Journal of Neuroscience, Vol 16, 2335-2341, Copyright © 1996 by Society for Neuroscience
GDNF slows loss of motoneurons but not axonal degeneration or premature death of pmn/pmn mice
Y Sagot, SA Tan, JP Hammang, P Aebischer and AC Kato
Department of Pharmacology, Geneva Universtiy, 1211 Geneva-4, Switzerland.
Glial cell line-derived neurotrophic factor (GDNF), a member of the TG
F-beta superfamily, has been shown to be a highly potent neurotrophic
factor that enhances survival of various neuronal cell types including
motoneurons. To assess its therapeutic potential in treating
neurodegenerative diseases such as amyotrophic lateral sclerosis, we
treated mutant mice displaying motoneuron degeneration (progressive motor
neuropathy; pmn) with encapsulated GDNF-secreting cells. Effects of GDNF
treatment on pmn/pmn mice were compared with previous results obtained with
ciliary neurotrophic factor (CNTF) [Sagot Y, Tan SA, Baetge E, Schmalbruch
H, Kato AC, Aebischer P (1995) Eur J Neurosci 7:1313-1322]. In contrast to
CNTF, GDNF did not increase the lifespan of pmn/pmn mice. However, GDNF
significantly reduced the loss of facial motoneurons by 50%, a value
similar to what was observed when CNTF was administered to the pmn/pmn
mice. Surprisingly, myelinated axon counts revealed that GDNF had no effect
on nerve degeneration. Therefore, despite its potential in rescuing
motoneuron cell bodies, the inability of GDNF to prevent nerve degeneration
in pmn/pmn mice suggests that its usefulness in the treatment of motor
neuron diseases may be restricted to cotreatment with other factors that
act on the nerve process.