Evidence that an RGD-dependent receptor mediates the binding of oligodendrocytes to a novel ligand in a glial-derived matrix.

Abstract

Abstract. A simple adhesion assay was used to measure the interaction between rat oligodendrocytes and various substrata, including a matrix secreted by glial cells. Oligodendrocytes bound to surfaces coated with fibronectin, vitronectin and a protein component of the glial matrix. The binding of cells to all of these substrates was inhibited by a synthetic peptide (GRGDSP) modeled after the cell-binding domain of fibronectin. The component of the glial matrix responsible for the oligodendrocyte interaction is a protein which is either secreted by the glial cells or removed from serum by products of these cultures; serum alone does not promote adhesion to the same extent as the glial-derived matrix. The interaction of cells with this glial-derived matrix requires divalent cations and is not mediated by several known RGD-containing extracellular proteins, including fibronectin, vitronectin, thrombospondin, type I and type IV collagen, and tenascin.

Astrocytes promote process outgrowth by adult human oligodendrocytes in vitro through interaction between bFGF and astrocyte extracellular matrix

“…The survival of mature oligodendrocytes in vitro is also promoted by astrocytes (Gard et al, 1995). Rome and colleagues (Cardwell and Rome, 1988;Malek-Hedayat and Rome, 1994) have demonstrated that OLs adhered well to an astrocyte matrix via integrin-dependent mechanisms. In lesion areas of MS, OLs have been observed to be invested within hypertropic astrocytes (Ghatak, 1992;Prineas et al, 1990;Wu and Raine, 1992); the role of such glial associations remains controversial and may represent a protective mechanism for OLs by astrocytes (Wu and Raine, 1992) or destruction of OLs by astrocytes (Prineas et al, 1990).…”

Oligodendrocytes utilize a matrix metalloproteinase, MMP-9, to extend processes along an astrocyte extracellular matrix

“…OLs were obtained in excess of 90% purity using a previously described protocol for adult specimens (Yong and Antel, 1997) and subsequently were seeded onto an astrocyte-derived extracellular matrix (ECM) within Lab-Tek 16 well chamber slides (Nunc, Naperville, IL). To generate Lab-Tek coverslips coated with astrocyte-derived ECM, we employed a protocol modified from that of Cardwell and Rome (Cardwell and Rome, 1988). Fetal human astrocytes, prepared to a purity of over 95%, as previously described (Yong et al, 1992), were seeded onto Lab-Tek chambers at a density of 2 ϫ 10 5 cells in 300 µl to achieve a near confluent layer of astrocytes on the surface of the coverslip.…”

Characterization of focal adhesion assembly in XR1 glial cells

“…Research related to integrin function in glial cells suggests several possible roles. There is evidence that integrins may be involved in mediating the differentiation of oligodendrocytes (Cardwell and Rome, 1988) and type 2 astrocytes (Lillien et al, 1990) through their interactions with the ECM. A role for integrins is also implicated in glial-neuronal interactions related to neuronal migration (Zhou et al, 1986;Fishman and Hatten, 1993).…”