Osteocytic Osteolysis in PTH-treated Wild-type and Rankl−/− Mice Examined by Transmission Electron Microscopy, Atomic Force Microscopy, and Isotope Microscopy
| Autor: | Paulo Henrique Luiz de Freitas, Tomomaya Yamamoto, Kanako Tsuboi, Minqi Li, Miki Abe, Hisayoshi Yurimoto, Nobuyuki Udagawa, Tomoka Hasegawa, Masami Saito, Hiromi Hongo, Norio Amizuka, Muneteru Sasaki |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Osteocytic osteolysis Histology Isotope biology Chemistry Wild type 030209 endocrinology & metabolism 03 medical and health sciences 030104 developmental biology 0302 clinical medicine medicine.anatomical_structure RANKL Transmission electron microscopy Osteocyte Microscopy Biophysics medicine Ultrastructure biology.protein Anatomy |
| Zdroj: | Journal of Histochemistry & Cytochemistry. 68:651-668 |
| ISSN: | 1551-5044 0022-1554 |
| DOI: | 10.1369/0022155420961375 |
| Popis: | To demonstrate the ultrastructure of osteocytic osteolysis and clarify whether osteocytic osteolysis occurs independently of osteoclastic activities, we examined osteocytes and their lacunae in the femora and tibiae of 11-week-old male wild-type and Rankl−/− mice after injection of human parathyroid hormone (PTH) [1-34] (80 µg/kg/dose). Serum calcium concentration rose temporarily 1 hr after PTH administration in wild-type and Rankl−/− mice, when renal arteries and veins were ligated. After 6 hr, enlargement of osteocytic lacunae was evident in the cortical bones of wild-type and Rankl−/− mice, but not so in their metaphyses. Von Kossa staining and transmission electron microscopy showed broadly demineralized bone matrix peripheral to enlarged osteocytic lacunae, which contained fragmented collagen fibrils and islets of mineralized matrices. Nano-indentation by atomic force microscopy revealed the reduced elastic modulus of the PTH-treated osteocytic perilacunar matrix, despite the microscopic verification of mineralized matrix in that region. In addition, 44Ca deposition was detected by isotope microscopy and calcein labeling in the eroded osteocytic lacunae of wild-type and Rankl−/− mice. Taken together, our findings suggest that osteocytes can erode the bone matrix around them and deposit minerals on their lacunar walls independently of osteoclastic activity, at least in the murine cortical bone. (J Histochem Cytochem 68: –XXX, 2020) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|