The localization and function of HSPG in mandibular condylar cartilage

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12671990
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 矯正・小児・社会系歯学
• Research Institution: Niigata University
• Principal Investigator: MORITA Shuuichi Graduate School of Medical and Dental Sciences, Niigata University, Associate Professor, 大学院・医歯学総合研究科, 助教授 (60157899)
• Co-Investigator(Kenkyū-buntansha): ASAHITO Toshikazu Dental Hospital, Niigata University, Assistant, 歯学部・附属病院, 助手 (90313519)
• Project Period (FY): 2000 – 2001
• Keywords: Mandibular condylar cartilage / HSPG / growth plate cartilage / Aging change

Research Abstract

The localization of HSPG was examined using the tibial growth plate of growth phase rats. Consequently, it became clear that HSPG existence over all layers in the growth plate. Moreover, chondrocytes are strongly stained by the anti-HSPG antibody, and it was suggested that the chondrocyte synthesize HSPG. Furthermore, since FGFR was found in the chondrocytes and bFGF was found in the cartilage, it was suggested that HSPG is involving to bind bFGF and FGFR in the cartilage. Next, the localization of HSPG in the growth plate and mandibular condylar cartilage of maturity and old age terms rats were examined. Although the localization of HSPG was shown in the whole cartilage matrix of the growth plate, the staining was weaker compared with the growth phase. The chondrocytes were stained like the growth phase. Consequently, although chondrocyte of the period of maturity also synthesize HSPG, it was suggested that the productivity of HSPG is decreasing. In the period-of-maturity, mandibular condylar cartilage is already in contact with the compact bone under the cartilage lower layer. Fibrous layer containing many fibroblast-like cells thickly covered the joint side surface, and HSPG was detected strongly in the whole fibrous layer. In the proliferative and the mature chondrocyte layers, although HSPG was detected in chondrocytes, the anti-HSPG antibody stained few cartilage matrixes. At the old age term, the fibrous layers became thin and contain few chondrocytes, and the staining against anti-HSPG antibody in matrix was also decreasing. Over all layers, HSPG was detected mostly in the chondrocytes and was hardly detected into the extracellular matrix. Consequently, although chondrocytes in the mandibular condylar cartilage synthesize HSPG, it was suggested after the period of maturity that the productivity of HSPG is further reduced as compared with a growth plate cartilage.