title: Additive effect of glial cell line-derived neurotrophic factor and neurotrophin-4/5 on rat fetal nigral explant cultures.
abstract: Transplantation of embryonic dopaminergic neurons is an experimental therapy for Parkinson's disease, but limited tissue availability and suboptimal survival of grafted dopaminergic neurons impede more widespread clinical application. Glial cell line-derived neurotrophic factor (GDNF) and neurotrophin-4/5 (NT-4/5) exert neurotrophic effects on dopaminergic neurons via different receptor systems. In this study, we investigated possible additive or synergistic effects of combined GDNF and NT-4/5 treatment on rat embryonic (embryonic day 14) nigral explant cultures grown for 8 days. Contrary to cultures treated with GDNF alone, cultures exposed to NT-4/5 and GDNF+NT-4/5 were significantly larger than controls (1.6- and 2.0-fold, respectively) and contained significantly more protein (1.6-fold). Treatment with GDNF, NT-4/5 and GDNF+NT-4/5 significantly increased dopamine levels in the culture medium by 1.5-, 2.5- and 4.7-fold, respectively, compared to control levels, and the numbers of surviving tyrosine hydroxylase-immunoreactive neurons increased by 1.7-, 2.1-, and 3.4-fold, respectively. Tyrosine hydroxylase enzyme activity was moderately increased in all treatment groups compared to controls. Counts of nigral neurons containing the calcium-binding protein, calbindin-D28k, revealed a marked increase in these cells by combined GDNF and NT-4/5 treatment. Western blots for neuron-specific enolase suggested an enhanced neuronal content in cultures after combination treatment, whereas the expression of glial markers was unaffected. The release of lactate dehydrogenase into the culture medium was significantly reduced for GDNF+NT-4/5-treated cultures only. These results indicate that combined treatment with GDNF and NT4/5 may be beneficial for embryonic nigral donor tissue either prior to, or in conjunction with, intrastriatal transplantation in Parkinson's disease.
authors.affiliation: Department of Neurosurgery, University of Bern, Inselspital, Bern, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Meyer
authors.forename: E R
authors.initials: ER
authors.lastname: Matarredona
authors.forename: R W
authors.initials: RW
authors.lastname: Seiler
authors.forename: J
authors.initials: J
authors.lastname: Zimmer
authors.forename: H R
authors.initials: HR
authors.lastname: Widmer
mesh_terms: D000818:Animals; D016380:Brain Tissue Transplantation / Q000379:methods*; D064092:Calbindin 1; D064026:Calbindins; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004298:Dopamine / Q000378:metabolism; D004347:Drug Interactions / Q000502:physiology; D005260:Female; D005333:Fetus; D051100:Glial Cell Line-Derived Neurotrophic Factor; D006085:Graft Survival / Q000187:drug effects / Q000502:physiology*; D007150:Immunohistochemistry; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D017072:Neostriatum / Q000601:surgery*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000494:pharmacology*; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000637:transplantation; D010300:Parkinson Disease / Q000601:surgery*; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects; D013378:Substantia Nigra / Q000166:cytology / Q000187:drug effects* / Q000637:transplantation; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: C576500:Calb1 protein, rat; D064092:Calbindin 1; D064026:Calbindins; C495041:Gdnf protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D064030:S100 Calcium Binding Protein G; D007770:L-Lactate Dehydrogenase; D014446:Tyrosine 3-Monooxygenase; D010751:Phosphopyruvate Hydratase; C073922:neurotrophin 4; D004298:Dopamine