An integrin inhibiting molecule decreases oxidative damage and improves neurological function after spinal cord injury

Spinal Cord Injury Laboratory, BioTherapeutics Research Group, Robarts Research Institute, Schulich School of Medicine and Dentistry, The University of Western Ontario, PO Box 5015, 100 Perth Drive, London, Ontario Canada.
Experimental Neurology (Impact Factor: 4.7). 10/2008; 214(2):160-7. DOI: 10.1016/j.expneurol.2008.09.006
Source: PubMed


Our previous studies have shown that treatment with an alpha4beta1 integrin blocking antibody after spinal cord injury (SCI) in rats decreases intraspinal inflammation and oxidative damage, improving neurological function. Here, we studied effects of a high affinity small molecule alpha4beta1 inhibitor, BIO5192. First, rats were treated intravenously with BIO5192 (10 mg/kg) or with vehicle (controls) to assess effects of integrin blockade for 24 h or 72 h after thoracic clip-compression SCI. BIO5192 treatment significantly decreased the MPO enzymatic activity (neutrophil infiltration) and ED-1 expression (macrophage density) by 40% and 38% at 24 h and by 52% and 25% at 72 h post injury, respectively. In cord homogenates, BIO5192 treatment decreased expression of the oxidative enzymes gp91(phox), inducible nitric oxide and cyclooxygenase-2 by approximately 40% at both times of analysis. Free radical concentration decreased by 30% and lipid peroxidation decreased by 34% and 46%, respectively, at 24 h and 72 h after SCI. Next, after blockade by BIO5192 for 72 h, neurological outcomes were analyzed for 1-6 weeks after SCI. Motor function significantly improved when assessed by an open-field test. Treated rats planter placed their hind paws and/or dorsal stepped, with weight support, whereas controls only swept their hindlimbs. BIO5192 treatment also decreased mechanical allodynia elicited from the trunk and hind paw by up to 35%. This improved function correlated with decreased lesion size and spared myelin-containing white matter. The neurological improvement offered by this neuroprotective strategy supports the potential for an anti-integrin treatment for SCI.

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    • "Similar to the blood-brain barrier (BBB), the BSCB is primarily formed by endothelial cells interconnected by tight junctions, which limits passive diffusion of blood-borne solutes and actively transports nutrients into the spinal cord (1,2). BSCB dysfunction leading to early inflammatory response and oxidative stress contributes to secondary pathogenesis following traumatic spinal cord injury (SCI) (3–10). BSCB disruption by traumatic SCI also generates harmful substances, including endothelins (ETs) (11–15), matrix metalloproteinases (MMPs) (7,9,10), inflammatory cytokines and reactive oxygen species (ROS) (3–6,8) that can induce programmed neuronal death and permanently impair neuron function. "
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    ABSTRACT: After spinal cord injury (SCI), the disruption of blood-spinal cord barrier by activation of the endothelin (ET) system is a critical event leading to leukocyte infiltration, inflammatory response and oxidative stress, contributing to neurological disability. In the present study, we showed that blockade of ET receptor A (ETAR) and/or ET receptor B (ETBR) prevented early inflammatory responses directly via the inhibition of neutrophil and monocyte diapedesis and inflammatory mediator production following traumatic SCI in mice. Long-term neurological improvement, based on a series of tests of locomotor performance, occurred only in the spinal cord‑injured mice following blockade of ETAR and ETBR. We also examined the post‑traumatic changes of the micro-environment within the injured spinal cord of mice following blockade of ET receptors. Oxidative stress reflects an imbalance between malondialdehyde and superoxide dismutase in spinal cord‑injured mice treated with vehicle, whereas blockade of ETAR and ETBR reversed the oxidation state imbalance. In addition, hemeoxygenase-1, a protective protease involved in early SCI, was increased in spinal cord‑injured mice following the blockade of ETAR and ETBR, or only ETBR. Matrix metalloproteinase-9, a tissue-destructive protease involved in early damage, was decreased in the injured spinal cord of mice following blockade of ETAR, ETBR or a combination thereof. The findings of the present study therefore suggested an association between ETAR and ETBR in regulating early pathogenesis of SCI and determining the outcomes of long‑term neurological recovery.
    International Journal of Molecular Medicine 04/2014; 34(1). DOI:10.3892/ijmm.2014.1751 · 2.09 Impact Factor
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    • "The significant reduction of H2O2-induced cell death obtained by the treatment with NX210 in a B104 cell line suggests a promising anti-oxidative property of the molecule. It is interesting to correlate these results to the decrease in free radical formation obtained by an integrin inhibitor [27], since most of NX210's effects are mediated by β1 integrin receptors [28]. At the present day, the efficacy of neuroprotective therapeutics remains limited in clinical practice, because in case of extensive destruction of the spinal cord the potential targets for neuroprotection may not be sufficient to support functional restoration. "
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    ABSTRACT: In mammals, the limited regenerating potential of the central nervous system (CNS) in adults contrasts with the plasticity of the embryonic and perinatal periods. SCO (subcommissural organ)-spondin is a protein secreted early by the developing central nervous system, potentially involved in the development of commissural fibers. SCO-spondin stimulates neuronal differentiation and neurite growth in vitro. NX210 oligopeptide was designed from SCO-spondin's specific thrombospondin type 1 repeat (TSR) sequences that support the main neurogenic properties of the molecule. The objective of this work was to assess the neuroprotective and neuroregenerative properties of NX210 in vitro and in vivo for the treatment of spinal cord injury (SCI). In vitro studies were carried out on the B104 neuroblastoma cell line demonstrating neuroprotection by the resistance to oxidative damage using hydrogen peroxide and the measure of cell viability by metabolic activity. In vivo studies were performed in two rat models of SCI: (1) a model of aspiration of dorsal funiculi followed by the insertion of a collagen tube in situ to limit collateral sprouting; white matter regeneration was assessed using neurofilament immunostaining; (2) a rat spinal cord contusion model to assess functional recovery using BBB scale and reflex testing. We demonstrate for the first time that NX210 (a) provides neuroprotection to oxidative stress in the B104 neuroblastoma cells, (b) stimulates axonal regrowth in longitudinally oriented neofibers in the aspiration model of SCI and (c) significantly improves functional recovery in the contusive model of SCI.
    PLoS ONE 03/2014; 9(3):e93179. DOI:10.1371/journal.pone.0093179 · 3.23 Impact Factor
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    • "Previous studies have reported that attenuation of IL-6 signaling [61,62], blocking neutrophil infiltration [15,16,39,40,63], or reducing MMP-9 expression [46] separately after SCI results in tissue preservation and improvement in hind-limb locomotor function. In this study, we show that IgG treatment is associated with a decrease in the area of scar and cavity (Figure 5A), an increase in tissue sparing (Figure 5B) and a significant improvement in neurobehavioral recovery (Figure 6A and B). "
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    ABSTRACT: Background Evidence suggests that the inflammatory events in the acute phase of spinal cord injury (SCI) exacerbate the initial trauma to the cord leading to poor functional recovery. As a result, minimizing the detrimental aspects of the inflammatory response after SCI is a promising treatment strategy. In this regard, immunoglobulin G (IgG) from pooled human serum is a promising treatment candidate. Due to its putative, though poorly characterized immuno-modulatory effects, IgG has been used clinically to treat neuroinflammatory disorders such as Guillain-Barré syndrome, but its effects in neurotrauma remain largely unexplored. Methods This study examines the potential neuroprotective effects of IgG in a well-characterized cervical model of SCI. Female Wistar rats were subject to moderate-severe clip compression injury at the C7-T1 level. IgG (0.4 g/kg) or saline was injected intravenously to randomly selected animals at 15 min post SCI. At several time points post SCI, biochemical assays, histology and immunohistochemistry analyses, and neurobehavioral assessments were used to examine the neuroprotective effects of IgG at the molecular, cellular, and neurobehavioral levels. Results We found that intravenous treatment of IgG following acute clip-compression SCI at C7-T1 significantly reduced two important inflammatory cytokines: interleukin (IL)-1β and IL-6. This early reduction in pro-inflammatory signaling was associated with significant reductions in neutrophils in the spinal cord and reductions in the expression of myeloperoxidase and matrix metalloproteinase-9 in the injured spinal cord at 24 h after SCI. These beneficial effects of IgG were associated with enhanced tissue preservation, improved neurobehavioral recovery as measured by the BBB and inclined plane tests, and enhanced electrophysiological evidence of central axonal conduction as determined by motor-evoked potentials. Conclusion The findings from this study indicate that IgG is a novel immuno-modulatory therapy which shows promise as a potential treatment for SCI.
    Journal of Neuroinflammation 09/2012; 9(1). DOI:10.1186/1742-2094-9-224 · 5.41 Impact Factor
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