Multiple signals underlie the axotomy-induced up-regulation of c-JUN in adult sensory neurons.
We examined the axotomy-induced expression of the immediate-early gene (proto-oncogene) c-jun in the Ola mouse mutant (which exhibits a dramatic delay in Wallerian degeneration) using immunocytochemistry to c-JUN (the protein product of the protooncogene c-jun). c-JUN-like protein immunoreactivity was present in a similar proportion (ca. 60%) of L4 dorsal root ganglion (DRG) neuronal cell bodies from normal (C57/6J/BL) and Ola mice at 1 week following a sciatic nerve crush (axotomy). In normal mice, the intensity and extent of staining declined at 3 weeks, correlating with regeneration. In contrast, Ola mice exhibited a marked reduction (by 77%) in the extent of staining at 2 weeks. At 3 weeks (coinciding to the onset of extensive axonal degeneration in this mutant), staining levels were increased to 1 week levels. Taken together, these findings suggest that multiple signals (both independent and dependent on axonal degeneration) regulate c-jun expression in DRG neuronal cell bodies.
Center for Research on Occupational and Environmental Toxicology, Oregon Health Sciences University, Portland 97201-3098.
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Gold
D R
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Austin
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Storm-Dickerson
D000818:Animals; D001369:Axons / Q000502:physiology*; D005727:Ganglia, Spinal / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008818:Mice, Neurologic Mutants; D009409:Nerve Crush; D009416:Nerve Regeneration; D009475:Neurons, Afferent / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000032:analysis / Q000096:biosynthesis*; D012016:Reference Values; D012584:Sciatic Nerve / Q000502:physiology*; D013045:Species Specificity
D016755:Proto-Oncogene Proteins c-jun