Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA.
Adv Exp Med Biol. 2010;658:105-9. doi: 10.1007/978-1-4419-1050-9_11.
The ruffled border is the most specific marker of the active osteoclast (OC) as it forms only when the cell is resorbing bone. We provide evidence that this complex cytoskeletal structure reflects insertion of the lysosomal vesicles into the bone-apposed plasma membrane under the aegis of the Ca-sensing, exocytic protein, synaptotagmin VII (SytVII). In the manner, SytVII permits transport of matrix-degrading molecules into the resorptive microenvironment. SytVII also regulates secretion of bone matrix molecules by osteoblasts. Thus, SytVII-deficient mice experience suppressed bone resorption and formation with the latter deficiency predominant thereby yielding osteoporosis characterized by attenuated remodeling.
皱襞边缘是活性破骨细胞 (OC) 最特异的标志，因为只有当细胞在吸收骨时才会形成。我们提供的证据表明，这种复杂的细胞骨架结构反映了在 Ca 感应的出胞蛋白突触结合蛋白 VII (SytVII) 的支持下，溶酶体囊泡插入到与骨相对的质膜中。通过这种方式，SytVII 允许将基质降解分子运送到吸收性微环境中。SytVII 还调节成骨细胞分泌骨基质分子。因此，SytVII 缺陷小鼠经历骨吸收和形成的抑制，后者的缺陷更为明显，从而导致骨质疏松症，其特征是骨重建减弱。
