Journal of neurotrauma
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Journal of neurotrauma · Jan 2009
Hyperbaric oxygen preconditioning attenuates early apoptosis after spinal cord ischemia in rats.
This study tested the hypothesis that spinal cord ischemic tolerance induced by hyperbaric oxygen preconditioning (HBO-PC) is mediated by inhibition of early apoptosis. Male Sprague-Dawley rats were preconditioned with consecutive 4 cycles of 1-h HBO exposures (2.5 atmospheres absolute [ATA], 100% O(2)) at a 12-h interval. At 24 h after the last HBO pretreatment, rats underwent 9 min of spinal cord ischemia induced by occlusion of the descending thoracic aorta in combination with systemic hypotension (40 mmHg). ⋯ L-nitroarginine-methyl-ester (L-NAME; 10 mg/kg), a nonselective NO synthase (NOS) inhibitor, applied before each HBO-PC protocol abolished these beneficial effects of HBO-PC. We conclude that HBO-PC reduced spinal cord ischemia-reperfusion injury by increasing Mn-SOD, catalase, and Bcl-2, and by suppressing mitochondrial apoptosis pathway. NO may be involved in this neuroprotection.
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Journal of neurotrauma · Jan 2009
NNZ-2566, a glypromate analog, improves functional recovery and attenuates apoptosis and inflammation in a rat model of penetrating ballistic-type brain injury.
Glycine-proline-glutamate (GPE) is an N-terminal tripeptide endogenously cleaved from insulin-like growth factor-1 in the brain and is neuroprotective against hypoxic-ischemic brain injury and neurodegeneration. NNZ-2566 is an analog of GPE designed to have improved bioavailability. In this study, we tested NNZ-2566 in a rat model of penetrating ballistic-type brain injury (PBBI) and assessed its effects on injury-induced histopathology, behavioral deficits, and molecular and cellular events associated with inflammation and apoptosis. ⋯ Although gross lesion volume was not affected, NNZ-2566 treatment significantly attenuated neutrophil infiltration and reduced the number of activated microglial cells in the peri-lesion regions of the PBBI. PBBI induced a significant upregulation in Bax expression (36%) and a concomitant downregulation in Bcl-2 expression (33%), both of which were significantly reversed by NNZ-2566. Collectively, these results demonstrated that NNZ-2566 treatment promoted functional recovery following PBBI, an effect related to the modulation of injury-induced neural inflammatory and apoptotic mechanisms.
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Journal of neurotrauma · Jan 2009
COG1410 improves cognitive performance and reduces cortical neuronal loss in the traumatically injured brain.
We have previously shown that a single dose of COG1410, a small molecule ApoE-mimetic peptide derived from the apolipoprotein E (ApoE) receptor binding region, improves sensorimotor and motor outcome following cortical contusion injury (CCI). The present study evaluated a regimen of COG1410 following frontal CCI in order to examine its preclinical efficacy on cognitive recovery. Animals were prepared with a bilateral CCI of the frontal cortex. ⋯ Administration of COG1410 also reduced the number of degenerating neurons, as measured by Fluoro-Jade C staining, in the frontal cortex at 48h post-CCI. These results suggest that a regimen of COG1410 appeared to block the development of significant behavioral deficits and reduced tissue loss. These combined findings suggest that COG1410 appears to have strong preclinical efficacy when administered following traumatic brain injury (TBI).
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Journal of neurotrauma · Jan 2009
Ibuprofen enhances recovery from spinal cord injury by limiting tissue loss and stimulating axonal growth.
The GTP-binding protein RhoA regulates microfilament dynamics in many cell types and mediates the inhibition of axonal regeneration by myelin and chondroitin sulfate proteoglycans. Unlike most other nonsteroidal anti-inflammatory drugs, ibuprofen suppresses basal RhoA activity (Zhou et al., 2003). A recent report suggested that ibuprofen promotes corticospinal axon regeneration after spinal cord injury (Fu et al., 2007). ⋯ Ibuprofen increases axonal sprouting from serotonergic raphespinal axons, and from rostral corticospinal fibers in the injured spinal cord, but does not permit caudal corticospinal regeneration after spinal contusion. Treatment of mice with complete spinal cord transection demonstrates long-distance raphespinal axon regeneration in the presence of ibuprofen. Thus, administration of ibuprofen improves the recovery of rats from a clinically relevant spinal cord trauma by protecting tissue, stimulating axonal sprouting, and allowing a minor degree of raphespinal regeneration.
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Journal of neurotrauma · Jan 2009
Role of Nrf2 in protection against traumatic brain injury in mice.
Previous studies have shown that nuclear factor erythroid 2-related factor 2 (Nrf2) plays a unique role in many physiological stress processes. The present study investigated the role of Nrf2 in modulating traumatic brain injury (TBI)-induced secondary brain injury. ⋯ This exacerbation of brain injury in Nrf2-deficient mice was associated with increased mRNA and protein expression of inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6), and with decreased mRNA expression and enzymatic activity of antioxidant and detoxifying enzymes including NAD(P)H:quinone oxidoreductase 1 (NQO1) and glutathione S-transferase alpha-1 (GST-alpha1), compared with their wild-type counterparts after TBI. In combination, these results suggest that Nrf2 plays an important role in protecting TBI-induced secondary brain injury, possibly by regulating inflammatory cytokines and inducing antioxidant and detoxifying enzymes.