Cementocyte Alterations Associated with Experimentally Induced Cellular Cementum Apposition in Hyp Mice
| Autor: | Brian L. Foster, Kamila Rosamilia Kantovitz, Márcio Zaffalon Casati, Enilson Antonio Sallum, Elis Janaina Lira dos Santos, Karina Gonzales Silvério Ruiz, Amanda Bandeira de Almeida, Francisco Humberto Nociti Junior, Cristiane R. Salmon, Michelle H Tan, Michael B. Chavez, Emily Y. Chu |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
Molar Connexin Matrix (biology) Article Extracellular matrix Mice 03 medical and health sciences 0302 clinical medicine stomatognathic system Dentin medicine Animals Cementum Tooth Root Dental Cementum Chemistry X-Ray Microtomography 030206 dentistry Cell biology stomatognathic diseases Apposition 030104 developmental biology medicine.anatomical_structure Ultrastructure Periodontics Tooth |
| Zdroj: | J Periodontol |
| Popis: | Background Cellular cementum, a mineralized tissue covering apical tooth roots, grows by apposition to maintain the tooth in its occlusal position. We hypothesized that resident cementocytes would show morphological changes in response to cementum apposition, possibly implicating a role in cementum biology. Methods Mandibular first molars were induced to super-erupt (EIA) by extraction of maxillary molars, promoting rapid new cementum formation. Tissue and cell responses were analyzed at 6 and/or 21 days post-procedure (dpp). Results High-resolution micro-computed tomography (micro-CT) and confocal laser scanning microscopy showed increased cellular cementum by 21 dpp. Transmission electron microscopy (TEM) revealed that cementocytes under EIA were 50% larger than control cells, supported by larger pore sizes detected by micro-CT. Cementocytes under EIA displayed ultrastructural changes consistent with increased activity, including increased cytoplasm and nuclear size. We applied EIA to Hyp mutant mice, where cementocytes have perilacunar hypomineralization defects, to test cell and tissue responses in an altered mechanoresponsive milieu. Hyp and WT molars displayed similar super-eruption, with Hyp molars exhibiting 28% increased cellular cementum area versus 22% in WT mice at 21 dpp. Compared to control, Hyp cementocytes featured well-defined, disperse euchromatin and a thick layer of peripherally condensed heterochromatin in nuclei, indicating cellular activity. Immunohistochemistry (IHC) for cementum markers revealed intense dentin matrix protein-1 expression and abnormal osteopontin deposition in Hyp mice. Both WT and Hyp cementocytes expressed gap junction protein, connexin 43. Conclusion This study provides new insights into the EIA model and cementocyte activity in association with new cementum formation. |
| Databáze: | OpenAIRE |
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