Plasticity of integrin expression by nerve-derived connective tissue cells. Human Schwann cells, perineurial cells, and fibroblasts express markedly different patterns of beta 1 integrins during nerve development, neoplasia, and in vitro.

Abstract

Strikingly selective expression patterns of 61, a2, a3, and a5 integrin subunits were revealed in endoneurium, perineurium, and epineurium of fetal and adult human peripheral nerve by immunostaining with specific antibodies. The a2 subunit was expressed only on Schwann cells both in fetal and adult nerve, whereas the a3 epitopes were expressed exclusively in the adult tissue and were primarily present on perineurial cells. The a5 epitopes were expressed only on the innermost cell layer of perineurium of fetal and adult nerve. The tumor cells within schwannomas and cutaneous neurofibromas expressed both a2 and a3 subunits, indicating that Schwann cells have the potential to express also the a3 subunit in vivo. Cell cultures established from human fetal nerve and neurofibromas revealed expression of the a2 and a5 epitopes on Schwann cells, perineurial cells, and fibroblasts, whereas only Schwann cells contained the a3 epitopes which were occasionally concentrated on the adjacent Schwann cells at cell-cell contacts. Our findings emphasize that nerve connective tissue cells afhange their profiles for expression of extracellular matrix receptors under conditions which have different regulatory control signals exerted by, for example, axons, humoral factors, or the extracellular matrix of the peripheral nerve. This plasticity may play an important role during nerve development and in neoplastic processes affecting the connective tissue compartments of peripheral nerve. (J. Clin. Invest. 1991. 87:811420.)

α7β1 integrin is a receptor for laminin‐2 on Schwann cells

“…As shown in Fig. 1, Schwann cells express a1b1, a3b1, a6b1, and a7b1 integrins and dystroglycan, consistent with previous results (Edgar, 1991;Hsiao et al, 1991;Milner et al, 1997;Previtali et al, 2003a;Stewart et al, 1997). We did not detect a2b1 integrin in Schwann cells (Fig.…”

“…Expression of a7 integrin is detected in neonatal and adult peripheral nerve, but not in embryonic nerves (Previtali et al, 2003a,b). In contrast, both a6 and a2 integrins are detected in embryonic nerves (Hsiao et al, 1991;Previtali et al, 2003b). We found that Schwann cell a6b1 integrin does not bind to laminin-2.…”

“…This phenotype is similar to those of laminin mutants, suggesting that lack of laminin-binding b1 integrins is responsible for the myelination defects observed in Schwann cell b1 knockout animals. Schwann cells express several b1 containing integrins that can potentially interact with laminins (Hsiao et al, 1991;Jaakkola et al, 1993;Milner et al, 1997;Previtali et al, 2003a;Stewart et al, 1997). a6b1 is abundantly expressed by Schwann cells during embryogenesis (Previtali et al, 2003b).…”

Schwann Cell Type V Collagen Inhibits Axonal Outgrowth and Promotes Schwann Cell Migration via Distinct Adhesive Activities of the Collagen and Noncollagen Domains

“…For comparison, the effects of these inhibitors on adhesion to collagen type IV were also determined. The best-characterized cellular receptors for collagen molecules are ␣1␤1-and ␣2␤1-integrins (Dickeson et al, 1999;Knight et al, 2000;Nykvist et al, 2000), which are expressed by Schwann cells (Hsiao et al, 1991;Milner et al, 1997). The function-blocking monoclonal anti-␣1-integrin antibody inhibited Schwann cell adhesion to collagen type IV by ϳ50% (Fig.…”

Glucose Transporters of Rat Peripheral Nerve: Differential Expression of GLUT1 Gene by Schwann Cells and Perineurial Cells In Vivo and In Vitro

“…Two lines of recent research have provided the tools to investigate the events of glucose metabolism of the neural connective tissue at the cellular level in a detailed manner: first, the characterization of sodium-independent GLUTs, a family of membrane-associated proteins that are responsible for facilitated diffusion of D-glucose into mammalian cells (4,5); and secondly, the development of a cell-culture method that allows identification of perineurial cells, Schwann cells, and neural fibroblasts, and assessment of their gene expression profiles in mixed cultures (6)(7)(8)(9)(10).…”