Development of original metabolically stable apelin‐17 analogs with diuretic and cardiovascular effects

Abstract

Apelin, a (neuro)vasoactive peptide, plays a prominent role in controlling cardiovascular functions and water balance. Because the in vivo apelin half-life is in the minute range, we aimed to identify metabolically stable apelin-17 (K17F) analogs. We generated P92 by classic chemical substitutions and LIT01-196 by original addition of a fluorocarbon chain to the N terminus of K17F. Both analogs were much more stable in plasma (half-life >24 h for LIT01-196) than K17F (4.6 min). Analogs displayed a subnanomolar affinity for the apelin receptor and behaved as full agonists with regard to cAMP production, ERK phosphorylation, and apelin receptor internalization. Ex vivo, these compounds induced vasorelaxation of rat aortas and glomerular arterioles, respectively, precontracted with norepinephrine and angiotensin II, and increased cardiac contractility. In vivo, after intracerebroventricular administration in water-deprived mice, P92 and LIT01-196 were 6 and 160 times, respectively, more efficient at inhibiting systemic vasopressin release than K17F. Administered intravenously (nmol/kg range) in normotensive rats, these analogs potently increased urine output and induced a profound and sustained decrease in arterial blood pressure. In summary, these new compounds, which favor diuresis and improve cardiac contractility while reducing vascular resistances, represent promising candidates for the treatment of heart failure and water retention/hyponatremic disorders.-Gerbier, R., Alvear-Perez, R., Margathe, J.-F., Flahault, A., Couvineau, P., Gao, J., De Mota, N., Dabire, H., Li, B., Ceraudo, E., Hus-Citharel, A., Esteoulle, L., Bisoo, C., Hibert, M., Berdeaux, A., Iturrioz, X., Bonnet, D., Llorens-Cortes, C. Development of original metabolically stable apelin-17 analogs with diuretic and cardiovascular effects.

Role of the Vasopressin/Apelin Balance and Potential Use of Metabolically Stable Apelin Analogs in Water Metabolism Disorders

“…However, K17F is 30 times more potent in inducing rat ApelinR internalization when compared to pE13F (33). Deletion of the C-terminal Phe of K17F (K16P) or its substitution by an alanine (K17A) strongly decreases the ability of the peptide to trigger ApelinR internalization without effect on its affinity for the ApelinR or its ability to activate Gαi-coupling (18, 20).…”

“…In addition, Gerbier et al (33) showed that K17F and pE13F have a half-life in mouse plasma of 4.6 and 7.2 min, respectively, and Murza et al (42) showed that pE13F has a 14 min half-life in rat plasma. Regarding apelin-36, Japp et al (43) suggested from experiments conducted in healthy human subjects that the half-life of apelin 36 is lower than 5 min.…”

“…Numerous technologies, such as PEGylation (44, 45), palmytoylation (46) conjugation to albumin, N-terminal acetylation (33), C-terminal amidation (47), use of unnatural amino acids (15, 33, 42, 48), or main chain modifications (cyclization) (49–51) have now been set up to increase the in vivo plasma half-life of peptides (52). Table 1 summarizes the pharmacological characteristics of the main metabolically stable apelin analogs described in this section.…”

“…Given these findings, metabolically stable K17F analogs were recently developed (15, 33). For this purpose, each amino acid of the sequence of K17F, which includes that of pE13F, was replaced with its D-isomer or with an unnatural amino acid.…”

“…P92 and LIT01-196 displayed full agonist activity for cAMP production, ERK1/2 phosphorylation (nanomolar range), induction of ApelinR internalization (subnanomolar range), and β-arrestin recruitment (33). …”