Damage to and loss of neurons and axons is correlated with disability in multiple sclerosis (MS), thus neuroprotective therapies are urgently needed. In previous studies we have found altered expression of mitochondrial genes and proteins involved in respiration resulting in dysfunctional mitochondrial activity in postmortem MS cortex. Recently, we have shown that hemoglobin is upregulated in MS cortex and have localized hemoglobin expression to neurons in the MS brain. We have also found hemoglobin expression in primary cultures of neurons isolated from rat brain. This is a surprising and novel finding and provides support for our hypothesis that hemoglobin expression may be involved in neuronal respiration. The goal of this study is to understand the function of hemoglobin expression in neurons and its significance to neuropathology in MS. In the proposed study we will investigate the extent and localization of hemoglobin expression in different regions of the MS brain by in situ hybridization, RT-PCR, western blotting, confocal imaging, and electron microscopy of postmortem MS and control tissue. We will investigate the mechanisms which regulate hemoglobin expression in primary neuronal cultures and will assess the role of hemoglobin in neuronal respiration and oxidative phosphorylation by performing high resolution respirometry on neuroblastoma cells expressing hemoglobin subunits from a mammalian expression vector, and on brain slices from mice treated with erythropoietin which increases hemoglobin expression in the brain. We will also investigate the possibility that hemoglobin serves a neuroprotective role in the brain as a scavenger of free radicals.

Public Health Relevance

Multiple sclerosis (MS) is a debilitating neurological disease which strikes patients in the prime of their life. We have previously shown that there is mitochondrial involvement in this disease. The proposed study is relevant to public health in that it will lead to a better understanding of mechanisms leading to altered mitochondrial activity in MS and will potentially identify new neuroprotective therapeutic targets.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21NS075645-02
Application #
8539856
Study Section
Neural Oxidative Metabolism and Death Study Section (NOMD)
Program Officer
Utz, Ursula
Project Start
2012-09-15
Project End
2014-08-31
Budget Start
2013-09-01
Budget End
2014-08-31
Support Year
2
Fiscal Year
2013
Total Cost
$177,560
Indirect Cost
$56,935
Name
Kent State University at Kent
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
041071101
City
Kent
State
OH
Country
United States
Zip Code
44242
Brown, Nolan; Alkhayer, Kholoud; Clements, Robert et al. (2016) Neuronal Hemoglobin Expression and Its Relevance to Multiple Sclerosis Neuropathology. J Mol Neurosci 59:1-17
Li, S; Clements, R; Sulak, M et al. (2013) Decreased NAA in gray matter is correlated with decreased availability of acetate in white matter in postmortem multiple sclerosis cortex. Neurochem Res 38:2385-96