Computational design and experimental characterization of a novel ?-common receptor inhibitory peptide.

ABSTRACT: In short-term animal models of ischemia, erythropoietin (EPO) signaling through the heterodimeric EPO receptor (EPOR)/?-common receptor (?CR) is believed to elicit tissue protective effects. However, large, randomized, controlled trials demonstrate that targeting a higher hemoglobin level by administering higher doses of EPO, which are more likely to activate the heterodimeric EPOR/?CR, is associated with an increase in adverse cardiovascular events. Thus, inhibition of long-term activation of the ?CR may have therapeutic implications. This study aimed to design and evaluate the efficacy of novel computationally designed ?CR inhibitory peptides (?IP). These novel ?IPs were designed based on a truncated portion of Helix-A from EPO, specifically residues 11-26 (VLERYLLEAKEAEKIT). Seven novel peptides (P1 to P7) were designed. Peptide 7 (P7), VLERYLHEAKHAEKIT, demonstrated the most robust inhibitory activity. We also report here the ability of P7 to inhibit ?CR-induced nitric oxide (NO) production and angiogenesis in human umbilical vein endothelial cells (HUVECs). Specifically, we found that P7 ?IP completely abolished EPO-induced NO production. The inhibitory effect could be overcome with super physiological doses of EPO, suggesting a competitive inhibition. ?CR-induced angiogenesis in HUVEC's was also abolished with treatment of P7 ?IP, but P7 ?IP did not inhibit vascular endothelial growth factor (VEGF)-induced angiogenesis. In addition, we demonstrate that the novel P7 ?IP does not inhibit EPO-induced erythropoiesis with use of peripheral blood mononuclear cells (PBMCs). These results, for the first time, describe a novel, potent ?CR peptide inhibitor that inhibit the actions of the ?CR without affecting erythropoiesis.

SUBMITTER: Kilar CR 

PROVIDER: S-EPMC6475910 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature