Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
Am J Physiol Heart Circ Physiol. 2012 Oct 15;303(8):H1001-10. doi: 10.1152/ajpheart.00475.2012. Epub 2012 Aug 10.
Pharmacological blockade of the ANG II type 1 receptor (AT1R) is a common therapy for treatment of congestive heart failure and hypertension. Increasing evidence suggests that selective engagement of β-arrestin-mediated AT1R signaling, referred to as biased signaling, promotes cardioprotective signaling. Here, we tested the hypothesis that a β-arrestin-biased AT1R ligand TRV120023 would confer cardioprotection in response to acute cardiac injury compared with the traditional AT1R blocker (ARB), losartan. TRV120023 promotes cardiac contractility, assessed by pressure-volume loop analyses, while blocking the effects of endogenous ANG II. Compared with losartan, TRV120023 significantly activates MAPK and Akt signaling pathways. These hemodynamic and biochemical effects were lost in β-arrestin-2 knockout (KO) mice. In response to cardiac injury induced by ischemia reperfusion injury or mechanical stretch, pretreatment with TRV120023 significantly diminishes cell death compared with losartan, which did not appear to be cardioprotective. This cytoprotective effect was lost in β-arrestin-2 KO mice. The β-arrestin-biased AT1R ligand, TRV120023, has cardioprotective and functional properties in vivo, which are distinct from losartan. Our data suggest that this novel class of drugs may provide an advantage over conventional ARBs by supporting cardiac function and reducing cellular injury during acute cardiac injury.
血管紧张素 II 型 1 型受体(AT1R)的药理学阻断是治疗充血性心力衰竭和高血压的常用疗法。越来越多的证据表明,β-arrestin 介导的 AT1R 信号的选择性参与,称为偏倚信号,促进心脏保护性信号。在这里,我们测试了这样一个假设,即与传统的 AT1R 阻滞剂(ARB)洛沙坦相比,β-arrestin 偏向性 AT1R 配体 TRV120023 在急性心脏损伤时会提供心脏保护作用。TRV120023 通过压力-容积环分析评估促进心肌收缩力,同时阻断内源性 ANG II 的作用。与洛沙坦相比,TRV120023 显著激活 MAPK 和 Akt 信号通路。这些血流动力学和生化作用在β-arrestin-2 敲除(KO)小鼠中丢失。在缺血再灌注损伤或机械拉伸引起的心脏损伤反应中,与洛沙坦相比,TRV120023 预处理可显著减少细胞死亡,而洛沙坦似乎没有心脏保护作用。这种细胞保护作用在β-arrestin-2 KO 小鼠中丢失。β-arrestin 偏向性 AT1R 配体 TRV120023 在体内具有心脏保护和功能特性,与洛沙坦不同。我们的数据表明,与传统的 ARBs 相比,这种新型药物类可能通过支持心脏功能和减少急性心脏损伤期间的细胞损伤提供优势。