This grant proposal represents the third competitive renewal (Years 16-20) of a highly productive research program investigating fundamental cellular and molecular signaling pathways relevant to human neurodegenerative disorders. Over the last 15 years of funding from this grant, our studies have characterized in detail a signaling cascade connecting the oxidative liberation of intracellular zinc to a neuronal cell death-enabling increase in the plasma membrane insertion of Kv2.1 channels. This process mediates a loss of cytoplasmic potassium, a requisite step for optimal protease and nuclease catalytic activity during programmed and other forms of cell death. In the current funding period (Years 11-15), we have studied the phosphorylation events leading to the syntaxin-dependent exocytotic insertion of Kv2.1 into the neuronal plasma membrane following injury. We also investigated the role of Kv2.1 somatodendritic clusters as dominant membrane channel insertion hubs during apoptosis. Most importantly, we established a novel in vivo neuroprotective approach to stroke injury by developing a cell-permeant peptide that interferes with a critical Kv2.1 interaction with syntaxin. Our work strongly indicates that specifically targeting Kv2.1-facilitated cell death processes can provide mechanistically driven, novel therapeutic strategies for neuroprotection. In this application we propose to decisively move forward with this strategic objective by: (i) characterizing the properties of novel neuroprotective peptides and derived small molecule analogs targeting the syntaxin/Kv2.1 interaction; (ii) establishing prototypical neuroprotective tools aimed at dispersing Kv2.1 somatodendritic clusters, and (iii) devising an innovative neuroprotective strategy that transfers a normally silent gene to neurons, designed to express a Kv2.1-targeted modulatory protein when cells are lethally injured. We thus have adopted three unique and potentially transformative strategies, all based on the premise that cell death-inducing pathways require a set of common conditions to operate optimally. The loss of intracellular potassium via a surge of Kv2.1-mediated ionic currents may constitute a widespread, if not ubiquitous, requirement for programmed cell death in many types of neurons. As such, the experiments described here are aimed at translating the cellular and molecular pathways we have characterized with long-term funding from this grant, into rational therapeutic approaches to neurodegeneration.

Public Health Relevance

The research proposed in this application is aimed at establishing novel methods to protect neurons in acute neuronal injury and set the stage to translate this work towards chronic/progressive degenerative brain disorders. The work is based on the PI?s extensive work performed during the first 15 years of funding from this grant, and is aimed at limiting the loss of intracellular potassium from neurons following injury, a requisite event in cell death processes. The PI will focus his attention not only in continuing and expanding his current work in this area, but explore radical new approaches to neuroprotection.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS043277-18
Application #
9959512
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Bosetti, Francesca
Project Start
2002-09-30
Project End
2023-07-31
Budget Start
2020-08-01
Budget End
2021-07-31
Support Year
18
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Pittsburgh
Department
Biology
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15260
Justice, Jason A; Manjooran, Daniel T; Yeh, Chung-Yang et al. (2018) Molecular Neuroprotection Induced by Zinc-Dependent Expression of Hepatitis C-Derived Protein NS5A Targeting Kv2.1 Potassium Channels. J Pharmacol Exp Ther 367:348-355
Justice, Jason A; Schulien, Anthony J; He, Kai et al. (2017) Disruption of KV2.1 somato-dendritic clusters prevents the apoptogenic increase of potassium currents. Neuroscience 354:158-167
Yeh, Chung-Yang; Bulas, Ashlyn M; Moutal, Aubin et al. (2017) Targeting a Potassium Channel/Syntaxin Interaction Ameliorates Cell Death in Ischemic Stroke. J Neurosci 37:5648-5658
Schulien, Anthony J; Justice, Jason A; Di Maio, Roberto et al. (2016) Zn(2+) -induced Ca(2+) release via ryanodine receptors triggers calcineurin-dependent redistribution of cortical neuronal Kv2.1 K(+) channels. J Physiol 594:2647-59
Li, Dong; Yuan, Hongjie; Ortiz-Gonzalez, Xilma R et al. (2016) GRIN2D Recurrent De Novo Dominant Mutation Causes a Severe Epileptic Encephalopathy Treatable with NMDA Receptor Channel Blockers. Am J Hum Genet 99:802-816
Clemens, Katerina; Yeh, Chung-Yang; Aizenman, Elias (2015) Critical role of Casein kinase 2 in hepatitis C NS5A-mediated inhibition of Kv2.1 K(+) channel function. Neurosci Lett 609:48-52
Aizenman, Elias; Mastroberardino, Pier G (2015) Metals and neurodegeneration. Neurobiol Dis 81:1-3
He, Kai; McCord, Meghan C; Hartnett, Karen A et al. (2015) Regulation of Pro-Apoptotic Phosphorylation of Kv2.1 K+ Channels. PLoS One 10:e0129498
Hershfinkel, Michal; Ford, Dianne; Kelleher, Shannon et al. (2015) Seashells by the zinc shore: a meeting report of the International Society for Zinc Biology, Asilomar, CA 2014. Metallomics 7:1299-304
Gilad, David; Shorer, Sharon; Ketzef, Maya et al. (2015) Homeostatic regulation of KCC2 activity by the zinc receptor mZnR/GPR39 during seizures. Neurobiol Dis 81:4-13

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