Expression and distribution of functional intergrins in rat CNS glia

In previous studies, we have reported on the expression of β1 intergrins in type 1 astrocytes and their function in cell-substratum attachment (Tawil et al., J Cell Biol 120:261–271, 1993). Here we extend those findings by providing evidence that type 1 astrocytes express integrins of the β3 and possibly β4 subclasses and that the former (αvβ3) functions in attachment by recognizing the peptide, Arg-Gly-Asp, in vitronectin. In addition, we have examined immunocyto-chemically the expression of β1 integrins on type 2 astrocytes and oligodendrocytes. The pattern of expression of integrins on these two cell types is distinct from type 1 astrocytes; most notably type 1 astrocytes but not oligodendrocytes or type 2 astrocytes express α1β1 heterodimers. Since type 2 astrocytes and oligodendrocytes originate from a common precursor (0-2A), the α1β1 heterodimer may be a functional marker which distinguishes O-2A-derived cells from those of the type 1 astrocyte lineage. © 1994 Wiley-Liss, Inc.