Hyaluronan metabolism in overloaded temporomandibular joint

The present study aimed to examine hyaluronan (HA) metabolism in relation to the onset and progression of temporomandibular joint osteoarthritis (TMJ-OA) induced by mechanical overloading. Two-month-old and 6-month-old C57BL/6N mice were divided into experimental and untreated control groups (n = 5/group). A sliding plate was attached to the maxillary incisors of the experimental mice for 10 days to overload the condylar cartilage in TMJ. In experimental group, profound cartilage degradation was detected in hematoxylin-eosin, Safranin-O-Fast Green stained sections. It was also shown that the cartilage degradation was greater in older mice in both the control and the experimental groups. The number of HABP positive cells was decreased by mechanical overloading and with age. The reduction of HA expression was correlated with the progression of cartilage degradation induced by mechanical overloading. The absolute quantification of the mRNA expression related to HA synthesis and HA degradation was also performed in each group. The mRNA expression levels of HA synthase (HAS) 2 and 3 were lower in the experimental group compared with the control group in the younger mice. In contrast, the mRNA expression levels of the HA degradation gene, HYAL2 and KIAA1199, were higher in the experimental group compared with the control group in the older mice. Thus, mechanical overload differently affected the balance of HA degradation and HA synthesis in the older and younger mice, respectively. In conclusion, mechanical overloading affects HA metabolism and it might initiate or amplify the condylar cartilage degradation.

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内容要旨：LID201704281007.pdf
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論文本文：k3073_fulltext.pdf
著者の申請により要約(2017-04-28公開)に替えて論文全文を公開(2019-06-13)
本論文は, 著者T. Shinoharaの学位論文として提出され, 学位審査・授与の対象となっている。

This is the peer reviewed version of the following article: Shinohara, T. , Izawa, T. , Mino‐Oka, A. , Mori, H. , Iwasa, A. , Inubushi, T. , Yamaguchi, Y. and Tanaka, E. (2016), Hyaluronan metabolism in overloaded temporomandibular joint. J Oral Rehabil, 43: 921-928. doi:10.1111/joor.12443, which has been published in final form at https://doi.org/10.1111/joor.12443. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.