Systemic Circulation and Bone Recruitment of Osteoclast Precursors Tracked by Using Fluorescent Imaging Techniques
Systemic Circulation and Bone Recruitment of Osteoclast Precursors Tracked by Using Fluorescent Imaging Techniques
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DOI：
10.4049/jimmunol.1201345
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发表时间：
2013-01-15
影响因子：
4.4
通讯作者：
Ishii, Masaru
中科院分区：
文献类型：
--
作者：
Kotani, Manato;Kikuta, Junichi;Ishii, Masaru
破骨细胞是从单核细胞/巨噬细胞谱系造血前体分化而来的骨吸收多核细胞。目前尚不清楚破骨细胞是否源自循环血单核细胞或骨组织驻留前体细胞。为了解决这个问题，我们结合了两种不同的实验程序：1）与荧光标记的破骨细胞前体共享血液循环“联体共生”，2）使用 Kikume 绿红蛋白（KikGR）进行基于光转换的细胞追踪。在联体共生中，破骨细胞前体被EGFP标记的CX(3)CR1-EGFP敲入小鼠通过手术与野生型小鼠连接以建立共享循环。在野生型小鼠的骨骼中发现了成熟的EGFP(+)破骨细胞，表明EGFP(+)破骨细胞前体从体循环中动员到骨骼中。 NF-κ B 配体刺激的受体激活剂增加了野生型小鼠中 EGFP(+) 破骨细胞的数量，表明这种动员取决于骨吸收状态。此外，将脾脏中的 KikGR(+) 单核细胞（包括破骨细胞前体）暴露于紫光下，2 天后，我们在骨表面检测到光转换的“红色”KikGR(+) 破骨细胞。这些结果表明，来自脾脏的循环单核细胞进入骨间隙并在一定时期内分化为成熟的破骨细胞。目前的研究使用基于荧光的方法清楚地证明，一旦循环单核细胞归巢到骨组织，破骨细胞就可以由它们产生。免疫学杂志，2013，190：605-612。
Osteoclasts are bone-resorbing polykaryons differentiated from monocyte/macrophage-lineage hematopoietic precursors. It remains unclear whether osteoclasts originate from circulating blood monocytes or from bone tissue-resident precursors. To address this question, we combined two different experimental procedures: 1) shared blood circulation "parabiosis" with fluorescently labeled osteoclast precursors, and 2) photoconversion-based cell tracking with a Kikume Green-Red protein (KikGR). In parabiosis, CX(3)CR1-EGFP knock-in mice in which osteoclast precursors were labeled with EGFP were surgically connected with wild-type mice to establish a shared circulation. Mature EGFP(+) osteoclasts were found in the bones of the wild-type mice, indicating the mobilization of EGFP(+) osteoclast precursors into bones from systemic circulation. Receptor activator for NF-kappa B ligand stimulation increased the number of EGFP(+) osteoclasts in wild-type mice, suggesting that this mobilization depends on the bone resorption state. Additionally, KikGR(+) monocytes (including osteoclast precursors) in the spleen were exposed to violet light, and 2 d later we detected photoconverted "red" KikGR(+) osteoclasts along the bone surfaces. These results indicate that circulating monocytes from the spleen entered the bone spaces and differentiated into mature osteoclasts during a certain period. The current study used fluorescence-based methods clearly to demonstrate that osteoclasts can be generated from circulating monocytes once they home to bone tissues. The Journal of Immunology, 2013, 190: 605-612.