Effect of chondroitinase ABC on inflammatory and oxidative response following spinal cord injury

Objective(s): Chondroitinase ABC (cABC) treatment improves functional recovery following spinal cord injury (SCI) through degrading inhibitory molecules to axon growth. However, cABC involvement in other pathological processes contributing to SCI remains to be investigated. Here, we studied the effect of cABC I on oxidative stress and inflammation developed in a rat model of SCI.Materials and Methods: Male rats (220–250 g) were divided into three groups (n=28) including rats that underwent SCI (SCI group), rats subjected to SCI and received an intrathecal injection of phosphate buffer saline (SCI+PBS group), and rats that underwent SCI and received cABC intrathecally (SCI+E group). Then, the level of TNF-α, Il-1β, malondialdehyde, nitric oxide, and myeloperoxidase in injured tissues, as well as hindlimb motor function, were measured at 4 hr, 1, 3 and 7 days post-SCI.Results: Our data showed that cABC treatment reduced the development of inflammation and oxidative stress associated with SCI at all-time points. In addition, functional recovery was improved in rats that received cABC at 7 days post-SCI.Conclusion: The present findings indicate that cABC treatment can exert its neuroprotective effect through modulation of post-traumatic inflammatory and oxidative response

Phosphate modulates receptor sulfotyrosine recognition by the chemokine monocyte chemoattractant protein-1 (MCP-1/CCL2)

Tyrosine sulfation is a widespread post-translational modification that mediates the interactions of secreted and membrane-associated proteins in such varied biological processes as peptide hormone action, adhesion, blood coagulation, complement activation and regulation of leukocyte trafficking. Due to the heterogeneous nature of tyrosine sulfation, detailed biochemical and biophysical studies of tyrosine sulfation rely on homogenous, synthetic sulfopeptides. Here we describe the synthesis of a fluorescent sulfopeptide (FL-R2D) derived from the chemokine receptor CCR2 and the application of FL-R2D in direct and competitive fluorescence anisotropy assays that enable the efficient measurement of binding affinities between sulfopeptides and their binding proteins. Using these assays, we have found that the binding of the chemokine monocyte chemoattractant protein-1 (MCP-1) to sulfated peptides derived from the chemokine receptor CCR2 is highly dependent on the assay buffer. In particular, phosphate buffer at close to physiological concentrations competes with the receptor sulfopeptide by binding to the sulfopeptide binding pocket on the chemokine surface. Thus, physiological phosphate may modulate the receptor binding selectivity of chemokines