Post-translational modifications of collagen upon BMP-induced osteoblast differentiation.
The pattern of collagen cross-linking is tissue specific primarily determined by the extent of hydroxylation and oxidation of specific lysine residues in the molecule. In this study, murine pre-myoblast cell line, C2C12 cells, were transdifferentiated into osteoblastic cells by bone morphogenetic protein (BMP)-2 treatment, and the gene expression of lysyl hydroxylases (LH1, 2a/b, and 3) and lysyl oxidase (LOX)/lysyl oxidase-like proteins (LOXL1-4), and the extent of hydroxylysine were analyzed. After 24h of treatment, the expression of most isoforms were upregulated up to 96h whereas LH2a and LOXL2 decreased with time. In the treated cells, both hydroxyproline and hydroxylysine were detected at day 7 and increased at day 14. The ratio of hydroxylysine to hydroxyproline was significantly increased at day 14. The results indicate that LHs and LOX/LOXLs are differentially responsive to BMP-induced osteoblast differentiation that may eventually lead to the specific collagen cross-linking pattern seen in bone.
Kaku
Masaru
M
CB#7455, Dental Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7455, USA.
Mochida
Yoshiyuki
Y
Atsawasuwan
Phimon
P
Parisuthiman
Duenpim
D
Yamauchi
Mitsuo
M
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D024042:Collagen Type I / Q000378:metabolism*; D006801:Humans; D006901:Hydroxylysine / Q000032:analysis / Q000378:metabolism; D006909:Hydroxyproline / Q000032:analysis / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D051379:Mice; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism*; D008240:Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase / Q000145:classification / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D008249:Protein-Lysine 6-Oxidase / Q000145:classification / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*
C525718:BMP2 protein, human; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D024042:Collagen Type I; D007527:Isoenzymes; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D006901:Hydroxylysine; D008240:Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; D008249:Protein-Lysine 6-Oxidase; D006909:Hydroxyproline