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Vascular lesions resulting from injury are characterized by a thickening of the intima brought about in part through the production of increased amounts of extracellular matrix proteins by the vascular smooth muscle cells (VSMCs). In this study, we tested the hypothesis that cGMP-dependent protein kinase (PKG), an important mediator of NO and cGMP signaling(More)
Malignant gliomas are the most common primary intracranial neoplasms in adults and are largely refractory to post-surgical therapy despite intensive therapeutic efforts. Using a number of different brain tumor-derived cell lines we have demonstrated that the mRNA for osteopontin (OPN), which is substantially over-expressed by some tumors in comparison with(More)
We investigated the effects of 1,25-dihydroxyvitamin D3 on the synthesis of osteopontin, a phosphorylated cell attachment glycoprotein, in ROS 17/2.8 cells, a clonal osteoblast-like rat osteosarcoma cell line. We observed a dose dependent increase in uptake of [32PO4] into osteopontin secreted into the medium. An increased incorporation of [35S]-methionine(More)
Osteopontin (OPN) is a ubiquitous multiphosphorylated secretory glycoprotein. Twenty-seven phosphorylated serines have been identified in bovine milk OPN (E. S. Sorensen et al. (1995) Protein Sci. 4, 2040-2049). Nineteen of these phosphoacceptor sites are fully conserved in rat OPN, all displaying the consensus for the Golgi apparatus casein kinase, G-CK(More)
Polyclonal antibodies against a 44-KD phosphoprotein (44K BPP) from rat bone were raised in rabbits, affinity-purified, and used as probes to study the protein's distribution in various types of developing bones from newborn rats. Three immunostaining procedures were applied utilizing indirect immunofluorescence, avidin-biotin-peroxidase complex, and(More)
Osteopontin is a phosphorylated bone matrix sialoprotein, postulated to play a regulatory role in biomineralization. The effects of a crude preparation of rat bone osteopontin and a more highly purified bovine bone osteopontin were evaluated using a gel diffusion system to measure effects of 0.1-100 micrograms/ml of this matrix protein on hydroxyapatite(More)
Type beta transforming growth factor (TGF beta) was shown to regulate the production of several extracellular matrix proteins. Osteopontin (OP) is a recently discovered bone matrix protein which was shown to promote the attachment of osteoblastic rat osteosarcoma ROS 17/2.8 cells to their substrate. We examined the effects of TGF beta on OP production and(More)
New aspects of the distribution and developmental appearance of the 44-kDa bone phosphoprotein (44K BPP, also called sialoprotein I or osteopontin) and bone gamma-carboxyglutamic acid (Gla)-containing protein (BGP, also called osteocalcin) during osteogenesis and dentinogenesis were investigated with immunocytochemical techniques using monospecific,(More)
A phosphorylated glycoprotein was purified from the mixture of proteins extracted by demineralization of rat bone with 0.5 M EDTA in 4 M guanidinium chloride. A high level of purity for the preparation was indicated by a single band on sodium dodecyl sulfate (SDS)-gradient gel electrophoresis, sedimentation equilibrium ultracentrifugal data, and by(More)
Proteins that promote cell migration, attachment and spreading are considered to play an important role in the regulation of cell function. Recently, a 44 kilodalton bone phosphoprotein (44K BPP) was shown to enhance the attachment of gingival fibroblasts and osteoblasts in vitro. The potential importance of this attachment protein in the regulation of(More)