Effects of Bisphosphonate on the Expression of Matrix Enzymes during Endochondral Ossification.
10.11637/kjpa.2015.28.3.155
- Author:
Hong Il YOO
1
;
Se Young JUNG
;
Sun Hun KIM
Author Information
1. Department of Oral Anatomy, School of Dentistry, Chonnam National University, Korea. ksh@jnu.ac.kr
- Publication Type:In Vitro ; Original Article
- Keywords:
Bisphosphonate;
MMP;
TIMP;
Endochondral ossification
- MeSH:
Alendronate;
Animals;
Antigens, CD147;
Cartilage;
Chondrocytes;
Diphosphonates;
Down-Regulation;
Epiphyses;
Fluorescent Antibody Technique;
Humans;
Infant, Newborn;
Matrix Metalloproteinases;
Osteogenesis;
Rats;
RNA, Messenger;
Tibia;
Tissue Inhibitor of Metalloproteinase-1;
Tissue Inhibitor of Metalloproteinase-2;
Tissue Inhibitor of Metalloproteinase-3;
Up-Regulation
- From:Korean Journal of Physical Anthropology
2015;28(3):155-165
- CountryRepublic of Korea
- Language:English
-
Abstract:
Bisphosphonates have been reported to have chondroprotective activities in addition to its original functions. However, mechanisms for these just began to be elucidated. Under the hypothesis that bisphosphonates may regulate expression and activities of matrix enzymes during degradation of cartilage for bone formation, we administrated an alendronate (1 mg/kg) to newborn rats subcutaneously once a day for 4, 7, and 10 days. To identify the effects of alendronate on cartilage, thickness of cartilage layer was measured by histomorphometry on the proximal epiphysis of tibia. Immunofluorescence staining and RT-PCR were performed to investigate the expressions of matrix enzymes in both in vitro and in vivo. MTS assay revealed that at 10(-3) M in concentration, alendronate significantly reduced viability of chondrocytes. The mRNA expressions of MMP-1, MMP-9, EMMPRIN, and TIMP-3 in primary chondrocytes were decreased by the alendronate treatment. Interestingly, TIMP-1 mRNA expression was significantly increased, whereas a constitutive form, TIMP-2 was relatively unchanged by the treatment. The thickness of proliferating layer at postnatal day 7 was not significantly different, whereas thickness of hypertrophied layer was significantly thicker in the alendronate group than in the control (p<0.01). Immunofluorescence demonstrated that the expressions of MMP-9, TIMP-2 and -3 were reduced, whereas TIMP-1 expression was increased by the alendronate administration. These results suggest that the alendronate have chondroprotective properties by down-regulation of MMPs and up-regulation of TIMPs during endochondral ossification.
