Korean J Phys Anthropol.  2015 Sep;28(3):155-165. 10.11637/kjpa.2015.28.3.155.

Effects of Bisphosphonate on the Expression of Matrix Enzymes during Endochondral Ossification

• Yoo HI
• Jung SY
• Kim SH

• KMID: 2068826
• DOI: http://doi.org/10.11637/kjpa.2015.28.3.155

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.

Keyword

Bisphosphonate; MMP; TIMP; Endochondral ossification

MeSH Terms

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
Alendronate
Antigens, CD147
Diphosphonates
Matrix Metalloproteinases
RNA, Messenger
Tissue Inhibitor of Metalloproteinase-1
Tissue Inhibitor of Metalloproteinase-2
Tissue Inhibitor of Metalloproteinase-3