The blood-brain and blood-spinal cord barriers (BBB/BSCB), lying between the CNS (brain and spinal cord) and its supplying capillary blood vessels, provide an immense interface for interaction and exchange of information between the CNS and the rest of the body. We have shown that the BSCB is not static or physically passive, but undergoes dynamic changes, to regulate the availability of the cytokine tumor necrosis factor a (TNFa) from blood to the CNS. In the proposed studies, we will test the hypothesis that TNFa, after being transported across the BBB/BSCB, can facilitate functional recovery after spinal cord injury (SCI). We will also characterize the mechanisms by which this specific transport can be regulated. To determine the functional implications of TNFe transport, we will first show that spinal cord uptake of radioactively labeled TNFe will increase specifically in a modified mouse model of thoracic hemisection, and that this increase will not coincide with passive disruption of the barrier (measured by increased paracellular permeability of albumin). We will then determine the effects of TNFa treatment by evaluating locomotor behavior, intraspinal conduction of evoked potentials, and histological evidence of long tract regeneration. We expect that small doses of TNFa will facilitate recovery whereas large doses will worsen the deficits resulting from SCI. To identify the roles of p55- and p75-receptors, we will study TNFa transport in the presence of receptor antibodies and in the receptor knockout mice. We predict that increased spinal cord uptake of TNFe after SCI will be dependent upon upregulation of the receptors, as determined by Western blot and quantitative PCR analysis. Since transcytosis of a cytokine across the BBB/BSCB is a complicated process involving not only the receptors but also other regulatory proteins, we will identify novel transport regulatory proteins by co-immunoprecipitation, comparative proteomics, transfection and transport assays. We predict that the transport process will be regulated by the receptors, vesicular and cytoskeletal proteins, and chaperons in different phosphorylation states. By completing the proposed study, we will better understand the dual roles of TNFa in SCI and in its transport process involving the regulatory proteins. These transporters could be novel drug targets and therefore provide promising therapeutic potential. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS045751-05
Application #
7162174
Study Section
Special Emphasis Panel (ZRG1-BDCN-3 (02))
Program Officer
Kleitman, Naomi
Project Start
2004-01-01
Project End
2008-12-31
Budget Start
2007-01-01
Budget End
2007-12-31
Support Year
5
Fiscal Year
2007
Total Cost
$225,626
Indirect Cost
Name
Lsu Pennington Biomedical Research Center
Department
Type
Organized Research Units
DUNS #
611012324
City
Baton Rouge
State
LA
Country
United States
Zip Code
70808
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Hsuchou, Hung; Kastin, Abba J; Wu, Xiaojun et al. (2010) Corticotropin-releasing hormone receptor-1 in cerebral microvessels changes during development and influences urocortin transport across the blood-brain barrier. Endocrinology 151:1221-7
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Wu, Xiaojun; He, Yi; Hsuchou, Hung et al. (2010) Essential role of interleukin-15 receptor in normal anxiety behavior. Brain Behav Immun 24:1340-6
Khan, Reas S; Yu, Chuanhui; Kastin, Abba J et al. (2010) Brain Activation by Peptide Pro-Leu-Gly-NH(2) (MIF-1). Int J Pept 2010:
He, Yi; Hsuchou, Hung; Wu, Xiaojun et al. (2010) Interleukin-15 receptor is essential to facilitate GABA transmission and hippocampal-dependent memory. J Neurosci 30:4725-34
Pan, Weihong; Yu, Chuanhui; Hsuchou, Hung et al. (2010) The role of cerebral vascular NFkappaB in LPS-induced inflammation: differential regulation of efflux transporter and transporting cytokine receptors. Cell Physiol Biochem 25:623-30

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