Read Cai, Yang Peiran, Kuc Rhoda E, Nyimanu Duuamene, Williams Thomas L, Glen Robert C, Holt Lucy J, Arulanantham Haren, Smart Andrew, Davenport Anthony P, Maguire Janet J
Experimental Medicine and Immunotherapeutics, Centre for Clinical Investigation, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.
The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, UK.
Basic Clin Pharmacol Toxicol. 2020 Jun;126 Suppl 6:96-103. doi: 10.1111/bcpt.13227. Epub 2019 Apr 10.
The apelin receptor is a potential target in the treatment of heart failure and pulmonary arterial hypertension where levels of endogenous apelin peptides are reduced but significant receptor levels remain. Our aim was to characterise the pharmacology of a modified peptide agonist, MM202, designed to have high affinity for the apelin receptor and resistance to peptidase degradation and linked to an anti-serum albumin domain antibody (AlbudAb) to extend half-life in the blood. In competition, binding experiments in human heart MM202-AlbudAb (pK = 9.39 ± 0.09) bound with similar high affinity as the endogenous peptides [Pyr ]apelin-13 (pK = 8.83 ± 0.06) and apelin-17 (pK = 9.57 ± 0.08). [Pyr ]apelin-13 was tenfold more potent in the cAMP (pD = 9.52 ± 0.05) compared to the β-arrestin (pD = 8.53 ± 0.03) assay, whereas apelin-17 (pD = 10.31 ± 0.28; pD = 10.15 ± 0.13, respectively) and MM202-AlbudAb (pD = 9.15 ± 0.12; pD = 9.26 ± 0.03, respectively) were equipotent in both assays, with MM202-AlbudAb tenfold less potent than apelin-17. MM202-AlbudAb bound to immobilised human serum albumin with high affinity (pK = 9.02). In anaesthetised, male Sprague Dawley rats, MM202-AlbudAb (5 nmol, n = 15) significantly reduced left ventricular systolic pressure by 6.61 ± 1.46 mm Hg and systolic arterial pressure by 14.12 ± 3.35 mm Hg and significantly increased cardiac contractility by 533 ± 170 mm Hg/s, cardiac output by 1277 ± 190 RVU/min, stroke volume by 3.09 ± 0.47 RVU and heart rate by 4.64 ± 2.24 bpm. This study demonstrates that conjugating an apelin mimetic peptide to the AlbudAb structure retains receptor and in vivo activity and may be a new strategy for development of apelin peptides as therapeutic agents.
在心力衰竭和肺动脉高压的治疗中，内源性apelin肽水平降低但受体水平仍显著，apelin受体是一个潜在的治疗靶点。我们的目标是对一种修饰的肽激动剂MM202的药理学特性进行表征，该激动剂设计为对apelin受体具有高亲和力且对肽酶降解具有抗性，并与抗血清白蛋白结构域抗体（AlbudAb）连接以延长其在血液中的半衰期。在竞争结合实验中，MM202 - AlbudAb（pK = 9.39 ± 0.09）与人心脏中的内源性肽[Pyr]apelin - 13（pK = 8.83 ± 0.06）和apelin - 17（pK = 9.57 ± 0.08）以相似的高亲和力结合。与β - 抑制蛋白（pD = 8.53 ± 0.03）检测相比，[Pyr]apelin - 13在cAMP（pD = 9.52 ± 0.05）检测中的效力高10倍，而apelin - 17（分别为pD = 10.31 ± 0.28；pD = 10.15 ± 0.13）和MM202 - AlbudAb（分别为pD = 9.15 ± 0.12；pD = 9.26 ± 0.03）在两种检测中效力相当，MM202 - AlbudAb的效力比apelin - 17低10倍。MM202 - AlbudAb以高亲和力（pK = 9.02）结合固定化的人血清白蛋白。在麻醉的雄性Sprague Dawley大鼠中，MM202 - AlbudAb（5 nmol，n = 15）使左心室收缩压显著降低6.61 ± 1.46 mmHg，收缩期动脉压显著降低14.12 ± 3.35 mmHg，并使心脏收缩力显著增加533 ± 170 mmHg/s，心输出量增加1277 ± 190 RVU/min，每搏输出量增加3.09 ± 0.47 RVU，心率增加4.64 ± 2.24 bpm。本研究表明，将apelin模拟肽与AlbudAb结构缀合可保留受体和体内活性，这可能是开发apelin肽作为治疗药物的一种新策略。
