No effective treatment strategies have yet been developed to prevent or reduce neonatal hypoxic/ischemic (HI) brain damage. Granulocyte-colony stimulating factor (G-CSF), a member of growth factor family, mainly stimulates the proliferation and differentiation of neutrophilic progenitor cells in the hematopoietic system. It has been widely used in clinical practice for the treatment of neutropenia associated with cytotoxic therapy. Recent studies have shown that systemic administration of G-CSF in adult animal models has mediated noteworthy neuroprotective effects in traumatic brain injury, focal transient cerebral ischemia, and intracerebral hemorrhage but its mechanism(s) are not fully elucidated. Whether G-CSF has neuroprotective effects following neonatal hypoxia-ischemia is not known. As a medical scientist and new investigator to the NIH, I have focused on this important question because of its health relevance, nationally and locally. Loma Linda University Medical Center has the largest Neonatal Intensive Care Unit (NICU) in the Western United States. I have bridged basic and clinical science disciplines to assemble an outstanding research team for this project. Our preliminary studies reveal a significant reduction in brain atrophy following systemic administration of G- CSF to an established rat model of neonatal HI and offer insight into mechanism of action. They support our central hypothesis that systemic G-CSF treatment protects the brain against HI-induced apoptosis. To test our main hypothesis, this project is designated to elucidate the impact of G-CSF-mediated neuroprotection on neurobehavioral outcomes, and thereby define its therapeutic potential. Equally important, this project is designed to determine the suppression of cell death mechanisms especially the mitochondrial apoptotic pathways that mediates the protective effects of G-CSF. The neuroprotective effects of G-CSF on neuronal death and brain atrophy will be related to neurobehavioral outcomes (Specific Aim 1). Brain damage will be measured by brain tissue loss, edema formation, blood-brain barrier disruption, brain infarction, and cellular morphological changes. To strengthen the clinical relevance of this project, the long-term effect and mechanisms of G-CSF treatment on sensorimotor functions, memory and learning abilities will be evaluated by a battery of neurological tests. Then G-CSF's underlying mechanism will be investigated in greater depth by measuring its effect on HI-induced activation of signaling pathways especially mitochondrial apoptotic pathways (Specific Aim 2). The apoptotic changes will be studied using biochemical and molecular approaches. Achieving our project goal through these specific aims will lay the foundation for clinical evaluation of systemic G-CSF in NICU neonates for prevention and treatment of brain damage from HI.

Public Health Relevance

No effective treatment strategies have yet been developed to prevent or reduce neonatal hypoxic/ischemic brain damage. Our project goal is to relate G-CSF's protection of neonates from hypoxia/ischemia-induced brain damage to both neurological function and underlying mechanism. Achieving our goal will lay the foundation for clinical evaluation of systemic administration of G-CSF in human neonates for prevention and treatment of brain damage from hypoxia/ischemia.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS060936-03
Application #
8112459
Study Section
Brain Injury and Neurovascular Pathologies Study Section (BINP)
Program Officer
Bosetti, Francesca
Project Start
2009-08-05
Project End
2013-07-31
Budget Start
2011-08-01
Budget End
2012-07-31
Support Year
3
Fiscal Year
2011
Total Cost
$318,347
Indirect Cost
Name
Loma Linda University
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
009656273
City
Loma Linda
State
CA
Country
United States
Zip Code
92350
Souvenir, Rhonda; Doycheva, Desislava; Zhang, John H et al. (2015) Erythropoietin in stroke therapy: friend or foe. Curr Med Chem 22:1205-13
Li, Li; Klebe, Damon; Doycheva, Desislava et al. (2015) G-CSF ameliorates neuronal apoptosis through GSK-3? inhibition in neonatal hypoxia-ischemia in rats. Exp Neurol 263:141-9
Li, Li; McBride, Devin W; Doycheva, Desislava et al. (2015) G-CSF attenuates neuroinflammation and stabilizes the blood-brain barrier via the PI3K/Akt/GSK-3? signaling pathway following neonatal hypoxia-ischemia in rats. Exp Neurol 272:135-44
Charles, Mélissa S; Drunalini Perera, Pradilka N; Doycheva, Desislava Met et al. (2015) Granulocyte-colony stimulating factor activates JAK2/PI3K/PDE3B pathway to inhibit corticosterone synthesis in a neonatal hypoxic-ischemic brain injury rat model. Exp Neurol 272:152-9
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Doycheva, Desislava M; Hadley, Tiffany; Li, Li et al. (2014) Anti-neutrophil antibody enhances the neuroprotective effects of G-CSF by decreasing number of neutrophils in hypoxic ischemic neonatal rat model. Neurobiol Dis 69:192-9
Ma, Qingyi; Chen, Sheng; Hu, Qin et al. (2014) NLRP3 inflammasome contributes to inflammation after intracerebral hemorrhage. Ann Neurol 75:209-19
Souvenir, Rhonda; Flores, Jerry J; Ostrowski, Robert P et al. (2014) Erythropoietin inhibits HIF-1? expression via upregulation of PHD-2 transcription and translation in an in vitro model of hypoxia-ischemia. Transl Stroke Res 5:118-27

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