title: Induced expressions of Rab24 GTPase and LC3 in nerve-injured motor neurons.
abstract: Rab24 is a member of the Rab GTPase family, but its function is unclear. Here, we demonstrated increase in Rab24 mRNA in nerve-injured hypoglossal motor neurons of rats. Expression of Rab24 mRNA was also induced in differentiated PC12 cells following proteasome inhibitor (MG132) treatment. MG132 treatment further induced expression of microtubule-associated protein light chain 3 (LC3), and accumulation of LC3-II, a processed form of LC3 and the most reliable marker for autophagy. Induction of LC3 mRNA and accumulation of LC3-II were also observed in nerve-injured hypoglossal motor neurons, and partial co-localization of Rab24 and LC3 was demonstrated by immunohistochemistry. The present data suggest that nerve injury promotes autophagy-like events, and this may be an important response for degradation of unnecessary and misfolded proteins to recycle limited amino acids, and synthesize new proteins that are necessary for survival and nerve regeneration responses.
authors.affiliation: Department of Anatomy and Neurobiology, Osaka City University, Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Youhei
authors.initials: Y
authors.lastname: Egami
authors.forename: Sumiko
authors.initials: S
authors.lastname: Kiryu-Seo
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Yoshimori
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kiyama
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000187:drug effects; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D009046:Motor Neurons / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D016716:PC12 Cells; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D051381:Rats; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D008869:Microtubule-Associated Proteins; D061988:Proteasome Inhibitors; D046988:Proteasome Endopeptidase Complex; C506546:Rab24 protein, rat; D020691:rab GTP-Binding Proteins