Page 46 - NNS 2014 Program & Abstract Book

contribution of defects in autophagy to acute neuronal loss, in ventral
horn motor neurons we observed co-localization of GFP-LC3 signal
with the marker of apoptotic cell death, caspase 12. Together our data
indicate that after SCI in GFP-LC3 reporter mice autophagy flux is
temporarily impaired and may contribute to motor neuron cell death.
Key words
autophagy, autophagy flux, GFP-LC3, transgenic mouse model
OC4-03
INHIBITION OF NOX2 REDUCES LOCOMOTOR IMPAIR-
MENT, INFLAMMATION AND OXIDATIVE STRESS AFTER
SPINAL CORD INJURY
Khayrullina, G., Bermudez, S., Byrnes, K.R.
Uniformed Services University, Department of Anatomy, Physiology
and Genetics, Bethesda, USA
Spinal cord injury (SCI) results in activation of the NADPH oxidase
enzyme, inducing production of superoxide, a reactive oxygen species
(ROS). As ROS play an integral role in inflammation and oxidative
damage, we aimed to investigate the role of the NADPH oxidase 2
(NOX2) enzyme in post-SCI inflammation and functional deficits. We
therefore performed moderate spinal cord contusion injury in adult
male mice and administered the NOX2 specific inhibitor, gp91ds-tat, or
scrambled-tat intrathecally immediately after impact. We then used
flow cytometry, western blot, and immunohistochemistry to assess
NOX2 activity and expression, inflammation, and M1/M2 microglia/
macrophage polarization at 24 hours and 7, 21, and 28 days post-injury.
The Basso mouse scale (BMS) was used to assess locomotor function at
24 hours post-injury and then weekly thereafter. Administration of the
NOX2 specific inhibitor significantly reduced acute oxidative stress, as
measured by immunohistochemistry for the DNA damage marker
8OHdG and western blotting for protein carbonylation, indicating a
reduction in ROS production by gp91ds-tat. Further, gp91ds-tat ad-
ministration resulted in a significant reduction in inflammatory cells, as
measured by flow cytometry at 24 hours and 7 days post-injury. Fur-
ther, at 24 hours post-injury, gp91ds-tat injection led to a reduction in
the protein expression of NOX2 and the M1 marker CD86. However,
by 28 days post-injury, there was no significant difference in number of
microglia, macrophages, T cells or neutrophils between groups, sug-
gesting that a single acute treatment does not induce chronic changes in
the inflammatory response. Despite this, significant and long lasting
improvements in motor function were observed in the BMS scores of
gp91ds-tat treated mice in comparison to those that received the
scrambled-tat. Based on our findings, we now conclude that inhibition
of NOX2 significantly improves motor function, possibly by reducing
inflammation and oxidative stress acutely after injury. NOX2 inhibition
may therefore have true potential as a therapeutic after SCI.
Key words
microglia polarization, motor function, NADPH oxidase, oxidative
stress
OC5-01
NEUROENDOCRINE-IMMUNE DYSFUNCTION IN IN-
DIVIDUALS WITH POOR OUTCOME AFTER SEVERE
TRAUMATIC BRAIN INJURY
Santarsieri, M.1 , Kumar, R.G.1, Niyonkuru, C.1, Kochanek, P.M.3,4,
Wagner, A.K.1–3
1Department of PM&R, Pittsburgh, USA
2Center for Neuroscience, Pittsburgh, USA
3Safar Center for Resuscitation Research, Pittsburgh, USA
4Department of Critical Care, University of Pittsburgh, Pittsburgh, USA
5Department of Obstetrics and Gynecology, Wake Forest University,
Winston Salem, USA
Bidirectional communication between the immune and neuroendocrine
systems is not well understood in traumatic brain injury (TBI). Thus our
objective was to characterize relationships between cerebrospinal fluid
(CSF) cortisol and inflammation after severe TBI, and determine how
this relationship differs by outcome. CSF samples were collected 0-5 d
post-injury in 91 adults and analyzed for cortisol and inflammatory
markers. Our primary outcome was Glasgow Outcome Scale (GOS)
score at 6 months. Group-based trajectory analysis (TRAJ) delineated
subpopulations with similar longitudinal cortisol profiles. Inflammatory
markers whose individual relationship to outcome was mediated by
cortisol TRAJ (IL-6, IL-10, sFas, sICAM-1, and TNF-a) made up a
cumulative inflammatory load score (ILS). Covariate associations with
ILS were explored concurrently with cortisol TRAJ, and showed age,
diffuse axonal injury, and intracranial hemorrhage influenced ILS. As
expected, cortisol TRAJ group membership mediated the relationship of
this cortisol-specific ILS on outcome after controlling for age and GCS.
Correlational analysis between mean cortisol levels and ILS were ex-
amined within each cortisol TRAJ group and by outcome. Within the
low cortisol TRAJ, subjects with unfavorable outcomes displayed a
negative correlation between ILS and mean cortisol (r = - 0.548,
p = 0.052). Conversely, subjects with unfavorable outcome in the high
cortisol TRAJ displayed a positive correlation between ILS and mean
cortisol (r = 0.391, p =0.006). Our results suggest unfavorable outcome
after TBI may result from dysfunctional neuroendocrine-immune
crosstalk. Importantly, the nature of inflammatory dysfunction, and
presumed relationships with hypothalamic-pituitary-adrenal function,
differs between cortisol TRAJ groups. Correlational analysis suggests
bidirectional inflammatory marker transit after TBI, uniquely supporting
current bidirectional characterization associated with neuroendocrine-
immune crosstalk. The present data support evaluating targeted anti-
inflammatory treatment strategies early after injury and investigating
chronic changes in neuroendocrine-immune crosstalk during recovery.
Support
CDCR49 CCR323155; DODW81XWH-071-0701; NIH5P01NS030318.
Key words
cortisol, hypothalamaic-pituitary-axis, inflammation, interleukins,
trajectory analysis, traumatic brain injury
OC5-02
PHASE II CLINICAL TRIALS OF CETHRIN IN ACUTE
CERVICAL SPINAL CORD INJURY
Bond, L.M., Anderson, K.D., McKerracher, L.
BioAxone BioSciences, Cambridge, United States
Spinal cord injury often results in lifelong paralysis. Axons damaged
in the spine fail to regenerate, largely due to Rho activation by growth
inhibitory proteins and inflammatory mediators. This Rho activation
signals cytoskeletal disassembly and axonal growth cone collapse.
Cethrin is a biologic drug derived from C3 transferase that prevents
Rho activation and promotes axon regeneration in rat models of
neurotrauma. A first-in-man, Phase I/IIa clinical study of Cethrin in
acute complete spinal cord injury (AIS A) demonstrated that the drug
was well tolerated and showed the potential to improve neurological
recovery in a functionally meaningful manner. Participants in all Cethrin
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