Journal of Neuroscience, Vol 2, 1252-1266, Copyright © 1982 by Society for Neuroscience
Studies on the control of myelinogenesis. IV. Neuronal induction of Schwann cell myelin-specific protein synthesis during nerve fiber regeneration
MJ Politis, N Sternberger, K Ederle and PS Spencer
The temporal sequence of axon-Schwann cell interaction during regeneration
is examined in cat tibial nerves surgically denervated for 8 weeks and,
subsequently, coated to a freshly severed peroneal nerve for 3 weeks. Prior
to association with regenerating axons, Schwann cells resident in
denervated and reinnervated stumps failed to synthesize proteins co-migrant
with P0, P1, and P2 myelin proteins in contrast to normal nerves. Axonal
association with Schwann cells stimulated synthesis of amino acid-labeled
proteins co-migrating with myelin-specific proteins prior to elaboration of
myelin lamellae. Radioactivity from these peaks was precipitated by
antibodies raised against myelin-specific proteins. The synthesis of P1 and
P2 proteins was evident before P0 synthesis in reinnervated stumps.
Immunocytochemical staining with antibody to P0, P1, P2, and myelin-
associated glycoprotein (MAG) appeared only after myelin lamellae had been
formed. These data suggest that Schwann cells: (a) synthesize proteins
co-migrant with P1, P2, P0, and MAG in normal cat nerves; (b) cease
detectable manufacture of these proteins after axonal loss; (c) regain
their capacity to synthesize these proteins upon re- establishment of
axonal association; and (d) during regeneration, express the synthesis of
P1 and P2 before that of P0.