Effects of GDNF on 6-OHDA-induced death in a dopaminergic cell line: modulation by inhibitors of PI3 kinase and MEK.
Parkinson's disease is a neurodegenerative disorder associated with the selective death of dopaminergic neurons. Glial cell line-derived neurotrophic factor (GDNF) can protect dopaminergic neurons in several parkinsonian models. We used the dopaminergic cell line MN9D to explore the mechanisms underlying GDNF-mediated protection against the neurotoxin 6-hydroxydopamine (6-OHDA). MN9D cell viability was decreased 24 hr after a 15-min exposure to 6-OHDA (50-1000 microM) as revealed by staining with Hoechst reagent and Trypan blue. The addition of GDNF (10 ng/ml) before, during, and after exposure to 6-OHDA significantly increased the number of viable cells as assessed by Hoechst staining. In contrast, 6-OHDA-induced cell membrane damage was unaffected as measured by Trypan blue exclusion. The PI3K specific inhibitor LY294002 (10-50 microM) blocked GDNF-mediated protection against nuclear condensation, as did the MAPK kinase (MEK) inhibitor U0126 (5- 20 microM). These studies suggest that GDNF can protect dopaminergic cells against some but not all aspects of 6-OHDA-induced toxicity by acting through both PI3K and MAPK signaling pathways.
Ugarte
Susana D
SD
Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Lin
Eva
E
Klann
Eric
E
Zigmond
Michael J
MJ
Perez
Ruth G
RG
D000818:Animals; D002070:Butadienes / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051100:Glial Cell Line-Derived Neurotrophic Factor; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009570:Nitriles / Q000494:pharmacology; D018384:Oxidative Stress / Q000502:physiology; D016627:Oxidopamine; D010300:Parkinson Disease / Q000378:metabolism / Q000473:pathology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013565:Sympatholytics
D002070:Butadienes; D002867:Chromones; D004298:Dopamine; D004791:Enzyme Inhibitors; D051100:Glial Cell Line-Derived Neurotrophic Factor; D020928:Mitogen-Activated Protein Kinases; D009025:Morpholines; D009414:Nerve Growth Factors; D018696:Neuroprotective Agents; D009570:Nitriles; D016627:Oxidopamine; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D013565:Sympatholytics; C113580:U 0126; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one