Alterations of ovariectomized rat bone and impact of non-collagenous proteins on mineralization.
OBJECTIVE
Noncollagenous proteins (NCPs) play distinct and overlap roles in controlling the mineralization of bone, while the relationship between the NCPs and the mineral phase in osteoporotic bone is nebulous. Ovariectomized (OVX) rats, as an animal model for osteopenia, were used in this study to evaluate the impact of NCPs on mineral metabolism in osteopenia development.


METHODS
Bone mineral was characterized with small-angle X-ray scattering study, extended X-ray absorption fine structure analysis, inductively coupled plasma mass spectroscopy, thermogravimetric and chemical analyses. NCPs were extracted from bone matrix, and analyzed with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). A constant composition titration system was used in the kinetic study of re-mineralization of bone residues after various extractions.


RESULTS
Bone density was reduced, whereas no significant changes were observed in the composition, crystal thickness and crystal structural parameters of minerals from OVX rat bone. The total content of NCPs in each extract decreased in the OVX group, but no selective loss of particular proteins was observed. The difference in mineralization kinetics between the OVX rat bone and the sham rat bone was resulted mainly from the mineral-bound NCPs.


CONCLUSIONS
The reduced quantity and unchanged quality of bone mineral seem to be positively associated with the total amount of NCPs and the proportions between some major NCPs in OVX rats, respectively.
Huang
Jian
J
Department of Chemical Biology, Peking University School of Pharmaceutical Sciences, 38 Xueyuan Road, Beijing 100191, PR China.
Wang
Xi
X
Zhang
Tian-Lan
TL
Wang
Kui
K
D015502:Absorptiometry, Photon; D000818:Animals; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D001842:Bone and Bones / Q000737:chemistry / Q000378:metabolism; D002113:Calcification, Physiologic / Q000502:physiology*; D004195:Disease Models, Animal; D004591:Electrophoresis, Polyacrylamide Gel; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D013058:Mass Spectrometry; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D053838:Scattering, Small Angle
D016326:Extracellular Matrix Proteins