Sasaki T, Debari K, Udagawa N
Department of Oral Anatomy, School of Dentistry, Showa University, Tokyo, Japan.
Calcif Tissue Int. 1993 Sep;53(3):217-21. doi: 10.1007/BF01321841.
The osteoclastic cytoskeleton has been demonstrated to be composed of microfilaments. Osteoclastic multinucleated cells were suspended on dentine slices and cultured for 24 hours in the presence or absence of cytochalasin D (CD), a specific and potent inhibitor of actin filament elongation to determine the role of this cytoskeleton. Cultured cells and co-cultured dentine slices were examined ultrastructurally. Unlike those in control cultures without CD, osteoclasts in CD-treated cultures became spherical in shape and lacked microvilli on their basolateral cell surfaces. Most importantly, CD treatment induced a complete disappearance of the ruffled border-clear zone complexes in osteoclasts, which resulted in loss of osteoclast-cytoplasmic polarity. Morphometric analysis of backscattered electron micrographs of co-cultured dentine slices revealed that CD treatment strongly inhibited the formation of resorption lacunae in a dose-dependent manner. These results suggest that the cytoarchitecture, as well as the bone-resorbing function, of the osteoclast is highly regulated by the F-actin-containing microfilamentous cytoskeleton in the ruffled border-clear zone complex.
破骨细胞的细胞骨架已被证明是由微丝组成的。将破骨细胞多核细胞悬浮在牙本质切片上，在存在或不存在细胞松弛素D（CD）的情况下培养24小时，细胞松弛素D是一种特异性且有效的肌动蛋白丝伸长抑制剂，以确定这种细胞骨架的作用。对培养的细胞和共培养的牙本质切片进行超微结构检查。与未使用CD的对照培养物中的破骨细胞不同，使用CD处理的培养物中的破骨细胞呈球形，其基底外侧细胞表面缺乏微绒毛。最重要的是，CD处理导致破骨细胞中皱褶缘-清亮区复合体完全消失，这导致破骨细胞细胞质极性丧失。对共培养的牙本质切片的背散射电子显微镜图像进行形态计量分析表明，CD处理以剂量依赖的方式强烈抑制吸收陷窝的形成。这些结果表明，破骨细胞的细胞结构以及骨吸收功能受到皱褶缘-清亮区复合体中含F-肌动蛋白的微丝细胞骨架的高度调节。
