Rp. Lisak et al., Inflammatory cytokines inhibit upregulation of glycolipid expression by Schwann cells in vitro, NEUROLOGY, 51(6), 1998, pp. 1661-1665
Objective: To determine whether products of inflammatory cells can inhibit
differentiation and synthesis of myelin glycolipids by Schwann cells. Backg
round: Infiltration of the peripheral nervous system by inflammatory cells
is a feature of acquired demyelinating neuropathies. It is not clear what r
ole these cells have in causing demyelination or inhibiting myelin synthesi
s. Methods: Nonmyelinating rat Schwann cells were incubated with 1) differe
nt concentrations of activated supernatants (AS) from mitogen-activated inf
lammatory cells; 2) 8-bromo cyclic adenosine monophosphate (8Br cAMP), know
n to induce Schwann cell differentiation and synthesis of glycolipids; 3) 8
Br cAMP and varying concentrations of AS; 4) 8Br cAMP and cytosine arabinos
ide (Ara Ci, which inhibits Schwann cell proliferation; 5) 8Br cAMP, AS, an
d Ara C; or 6) additional medium. Results: AS inhibits the capacity of cAMP
to induce Schwann cell expression of myelin-associated glycolipids. Inhibi
tion of glycolipid expression was independent of the capacity of these AS t
o induce Schwann cell proliferation. Conclusions: These data suggest that i
nflammatory mediators are capable of inhibition of Schwann cell differentia
tion and synthesis of myelin.