KHUREL-OCHIR, TSENDSUREN Tokushima University
Iwasa, Akihiko Tokushima University Tokushima University Educator and Researcher Directory KAKEN Search Researchers
Kano, Fumiya Tokushima University Tokushima University Educator and Researcher Directory
Yamamoto, Akihito Tokushima University Tokushima University Educator and Researcher Directory
Tanaka, Eiji Tokushima University Tokushima University Educator and Researcher Directory KAKEN Search Researchers
Thesis or Dissertation
Objective: We aimed to identify the immunoregulatory role of the cyclin-dependent kinase inhibitor p21 in the homeostasis of mandibular condylar cartilage affected by mechanical stress.
Materials and Methods: Ten C57BL/6 wild-type (WT) and ten p21–/– mice aged 8 weeks were divided into the untreated and treated groups. In the treated groups, mechanical stress was applied to the temporomandibular joint (TMJ) through forced mouth opening for 3 h/day for 7 days. The dissected TMJs were assessed using micro-CT, histology, and immunohistochemistry.
Results: Treated p21–/– condyles with mechanical stress revealed more severe subchondral bone destruction, with thinner cartilage layers and smaller proteoglycan area relative to treated WT condyles; untreated WT and p21–/– condyles had smoother surfaces. Immunohistochemistry revealed significant increases in the numbers of Caspase-3, interleukin-1β, matrix metalloprotease (MMP)-9, and MMP-13 positive cells, and few aggrecan positive cells, in treated p21–/– than in treated WT samples. Moreover, the number of TUNEL positive cells markedly increased in p21–/– condyles affected by mechanical stress.
Conclusion: Our findings indicate that p21 in chondrocytes contributes to regulate matrix synthesis via the control of aggrecan and MMP-13 expression under mechanical stress. Thus, p21 might regulate the pathogenesis of osteoarthritis in the TMJ.
Clinical and Experimental Dental Research
This is an open access article under the terms of the Creative Commons Attribution License ( https://creativecommons.org/licenses/by/4.0/ ), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
|DOI (Published Version)|
|URL ( Publisher's Version )|
k3493_abstract.pdf 105 KB
k3493_review.pdf 54.8 KB
k3493_fulltext.pdf 20.4 MB
|MEXT report number||
Doctor of Dental Science