33 / 162
Conclusions:
These results support the prior findings of potential
role of GFAP and UCH-L1 in acute phase and prognostic diagnostics
of TBI. The novel finding is that GFAP and UCH-L1 levels correlated
both with the initial severity and outcome of TBI during the first two
days after the injury, thus providing potentially useful information
also after the day of admission.
Keywords: severity, outcome, traumatic brain injury, GFAP, UCH-L1
A5-11
A NEW PANEL OF HUMAN ASTROGLIAL NEUROTRAUMA
BIOMARKERS AND TRAUMA RELEASE MECHANISMS
Julia Halford
1
, Kyohei Itamura
1
, Jaclynn Levine
1
, Joseph Loo
2
,
Thomas Glenn
3
, David Hovda
3
, Ross Bullock
4
, Dalton Dietrich
4
,
Stefania Mondello
5
,
Ina-Beate Wanner
1
1
UCLA, Semel Institute for Neuroscience and Human Behavior, Los
Angeles, USA
2
UCLA, Dept. of Chemistry, Los Angeles, USA
3
UCLA, Dept. of Neurosurgery, Los Angeles, USA
4
Univ. of Miami, Dept of Neurological Surgery, Miami, USA
5
Univ. of Messina, Dept. of Neuroscience, Messina, Italy
Despite increasing interest in diagnostic use of traumatic brain injury
(TBI) biomarkers, a clinically applicable high fidelity neurotrauma bio-
marker has been elusive. Large disparities in severity, progression and
outcome among TBI patients demand unambiguous post-injury diagnostic
monitoring to improve patient care and classification. We previously
identified a panel of astroglial-enriched markers that are acutely released
after mechanical trauma (Levine et al., in press). Abrupt pressure-pulse
stretching of
in vitro
matured fetal human astrocytes caused severity and
time-dependent marker release. A preclinical study validated the elevation
of six, highly correlated astroglial markers in biofluid samples of 25 TBI
patients compared with 11 healthy subjects. Sensitive immunoblotting
with scaled densitometry and pure protein quantification measured
markers in raw cerebrospinal fluid (CSF) as well as serum and plasma
depleted of abundant proteins. While CSF levels of known astroglial
markers GFAP and S100b significantly decreased during the first week
post-injury, four additional astroglial proteins remained comparatively
stable during the same time-period after TBI. Astroglial-release markers
correlated with the presence of a serum-specific protein in CSF, suggesting
post-injury brain bleeding associated with astroglial injury. A CSF marker
was dramatically decreased after TBI and levels recovered over subse-
quent post-injury days. Importantly, four astroglial-released markers were
consistently elevated in blood samples of TBI patients versus Controls. In
conclusion, this new panel of human astroglial TBI biomarkers shows
in vitro
defined release mechanisms, is acutely elevated in TBI patients
and is detectable in blood. Combined, this work identifies a brain-specific
panel of neurotrauma biofluid markers with diagnostic potential.
Funding: NIH #1R21NS072606-01A1; Buoniconti Fund, The Mi-
ami Project to Cure Paralysis, Abbott Diagnostics
Keywords: cerebrospinal fluid, in vitro trauma model, human glia,
serum, plasma
A5-12
EVALUATION OF THE EXTRACELLULAR MATRIX AS A
SOURCE OF BIOMARKERS FOR INJURY SEVERITY
WITHIN 24 HOURS OF DIFFUSE BRAIN INJURY
Taylor Jenkins
1,2
,
Daniel R. Griffiths
1,2
, Caroline Addington
3
,
P. David Adelson
1–3
, Sarah Stabenfeldt
3,4
, Jonathan Lifshitz
1,2,4
1
UofA College of Medicine- Phoenix, Department of Child Health,
Phoenix, USA
2
PCH, Barrow Neurological Institute, Phoenix, USA
3
ASU, School of Biological and Health Systems Engineering, Tempe,
USA
4
ASU, Neuroscience Program, Tempe, USA
The extracellular matrix (ECM) provides structural support for
neuronal, glial and vascular components of the brain, and regulates
intercellular signaling required for cellular morphogenesis, differ-
entiation and homeostasis through constant remodeling. We hy-
pothesize that the ECM is susceptible to degradation and
accumulation of glycoproteins, which serve as biomarkers specific
to diffuse brain injury severity and region. Experimental TBI
was induced in male Sprague Dawley rats (325–375 g) by midline
fluid percussion injury (FPI) at sham (n
=
6), mild (1.4 atm, n
=
16)
and moderate (2.0 atm, n
=
16) severity. Tissue from the cortex,
hippocampus and thalamus was collected at 1, 3, 7 and 14 days post-
injury. All samples were quantified by western blot for glycopro-
teins: reelin, fibronectin, laminin, and tenascin-c. Band intensities
were normalized to sham and relative to
b
-actin. In the hippocam-
pus, fibronectin increased over 1 and 3 days post-injury at mild and
moderate severity, returning to sham levels by 7 days post-injury.
Tenascin-c increased at 7 and 14 days post-injury. Based on the
observed changes, we investigated the onset time course of ECM
glycoprotein expression at 15 minutes, 1 and 2 hours post-injury in
mild and moderate diffuse TBI. Results show significant decreases in
fibronectin for mild injury at 15 minutes in the thalamus, and at 15
minutes and 2 hours in the cortex. Reelin was decreased in the
hippocampus at all three time points. Changes in levels of these
glycoproteins at acute time points suggest that they may be useful
diagnostic biomarkers in an emergency room setting. The specificity
and sensitivity of these biomarkers remain to be validated as clini-
cally useful tools.
Funding:
Translational Collaboration Grant PCH-ASU; PCH
Mission Support Funds
Keywords: Biomarker, Extracellular Matrix, Emergency Medicine
A5-13
OPERATION BRAIN TRAUMA THERAPY (OBTT): SERUM-
BASED BIOMARKER INVESTIGATION IN A MICROPIG
FLUID PERCUSSION INJURY MODEL
Zhihui Yang
1
, Audrey Lafrenaye
2
, Ronald Hayes
3
, Patrick M.
Kochanek
4
, John T. Povlishock
2
,
Kevin Wang
1
1
University of Florida, Psychiatry/Neuroscience, Gainesville, FL,
USA
2
Virginia Commonwealth University, Anatomy and Neurobiology,
Richmond, VA, USA
3
Banyan Biomarkers, Banyan Laboratories, Alachua, FL, USA
4
University of Pittsburgh, Department of Critical Care Medicine,
Pittsburgh, PA, USA
As part of the consortium-based OBTT study, 16 micropigs were
subjected to mild TBI involving sham or central fluid percussion
injury (cFPI). Serial blood samples were obtained pre-craniotomy
and post-craniotomy, as well as at 1 min, 30 min, 1h, 3h, and 6h
post-injury. All blood samples were processed to obtain serum
following OBTT standard operations for detailed biomarker
analysis.
Four biomarker assays were run, including neuronal biomarker
UCH-L1, astroglia biomarker GFAP, microglial biomarker Iba-1
and neuroinflammatory biomarker interleukin-6 (IL-6). Serum
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