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BioMed Research International
Volume 2013, Article ID 760236, 9 pages
Research Article

Heparanase Localization during Palatogenesis in Mice

1Department of Anatomy and Cell Biology, Faculty of Medicine, Osaka Medical College, Takatsuki 569-8686, Japan
2Laboratory of Veterinary Physiology, Nippon Veterinary and Life Science University, Musashino 180-8602, Japan
3Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan
4Division of Research and Treatment for Oral and Maxillofacial Congenital Anomalies, School of Dentistry, Aichi Gakuin University, Nagoya 464-0821, Japan
5Departments of Material and Life Science, Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
6Laboratory of Biological Chemistry, Department of Biomolecular Chemistry, Kyoto Prefectural University, Kyoto 606-8522, Japan
7Department of Oral Histology, Matsumoto Dental University, Shiojiri 399-0781, Japan

Received 14 November 2012; Accepted 1 January 2013

Academic Editor: Erica L. Scheller

Copyright © 2013 Azumi Hirata et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Palatogenesis is directed by epithelial-mesenchymal interactions and results partly from remodeling of the extracellular matrix (ECM) of the palatal shelves. Here, we assessed heparanase distribution in developing mouse palates. No heparanase was observed in the vertically oriented palatal shelves in early stages of palate formation. As palate formation progressed, the palatal shelves were reorganized and arranged horizontally above the tongue, and heparanase localized to the epithelial cells of these shelves. When the palatal bilateral shelves first made contact, the heparanase localized to epithelial cells at the tips of shelves. Later in fusing palatal shelves, the cells of the medial epithelial seam (MES) were labeled with intense heparanase signal. In contrast, the basement membrane heparan sulfate (HS) was scarcely observed in the palatal shelves in contact. Moreover, perlecan labeling was sparse in the basement membrane of the MES, on which laminin and type IV collagen were observed. Moreover, we assessed the distribution of matrix metalloproteinase- (MMP-) 9, MMP-2, and MMP-3 in developing mouse palates and these MMPs were observed in the MES. Our findings indicated that heparanase was important for palate formation because it mediated degradation of the ECM of palatal shelves. Heparanase may, in concert with other proteases, participate in the regression of the MES.