Neuroprotective properties of ciliary neurotrophic factor for cultured adult rat dorsal root ganglion neurons.
We observed that recombinant ciliary neurotrophic factor (CNTF) enhanced survival and neurite outgrowth of cultured adult rat dorsal root ganglion (DRG) neurons. Among other neurotrophic factors (NGF and GDNF) and interleukin (IL)-6 cytokine members [IL-6, LIF, cardiotrophin-1, and oncostatin M (OSM)] at the same concentration (50 ng/ml), CNTF, as well as LIF and OSM, displayed high efficacy for the promotion of the number of viable neurons and neurite-bearing cells. CNTF enhanced the number of neurite-bearing cells in both small neurons (soma diameter <30 microm) and large neurons (soma diameter > or =30 microm), whereas NGF and GDNF promoted that in only small neurons. Western blot analysis revealed that CNTF induced phosphorylation of STAT3, Akt, and ERK1/2 in the neurons. Furthermore, the neurite outgrowth-promoting activity of CNTF was diminished by co-treatment with Janus kinase (JAK) 2 inhibitor, AG490; STAT3 inhibitor, STA-21; phosphatidyl inositol-3'-phosphate-kinase (PI3K) inhibitor, LY294002; and mitogen-activated protein kinase kinase (MEK) inhibitor, PD98059, in a concentration-dependent manner. Its survival-promoting activity was also affected by AG490, STA-21, and LY294002 at higher concentrations, but not by PD98059. These findings suggest the involvement of JAK2/STAT3, PI3K/Akt, and MEK/ERK signaling pathways in CNTF-induced neurite outgrowth, where the former two pathways are thought to play major roles in mediating the survival response of neurons to CNTF.
Sango
Kazunori
K
Division of Neural Development and Regeneration, Department of Developmental Morphology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan. kazsango@tmin.ac.jp
Yanagisawa
Hiroko
H
Komuta
Yukari
Y
Si
Yang
Y
Kawano
Hitoshi
H
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D020934:Ciliary Neurotrophic Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005419:Flavonoids / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000166:cytology* / Q000187:drug effects* / Q000254:growth & development; D007150:Immunohistochemistry; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D009474:Neurons / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D018696:Neuroprotective Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D011083:Polycyclic Compounds / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D020032:Tyrphostins / Q000494:pharmacology
D002867:Chromones; D020934:Ciliary Neurotrophic Factor; D005419:Flavonoids; D009025:Morpholines; D018696:Neuroprotective Agents; D011083:Polycyclic Compounds; C500947:STA-21; D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat; D020032:Tyrphostins; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one