The survival response of mesencephalic dopaminergic neurons to the neurotrophins BDNF and NT-4 requires priming with serum: comparison with members of the TGF-β superfamily and characterization of the serum-free culture system
The neurotrophins, brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4), are established survival promoting molecules for dopaminergic (DAergic) neurons cultured from the fetal rat midbrain floor. We have cultured and compared the survival of embryonic day (E) 14 mesencephalic cells in fully defined, serum-free medium, with serum-primed cultures (one hour during dissociation). Cultures were characterized using antibodies against neuron-specific enolase (NSE), tyrosine hydroxylase (TH), vimentin, glial fibrillary acidic protein (GFAP), and the antigen A2B5. The absolute absence of serum did not reduce the survival of TH-positive DAergic neurons nor alter the percentages of cells staining for the above markers. Transforming growth factor-β3 (TGF-β3) and glial cell line-derived neurotrophic factor (GDNF), two members of the TGF-β superfamily, both promoted the survival of TH-positive cells (TGF-β3: 2-fold; GDNF: 1.6-fold) over the 8-day culture period. Survival mediated by TGF-β3 and GDNF was independent of whether or not the cells had been initially exposed to serum. In contrast, the survival promoting effects of BDNF and NT-4 were crucially dependent on serum priming. RT-PCR for the full-length trkB high affinity neurotrophin receptor revealed its presence in both culture systems. We conclude that priming with serum is important to make DAergic neurons fully responsive to BDNF and NT-4. Underlying mechanisms might be sought at the level or distal of trkB receptor expression, without excluding the possiblity that serum elicits production of growth factors that synergistically act with neurotrophins in these cultures.
KeywordsGlial Fibrillary Acidic Protein Tyrosine Hydroxylase Dopaminergic Neuron DAergic Neuron Midbrain Dopaminergic Neuron
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- Cohen G, Werner P (1994) Free radicals, oxidative stress, and neurodegeneration. In: Calne DB (ed) Neurodegenerative diseases. Saunders, pp 139–161Google Scholar
- Edwards RH (1993) Pathogenesis of Parkinson’s disease. Clin Neurosci 1: 36–44Google Scholar
- Hantzopoulos PA, Suri C, Glass DJ, Goldfarb MP, Yancopoulos GD (1994) The low affinity NGF receptor, p75, can collaborate with each of the trks to potentiate functional responses to the neurotrophins Neuron 13: 187–201Google Scholar
- Hyman C, Juhasz M, Jackson C, Wright P, Ip NY, Lindsay RM (1993) Overlapping and distinct actions of the neurotrophins, BDNF, NT-3 and NT-4/5, on cultured dopaminergic and GABAegic neurons of the ventral mesencephalon. J Neurosci 14: 335–347Google Scholar
- Middlemas DS, Lindberg RA, Hunter T (1991) TrkB, a neural receptor protein-tyrosine kinase: evidence for full-length and two truncated receptors. GenBank M55291Google Scholar
- Reichmann H, Riederer P (1994) Mitochondrial disturbances in neurodegeneration. In: Calne DB (ed) Neurodegenerative diseases. Saunders, Philadelphia, pp 195–204Google Scholar
- Schapira AHV (1995) Oxidative stress in Parkinson’s disease. Neuropathol ApplGoogle Scholar
- Neurobiol 21: 3–9Google Scholar