title: Optimized quantities of GDNF overexpressed by engineered astrocytes are critical for protection of neuroblastoma cells against 6-OHDA toxicity.
abstract: Optimized levels of glial cell line-derived neurotrophic factor (GDNF) are critical for protection of dopaminergic neurons against parkinsonian cell death. Recombinant lentiviruses harboring GDNF coding sequence were constructed and used to infect astrocytoma cell line 1321N1. The infected astrocytes overexpressed GDNF mRNA and secreted an average of 2.2 ng/mL recombinant protein as tested in both 2 and 16 weeks post-infection. Serial dilutions of GDNF-enriched conditioned medium from infected astrocytes added to growing neuroblastoma cell line SK-N-MC resulted in commensurate resistance against 6-OHDA toxicity. SK-N-MC cell survival rate rose from 51% in control group to 84% in the cells grown with astro-CM containing 453 pg secreted GDNF, an increase that was highly significant (P < 0.0001). However, larger volumes of the GDNF-enriched conditioned medium failed to improve cell survival and addition of volumes that contained 1,600 pg or more GDNF further reduced survival rate to below 70%. Changes in cell survival paralleled to changes in the percent of apoptotic cell morphologies. These data demonstrate the feasibility of using astrocytes as minipumps to stably oversecrete neurotrophic factors and further indicate that GDNF can be applied to neuroprotection studies in PD pending the optimization of its concentrations.
authors.affiliation: Molecular Genetics Group, National Institute of Genetic Engineering and Biotechnology (NIGEB), Pajoohesh Blvd, Tehran-Karaj HWY, Kilometer 15, PO Box 14965/161, Tehran, Iran.
authors.forename: Roya
authors.initials: R
authors.lastname: Safi
authors.forename: Mossa
authors.initials: M
authors.lastname: Gardaneh
authors.forename: Yasin
authors.initials: Y
authors.lastname: Panahi
authors.forename: Nader
authors.initials: N
authors.lastname: Maghsoudi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Zaefizadeh
authors.forename: Ehsan
authors.initials: E
authors.lastname: Gharib
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001253:Astrocytes / Q000473:pathology*; D001254:Astrocytoma / Q000235:genetics / Q000473:pathology; D016923:Cell Death / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D019610:Cytoprotection / Q000235:genetics; D005240:Feasibility Studies; D005818:Genetic Engineering / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000235:genetics*; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D009447:Neuroblastoma / Q000235:genetics / Q000473:pathology*; D016627:Oxidopamine / Q000633:toxicity*; D010300:Parkinson Disease / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D013565:Sympatholytics / Q000633:toxicity
chemical_list: D051100:Glial Cell Line-Derived Neurotrophic Factor; D013565:Sympatholytics; D016627:Oxidopamine