Immunolocalization of receptor activator of nuclear factor‐κB ligand (RANKL) and osteoprotegerin (OPG) in Meckel's cartilage compared with developing endochondral bones in mice
Immunolocalization of receptor activator of nuclear factor‐κB ligand (RANKL) and osteoprotegerin (OPG) in Meckel's cartilage compared with developing endochondral bones in mice
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DOI：
10.1111/j.1469-7580.2005.00466.x
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发表时间：
2005-10
影响因子：
2.4
通讯作者：
Y. Sakakura;E. Tsuruga;K. Irie;Y. Hosokawa;Hiroaki Nakamura;T. Yajima
中科院分区：
文献类型：
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作者：
Y. Sakakura;E. Tsuruga;K. Irie;Y. Hosokawa;Hiroaki Nakamura;T. Yajima
本文观察了胚胎14-16天(E14-16)Meckel‘s软骨中核因子受体激活剂κB配体(RANKL)和护骨素(OPG)在破骨细胞/软骨破骨细胞引起的骨吸收区的免疫定位，并与小鼠软骨内骨的结果进行了比较。Meckel‘s软骨细胞RANKL和OPG免疫反应阳性。E15时，切牙最靠近Meckel‘s软骨中部时，软骨外侧出现抗酒石酸酸性磷酸酶(TRAP)阳性细胞。此外，牙囊对RANKL和OPG呈中等免疫反应，而来自软骨膜细胞的成骨细胞对该区域的RANKL和OPG呈免疫阴性。在E16，TRAP阳性细胞对软骨的吸收已在不同的部位进行，RANKL的强烈免疫反应产物重叠在吸收区域内，并与TRAP阳性细胞相邻。在发育中的跖骨组织中，OPG免疫反应在骨膜成骨细胞中呈强阳性反应，而RANKL仅在部分骨膜细胞中微弱表达。在发育中的股骨的骨痂软骨细胞中，RANKL免疫反应呈中等强度，OPG几乎不表达。这些结果表明RANKL和OPG在Meckel‘s软骨吸收中的免疫定位具有特殊性。切牙的生长可能通过局部调节牙囊细胞和骨膜成骨细胞中的RANKL/OPG系统参与Meckel‘s软骨的时间和位置特异性吸收，而软骨细胞中的RANKL和OPG似乎通过调节软骨破骨细胞的功能而参与Meckel’s软骨的吸收。
We examined the immunolocalization of receptor activator of nuclear factor‐κB ligand (RANKL) and osteoprotegerin (OPG) in areas of resorption caused by osteoclasts/chondroclasts on embryonic days 14–16 (E14–16) in Meckel's cartilage, and compared the results with those in endochondral bones in mice. Intense RANKL and OPG immunoreactivity was detected in the chondrocytes in Meckel's cartilage. On E15, when the incisor teeth were closest to the middle portion of Meckel's cartilage, tartrate‐resistant acid phosphatase (TRAP)‐positive cells appeared on the lateral side of the cartilage. Furthermore, the dental follicle showed moderate immunoreactivity for RANKL and OPG, whereas osteoblasts derived from perichondral cells were immunonegative for RANKL and OPG in that area. On E16, cartilage resorption by TRAP‐positive cells had progressed at the differential position, and intensely immunoreactive products of RANKL were overlapped on and found to exist next to TRAP‐positive cells in the resorption area. In developing metatarsal tissue, OPG immunoreactivity was intense in periosteal osteoblasts, whereas RANKL was only faintly seen in some of the periosteal cells. In epiphyseal chondrocytes of the developing femur, RANKL immunoreactivity was moderate, and OPG scarcely detected. These results indicate a peculiarity of RANKL and OPG immunolocalization in resorption of Meckel's cartilage. Growth of the incisor teeth may be involved in the time‐ and position‐specific resorption of Meckel's cartilage through local regulation of the RANKL/OPG system in dental follicular cells and periosteal osteoblasts, whereas RANKL and OPG in chondrocytes seem to contribute to resorption through regulation of the chondroclast function.