Pepducin ICL1-9-Mediated β2-Adrenergic Receptor-Dependent Cardiomyocyte Contractility Occurs in a Gi Protein/ROCK/PKD-Sensitive Manner.
Pepducin ICL1-9-Mediated β2-Adrenergic Receptor-Dependent Cardiomyocyte Contractility Occurs in a Gi Protein/ROCK/PKD-Sensitive Manner.
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Pepducin ICL1-9 介导的 β2 肾上腺素受体依赖性心肌细胞收缩性以 Gi 蛋白/ROCK/PKD 敏感方式发生。
DOI：
10.1007/s10557-021-07299-4
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发表时间：
2023
影响因子：
3.4
通讯作者：
Tilley,DouglasG
中科院分区：
文献类型：
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作者：
Okyere,AmaDedo;Song,Jianliang;Patwa,Viren;Carter,RhondaL;Enjamuri,Nitya;Lucchese,AnnaMaria;Ibetti,Jessica;deLucia,Claudio;Schumacher,SarahM;Koch,WalterJ;Cheung,JosephY;Benovic,JeffreyL;Tilley,DouglasG
目的β-肾上腺素能受体(β-AR)是治疗心力衰竭(HF)的重要靶点；然而，长期使用β-AR激动剂作为正性肌力受体，以Gs蛋白依赖的方式增加收缩功能，会增加死亡率。或者，我们先前报道了β2AR与肽蛋白胞内环(βin cell loop，ICL)1-9的变构调节以β-arrestin(RhoA)依赖的方式增加心肌细胞的收缩能力，随后我们发现ICL1-9激活了RAS同源家族成员A(RhoA)。在此，我们旨在阐明参与ICL1-9促进心肌细胞收缩的近端和下游信号介质。方法我们测量了成年小鼠心肌细胞对ICL1-9或异丙肾上腺素(ISO，作为阳性对照)单独或在βARR或RhoA依赖信号的各种潜在成分的抑制剂存在下的心肌收缩能力。我们还观察了ICL1-9对缺乏G蛋白偶联受体(GPCRK)2(GRK2)或GRK5(GRK5)的心肌细胞的收缩作用。结果与ICL1-9激活RhoA一致，抑制Rho相关蛋白激酶(ROCK)和蛋白激酶D(PKD)都能减弱ICL1-9介导的收缩作用，肌球蛋白轻链激酶(MLCK)的抑制也是如此。虽然GRK2和GRK5缺失均不影响ICL1-9介导的心肌收缩能力，但百日咳毒素可减弱这种反应，提示ICL1-9以一种依赖于GiProtein的方式促进下游RhoA依赖的信号转导。结论本研究提出了一种新的信号转导途径，可通过β2AR的变构调节促进GiProtein/β依赖的RhoA/ROCK/PKD信号的激活，从而为心衰时心肌收缩功能的增强或保护提供新的途径。
Purposeβ-Adrenergic receptors (βAR) are essential targets for the treatment of heart failure (HF); however, chronic use of βAR agonists as positive inotropes to increase contractility in a Gsprotein-dependent manner is associated with increased mortality. Alternatively, we previously reported that allosteric modulation of β2AR with the pepducin intracellular loop (ICL)1-9 increased cardiomyocyte contractility in a β-arrestin (βarr)-dependent manner, and subsequently showed that ICL1-9 activates the Ras homolog family member A (RhoA). Here, we aimed to elucidate both the proximal and downstream signaling mediators involved in the promotion of cardiomyocyte contractility in response to ICL1-9.MethodsWe measured adult mouse cardiomyocyte contractility in response to ICL1-9 or isoproterenol (ISO, as a positive control) alone or in the presence of inhibitors of various potential components of βarr- or RhoA-dependent signaling. We also assessed the contractile effects of ICL1-9 on cardiomyocytes lacking G protein-coupled receptor (GPCR) kinase 2 (GRK2) or 5 (GRK5).ResultsConsistent with RhoA activation by ICL1-9, both Rho-associated protein kinase (ROCK) and protein kinase D (PKD) inhibition were able to attenuate ICL1-9-mediated contractility, as was inhibition of myosin light chain kinase (MLCK). While neither GRK2 nor GRK5 deletion impacted ICL1-9-mediated contractility, pertussis toxin attenuated the response, suggesting that ICL1-9 promotes downstream RhoA-dependent signaling in a Giprotein-dependent manner.ConclusionAltogether, our study highlights a novel signaling modality that may offer a new approach to the promotion, or preservation, of cardiac contractility during HF via the allosteric regulation of β2AR to promote Giprotein/βarr-dependent activation of RhoA/ROCK/PKD signaling.