Increased Cell Surface Expression of Receptors for Transforming Growth Factor-β on Osteoblasts from Patients with Osteogenesis imperfecta
Abstract
Osteogenesis imperfecta (OI) is a heritable connective tissue disorder usually characterized by either a reduction in the production of normal collagen I or the synthesis of abnormal collagen. The variability in the clinical phenotype is not in each case sufficiently explained by the underlying mutation in the collagen I genes. Also, biochemical differences between mutant collagen from different tissues suggest additional regulatory mechanisms possibly involved in matrix deposition and maturation, two processes in which transforming growth factor-beta (TGF-beta) plays an important role. We, therefore, studied the cell surface expression and functional properties of TGF-beta receptors I, II and III on osteoblasts from a group of OI patients compared to healthy controls. Receptor number and affinity were determined by Scatchard analysis of binding data and TGF-beta receptor II gene expression was assessed by RT-PCR. Ligand-induced downregulation of TGF-beta receptors was analyzed to demonstrate the dynamic response to exogenous stimuli. All experiments were performed in parallel in human osteoblastic cells from OI patients and from age-matched controls. TGF-beta receptors I, II and III (betaglycan) were present on osteoblasts from both healthy donors and OI patients. The receptor numbers were significantly higher (29,000 per cell) on OI osteoblasts than on age-matched control osteoblasts (12,000 per cell) in spite of similar steady state levels for TGF-beta receptor II mRNA in…
Read the paper
Related studies
- Irisin Enhances Osteoblast DifferentiationIn Vitro
- Glucocorticoids suppress Wnt16 expression in osteoblasts in vitro and in vivo
- Interaction between Schwann Cells and Osteoblasts In Vitro
- Administration of cinnamaldehyde promotes osteogenesis in ovariectomized rats and differentiation of osteoblast in vitro
- The Effect of the Major Components of Fructus Cnidii on Osteoblasts In Vitro
- Estrogen depletion alters osteogenic differentiation and matrix production by osteoblasts in vitro
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.