Neutrophils as determinants of vascular stability in the injured spinal cord

Abstract

While a number of studies have examined the complex roles of leukocytes in the acute and chronically injured cord, few have specifically focused on neutrophils, where we have only recently begun to appreciate their involvement in both vascular pathogenesis and early wound healing. Here we address the mechanisms underlying neutrophil-mediated endothelial destabilization, their synergism with monocytes in modulating permeability, and their putative role as initiators of angiogenesis in the acutely injured spinal cord. Neutrophils contain a variety of bioactive molecules that are stored in granules. Studies have shown that certain of these molecules, and most notably proteases, contribute to endothelial destabilization as neutrophils degranulate during their transmigration across this front. Neutrophils have historically been regarded as detrimental to the acutely injured cord. However, there is growing evidence that this may be an oversimplified view as it fails to take into account their ability to release proteases that degrade the extracellular matrix, releasing latent growth factors that may in turn support early angiogenesis.