TNF-alpha blockage in a mouse model of SCI: evidence for improved outcome.

The aim of our study was to evaluate in vivo the therapeutic efficacy of genetic inhibition of TNF-alpha using TNF-R1 knockout mice in an experimental model of spinal cord trauma. Spinal cord injury was induced by the application of vascular clips to the dura via a four-level T5-T8 laminectomy. To elucidate whether the observed anti-inflammatory status is related to the inhibition of TNF-alpha, we also investigated the effect of infliximab, a TNF-alpha-soluble receptor construct, on spinal cord damage. Pharmacological and genetic TNF-alpha inhibition significantly reduced the degree of (1) spinal cord inflammation and tissue injury (histological score), (2) neutrophil infiltration (evaluated by myeloperoxidase activity), (3) cytokine expression (TNF-alpha), (4) and apoptosis (terminal deoxynucleotidyltransferase-mediated uridine triphosphate end labeling staining, Bax, Bcl-2, and Fas-L expression). In a separate set of experiments, we have also demonstrated that TNF-alpha inhibition significantly ameliorated the recovery of limb function (evaluated by motor recovery score). Taken together, our results demonstrate that inhibition of TNF-alpha reduces the development of inflammation and tissue injury associated with spinal cord trauma, suggesting a possible role of TNF-alpha on the pathogenesis of spinal cord injury.