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

Our previous studies have shown that treatment with an alpha 4 beta 1 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 alpha 4 beta 1 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 similar to 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. (C) 2008 Elsevier Inc. All rights reserved.