Angiopoietin-1 and C16 Peptide Attenuate Vascular and Inflammatory Responses in Experimental Allergic Encephalomyelitis

Breakdown of normal blood-brain barrier function and accompanying vascular leakage are fundamental stages in the onset of multiple sclerosis and its animal counterpart, experimental allergic encephalomyelitis. In the present study, angiopoietin-1, an endothelial growth factor well known for its role in establishing and maintaining vascular integrity, and C16, a peptide that competitively binds to integrin αvβ3 expressed on endothelial cells, were used to treat acute experimental allergic encephalomyelitis in Lewis rats. Angiopoietin-1 was more effective than C16 for reducing inflammation-induced vascular leakage. Moreover, treatment with a combination of angiopoietin-1 and C16 resulted in greater effects, not only in alleviating inflammation and reducing axonal loss/demyelination but also in down-regulating pro-inflammatory cytokine expression and improving electrophysiological dysfunction, than treatment with either angiopoietin-1 or C16 alone. Different protective effects were observed with angiopoietin-1 and C16 treatment suggesting that these proteins target specific receptors to act through different pathways. Furthermore, angiopoietin-1 and C16 may form the basis of a promising therapeutic strategy for experimental allergic encephalomyelitis and multiple sclerosis.