There is growing evidence that estrogen (E2) and SERMs may have beneficial effects upon the CNS in neurodegenerative diseases. This application would study the potential mechanisms of E2/SERM neuroprotection in cerebral ischemia, and would follow up on exciting preliminary work by our lab which suggests that E2/SERMs enhance neurogenesis following cerebral ischemia. With regards to neuroprotection, our preliminary studies suggest that E2 and the SERM, tamoxifen (TMX) inhibit activation of putative prodeath factors (ROS, ERKs, INK, c-Jun), with an increase in activation of the prosurvival factor, Akt. To confirm these preliminary findings and clarify the underlying mechanisms, Aim 1 would determine the temporal pattern and cell type of ERK/JNK/Akt activation following cerebral ischemia in female animals (which is currently lacking), establish the onset and duration of E2/SERM regulatory effects upon these key kinases, and determine the role of estrogen receptors in the regulatory effects.
Aim 2 would determine whether reactive oxygen species (ROS) function as the major upstream activator of ERKs/JNK following cerebral ischemia, and establish whether E2 and TMX can suppress ROS production as a mechanism for suppression of ERK/JNK activation. Causation between ROS and ERK/JNK activation would be determined through the use of the antioxidant SOD mimetic compound, tempol (which scavenges/reduces ROS production).
Aim 3 would determine whether AP-1 transcription complex and proapoptotic BH-3 proteins act downstream of ERKs/JNK to induce apoptosis in the penumbra region, and establish whether E2 and TMX suppress AP-1 activation and induction of BH-3 proteins as a means of neuroprotection.
Aim 4 would characterize the temporal pattern of E2/SERM effects on neurogenesis, and characterize the migration, differentiation and long-term survival of newly generated cells into the injured regions of the brain following cerebral ischemia. Correlation to functional neurological outcomes will also be determined. As a whole, the proposed studies would significantly advance our understanding of the neuroprotective and neurogenic actions of E2 and SERMs in the injured brain.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS050730-05
Application #
7587527
Study Section
Integrative and Clinical Endocrinology and Reproduction Study Section (ICER)
Program Officer
Jacobs, Tom P
Project Start
2005-05-24
Project End
2010-04-30
Budget Start
2009-05-01
Budget End
2010-04-30
Support Year
5
Fiscal Year
2009
Total Cost
$313,552
Indirect Cost
Name
Georgia Regents University
Department
Neurology
Type
Schools of Medicine
DUNS #
966668691
City
Augusta
State
GA
Country
United States
Zip Code
30912
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