| Autor: |
Toray H; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Hasegawa T; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Sakagami N; Divisions of Reconstructive Surgery for Oral and Maxillofacial Region, Niigata University Graduate School of Medical and Dental Sciences., Tsuchiya E; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Kudo A; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Zhao S; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Moritani Y; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Abe M; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Yoshida T; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Yamamoto T; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Yamamoto T; Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University., Oda K; Divisions of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences., Udagawa N; Department of Biochemistry, Matsumoto Dental University., Luiz de Freitas PH; Department of Dentistry, Federal University of Sergipe at Lagarto., Li M; Shandong Provincial Key Laboratory of Oral Biomedicine, The School of Stomatology, Shandong University. |
| Abstrakt: |
Since osteoblastic activities are believed to be coupled with osteoclasts, we have attempted to histologically verify which of the distinct cellular circumstances, the presence of osteoclasts themselves or bone resorption by osteoclasts, is essential for coupled osteoblastic activity, by examining c-fos -/- or c-src -/- mice. Osteopetrotic c-fos deficient (c-fos -/- ) mice have no osteoclasts, while c-src deficient (c-src -/- ) mice, another osteopetrotic model, develop dysfunctional osteoclasts due to a lack of ruffled borders. c-fos -/- mice possessed no tartrate-resistant acid phosphatase (TRAPase)-reactive osteoclasts, and showed very weak tissue nonspecific alkaline phosphatase (TNALPase)-reactive mature osteoblasts. In contrast, c-src -/- mice had many TNALPase-positive osteoblasts and TRAPase-reactive osteoclasts. Interestingly, the parallel layers of TRAPase-reactive/osteopontin-positive cement lines were observed in the superficial region of c-src -/- bone matrix. This indicates the possibility that in c-src -/- mice, osteoblasts were activated to deposit new bone matrices on the surfaces that osteoclasts previously passed along, even without bone resorption. Transmission electron microscopy demonstrated cell-to-cell contacts between mature osteoblasts and neighboring ruffled border-less osteoclasts, and osteoid including many mineralized nodules in c-src -/- mice. Thus, it seems likely that osteoblastic activities would be maintained in the presence of osteoclasts, even if they are dysfunctional. |
