Insulin growth factors regulate the mitotic cycle in cultured rat sympathetic neuroblasts

Journal Article · Wed Jun 01 00:00:00 EDT 1988 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.85.11.4066· OSTI ID:5365224

DiCicco-Bloom, E; Black, I B ^[1]

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1. Cornell Univ. Medical College, New York, NY (USA)

While neuronal mitosis is uniquely restricted to early development, the underlying regulation remains to be defined. The authors have now developed a dissociated, embryonic sympathetic neuron culture system that uses fully defined medium in which cells enter the mitotic cycle. The cultured cells expressed two neuronal traits, tyrosine hydroxylase and the neuron-specific 160-kDa neurofilament subunit protein, but were devoid of glial fibrillary acidic protein, a marker for non-myelin-forming Schwann cells in ganglia. Approximately one-third of the tyrosine hydroxylase-positive cells synthesized DNA in culture, specifically incorporating ({sup 3}H)thymidine into their nuclei. They used this system to define factors regulating the mitotic cycle in sympathetic neuroblasts. Members of the insulin family of growth factors, including insulin and insulin-like growth factors I and II, regulated DNA synthesis in the presumptive neuroblasts. Insulin more than doubled the proportion of tyrosine hydroxylase-positive cells entering the mitotic cycle, as indicated by autoradiography of ({sup 3}H)thymidine incorporation into nuclei. Scintillation spectrometry was an even more sensitive index of DNA synthesis. In contrast, the trophic protein nerve growth factor exhibited no mitogenic effect, suggesting that the mitogenic action of insulin growth factors is highly specific. The observations are discussed in the context of the detection of insulin growth factors and receptors in the developing brain.

• OSTI ID: 5365224
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 85:11; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GROWTH FACTORS
BIOCHEMISTRY
NERVE CELLS
CYTOCHEMISTRY
TYROSINASE
ENZYME ACTIVITY
CELL CULTURES
INSULIN
MITOSIS
PROTEINS
THYMIDINE
TRITIUM COMPOUNDS
ANIMAL CELLS
AZINES
CELL DIVISION
CHEMISTRY
ENZYMES
HETEROCYCLIC COMPOUNDS
HORMONES
HYDROGEN COMPOUNDS
HYDROXYLASES
MITOGENS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDOREDUCTASES
PEPTIDE HORMONES
PYRIMIDINES
RIBOSIDES
SOMATIC CELLS
550201* - Biochemistry- Tracer Techniques