Characterisation of the constitutive over-expression of AJ18 in a novel rat stromal bone marrow cell line (D8-SBMC).

Objective: The elucidation of the molecular pathways involved in osteoblast proliferation and differentiation has been greatly enhanced by the availability of cell culture model systems. However, many of the current bone cell culture systems suffer from disadvantages such as the inability to generate mineralised bone-like nodules, a transformed genetic background, cell heterogeneity, and a relatively long time frame from cell seeding to mineralisation, often in the order of several weeks. Here we describe the establishment and characterisation of a novel bone cell line named D8-SBMC.

Polarization and directed migration of murine neutrophils is dependent on cell surface expression of CD44.

The importance of CD44 in murine neutrophil chemotaxis was studied in a Zigmond chamber. WT neutrophils polarized more rapidly and more extensively than CD44-/- neutrophils, which showed slow random migration and reduced activation of RhoA. CD44+/- neutrophils polarized more slowly, formed fewer directionally polarized cells, and migrated more slowly than WT cells.

Analysis of human bone sialoprotein in normal and pathological tissues using a monoclonal antibody (BSP 1.2 mab).

Bone sialoprotein (BSP), a phosphorylated and sulphated glycoprotein that is expressed by mineralized connective tissues is also produced in tumors that metastasize to bone. To facilitate studies of BSP expression in normal and pathological human tissues a monoclonal antibody (BSP 1.2 mab) was raised against human bone BSP.

Increased cell death in osteopontin-deficient cardiac fibroblasts occurs by a caspase-3-independent pathway.

Reperfusion-induced oxidative injury to the myocardium promotes activation and proliferation of cardiac fibroblasts and repair by scar formation. Osteopontin (OPN) is a proinflammatory cytokine that is upregulated after reperfusion. To determine whether OPN enhances fibroblast survival after exposure to oxidants, cardiac fibroblasts from wild-type (WT) or OPN-null (OPN(-/-)) mice were treated in vitro with H(2)O(2) to model reperfusion injury.

Osteopontin modulates CD44-dependent chemotaxis of peritoneal macrophages through G-protein-coupled receptors: evidence of a role for an intracellular form of osteopontin.

Expression of osteopontin (OPN) by activated T-cells and macrophages is required for the development of cell-mediated inflammatory responses. Acting through integrin alpha(v)beta(3) and CD44 receptors, OPN can promote chemoattraction and pro-inflammatory cytokine expression by macrophages. In this study, we have used peritoneal macrophages from OPN-/, CD44-/-, and WT mice to study the relationship between OPN and CD44 in macrophage migration.

Novel functions of the matricellular proteins osteopontin and osteonectin/SPARC.

Osteopontin (OPN) and osteonectin/SPARC (ON/SPARC) are prominent matricellular components of the extracellular matrix of mineralized tissues of bones and teeth in which they can regulate the formation and growth of hydroxyapatite crystals and influence a variety of cell activities. OPN regulates cell responses through several integrin receptors and is also a ligand for the CD44 receptor, through which it acts as a chemoattractant. Although a cell-surface receptor for SPARC has not been identified it can block cell-cell and cell-matrix interactions and inhibit cell migration and chemotaxis.

Inhibition of cell proliferation, invasion, tumor growth and metastasis by an oral non-antimicrobial tetracycline analog (COL-3) in a metastatic prostate cancer model.

Antibiotic forms of tetracycline exhibit antitumor activity in some tumor models. However, their low in vivo efficacy and associated morbidity limit their long-term application in cancer therapy. This report appraises the efficacy of doxycycline (DC) and non-antimicrobial, chemically modified tetracyclines (CMTs) against prostate cancer.