This Competitive Revision Application is in response to Notice Number (NOT-OD-09-058) and Notice Title "NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications". In our parent grant, we study the Wingless (Wnt1) gene with the forkhead transcription factor FoxO3a in neurons and inflammatory microglial cells during cell injury. Our Competitive Revision Application expands these studies with new research objectives and aims that are outside the scope of the approved and funded parent grant that will investigate the ability of the growth factor and cytokine erythropoietin (EPO) to employ previously unrecognized novel Wnt1 gene downstream pathways that are crucial for neuronal survival and longevity. We will employ both in vitro and in vivo models directly relevant to neurodegenerative disease. In Specific Aim I, we will examine the hypothesis that EPO through Wnt1 can protect primary hippocampal neuronal cells and neuronal cell lines from oxidative stress. Since individuals with neurodegenerative disorders may have alternate cellular sources of oxidative injury, investigation of EPO must address different experimental models of oxidative stress with nitric oxide (NO) exposure and combined oxygen-glucose deprivation (OGD). In these studies, we also will examine EPO and Wnt1 signaling in astrocytes, since astrocytes may be protective for neurons. In Specific Aim II, we will investigate the hypothesis that EPO protection requires Wnt1 and modulation of phosphoinositide 3 kinase (PI 3-K) pathways that involve the novel regulation of mammalian target of rapamycin (mTOR), protein kinase B (Akt1), 2-catenin, the sirtuin cell longevity gene SIRT1, and caspase activity during oxidative stress. In Specific Aim III, we will translate our in vitro cell culture studies to clinically relevant in vivo animal studies to investigate the hypothesis that EPO uses Wnt1 and the downstream pathways of mTOR, Akt1, 2-catenin, SIRT1, and caspase activity to foster cytoprotection in animal models of oxidative stress with middle cerebral artery occlusion (MCAO)/reperfusion. Our proposed Competitive Revision Award will allow us to accelerate the tempo of our new scientific research and promote economic development in the US. A total of FOUR (4) new positions will be generated for job creation and retention as well as investment in needed equipment. Our new preliminary results provide exciting evidence that EPO, in conjunction with Wnt1, mTOR, Akt1, 2- catenin, SIRT1, and modulation of caspase activity, are critical for neuronal survival. Our novel and high impact studies with EPO and Wnt1 downstream pathways form the basis for exceedingly novel treatment strategies for neurodegenerative disorders such as stroke and Alzheimer's disease consistent with the mission of the National Institute of Neurological Disorders and Stroke. PHS 398/2590 (Rev. 11/07) Page Continuation Format Page PUBLIC HEALTH RELEVANCE: Our Competitive Revision Application expands the studies in our parent grant with new research objectives and aims that are outside the scope of the approved and funded parent grant that will investigate the ability of the growth factor and cytokine erythropoietin (EPO) to employ previously unrecognized novel Wnt1 gene downstream pathways that are crucial for brain cell survival and longevity during nervous system disorders. Our novel and high impact studies with EPO, Wnt1 the mammalian target of rapamycin (mTOR), protein kinase B (Akt1), 2-catenin, the sirtuin cell longevity gene SIRT1, and caspase activity form the basis for exceedingly novel treatment strategies for nervous system disorders such as stroke and Alzheimer's disease consistent with the mission of the National Institute of Neurological Disorders and Stroke and will allow us to accelerate and expand our research efforts, allow for job creation and retention, allow for the procurement of additional needed equipment, and promote economic development in the US. PHS 398/2590 (Rev. 11/07) Page Continuation Format Page