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Effects of in vivo static compressive loading on aggrecan and type II and X collagens in the rat growth plate extracellular matrix.
- Source :
-
Bone [Bone] 2009 Feb; Vol. 44 (2), pp. 306-15. Date of Electronic Publication: 2008 Sep 24. - Publication Year :
- 2009
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Abstract
- Mechanical loads are essential to normal bone growth, but excessive loads can lead to progressive deformities. In addition, growth plate extracellular matrix remodelling is essential to regulate the normal longitudinal bone growth process and to ensure physiological bone mineralization. In order to investigate the effects of static compression on growth plate extracellular matrix using an in vivo animal model, a loading device was used to precisely apply a compressive stress of 0.2 MPa for two weeks on the seventh caudal vertebra (Cd7) of rats during the pubertal growth spurt. Control, sham and loaded groups were studied. Growth modulation was quantified based on calcein labelling, and three matrix components (type II and X collagens, and aggrecan) were assessed using immunohistochemistry/safranin-O staining. As well, extracellular matrix components and enzymes (MMP-3 and -13, ADAMTS-4 and -5) were studied by qRT-PCR. Loading reduced Cd7 growth by 29% (p<0.05) and 15% (p=0.07) when compared to controls and shams respectively. No significant change could be observed in the mRNA expression of collagens and the proteolytic enzyme MMP-13. However, MMP-3 was significantly increased in the loaded group as compared to the control group (p<0.05). No change was observed in aggrecan and ADAMTS-4 and -5 expression. Low immunostaining for type II and X collagens was observed in 83% of the loaded rats as compared to the control rats. This in vivo study shows that, during pubertal growth spurt, two-week static compression reduced caudal vertebrae growth rates; this mechanical growth modulation occurred with decreased type II and X collagen proteins in the growth plate.
- Subjects :
- ADAM Proteins genetics
ADAM Proteins metabolism
ADAMTS4 Protein
ADAMTS5 Protein
Aggrecans genetics
Animals
Calibration
Cell Proliferation
Collagen Type II genetics
Collagen Type X genetics
Extracellular Matrix enzymology
Gene Expression Regulation
Growth Plate cytology
Growth Plate enzymology
Growth Plate growth & development
Immunohistochemistry
Male
Matrix Metalloproteinase 13 genetics
Matrix Metalloproteinase 13 metabolism
Matrix Metalloproteinase 3 genetics
Matrix Metalloproteinase 3 metabolism
Procollagen N-Endopeptidase genetics
Procollagen N-Endopeptidase metabolism
Proteoglycans metabolism
RNA, Messenger genetics
RNA, Messenger metabolism
Rats
Rats, Sprague-Dawley
Spine cytology
Spine metabolism
Weight-Bearing
Aggrecans metabolism
Collagen Type II metabolism
Collagen Type X metabolism
Extracellular Matrix metabolism
Growth Plate metabolism
Stress, Mechanical
Subjects
Details
- Language :
- English
- ISSN :
- 1873-2763
- Volume :
- 44
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Bone
- Publication Type :
- Academic Journal
- Accession number :
- 18849019
- Full Text :
- https://doi.org/10.1016/j.bone.2008.09.005