Jia Yu, Sakari Laaksonen, Eerika Mursu, Matleena Typpö, Paula Pesonen, Hanna-Marja Voipio, Simo Saarakkala, Aune Raustia, Pertti Pirttiniemi
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引用次数: 1
Abstract
Aims: To investigate how estrogen level, dietary loading, and aging affect cartilage structure and the expression of major collagens (types I, II, and X) in rat mandibular condylar cartilage (MCC).
Methods: A total of 96 outbred Sprague Dawley female rats were randomly divided into two groups by ovariectomy (OVX) at 7 weeks old. One week later, the rats in each group were further divided into three subgroups on the basis of food hardness: hard food (diet board), normal food (pellet), and soft food (powder). The rats were sacrificed at the age of 5 or 14 months. The thickness of the fibrous, proliferative, and chondroblastic layers of the mandibular condylar cartilage were measured after toluidine blue staining. Immunohistochemical analysis was performed to evaluate the expression levels of types I, II, and X collagen. A linear regression model was used to investigate the main factors affecting changes in thickness and collagen expression.
Results: The expression levels of types II and X collagen were decreased by ovarian estrogen deficiency and increased by dietary loading. Increased dietary loading was the main factor affecting an increase in thickness of the cartilage layers, while aging was the main factor affecting a decrease in thickness of the fibrous layer. A significant age-related increase was found in the expression of type I collagen. There was some degree of interaction between aging and dietary loading that affected the thickness of the chondroblastic layer and the expression of type X collagen.
Conclusion: The physiologic level of estrogen plays a role in MCC development by promoting the expression of types II and X collagen. Dietary loading is essential to increase the expression of types II and X collagen, as well as the thickness of cellular layers, to maintain the integrity of the MCC. Aging seems to reduce the ability of the MCC to withstand occlusal loading.
期刊介绍：
Accounts of Chemical Research presents short, concise and critical articles offering easy-to-read overviews of basic research and applications in all areas of chemistry and biochemistry. These short reviews focus on research from the author’s own laboratory and are designed to teach the reader about a research project. In addition, Accounts of Chemical Research publishes commentaries that give an informed opinion on a current research problem. Special Issues online are devoted to a single topic of unusual activity and significance.
Accounts of Chemical Research replaces the traditional article abstract with an article "Conspectus." These entries synopsize the research affording the reader a closer look at the content and significance of an article. Through this provision of a more detailed description of the article contents, the Conspectus enhances the article's discoverability by search engines and the exposure for the research.
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