Abstract
Nuclear matrix protein (NMP) composition of osteoblasts shows distinct two-dimensional gel electrophoretic profiles of labeled proteins as a function of stages of cellular differentiation. Because NMPs are involved in the control of gene expression, we examined modifications in the representation of NMPs induced by TGF-β1 treatment of osteoblasts to gain insight into the effects of TGF-β on development of the osteoblast phenotype. Exposure of proliferating fetal rat calvarial derived primary cells in culture to TGF-β1 for 48 h (day 4-6) modifies osteoblast cell morphology and proliferation and blocks subsequent formation of mineralized nodules. Nuclear matrix protein profiles were very similar between control and TGF-β-treated cultures until day 14, but subsequently differences in nuclear matrix proteins were apparent in TGF-β-treated cultures. These findings support the concept that TGF-β1 modifies the final stage of osteoblast mineralization and alters the composition of the osteoblast nuclear matrix as reflected by selective and TGF-β-dependent modifications in the levels of specific nuclear matrix proteins. The specific changes induced by TGF-β in nuclear matrix associated proteins may reflect specialized mechanisms by which TGF-β signalling mediates the alterations in cell organization and nodule formation and/or the consequential block in extracellular mineralization.
Original language | English (US) |
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Pages (from-to) | 291-303 |
Number of pages | 13 |
Journal | Journal of cellular biochemistry |
Volume | 69 |
Issue number | 3 |
DOIs | |
State | Published - Jun 1 1998 |
Keywords
- Bone
- Mineralization
- Nuclear matrix
- Osteoblast differentiation
- TGF-β1
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology