Eccentric localization of osteocytes expressing enzymatic activities, protein, and mRNA signals for type 5 tartrate-resistant acid phosphatase (TRAP)
Eccentric localization of osteocytes expressing enzymatic activities, protein, and mRNA signals for type 5 tartrate-resistant acid phosphatase (TRAP)
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DOI：
10.1369/jhc.4a6378.2004
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发表时间：
2004-11-01
影响因子：
3.2
通讯作者：
Takano, Y
中科院分区：
文献类型：
--
作者：
Nakano, Y;Toyosawa, S;Takano, Y
5型抗酒石酸酸性磷酸酶（TRAP）的活性被认为是破骨细胞及其前体细胞的可靠标志物之一。在一些报告中也指出了TRAP活性存在于骨吸收表面附近的骨细胞中。然而，TRAP反应在骨细胞中的意义仍然存在争议，事实上，对于骨细胞中的组织化学酶反应是否代表各自骨细胞产生的TRAP酶，或者仅仅是来自附近破骨细胞的反应产物的扩散伪影，还没有达成一致。目前的组织化学，免疫组织化学和原位杂交研究，大鼠和犬的骨证实TRAP酶活性，TRAP免疫反应性，并在位于骨吸收表面附近的骨细胞中的陷阱mRNA信号的表达。由此鉴定的TRAP/Trap阳性骨细胞局限于距离骨吸收表面不超过200 μ m的区域，并且显示出TRAP/Trap表达对活性破骨细胞的明显上调。TRAP/Trap在骨细胞中表达的空间和时间模式应作为进一步分析骨细胞和破骨细胞之间与骨重建相关的生物学相互作用的有价值的参数。
Enzymatic activity of type 5 tartrate-resistant acid phosphatase (TRAP) has been regarded as one of the reliable markers for osteoclasts and their precursors. The presence of TRAP activity in osteocytes near the bone resorbing surface has also been pointed out in some reports. However, the significance of TRAP reactions in osteocytes remains controversial and, in fact, there is no agreement as to whether the histochemical enzyme reactions in osteocytes represent the TRAP enzyme generated by the respective osteocytes or is a mere diffusion artifact of the reaction products derived from the nearby osteoclasts. Current histochemical, immunohistochemical, and in situ hybridization studies of rat and canine bones confirmed TRAP enzyme activity, TRAP immunoreactivity, and the expression of Trap mRNA signals in osteocytes located close to the bone-resorbing surface. TRAP/Trap-positive osteocytes thus identified were confined to the areas no further than 200 mum from the bone-resorbing surface and showed apparent upregulation of TRAP/Trap expression toward the active osteoclasts. Spatial and temporal patterns of TRAP/Trap expression in the osteocytes should serve as a valuable parameter for further analyses of biological interactions between the osteocytes and the osteoclasts associated with bone remodeling.