The long-term goal of this revised research proposal is to determine the specific mechanisms by which progesterone mediates neuronal rescue and recovery of function in traumatic brain injury (TBI); the major cause of death in young adults under the age of 35. These findings will be employed in the evaluation of progesterone as a safe and effective treatment for TBI. Progesterone has recently been classified as a neurosteroid because it is also synthesized in astrocytes and oligodendrocytes in the brains of both males and female, where it may play other roles than that of a sex hormone. Previous research has already shown that systemic injection of progesterone in laboratory rats can reduce some of the neuropathological consequences of TBI and enhance behavioral recovery of function. Progesterone treatments reduce cerebral edema dramatically in both males and females when administered within 24 hours of the injury. This is one type of protective effect that can lead to reduced neuronal death and improved functional outcomes. The primary goal of the current proposal is to understand better the physiological mechanisms by which progesterone mediates its neuroprotective actions. We propose a series of 4 Aims using both in vitro and in vivo models of neural injury to determine: (1) if progesterone exerts its effects via its specific receptors. This will be studied by co-administering the hormone with ORG31710, a known progesterone receptor antagonist, or substituting progesterone with an agonist that cannot be metabolized (R5020) in both in vivo and in vitro models of TBI; (2) if, in an in vitro model of injury, progesterone's short-term neuroprotective effects are mediated specifically via sigma receptors; (3) if progesterone will prevent loss of mitochondrial function by reducing oxidative stress initiated in both in vivo and in vitro models of TBI; and (4) if progesterone will reduce the destructive aspects of the inflammatory immune reaction that occurs after TBI. The combination of in vivo and in vitro models will provide parallel evaluation of the mechanisms of progesterone's action. The research proposed here will help to determine whether progesterone can be used as a low-cost, safe and effective therapeutic agent in the acute stages of CNS injury. Furthermore, the detailed assessment of progesterone's mechanisms of action will provide a foundation for the intelligent design of artificial therapeutic pharmaceuticals.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS038664-03
Application #
6629312
Study Section
Special Emphasis Panel (ZRG1-BDCN-3 (01))
Project Start
2001-02-15
Project End
2005-01-31
Budget Start
2003-02-01
Budget End
2004-01-31
Support Year
3
Fiscal Year
2003
Total Cost
$245,583
Indirect Cost
Name
Emory University
Department
Emergency Medicine
Type
Schools of Medicine
DUNS #
066469933
City
Atlanta
State
GA
Country
United States
Zip Code
30322
Grossman, Kimberly J; Goss, Cynthia W; Stein, Donald G (2011) Sickness behaviors following medial frontal cortical contusions in male rats. Behav Brain Res 217:202-8
Cekic, Milos; Cutler, Sarah M; VanLandingham, Jacob W et al. (2011) Vitamin D deficiency reduces the benefits of progesterone treatment after brain injury in aged rats. Neurobiol Aging 32:864-74
Cekic, Milos; Sayeed, Iqbal; Stein, Donald G (2009) Combination treatment with progesterone and vitamin D hormone may be more effective than monotherapy for nervous system injury and disease. Front Neuroendocrinol 30:158-72
Sayeed, Iqbal; Wali, Bushra; Stein, Donald G (2007) Progesterone inhibits ischemic brain injury in a rat model of permanent middle cerebral artery occlusion. Restor Neurol Neurosci 25:151-9
Guo, Qingmin; Sayeed, Iqbal; Baronne, Lon M et al. (2006) Progesterone administration modulates AQP4 expression and edema after traumatic brain injury in male rats. Exp Neurol 198:469-78
Sayeed, Iqbal; Guo, Qingmin; Hoffman, Stuart W et al. (2006) Allopregnanolone, a progesterone metabolite, is more effective than progesterone in reducing cortical infarct volume after transient middle cerebral artery occlusion. Ann Emerg Med 47:381-9
Djebaili, Myriam; Guo, Qingmin; Pettus, Edward H et al. (2005) The neurosteroids progesterone and allopregnanolone reduce cell death, gliosis, and functional deficits after traumatic brain injury in rats. J Neurotrauma 22:106-18
Pettus, Edward H; Wright, David W; Stein, Donald G et al. (2005) Progesterone treatment inhibits the inflammatory agents that accompany traumatic brain injury. Brain Res 1049:112-9
Stein, Donald G (2005) The case for progesterone. Ann N Y Acad Sci 1052:152-69
He, Jun; Hoffman, Stuart W; Stein, Donald G (2004) Allopregnanolone, a progesterone metabolite, enhances behavioral recovery and decreases neuronal loss after traumatic brain injury. Restor Neurol Neurosci 22:19-31

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