Page 106 - NNS 2014 Abstract Book

University of Kentucky, Spinal Cord & Brain Injury Research Center,
College of Medicine, Lexington, USA
Following a traumatic brain injury (TBI) excessive reactive oxygen
species are generated, which induce lipid peroxidation (LP) of
membrane polyunsaturated fatty acids. A consequence of LP is the
formation of toxic reactive aldehydes such as 4-hydroxy-2-nonenal (4-
HNE) and the more reactive 2-propenal (acrolein) that can covalently
bind to proteins and disrupt cellular processes. For example, the al-
dehydic protein adducts in mitochondria cause respiratory dysfunction
and neuronal loss. We have recently shown that the drug phenelzine
(PZ) possesses a hydrazine moiety enabling it to scavenge 4-HNE
preventing it from disrupting mitochondrial function in the injured rat
brain in parallel with a reduction in cortical contusion volume (Singh
et al, JCBFM 33:593, 2013). The current study investigates the ability
of PZ to protect isolated mitochondria from the more reactive acro-
lein. Mitochondria function was assessed by measuring the respiratory
capacity of complex I and II after PZ-pretreated mitochondria were
exposed to 4-HNE or acrolein. Initial dose response curves for acro-
lein demonstrate that all tested concentrations (1, 3, 10, and 20 lM)
reduce complex I and II driven respiration in concentration-related
manner. These concentrations reduced complex I driven respiration
compared to untreated mitochondria by 7.8%, 11.2%, 56.6%, and
81.6%, respectively. Similarly, complex II driven respiration was
reduced 32.7%, 49.4%, 64.9%, 80.8%, respectively. Pretreatment of
30 lM PZ protected mitochondria complex I & II driven respiration
from 3 lM acrolein exposure (p < 0.05 vs. acrolein treated). In con-
trast, the PZ analogue pargyline (PG) that lacks a hydrazine moiety
when applied in an equimolar concentration was unable to protect
mitochondria from acrolein supporting the importance of the hydra-
zine moiety in the mitochondrial protective effect of PZ. Additionally,
because PZ is able to exert a mitochondrial protective effect in vitro
and in the injured brain (Singh et al, 2013), implies that PZ has a rate
constant that can out compete acrolein’s reactivity with cellular pro-
teins.
Key words
acrolein, lipid peroxidation, mitochondria, phenelzine
D1-16
POLYNITROXYLATED PEGYLATED HEMOGLOBIN IM-
PROVES ACUTE PHYSIOLOGY VS. BLOOD AFTER TRAU-
MATIC BRAIN INJURY PLUS HEMORRHAGIC SHOCK
Brockman, E.C.1,2, Jackson, T.C.1,2, Dixon, C.E.2,4, Bayir, H.1,2,5,
Clark, R.S.1,2, Vagni, V.2, Ma, L.3 , Hsia, C.3, Feldman, K.2, Kochanek,
P.M.1,2
1Department of Critical Care Medicine, University of Pittsburgh,
Pittsburgh, US
2Safar Center for Resuscitation Research, Pittsburgh, US
3Synzyme Technologies, LLC, Irvine, US
4Department of Neurosurgery, University of Pittsburgh, Pittsburgh,
US
Resuscitation with polynitroxylated pegylated hemoglobin (PNPH), a
PEGylated bovine hemoglobin decorated with nitroxides, required
significantly less fluid and produced neuroprotection in vitro and
in vivo vs. lactated Ringer’s (LR) in experimental traumatic brain
injury (TBI) plus hemorrhagic shock (HS). Hypothesis: Resuscitation
with PNPH will improve acute physiologic parameters vs. whole
blood or LR after TBI + HS. Anesthetized mice underwent controlled
cortical impact followed by severe HS to mean arterial pressure
(MAP) of 25-27 mm Hg for 35 min. Mice (n = 5/group) were then
resuscitated with 20 ml/kg of 4% PNPH, 20 ml/kg of autologous
whole blood, or 60 ml/kg of LR. Markers of acute physiology (MAP,
heart rate, blood gases, chemistries) were monitored after resuscita-
tion for 105 minutes. PNPH-resuscitated mice had higher MAPs fol-
lowing resuscitation vs. blood or LR (82.2 – 2.0 vs. 65.3 – 3.8 and
38.4 – 3.6 mm Hg, P < 0.001). Following resuscitation, both PNPH
and blood-resuscitated mice had lower heart rates vs. LR (602 – 13
and 608 – 13 vs. 634 – 19 BPM, P < 0.001). PNPH-resuscitated mice,
vs. blood or LR, had higher pH (7.38 – 0.02 vs. 7.31 – 0.02 and
7.29 – 0.04, P < 0.05) and lower serum potassium (5.4 – 0.1 vs. 6.2 –
0.4 and 7.8 – 0.5 mg/dL, P < 0.05). Arterial oxygen saturations were
higher in both PNPH and LR-resuscitated mice vs. blood (99.3 – 0.7
and 97.1 – 1.5 vs. 92.0 – 0.7%, P < 0.01). Blood-resuscitated mice, vs.
PNPH and LR, had higher hemoglobin concentrations (10.9 – 0.24
vs. 7.1 – 0.3 and 7.7 – 0.1 g/dL, P< 0.001) and hematocrit (34.4 –
0.7 vs. 24.3 – 1.8 and 24.1 – 0.5%, P < 0.001). Resuscitation with
PNPH, vs. standard resuscitation (LR or blood), improved MAP and
heart rate, reduced acidosis and hyperkalemia, and improved oxygen
saturation, despite blood-resuscitated mice having higher hemoglobin/
hematocrit. Our data support ongoing pre-clinical development of
PNPH for TBI resuscitation. Support: U44NS070324
Key words
hemoglobin based oxygen carrier, hemorrhagic shock, resuscitation,
traumatic brain injury
D1-17
INTRANASAL INSULIN TREATMENT OF TRAUMATIC
BRAIN INJURY
Brabazon, F.P.1, Khayrullina, G.I.1 , Frey, W.H.2, Byrnes, K.R.1
1Uniformed Services University, Bethesda, USA
2University of Minnesota, Minneapolis, USA
Traumatic brain injury (TBI) is a serious health problem that affects
approximately 1.5 million people in the United States each year and
causes long term cognitive deficits. After injury there is a transient
but marked reduction in cerebral glucose uptake. The length and
severity of this metabolic crisis is directly correlated with patient
outcome. We hypothesized that administration of intranasal insulin,
a treatment shown to improve cerebral glucose uptake and memory
in Alzheimer’s patients, will increase cerebral glucose uptake,
neuronal survival and reduce glial mediated inflammation, leading to
a reduction in TBI-related histological and functional impairment.
To test our hypothesis, adult male Sprague Dawley rats received a
moderate brain injury in the left motor cortex using the controlled
cortical impact (CCI) model of brain injury. The animals were
treated once a day for 7 days with either intranasal insulin (II) or
intranasal vehicle (saline; IS). II treatment significantly improved the
performance of injured animals on a balance beam in comparison to
the IS group. Qualitative assessment of histology showed improved
neuronal viability in the hippocampus of the II treated rats. In ad-
dition, markers of anti-inflammatory, pro-healing M2 microglia/
macrophages were significantly increased in the II group in com-
parison the IS group. There was no significant increase in expression
of M1 markers indicating that the drug treatment is pushing mi-
croglia toward an anti-inflammatory phenotype. In conclusion our
studies indicate that intranasal insulin, a clinically proven treatment
for Alzheimer’s disease, increases neuronal viability, M2 activation
and functional recovery following TBI.
Key words
CCI, hippocampus, insulin
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