FGF-2-mediated protection of cultured mesencephalic dopaminergic neurons against MPTP and MPP+: specificity and impact of culture conditions, non-dopaminergic neurons, and astroglial cells.
The protective role of basic fibroblast growth factor (FGF-2) for 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)- and methylpyridiniumion (MPP+)-lesioned dopaminergic (DAergic) nigrostriatal neurons was studied, using dissociated cell cultures of embryonic day (E) 14 rat mesencephalon. Cells were grown in different culture media and received FGF-2 (5 ng/ml) and/or the toxins (5 microM) at various schedules, but were consistently allowed to differentiate for 3 days prior to becoming exposed to the toxin. Survival of tyrosine hydroxylase (TH)-immunoreactive cells at 7 days was only markedly impaired by MPTP, if horse serum (HS) or bovine serum albumin (BSA) were omitted from the culture medium. FGF-2 increased the number of TH-immunoreactive cells, and this increase was not diminished by MPTP under any culture condition. Uptake of 3H-DA was significantly reduced by MPTP in HS- and BSA-containing, but not in protein-less cultures. A protective effect by FGF-2 was only seen in the presence of BSA. MPP+ caused a more pronounced reduction in 3H-DA uptake than MPTP, and this effect was partially reversed by the addition of FGF-2, unless cultures contained HS. Neurofilament protein (NF), and indirect measure for the total number of neurons present in the cultures, was not significantly reduced by MPTP or MPP+ corroborating the specificity of the toxin for DAergic neurons, which constitute only a minor fraction in these cultures. In line with the wide spectrum of target neurons of FGF-2, this factor significantly increased NF contents under any culture condition. Quantification of the amounts of glial fibrillary acidic protein (GFAP) revealed stimulatory effects of FGF-2 (2.5- to 4-fold) and at least 10-fold higher levels in the presence as compared to the absence of HS. These data show that FGF-2 can protect DAergic neurons against MPTP- and MPP(+)-mediated damage. However, the effects of the toxins as well as of FGF-2 are partially dependent on culture conditions. Variations in the effectiveness of toxins and FGF-2 are not overtly related to the total numbers of neurons or astroglial cells, but may reflect culture type-dependent alterations of neuronal and glial metabolism.
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Department of Anatomy and Cell Biology, University of Heidelberg, Germany.
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D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004298:Dopamine / Q000378:metabolism / Q000502:physiology*; D015259:Dopamine Agents / Q000037:antagonists & inhibitors* / Q000633:toxicity; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis; D007150:Immunohistochemistry; D020267:MPTP Poisoning; D008636:Mesencephalon / Q000187:drug effects* / Q000378:metabolism; D016501:Neurites / Q000187:drug effects / Q000378:metabolism; D016900:Neurofilament Proteins / Q000096:biosynthesis; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D011247:Pregnancy; D011726:Pyridinium Compounds / Q000037:antagonists & inhibitors* / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D014446:Tyrosine 3-Monooxygenase / Q000276:immunology / Q000378:metabolism
D015259:Dopamine Agents; D005904:Glial Fibrillary Acidic Protein; D016900:Neurofilament Proteins; D011726:Pyridinium Compounds; C048977:1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine; D016222:Fibroblast Growth Factor 2; C026560:1-(4-methoxyphenyl)pyridinium; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine