Page 74 - NNS 2014 Program & Abstract Book

glycoproteins. The ECM regulates intercellular signaling required for
cellular morphogenesis, differentiation and homeostasis through
constant remodeling. We hypothesize that the ECM is susceptible to
degradation and accumulation of glycoproteins, which then serve as
biomarkers specific to diffuse brain injury severity and region. Ex-
perimental 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 cor-
tex, hippocampus and thalamus, and blood were collected at 1, 3, 7
and 14 days post-injury. All samples were quantified by western blot
for the glycoproteins: reelin, fibronectin, laminin, and tenascin-c.
Band intensities were normalized to sham and relative to b-actin. The
lateral hippocampus, containing area CA3, was most sensitive to in-
jury-induced change in ECM protein levels. In this region, reelin did
not show significant changes in the primary band of interest (415 kDa)
over time post-injury. Fibronectin increased over 1 day and 3 days
post-injury at mild and moderate severity, returning to sham levels by
7 days post-injury. Laminin levels increased at 7 days post-injury for
the moderate severity. Tenascin-c was differentially affected over
time post-injury compared to other ECM components. The ECM re-
mains a potential source of biomarkers to distinguish ongoing pro-
cesses of circuit dismantling and repair in the wake of diffuse TBI,
based on the expression profile of ECM molecules. Further investi-
gation into breakdown products and penetrance into blood is needed.
Funding: Translational Collaboration Grant from PCH and ASU
Key words
biomarker, diffuse brain injury, extra cellular matrix, glycoproteins
A4-16
IDENTIFICATION OF A PUTATIVE PANEL OF SERUM MI-
CRORNAS FOR DIAGNOSIS OF HUMAN TRAUMATIC
BRAIN INJURY
Bhomia, M.1, Balakathiresan, N.1 , Zhang, Z.2 , Wang, K.K.2, Papa, L.3,
Maheshwari, R.K.1
1Uniformed Services University of Health Sciences (USUHS), Be-
thesda, USA
2University of Florida (UF), Gainesville, USA
3Orlando Regional Medical Center (ORMC), Orlando, USA
MicroRNAs (MiRNAs) are small endogenous RNA molecules and
have emerged as novel serum diagnostic biomarkers for many dis-
eases due to their stability and detection at minute quantities. In this
study, we have putatively identified a novel serum miRNA signature
in human serum samples of mild and severe TBI, which can be used
for diagnosis of mild TBI (mTBI).
Human serum samples (n = 8 each) of mTBI, severe TBI, ortho-
pedic injury and healthy controls were used which were collected
within 24 hr of injury. MiRNA profiling was done using taqman low
density array platform followed by data analysis.
The real time PCR data for the mTBI, severe TBI and orthopedic
injury was normalized to the control samples. Our analysis showed
that 89, 82 and 116 miRNAs were significantly modulated in se-
rum samples of mild, severe and orthopedic injury groups re-
spectively. To identify ‘‘TBI-specific’’ miRNAs, TBI groups were
compared to orthopedic injury group which showed up-regulation
of 13 and 17 miRNAs in mTBI and severe TBI groups. Among
these, a signature of 5 miRNAs was found to be present in both
mTBI and severe TBI cases only. Comparison of these 5 miRNAs
with serum miRNA profiles of animal TBI models in our labora-
tory revealed similar miRNAs between human and animal serum
post injury.
MiRNAs profiles of orthopedic injury showed an overlap with many
miRNAs expressed in TBI samples. By subtraction, we identified a
subset of five unique miRNAs which were only present in serum from
mild and severe TBI subjects. These five miRNAs are reported for the
first time as diagnostic markers of mTBI and severe TBI.
The views presented here are of the authors and should not be
construed as that of UF, ORMC or USUHS.
Key words
biomarker, microRNA, mild TBI, serum
A4-17
LIPIDOMIC PROFILING OF SERUM FOR THE DEVELOP-
MENT OF BLOOD BASED BIOMARKERS FOR TRAUMATIC
BRAIN INJURY
Hogan, S.2, Jones, C.M.2, Gaul, D.A.2, Zhou, M.2, Rooney, B.A.1,
Fernandez, F.2, LaPlaca, M.C.1
1Georgia Institute of Technology, Department of Biomedical En-
gineering, Atlanta, USA
2Georgia Institute of Technology, School of Chemistry and Bio-
chemistry, Atlanta, USA
Biomarkers are a promising diagnostic adjunct for TBI, yet there are no
candidate blood and/or cerebrospinal fluid biomarkers that have translated
to clinical use. The vast majority of the proposed biomarkers have been
identified by targeting astroglial and neuronal proteins that are affected by
secondary injury. Changes in the lipid profile of blood following TBI
have not been well studied, despite evidence of membrane phospholipid
degradation and the release of polyunsaturated fatty acids following TBI.
We use an untargeted approach to study the global lipidomic profile of
serum utilizing high resolution liquid chromatography mass spectrometry
(LC-MS) in rats injured by the controlled cortical impact (CCI) model
(n = 23) at 3 and 7 days post-CCI. LCMS run in positive mode identified
870 features, and an iterative algorithm was used to identify the features
most indicative of injury. Initial results show that concentration changes
in a panel of 8 lipids on the mass range 524 to 835 can differentiate
injured samples (n = 14) from sham and naı¨ve control (n = 9) with 100%
specificity and 93% sensitivity. The exact mass of each lipid matches an
existing phosphatidylcholine structure within 10 ppm error, allowing for
the assignment of elemental formulae. Tandem MS supports this class
identification as evidenced by the presence of a phosphatidylcholine
headgroup upon fragmentation. These preliminary data gives support to
the lipidomic approach to identifying TBI biomarkers, warranting further
study. Novel biomarker panels for TBI diagnosis should consider inclu-
sion of lipid-based molecules. (NIH 5T32EB006343-05).
Key words
lipid, mass spectrometry, phospholipid
A5-01
CLOSED HEAD INJURY ENHANCES COGNITIVE DEFICITS
AND DISRUPTS THE RESOLUTION OF THE GLIA RE-
SPONSE IN AN ALZHEIMER’S MOUSE MODEL
Bachstetter, A.D., Webster, S.J., Van Eldik, L.J.
University of Kentucky, Sanders-Brown Center on Aging, Lexington,
USA
Epidemiological studies have found a self-reported history of head
injury is associated with earlier onset, and increased Alzheimer’s
A-42