Signaling pathways and survival effects of BDNF and NT-3 on cultured cerebellar granule cells.
We investigated the signaling pathways exerted by brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in relation to their survival-promoting effects on dissociated cultures of cerebellar granule cells prepared from postnatal 9-day-old rats. Granule neuron survival in culture was supported by BDNF, but not significantly by either nerve growth factor (NGF) or NT-3. BDNF and NT-3 resulted in not only the respective autophosphorylation of the Trk receptors, TrkB or TrkC, but also tyrosine phosphorylation of SHC, a protein involved in controlling p21ras activity, and phosphatidylinositol-3' (PI-3') kinase. NGF does not result in TrkA phosphorylation. In parallel, c-fos was induced within 30 min, in response to BDNF and NT-3. NT-3 induced the phosphorylation of these proteins to a lesser extent than BDNF. BDNF also induced the tyrosine phosphorylation of phospholipase C gamma (PLC gamma), but the NT-3-induced one was not detected. We postulate that no survival promotion by NT-3 is due to lesser level of trkC expression and of the NT-3-induced signaling in the cultured cerebellar granule neurons. Wortmannin, a specific inhibitor of PI-3' inhibited the BDNF effect on neuronal survival. PI-3' kinase-dependent pathways might be involved in the promotion of cerebellar granule cell survival by BDNF.
Nonomura
T
T
Division of Protein Biosynthesis, Osaka University, Japan.
Kubo
T
T
Oka
T
T
Shimoke
K
K
Yamada
M
M
Enokido
Y
Y
Hatanaka
H
H
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D015152:Blotting, Northern; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D002531:Cerebellum / Q000166:cytology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D007527:Isoenzymes / Q000378:metabolism; D009414:Nerve Growth Factors / Q000494:pharmacology*; D020933:Neurotrophin 3; D019869:Phosphatidylinositol 3-Kinases; D051966:Phospholipase C gamma; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D055765:Shc Signaling Adaptor Proteins; D015398:Signal Transduction / Q000502:physiology*; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D010738:Type C Phospholipases / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism; D000077191:Wortmannin
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000730:Androstadienes; D019208:Brain-Derived Neurotrophic Factor; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D009414:Nerve Growth Factors; D020933:Neurotrophin 3; D011506:Proteins; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D055765:Shc Signaling Adaptor Proteins; C528035:Shc1 protein, rat; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014443:Tyrosine; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D020794:Receptor Protein-Tyrosine Kinases; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D000077191:Wortmannin