I. Mocchetti et al., INCREASED BASIC FIBROBLAST GROWTH-FACTOR EXPRESSION FOLLOWING CONTUSIVE SPINAL-CORD INJURY, Experimental neurology, 141(1), 1996, pp. 154-164
Neurotrophic factors appear to be crucial for the survival and potenti
al regeneration of injured neurons. We have previously demonstrated th
at contusive spinal cord injury (SCI) increases the levels of mRNA for
basic fibroblast growth factor (FGF2). To determine whether FGF2 prot
ein levels also increase, Western blot analysis was performed on extra
cts of spinal cord tissue after a standardized SCI and compared to lam
inectomy controls, In spinal cord extracts, a monoclonal antibody to F
GF2 recognized various molecular forms of FGF2 (18-24 kDa) and some ch
aracteristic proteolytic fragments. Extracts of spinal cords 1 day aft
er SCI showed a slight increase in the levels of these polypeptides. B
y 4 days, a significant increase (twofold) was detected ill the levels
of the 18-kDa and higher molecular weight forms as well as the proteo
lytic fragments. Immunohistochemical analyses on spinal cord tissue se
ctions confirmed an increased cellular (glial) FGF2 as well as interst
itial immunoreactivity surrounding neurons and along blood vessels. He
parin-purified spinal cord extracts from tissue 4 days after SCI showe
d increased biological activity as indicated by their ability to (i) i
ncrease [H-3]thymidine incorporation in cultures of Balb/c 3T3 cells a
nd (ii) induce phosphorylation of suc-associated neurotrophic factor-i
nduced tyrosine-phosphorylated target, a FGF2 target protein. These da
ta suggest that SCI induces increased FGF2 expression and support the
hypothesis that FGF2 may play a role in the partial recovery of functi
on seen following SCI. (C) 1996 Academic Press, Inc.