Effects of ciliary neuronotrophic factor on rat spinal cord neurons in vitro: survival and expression of choline acetyltransferase and low-affinity nerve growth factor receptors.
We have studied the effects of ciliary neuronotrophic factor (CNTF) and nerve growth factor (NGF) on cultures of E14 rat spinal cord cells maintained for 7 days. The trophic factors were supplied at the day of seeding and every other day thereafter. Treatments with CNTF (human recombinant or purified from rat sciatic nerve, 100 TU/ml) resulted after 7 days in an increase, relative to control cultures, of: (i) the total number of neurons (identified by neurofilament protein and neuron-specific enolase immunostaining) that were not stained with choline, acetyltransferase (ChAT) and low affinity nerve growth factor receptor (LNGFR) antibodies; (ii) the number of motoneurons (0.5% of the neuronal population) as identified by size (greater than 25 microns), morphology and immunostaining for ChAT and LNGFR; and (iii) a population of small- to medium-sized (less than 25 microns), ChAT- and LNGFR-positive neurons, representing 5-10% of the total neuronal population. NGF treatments (mouse submaxillary beta NGF; 10-3000 TU/ml) were without effect on all 3 neuronal populations. Experiments in which CNTF administration was delayed revealed that the population of ChAT- and LNGFR-negative neurons and the population of motoneurons, were both dependent on CNTF for their survival. The third population, small ChAT and LNGFR-positive neurons, was not dependent on CNTF for survival but was induced by CNTF to express its two markers. These observations indicate that CNTF is a neuronotrophic factor for motoneurons, but that the effect of CNTF is not restricted to that cell population. In addition to its survival promoting effect, CNTF has also a regulatory role on the expression of ChAT and LNGFR for some spinal cord neurons.
Magal
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Department of Biology 0601, University of California San Diego, La Jolla 92093.
Burnham
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Varon
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D000109:Acetylcholine / Q000502:physiology; D000818:Animals; D002452:Cell Count / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002795:Choline O-Acetyltransferase / Q000032:analysis*; D020934:Ciliary Neurotrophic Factor; D007150:Immunohistochemistry; D009046:Motor Neurons / Q000737:chemistry / Q000187:drug effects; D009410:Nerve Degeneration / Q000187:drug effects; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D009474:Neurons / Q000737:chemistry / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000032:analysis*; D017475:Receptors, Nerve Growth Factor; D013116:Spinal Cord / Q000166:cytology / Q000187:drug effects* / Q000196:embryology
D020934:Ciliary Neurotrophic Factor; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D017475:Receptors, Nerve Growth Factor; D002795:Choline O-Acetyltransferase; D000109:Acetylcholine