Cutaneous neurofibromas, characteristic lesions of neurofibromatosis 1, are composed of an abundant extracellular matrix and nerve connective tissue-derived cell types: Schwann cells, perineurial cells, and fibroblasts. In this study, the extracellular matrix gene expression by these cells was examined under culture conditions that allowed them to be metabolically active and readily identifiabl...

Carcinoembryonic antigen cell adhesion molecule-1 (CEACAM1) is a surface glycoprotein expressed on various blood cells, epithelial cells, and vascular cells. CEACAM1 possesses adhesive and signaling properties mediated by its intrinsic immunoreceptor tyrosine-based inhibitory motifs that recruit SHP-1 protein-tyrosine phosphatase. In this study, we demonstrate that CEACAM1 is expressed on the s...

The functional importance of platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) in platelets is unclear. Because PECAM-1 represents a newly assigned immunoglobulin–ITIM superfamily member expressed on the surface of platelets, it was hypothesized that it may play an important regulatory role in modulating ITAM-bearing receptors such as collagen (GP)VI receptor and FcgRIIA. To examine ...

Skeletal dysplasias represent in vivo models of genetic defects. Achondrogenesis type II (Langer-Saldino), caused by a genetic defect in the major cartilage matrix protein, collagen type II, is a rare and severe skeletal dysplasia. It comprises a severe derangement of the fetal growth plate cartilage with subsequent ossification defects. In this study, we analyzed the matrix composition and cel...

Glycoprotein (GP) VI, the primary collagen receptor on platelets, has been shown to have variable expression, possibly as a consequence of immune modulation. The present study was designed to determine the mechanism by which GP VI clearance occurs. We found that direct activation of GP VI both by a GP VI–specific antibody and by GP VI ligands (collagen and convulxin) reduced binding of biotinyl...

Glycoprotein (GP) VI, the primary collagen receptor on platelets, has been shown to have variable expression, possibly as a consequence of immune modulation. The present study was designed to determine the mechanism by which GP VI clearance occurs. We found that direct activation of GP VI both by a GP VI-specific antibody and by GP VI ligands (collagen and convulxin) reduced binding of biotinyl...

The aim of this study was to investigate the effects of serum and compressive dynamic loading on the cartilaginous matrix spatiotemporal distribution around chondrocytes in vitro. Murine chondrocytes suspended in agarose were cultured in serum-free media or in varying concentrations of serum with or without compressive dynamic loading. Gene expression was assayed by quantitative polymerase chai...

The synthetic cell attachment-promoting peptides from fibronectin (Pierschbacher, M. D., and E. Ruoslahti, 1984, Nature (Lond.)., 309:30-33) were found to detach cultured cells from the substratum when added to the culture in a soluble form. Peptides ranging in length from tetrapeptide to heptapeptide and containing the active L-arginyl-glycyl-L-aspartic acid (Arg-Gly-Asp) sequence had the deta...

Many inherited abnormalities of collagen are likely and may be listed under the following headings as proved, probable, or possible. Proved Ehlers-Danlos syndrome (EDS) (types III, IV, V, VI, VII); osteogenesis imperfecta (broadboned type); thanatophoric dwarfism; dermatosparaxis (animal equivalent of EDS VII); blotchy mice (animal equivalent of EDS V). Probable Marfan syndrome; pseudoxanthoma ...

Treatment of bovine corneal stroma using SDS-containing extracting solutions removes a 135,000 MW glycoprotein from the main collagen framework of the tissue. Low-angle synchrotron X-ray diffraction patterns obtained from corneas extracted in this way indicate that the glycoprotein has been removed from the gap regions of the collagen fibrils and is thus an important structural component of the...