Publication: Overexpression of lysyl hydroxylase-2b leads to defective collagen fibrillogenesis and matrix mineralization
Issued Date
2005-12-09
Resource Type
ISSN
08840431
Other identifier(s)
2-s2.0-21644439471
Rights
Mahidol University
Rights Holder(s)
SCOPUS
Bibliographic Citation
Journal of Bone and Mineral Research. Vol.20, No.1 (2005), 81-87
Suggested Citation
Suchaya Pornprasertsuk, Wagner R. Duarte, Yoshiyuki Mochida, Mitsuo Yamauchi Overexpression of lysyl hydroxylase-2b leads to defective collagen fibrillogenesis and matrix mineralization. Journal of Bone and Mineral Research. Vol.20, No.1 (2005), 81-87. doi:10.1359/jbmr.2005.20.1.81 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/16649
Research Projects
Organizational Units
Authors
Journal Issue
Thesis
Title
Overexpression of lysyl hydroxylase-2b leads to defective collagen fibrillogenesis and matrix mineralization
Other Contributor(s)
Abstract
Several MC3T3-E1 cell-derived clones expressing higher levels of LH2b were analyzed for their abilities to form collagen fibrils and mineralization. The clones all exhibited smaller collagen fibrils and defective matrix mineralization in vitro and in vivo, indicating a critical role of LH2b-catalyzed posttranslational modifications of collagen in bone matrix formation and mineralization. Introduction: We have recently shown that lysyl hydroxylase (LH) 2b, through its action on the telopeptidyl lysine residues of collagen, regulates collagen cross-linking pathway in the osteoblastic cell line, MC3T3-E1. To further elucidate the roles of LH2b in bone physiology, the effects of overexpression of LH2b on collagen fibrillogenesis and matrix mineralization were investigated. Materials and Methods: Several MC3T3-E1-derived osteoblastic cell clones expressing higher levels of LH2b (S clones) and two controls (i.e., MC3T3-E1 cells and those transfected with an empty vector) were cultured. MALDI-TOF mass spectrometry was used to identify the LH2b. The collagen fibrillogenesis in the cultures was characterized by transmission electron microscopy, and the ability of these clones and cells to form mineralized matrix was analyzed by both in vitro and in vivo mineralization assays. Results: The diameter of collagen fibrils in the S clone cultures was markedly smaller than that of the controls. The onset of matrix mineralization in the S clones was significantly delayed, and considerably fewer mineralized nodules were formed in their cultures in comparison with the controls. When transplanted into immunodeficient mice, the S clones failed to form mineralized matrices in vivo, whereas a bone-like mineralized matrix was well formed by the controls. The diameter of the collagen fibrils and the timing/extent of matrix mineralization in vitro were inversely correlated with the level of LH2b. In vitro cell differentiation was unaffected by the LH2b overexpression. Conclusions: These results indicate a critical role of LH2b catalyzed post-translational modification of collagen (i.e., telopeptidyl lysine hydroxylation and subsequent cross-linking) in collagen matrix formation and mineralization in bone. © 2005 American Society for Bone and Mineral Research.