作者：
M. H. Davies;J. Eubanks;M. R. Powers
目的小胶质细胞（MG）和巨噬细胞（MAC）释放细胞因子、诱导细胞凋亡以及执行吞噬功能的能力表明其在氧诱导损伤后的伤口愈合中可能发挥作用。本研究旨在确定氧诱导视网膜病变小鼠模型视网膜损伤区域中 F4/80 (F4/80+) 阳性小胶质细胞/巨噬细胞 (MG/MAC) 的时间和空间表达。方法 C57BL/6 出生后第 7 天 (P7) 小鼠暴露于 75% O2 5 天 (P12)，然后在室内空气中恢复。在 P12、P14、P17 和 P21 处死高氧暴露 (O2) 小鼠（O2 指仅从 P7 到 P12 的高氧暴露）并检查其眼睛。 F4/80+ 细胞在 FITC-葡聚糖灌注的视网膜中的定位允许通过荧光显微镜对视网膜血管和 MG/MAC 进行坐标可视化。 BrdU 是一种细胞增殖标记物，在处死前 1 小时腹腔内注射。对小胶质细胞和巨噬细胞特异性抗原 (F4/80) 和 BrdU 进行免疫染色。通过定量实时逆转录聚合酶链反应 (RT-PCR) 检查 CCL2（单核细胞趋化蛋白-1；MCP-1）表达。结果 与对照视网膜相比，P17O2 和 P21O2 的高氧暴露视网膜中 MG/MAC 显着增加 (>500%)。在 P17O2 时，MG/MAC 位于新生血管 (NV) 区域，揭示了 MG/MAC 与新生血管簇之间的密切关系。然而，P21O2 视网膜显示 MG/MAC 与视网膜外层无血管区域相关。 F4/80 和 BrdU 的免疫染色揭示了在高氧暴露的视网膜中罕见的共定位。实时 RT-PCR 结果表明，P14O2 和 P17O2 暴露的视网膜中 CCL2 的表达增加。结论 我们的结果表明，在该模型中，常驻视网膜小胶质细胞在损伤后以较低频率发生增殖。高氧暴露的视网膜中 F4/80+ 细胞总数的大幅增加以及 CCL2 的上调与血源性巨噬细胞招募到视网膜的情况一致。 MG/MAC 邻近新生血管簇的时间和空间定位表明这些细胞正在调节视网膜对缺血引起的视网膜病变的反应。
PURPOSE The ability of microglial cells (MG) and macrophages (MAC) to release cytokines, induce apoptosis, as well as perform phagocytic functions suggests a possible role in wound healing following oxygen-induced injury. This study was performed to determine the temporal and spatial expression of F4/80 (F4/80+) positive microglia/macrophages (MG/MAC) in areas of retinal damage in the mouse model of oxygen-induced retinopathy. METHODS C57BL/6 postnatal day 7 (P7) mice were exposed to 75% O2 for 5 days (P12) then allowed to recover in room air. Hyperoxia-exposed (O2) mice (O2 refers to hyperoxia exposure from P7 to P12 only) were sacrificed on P12, P14, P17, and P21 and their eyes were examined. Localization of F4/80+ cells in FITC-dextran-perfused retinas allowed coordinate visualization of retinal vessels and MG/MAC via fluorescence microscopy. BrdU, a cellular proliferation marker, was injected intraperitoneally 1 h prior to sacrifice. Immunostaining was performed for a microglia and macrophage-specific antigen (F4/80) and BrdU. CCL2 (monocyte chemoattractant protein-1; MCP-1) expression was examined by quantitative real time reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS There was a marked increase (>500%) in MG/MAC in hyperoxia-exposed retinas on P17O2 and P21O2 compared to control retinas. At P17O2, MG/MAC were localized in areas of neovascularization (NV), revealing an intimate relationship between MG/MAC and neovascular tufts. However, P21O2 retinas demonstrated MG/MAC associated with avascular regions in the outer layers of the retina. Immunostaining for F4/80 and BrdU revealed rare co-localization in hyperoxia-exposed retinas. Real time RT-PCR results demonstrated increased expression of CCL2 in P14O2- and P17O2- exposed retinas. CONCLUSIONS Our results suggest that resident retinal microglia proliferation occurs at a low frequency in response to injury in this model. The substantial increase in total F4/80+ cells in hyperoxia-exposed retinas in conjunction with the upregulation of CCL2 is consistent with recruitment of hematogenous macrophages into the retina. The temporal and spatial localization of MG/MAC adjacent to neovascular tufts suggests these cells are modulating the retinal response to ischemia-induced retinopathy.