Protamine is an antagonist of apelin receptor, and its activity is reversed by heparin.

Journal Article (Journal Article)

Apelin signaling plays an important role during embryo development and regulates angiogenesis, cardiovascular activity, and energy metabolism in adulthood. Overexpression and hyperactivity of this signaling pathway is observed in various pathologic states, such as cardiovascular diseases and cancer, which highlights the importance of inhibiting apelin receptor (APJ); therefore, we developed a cell-based screening assay that uses fluorescence microscopy to identify APJ antagonists. This approach led us to identify the U.S. Food and Drug Administration-approved compound protamine-already used clinically after cardiac surgery-as an agent to bind to heparin and thereby reverse its anticlotting activity. Protamine displays a 390-nM affinity for APJ and behaves as a full antagonist with regard to G protein and β-arrestin-dependent intracellular signaling. Ex vivo and in vivo, protamine abolishes well-known apelin effects, such as angiogenesis, glucose tolerance, and vasodilatation. Remarkably, protamine antagonist activity is fully reversed by heparin treatment both in vitro and in vivo Thus, our results demonstrate a new pharmacologic property of protamine-blockade of APJ-that could explain some adverse effects observed in protamine-treated patients. Moreover, our data reveal that the established antiangiogenic activity of protamine would rely on APJ antagonism.-Le Gonidec, S., Chaves-Almagro, C., Bai, Y., Kang, H. J., Smith, A., Wanecq, E., Huang, X.-P., Prats, H., Knibiehler, B., Roth, B. L., Barak, L. S., Caron, M. G., Valet, P., Audigier, Y., Masri, B. Protamine is an antagonist of apelin receptor, and its activity is reversed by heparin.

Full Text

Duke Authors

Cited Authors

  • Le Gonidec, S; Chaves-Almagro, C; Bai, Y; Kang, HJ; Smith, A; Wanecq, E; Huang, X-P; Prats, H; Knibiehler, B; Roth, BL; Barak, LS; Caron, MG; Valet, P; Audigier, Y; Masri, B

Published Date

  • June 2017

Published In

Volume / Issue

  • 31 / 6

Start / End Page

  • 2507 - 2519

PubMed ID

  • 28242772

Pubmed Central ID

  • PMC6191096

Electronic International Standard Serial Number (EISSN)

  • 1530-6860

Digital Object Identifier (DOI)

  • 10.1096/fj.201601074R


  • eng

Conference Location

  • United States