Cerebrovascular disease, most notably brain ischemia, is a leading cause of death and long-term disability in the US. The current and only treatment is prompt restoration of blood flow to the ischemic tissue. However, a substantial portion of the damage caused by ischemia/reperfusion occurs during the reperfusion phase: as ischemic tissue is reoxygenated reactive oxygen species (ROS) are quickly generated, starting early during reflow. Reperfusion injury has proved difficult to treat pharmacologically, likely because effective drug concentrations have not built up sufficiently during the early phase of reperfusion. The mitochondrial electron transport chain (ETC) is a major site of ROS production during cellular stress due to ETC hyper-activation, which causes high mitochondrial membrane potentials (??m), which in turn trigger excessive ROS production. We thus propose that the ideal therapy should target the ETC non-invasively to prevent the generation of ROS from the onset of reflow. Accordingly, our overall goal in this application is to develop a new, non-invasive therapy to normalize mitochondrial hyperactivity during reflow. We will capitalize on the photoreceptive properties of cytochrome c oxidase (COX) for infrared light (IRL) to modulate mitochondrial activity, thereby attenuating the production of ROS and, as a result, limit ischemia/reperfusion injury in the brain. Cytochrome c oxidase is the primary cellular photo-acceptor of IRL and the terminal enzyme of the ETC. We have discovered four specific IRL wavelengths that partially inhibit COX (instead of activating COX, i.e., the current paradigm). We show that inhibitory IRL, applied at the time of reperfusion, provides profound neuroprotection. In this proposal, we will build on these compelling preliminary data and capitalize on the unique, multi-disciplinary expertise of our research team to: Identify the combinations and energies of our four IRL wavelengths that yield optimal inhibition of COX and mitochondria in vitro using isolated rat brain COX and mitochondria (Aim 1). Investigate the mechanism of IRL-mediated protection in support of our central hypothesis of IRL action during reperfusion: IRL ? COX activity? ? ??m? ? ROS? ? viability?, using real-time imaging of mitochondrial funtion in rat primary neural cells exposed to simulated ischemia-reperfusion (Aim 2). Develop IRL-mediated protection and identify the optimal temporal treatment paradigm using a rat model for global brain ischemia to maximize post-ischemic neuroprotection (Aim 3).

Public Health Relevance

Interruption of blood flow to the brain during cardiac arrest can result in extensive brain damage. However, restoration of blood flow to oxygen-starved tissue by successful resuscitation also produces free radicals that induce additional brain damage. We will investigate the ability of infrared light, which non-invasively penetrates tissues, to prevent the formation of these free radicals through inhibition of a key metabolic enzyme in the process responsible for generating most of the free radicals under conditions of stress.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS091242-03
Application #
9294174
Study Section
Brain Injury and Neurovascular Pathologies Study Section (BINP)
Program Officer
Koenig, James I
Project Start
2015-09-30
Project End
2017-08-31
Budget Start
2017-07-01
Budget End
2017-08-31
Support Year
3
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Wayne State University
Department
Genetics
Type
Schools of Medicine
DUNS #
001962224
City
Detroit
State
MI
Country
United States
Zip Code
48202
Sanderson, Thomas H; Wider, Joseph M; Lee, Icksoo et al. (2018) Inhibitory modulation of cytochrome c oxidase activity with specific near-infrared light wavelengths attenuates brain ischemia/reperfusion injury. Sci Rep 8:3481
Kalpage, Hasini A; Bazylianska, Viktoriia; Recanati, Maurice A et al. (2018) Tissue-specific regulation of cytochrome c by post-translational modifications: respiration, the mitochondrial membrane potential, ROS, and apoptosis. FASEB J :fj201801417R
Sinkler, Christopher A; Kalpage, Hasini; Shay, Joseph et al. (2017) Tissue- and Condition-Specific Isoforms of Mammalian Cytochrome c Oxidase Subunits: From Function to Human Disease. Oxid Med Cell Longev 2017:1534056
Mahapatra, Gargi; Varughese, Ashwathy; Ji, Qinqin et al. (2017) Phosphorylation of Cytochrome c Threonine 28 Regulates Electron Transport Chain Activity in Kidney: IMPLICATIONS FOR AMP KINASE. J Biol Chem 292:64-79
Kumar, Rita; Bukowski, Melissa J; Wider, Joseph M et al. (2016) Mitochondrial dynamics following global cerebral ischemia. Mol Cell Neurosci 76:68-75