Traumatic brain injury (TBI) is a devastating neurological injury afflicting over 1 million people annually, including a large number of young adults and military personnel. Cerebral edema is associated with increased intracranial pressure (ICP) and a poor clinical outcome following TBI, although the cellular mechanisms underlying this process remain unknown. This gap in the understanding of cerebral edema formation contributes to the lack of clinically- effective therapeutics for TBI patients. Recent work by our laboratory demonstrates that acute neuronal necrosis stimulates the passive release of high mobility group box protein 1 (HMGB1), which in turn induces glial swelling and cerebral edema.
Specific Aim 1 will establish whether activation of individual NMDA receptor subunits increase neuronal injury and cerebral edema following experimental TBI. The incorporation of NR2A and NR2B knockout mice will determine whether individual NR2 subunits contribute to HMGB1 release, brain swelling, and neurological outcome using following head trauma.
Specific Aim 2 will determine whether toll-like receptor-4 (TLR4) mediates the pro- inflammatory and cerebral edema promoting effects of HMGB1. The ability of HMGB1 to stimulate the astrocytic water channel, AQP4, will also be addressed in TLR4 mutant mice.
Specific Aim 3 will determine whether HMGB1 may represent a novel biomarker to predict the development of cerebral edema folowing head trauma in humans. Measurement of HMGB1 levels within the cerebrospinal fluid (CSF) and serum of neurotrauma patients will be correlated with acute neuronal injury and neurological outcome. Together, the proposed studies will investigate the novel possibility that HMGB1-TLR4 signaling contributes to the development of cerebral edema and increased ICP following TBI. The results of these studies may support the future development of novel therapeutics directed against this pathway to limit neurological injury following head trauma.

Public Health Relevance

Traumatic brain injury (TBI) is a serious medical condition that hospitalizes and disables many Americans, placing a large economic burden on society. Current medical therapies do not effectively control brain swelling, in part, due to a lack of mechanistic understanding regarding the development of cerebral edema following TBI. An improved understanding of these mechanisms at the cellular levels may aid in the discovery of novel therapeutics, which could substantially reduce patient mortality and improve patient outcome. The present application will assess the potential role of neuronal necrosis, secondary to glutamate excitotoxicity, as a causative factor in the development of cellular edema following TBI.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS065172-04
Application #
8316213
Study Section
Clinical Neuroimmunology and Brain Tumors Study Section (CNBT)
Program Officer
Hicks, Ramona R
Project Start
2009-09-01
Project End
2014-08-31
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
4
Fiscal Year
2012
Total Cost
$315,131
Indirect Cost
$100,756
Name
Georgia Regents University
Department
Neurosurgery
Type
Schools of Medicine
DUNS #
966668691
City
Augusta
State
GA
Country
United States
Zip Code
30912
Vaibhav, Kumar; Braun, Molly; Khan, Mohammad Badruzzaman et al. (2018) Remote ischemic post-conditioning promotes hematoma resolution via AMPK-dependent immune regulation. J Exp Med 215:2636-2654
Braun, Molly; Khan, Zenab T; Khan, Mohammad B et al. (2018) Selective activation of cannabinoid receptor-2 reduces neuroinflammation after traumatic brain injury via alternative macrophage polarization. Brain Behav Immun 68:224-237
Braun, Molly; Vaibhav, Kumar; Saad, Nancy et al. (2017) Activation of Myeloid TLR4 Mediates T Lymphocyte Polarization after Traumatic Brain Injury. J Immunol 198:3615-3626
Braun, Molly; Vaibhav, Kumar; Saad, Nancy M et al. (2017) White matter damage after traumatic brain injury: A role for damage associated molecular patterns. Biochim Biophys Acta Mol Basis Dis 1863:2614-2626
Sukumari-Ramesh, Sangeetha; Alleyne Jr, Cargill H; Dhandapani, Krishnan M (2016) The Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid (SAHA) Confers Acute Neuroprotection After Intracerebral Hemorrhage in Mice. Transl Stroke Res 7:141-8
Khan, Mohammad Badruzzaman; Hoda, Md Nasrul; Vaibhav, Kumar et al. (2015) Remote ischemic postconditioning: harnessing endogenous protection in a murine model of vascular cognitive impairment. Transl Stroke Res 6:69-77
Sukumari-Ramesh, Sangeetha; Prasad, Niyathi; Alleyne, Cargill H et al. (2015) Overexpression of Nrf2 attenuates Carmustine-induced cytotoxicity in U87MG human glioma cells. BMC Cancer 15:118
King, Melanie D; Whitaker-Lea, Wittstatt A; Campbell, James M et al. (2014) Necrostatin-1 reduces neurovascular injury after intracerebral hemorrhage. Int J Cell Biol 2014:495817
Laird, Melissa D; Shields, Jessica S; Sukumari-Ramesh, Sangeetha et al. (2014) High mobility group box protein-1 promotes cerebral edema after traumatic brain injury via activation of toll-like receptor 4. Glia 62:26-38
Eroglu, Binnur; Kimbler, Donald E; Pang, Junfeng et al. (2014) Therapeutic inducers of the HSP70/HSP110 protect mice against traumatic brain injury. J Neurochem 130:626-41

Showing the most recent 10 out of 22 publications