Page 106 - NNS 2014 Program & Abstract Book

inflammatory cytokines are significantly up-regulated in both spinal
cord and peripheral tissues (serum and spleen). Intrathecal sTNFR1
reduces spinal cord TNFa levels and modulates key anti-inflamma-
tory mediators in the serum and spleen. Histology reveals reduced
numbers of ED-1 positive cells at the injury site after sTNFR1 at
both 24 h and 7d post-SCI. Further, by flow cytometry, we find
decreased CD11b high monocytes in peripheral blood following
sTNFR1 treatment.
Our data demonstrate both local and systemic inflammatory re-
sponses are activated following SCI and improved functional outcome
with TNFa inhibition is associated with mitigated local inflammatory
responses in the spinal cord. Intrathecal sTNFR1 also results in re-
duced expression of peripheral inflammatory markers and mediates a
reduction in the circulating pool of inflammatory monocytes.
Key words
immune response, macrophage, neuroinflammation, soluble TNF re-
ceptor, tumor necrosis factor alpha
C1-05
KALLIKREIN CASCADES IN TRAUMATIC SPINAL CORD
INJURY: DIFFERENTIAL ROLES IN AXONOPATHY AND
NEURON DEGENERATION
Radulovic, M., Yoon, H., Scarisbrick, I.A.
Mayo Clinic, Neurobiology of Disease Program, Department of
Physical Medicine and Rehabilitation, Rochester, MN, USA
The inventory of proteases involved in traumatic spinal cord injury
(SCI) is long and growing and includes members of the matrix me-
talloprotease family, cysteine proteases and serine proteases of the
thrombolytic, fibrinolytic and tissue kallikrein (KLK) families. The
current effort focused on defining the involvement of kallikreins in
traumatic SCI, with an emphasis on those expressed at significant
levels in the CNS or which are linked to pathology in other neuro-
pathologies. Kallikreins comprise a family of 15 secreted serine
proteases that form the largest contiguous cluster of serine proteases
in the human genome. To illuminate their contributions to the path-
ophysiology of SCI, we evaluated alterations in the immunohisto-
chemical appearance of six kallikreins, KLK1, KLK5, KLK6, KLK7,
KLK8 and KLK9 in post-mortem human SCI cases from acute
through chronic time points, quantified changes in the expression of
each at an RNA level in a murine SCI model, and assessed their
neurotoxic properties toward murine cortical neurons in vitro. Tem-
porally and spatially distinct changes in kallikrein expression were
observed with partially overlapping patterns between human and
murine SCI, including peak elevations during the acute and subacute
periods. In the SCI model, alterations in kallikrein expression paral-
leled peak transcriptional elevations in pro-inflammatory cytokines
IL-6, TNF-a and IL-1b, in elevated levels of expression of GFAP, and
in transcriptional reductions in RNA encoding for myelin genes. In
both human and murine SCI, KLK9 showed the most significant
changes and remained elevated chronically. In cases of human SCI,
each kallikrein was also associated with swollen axons and retraction
bulbs. Importantly, a subset of kallikreins, KLK1, KLK5, KLK6,
KLK7 and KLK9 were shown to be neurotoxic toward primary neu-
rons in vitro . The injury-related changes in kallikrein expression
documented, taken with their differential neurotoxic effects, indicate
that elevated levels of a large subset of kallikreins are positioned to
contribute to pathogenesis secondary to SCI and therefore may rep-
resent new therapeutic targets.
Key words
human, protease, spinal cord injury
C1-06
MODULATION OF MATRIX METALLOPROTEINASES
AFTER SPINAL CORD INJURY IMPROVES FUNCTIONAL
RECOVERY OF RATS
Chelluboina, B., Veeravalli, K.K., Dinh, D.H., Rao, J.S., Dasari, V.R.
University of Illinois College of Medicine at Peoria, Peoria, USA
Spinal cord injury (SCI) results in a multitude of changes affecting
several different cell types, leading to a complex pathological picture.
Secretion of matrix metalloproteinases (MMPs) into the injured spinal
cord results in activation of several signaling pathways which contributes
to secondary damage. Based on our published results, we hypothesized
that intraspinal administration of MMPs would aid in the alleviation of
neuropathic pain, help prevent further secondary damage, and activate
signaling pathways which help in tissue restoration and functional re-
covery. We used contusive injury in the rats using NYU impactor and
observed that infiltration of microglia to the site of injury started as early
as 1d post-SCI. We observed that maximum infiltration of microglia took
place by 7d post-SCI at the injury epicenter; and therefore we decided to
administer MMPs on 8th day after SCI. On the 8th day after SCI, MMP2
overexpression plasmid/shMMP9/shMMP12 dissolved in sterile PBS
was injected intraspinally at a distance of 5mm away from the site of
injury on each side (rostral and caudal). Our results indicated that intra-
spinal administration of MMP2 inhibited glial scar formation and ex-
pression of neurocan. Treatment either with shMMP9 or with both
shMMP9 and shMMP12 seemed to highly upregulate Osteopontin in the
injury epicenter, suggesting that knockdown of both MMP9 and MMP12
helped the extracellular matrix of injured portion of spinal cord to un-
dergo reparative processes. Intraspinal administration of MMP2 showed
greater improvement of hind limbs compared to injured rats. On the other
hand, the shMMP-12 group rats showed considerable improvement in the
functional scores compared to shMMP9 group rats. However, we ob-
served an additive effect when both shMMP9 and shMMP12 were given
together. These results suggest that treatment with either overexpression
of MMP2 or knockdown of MMP9/MMP12 shows promising results,
which can be exploited for future translation therapy after SCI.
Key words
glial scar, matrix metalloproteinases, neuropathic pain, osteopontin
C1-07
PHARMACOLOGICALLY TARGETING L-SELECTIN IM-
PROVES OUTCOMES FOLLOWING SPINAL CORD INJURY
Sontag, C.J.1, Lee, S.M.1, Rosen, S.D.2 , Noble-Haeusslein, L.J.1
1University of California San Francisco, Department of Neurological
Surgery, San Francisco, USA
2University of California San Francisco, Department of Anatomy, San
Francisco, USA
Demyelination is a key determinant of neurological recovery following
spinal cord injury (SCI). There is no widely accepted therapeutic for SCI
or effective interventions for secondary demyelination. While leukocyte
depletion studies have shown attenuation of early demyelination fol-
lowing SCI, the underlying mechanisms mediating pathogenicity be-
tween leukocytes and myelin have remained elusive. We have found
reduced degradation of myelin basic protein, long-term improved neu-
rologic recovery, and increased white matter sparing in L-selectin
knockout (KO) mice following SCI. These data suggest that L-selectin, a
receptor expressed on all leukocytes, could be a novel target for thera-
peutic intervention for SCI. To test this hypothesis, we conducted blin-
A-74