We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
258. CNS-Directed Antioxidant Enzyme Delivery: Protecting Neurons from Oxidative Stress and Apoptosis Induced by HIV-1.
- Authors
Agrawal, Lokesh; Louboutin, Jean-pierre; Strayer, David S.
- Abstract
Oxidant stress-induced neuron apoptosis is a feature of many diseases affecting the CNS, including stroke, Alzheimer's disease and others. HIV-1 Tat is a soluble protein that induces neuronal apoptosis and is felt to play a critical role in HIV-1 induced CNS disease. Tat causes disruption of calcium homeostasis, increased production of reactive oxygen species (ROS) with consequent oxidative stress and apoptosis.We tested whether the anti-oxidant enzymes superoxide-dismutase (SOD1) or glutathione peroxidase (GPx1) delivered by rSV40 vectors could be used to mitigate HIV-1 Tat-induced neurotoxicity. Both enzymes detoxify oxygen free radicals. NT-2 derived neurons and primary neurons were transduced either with rSV40s carrying each transgene individually or in combination, first with one vector then the other. Post-transduction, cells were challenged with HIV-1 Tat. Apoptosis was measured by TUNEL assay. Cytosolic calcium was measured by split-beam photometry after preloading cells with FURA-2AM.Transduction with SOD1- and GPX1-carrying vectors provided excellent transgene expression (>90%), as assessed by Western blotting, direct assays of enzyme activity and immunostaining. Tat- induced maximal apoptosis at a concentration of 100 ng/ml at 6 hours, and showed a linear dose-response relationship. Neuronal cells transduced singly with either of the vectors, SV(SOD1) or SV(GPx1), were not protected from Tat-induced apoptosis. Interestingly, when doubly transduced cells were challenged with Tat they were >90% protected from apoptosis.Exposing neurons to Tat increased cytosolic free calcium. The patterns of protection from Tat-induced apoptosis were seen in these studies as well: intracellular Ca2+ release stimulated by Tat was not affected by single transduction. However, cells doubly transduced with both anti-oxidant enzymes were protected from Tat-induced calcium overload. These findings suggest that Tat-induced calcium fluxes are signaled via two different pathways involving ROS.We have therefore shown that SV40 vectors carrying anti-oxidant transgenes can protect neuronal cells from HIV-1 Tat-induced apoptosis. Gene therapy using these vectors may thus be useful in mitigating ROS-related neurotoxicity as is seen in HIV-1 encephalopathy and other CNS diseases.Molecular Therapy (2006) 13, S99–S99; doi: 10.1016/j.ymthe.2006.08.285
- Subjects
CENTRAL nervous system diseases; NEURONS; APOPTOSIS; ALZHEIMER'S disease; HIV infections; HOMEOSTASIS; ENZYMES
- Publication
Molecular Therapy, 2006, Vol 13, pS99
- ISSN
1525-0016
- Publication type
Article
- DOI
10.1016/j.ymthe.2006.08.285