The mechanism of beta-glycerophosphate action in mineralizing chick limb-bud mesenchymal cell cultures
Autor: | Stephen B. Doty, Phoebe S. Leboy, Adele L. Boskey, Dalina Stiner, Itzhak Binderman, Peter T. Guidon |
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Rok vydání: | 1996 |
Předmět: |
Cartilage
Articular Fetal Proteins Limb Buds Endocrinology Diabetes and Metabolism chemistry.chemical_element Phosphoprotein phosphatase activity Chick Embryo Calcium Biology Mineralization (biology) Substrate Specificity Extracellular matrix Mesoderm Limb bud Animals Orthopedics and Sports Medicine Enzyme Inhibitors Cells Cultured Minerals Hydrolysis Gene Expression Regulation Developmental DNA Alkaline Phosphatase chemistry Biochemistry Glycerophosphates Alkaline phosphatase Phosphorylation Casein kinase 1 Cell Division |
Zdroj: | Scopus-Elsevier |
ISSN: | 0884-0431 |
Popis: | Differentiating chick limb-bud mesenchymal cells plated in micromass culture form a cartilage matrix that can be mineralized in the presence of 4 mM inorganic phosphate (Pi), and 1 mM calcium. Previous studies showed that when beta-glycerophosphate (beta GP) is used in place of Pi, the mineral crystals formed are larger and differ in distribution. The present study shows that the difference in distribution is not associated with alterations in cell proliferation, protein synthesis, or with collagen, proteoglycan core protein, or alkaline phosphatase gene expression. Cultures with 2.5, 5, and 10 mM beta GP did show different levels of alkaline phosphatase activity, and in the presence of low (0.3 mM) Ca had different Pi contents (4, 6 and 9 mM, respectively), indicating that the increase in CaxP product may in part be responsible for the altered pattern of mineralization. However, cultures with beta GP in which alkaline phosphatase activity was inhibited with levamisole still had an altered mineral distribution as revealed by Fourier transform-infrared (FT-IR) microspectroscopy. The presence of a casein kinase II-like activity in the mineralizing cultures, the ability of specific inhibitors of this enzyme to block mineralization, and the known ability of beta GP to block phosphoprotein phosphatase activity suggests that altered patterns of matrix protein phosphorylation may influence mineral deposition in these cultures. |
Databáze: | OpenAIRE |
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