Astrocyte-secreted GDNF and glutathione antioxidant system protect neurons against 6OHDA cytotoxicity.
In recent years, GDNF has emerged as a protective and restorative agent in several models of neurodegeneration; however, the exact molecular mechanisms responsible for these effects are not yet fully understood. Here we examined the effects of astrocytes secreting GDNF on neurons subjected to 6OHDA toxicity using in vitro neuron-astroglia co-cultures. Astrocytes were transduced with lentiviral vectors carrying the GDNF gene under the control of either human glial fibrillary acidic protein or cytomegalovirus promoters. The overexpression of GDNF, regardless of the promoter employed, had no obvious adverse effects on astroglia and the engineered cells stably produced and secreted GDNF for extended periods of time (> or =3 weeks). These astrocytes very effectively protected neurons against 6OHDA, in both mouse and human co-culture systems. The neuroprotective effects were mediated not only by GDNF, but also by the antioxidant GSH since its depletion reduced the level of GDNF protection. Furthermore, neurons and astrocytes expressed different components of GDNF signaling complex, suggesting that they might utilize separate pathways to mediate autocrine and paracrine effects of GDNF.
Sandhu
Jagdeep K
JK
Neurogenesis and Brain Repair Group, M54, Institute for Biological Sciences, National Research Council Canada, 1200 Montreal Road, Ottawa, Ontario, Canada K1A 0R6. jagdeep.sandhu@nrc.ca
Gardaneh
Mossa
M
Iwasiow
Rafal
R
Lanthier
Patricia
P
Gangaraju
Sandhya
S
Ribecco-Lutkiewicz
Maria
M
Tremblay
Roger
R
Kiuchi
Kazutoshi
K
Sikorska
Marianna
M
D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001253:Astrocytes / Q000378:metabolism*; D015153:Blotting, Western; D019328:Buthionine Sulfoximine / Q000008:administration & dosage; D002470:Cell Survival / Q000502:physiology; D018920:Coculture Techniques; D015870:Gene Expression; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism*; D005978:Glutathione / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D016627:Oxidopamine / Q000633:toxicity*; D016133:Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D014162:Transfection
D000975:Antioxidants; D051100:Glial Cell Line-Derived Neurotrophic Factor; D019328:Buthionine Sulfoximine; D016627:Oxidopamine; D005978:Glutathione