Discovery of new antagonists aimed at discriminating UII and URP-mediated biological activities: insight into UII and URP receptor activation

Autor: Chatenet, D, Létourneau, M, Nguyen, QT, Doan, ND, Dupuis, J, Fournier, A
Přispěvatelé: International Associated laboratory Samuel de Champlain, Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de la Recherche Scientifique [Québec] (INRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP), Montreal Heart Institute, Université de Montréal (UdeM), Department of Medicine
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: British Journal of Pharmacology
British Journal of Pharmacology, Wiley, 2013, 168 (4), pp.807-21. ⟨10.1111/j.1476-5381.2012.02217.x⟩
ISSN: 0007-1188
1476-5381
DOI: 10.1111/j.1476-5381.2012.02217.x⟩
Popis: International audience; BACKGROUND AND PURPOSE: Recent evidence suggested that urotensin II (UII) and its paralog peptide UII-related peptide (URP) might exert common but also divergent physiological actions. Unfortunately, none of the existing antagonists were designed to discriminate specific UII- or URP-associated actions, and our understanding, on how these two endogenous peptides can trigger different, but also common responses, is limited. EXPERIMENTAL APPROACH: Ex vivo rat and monkey aortic ring contraction as well as dissociation kinetics studies using transfected CHO cells expressing the human urotensin (UT) receptors were used in this study. KEY RESULTS: Ex vivo rat and monkey aortic ring contraction studies revealed the propensity of [Pep(4)]URP to decrease the maximal response of human UII (hUII) without any significant change in potency, whereas no effect was noticeable on the URP-induced vasoconstriction. Dissociation experiments demonstrated the ability of [Pep(4)]URP to increase the dissociation rate of hUII, but not URP. Surprisingly, URP, an equipotent UII paralog, was also able to accelerate the dissociation rate of membrane-bound (125)I-hUII, whereas hUII had no noticeable effect on URP dissociation kinetics. Further experiments suggested that an interaction between the glutamic residue at position 1 of hUII and the UT receptor seems to be critical to induce conformational changes associated with agonistic activation. Finally, we demonstrated that the N-terminal domain of the rat UII isoform was able to act as a specific antagonist of the URP-associated actions. CONCLUSION: Such compounds, that is [Pep(4)]URP and rUII(1-7), should prove to be useful as new pharmacological tools to decipher the specific role of UII and URP in vitro but also in vivo.
Databáze: OpenAIRE
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