title: Onset of CNTFRalpha expression and signal transduction during neurogenesis in chick sensory dorsal root ganglia.
abstract: The expression of ciliary neurotrophic factor receptor alpha (CNTFRalpha) was investigated in the developing chick dorsal root ganglion (DRG) using affinity-purified anti-CNTFRalpha antibodies. At thoracic levels, CNTFRalpha-immunoreactivity (CNTFRalpha-IR) was first observed at stage 19 (E3) in cells with neuronal morphology. CNTFRalpha-IR is restricted to the neuronal lineage in the DRG throughout development. CNTFRalpha expression precedes that of neuron-specific beta tubulin, Hu antigen, and Q211 antigen, which are markers expressed in developing sensory neurons. [3H]Thymidine-labeling studies showed the onset of CNTFRalpha expression during terminal mitosis of sensory neuron precursors, making CNTFRalpha the earliest known neuronal marker in the DRG. CNTFRalpha-mediated signal transduction was demonstrated in E7 and E11 DRG neuron cultures by CNTF-induced STAT3 phosphorylation. Although low ligand concentrations (5 pM) elicit STAT3 phosphorylation in E7 and E11 DRG neurons, a survival response is only observed in neurons from E11 DRG. This implicates a complex readout mechanism downstream of STAT3 phosphorylation leading to different cellular responses that depend on the age of the DRG neuron. These results argue against a role of CNTFRalpha ligands in the control of early neuron survival but are compatible with other functions in neurogenesis and sensory neuron development.
authors.affiliation: Max-Planck-Institut für Hirnforschung, Deutschordenstrasse 46, Frankfurt, D-60528, Federal Republic of Germany.
authors.forename: A
authors.initials: A
authors.lastname: Holst
authors.forename: S
authors.initials: S
authors.lastname: Heller
authors.forename: D
authors.initials: D
authors.lastname: Junghans
authors.forename: M
authors.initials: M
authors.lastname: Geissen
authors.forename: U
authors.initials: U
authors.lastname: Ernsberger
authors.forename: H
authors.initials: H
authors.lastname: Rohrer
mesh_terms: D000818:Animals; D000906:Antibodies; D002455:Cell Division; D002478:Cells, Cultured; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000378:metabolism; D005727:Ganglia, Spinal / Q000196:embryology* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009475:Neurons, Afferent / Q000166:cytology / Q000502:physiology; D010766:Phosphorylation; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis*; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor / Q000096:biosynthesis* / Q000502:physiology; D050796:STAT3 Transcription Factor; D015398:Signal Transduction; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology*; D013234:Stem Cells / Q000502:physiology; D013936:Thymidine / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D000906:Antibodies; D004268:DNA-Binding Proteins; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor; D050796:STAT3 Transcription Factor; D015534:Trans-Activators; C095578:growth promoting activity receptor; D020794:Receptor Protein-Tyrosine Kinases; D013936:Thymidine