Localization of cathepsin D in human odontoclasts.: A light and electron microscopical immunocytochemical study
Localization of cathepsin D in human odontoclasts.: A light and electron microscopical immunocytochemical study
复制标题
DOI：
10.3109/03008200009005289
复制
发表时间：
2000-01-01
影响因子：
2.9
通讯作者：
Jäger, A
中科院分区：
文献类型：
--
作者：
Götz, W;Quondamatteo, F;Jäger, A
破牙本质细胞是牙本质和牙骨质吸收细胞，其与弯曲吸收破骨细胞的关系尚不清楚。与破骨细胞一样，它们具有不同的组织蛋白酶，这些组织蛋白酶参与乳牙牙根吸收过程中矿化组织的降解。组织蛋白酶D，在破骨细胞中可能作为其他组织蛋白酶的激活剂，是否可以在破牙细胞中发现，然而，以前没有调查过。为了确定其发生和定位，组织蛋白酶D免疫细胞化学法应用于石蜡包埋切片从30人乳牙牙根吸收。应用免疫金包埋后免疫细胞化学技术，在超微结构水平上观察组织蛋白酶D的分布。我们在牙根附近和牙周表面鉴定了抗酒石酸盐的酸性磷酸酶阳性单核和多核破牙细胞。几乎所有的这些细胞都表现出细胞质颗粒组织蛋白酶D免疫反应。在电镜下，金标记的液泡和囊泡的破牙细胞，这被确定为次级溶酶体和吞噬体。细胞外可见沿着皱褶边缘和相邻的牙本质和牙骨质吸收区。这些发现表明，组织蛋白酶D分泌到人破牙细胞的再吸收区，以参与矿化牙基质的降解，但也可能作为溶酶体细胞器中其他蛋白酶的激活剂。
Odontoclasts are dentine and cementum resorbing cells whose relationship to bent: resorbing osteoclasts is not clear. Like osteoclasts, they possess different cathepsins which are involved in mineralized tissue degradation during the tooth root resorption process in deciduous teeth. Whether cathepsin D, which in osteoclasts probably functions as an activator of other cathepsins, can be found in odontoclasts, has, however, not been investigated before. In order to determine its occurrence and localization, cathepsin D immunocytochemistry was applied to paraffin-embedded sections from 30 human deciduous tooth roots undergoing resorption. Using immunogold postembedding immunocytochemsitry on LR-Gold embedded specimens, the distribution of cathepsin D was investigated at the ultrastructural level. We identified tartrate-resistent acid phosphatase-positive mono- and multinuclear odontoclasts near and on the periodontal surfaces of tooth roots. Nearly all of these cells showed cytoplasmic granular cathepsin D immunoreactivity. At the electron microscopical level, gold labelling was seen on vacuoles and vesicles of the odontoclasts, which were identified as secondary lysosomes and phagosomes. Extracellularly it was seen along the ruffled border and in neighboured resorption areas of dentine and cementum. These findings indicate that cathepsin D is secreted into the resorbing area of human odontoclasts in order to participate in degradation of mineralized tooth matrix, but may also function as an activator of other proteases in lysosomal organelles.