Dysregulation of Glutamine Synthetase in Human Temporal Lobe Epilepsy: The main objective of this K08 proposal is to facilitate the applicant's development towards independence as a physician-scientist investigator in basic science/translational research. This will be achieved through a series of complementary educational and mentored research training experiences in which the applicant will learn state-of-the-art methodologies in molecular biology, proteomics, cell culture and flow cytometry. The scientific question addressed by these methodologies is: what is the mechanism underlying the down-regulation of glutamine synthetase in the hippocampus of patients with mesial temporal lobe epilepsy? This question is important because experimental inhibition of glutamine synthetase in the hippocampus of animals causes epileptic seizures followed by cessation of the seizures once the enzyme has been restored.
The specific aims of this proposal are: 1) Analysis of transcriptional regulation of glutamine synthetase using laser capture microdissection, quantitative real time PCR, and in situ hybridization on surgically resected human epilepsy hippocampi. 2) Analysis of posttranslational modification of glutamine synthetase by 2D gel electrophoresis, immunological techniques, and mass spectrometry. 3) Establish an in vitro system for experimental studies of glutamine synthetase regulation, using acute and chronic cultures of astrocytes from human epileptogenic hippocampi combined with flow cytometric analysis of the cultured cells. Layman's Abstract: People with temporal lobe epilepsy have low levels of brain glutamine synthetase, an enzyme that transforms glutamate to the non toxic chemical glutamine. The goal is to understand why the enzyme is down-regulated, so that new antiepileptic treatments targeting glutamine synthetase can be developed.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08NS058674-04
Application #
8018055
Study Section
NST-2 Subcommittee (NST)
Program Officer
Whittemore, Vicky R
Project Start
2008-02-01
Project End
2013-01-31
Budget Start
2011-02-01
Budget End
2012-01-31
Support Year
4
Fiscal Year
2011
Total Cost
$173,340
Indirect Cost
Name
Yale University
Department
Neurosurgery
Type
Schools of Medicine
DUNS #
043207562
City
New Haven
State
CT
Country
United States
Zip Code
06520
Albright, Benjamin; Dhaher, Roni; Wang, Helen et al. (2017) Progressive neuronal activation accompanies epileptogenesis caused by hippocampal glutamine synthetase inhibition. Exp Neurol 288:122-133
Wang, Helen; Huang, Yuegao; Coman, Daniel et al. (2017) Network evolution in mesial temporal lobe epilepsy revealed by diffusion tensor imaging. Epilepsia 58:824-834
Lauritzen, Fredrik; Eid, Tore; Bergersen, Linda H (2015) Monocarboxylate transporters in temporal lobe epilepsy: roles of lactate and ketogenic diet. Brain Struct Funct 220:1-12
Dhaher, Roni; Wang, Helen; Gruenbaum, Shaun E et al. (2015) Effects of site-specific infusions of methionine sulfoximine on the temporal progression of seizures in a rat model of mesial temporal lobe epilepsy. Epilepsy Res 115:45-54
Dhaher, Roni; Damisah, Eyiyemisi C; Wang, Helen et al. (2014) 5-aminovaleric acid suppresses the development of severe seizures in the methionine sulfoximine model of mesial temporal lobe epilepsy. Neurobiol Dis 67:18-23
Eid, Tore; Tu, Nathan; Lee, Tih-Shih W et al. (2013) Regulation of astrocyte glutamine synthetase in epilepsy. Neurochem Int 63:670-81
Eid, Tore; Lee, Tih-Shih W; Wang, Yue et al. (2013) Gene expression of glutamate metabolizing enzymes in the hippocampal formation in human temporal lobe epilepsy. Epilepsia 54:228-38
Perez, Edgar L; Lauritzen, Fredrik; Wang, Yue et al. (2012) Evidence for astrocytes as a potential source of the glutamate excess in temporal lobe epilepsy. Neurobiol Dis 47:331-7
Coulter, Douglas A; Eid, Tore (2012) Astrocytic regulation of glutamate homeostasis in epilepsy. Glia 60:1215-26
Lauritzen, Fredrik; Perez, Edgar L; Melillo, Eric R et al. (2012) Altered expression of brain monocarboxylate transporter 1 in models of temporal lobe epilepsy. Neurobiol Dis 45:165-76

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