GRK2/β‐arrestin mediates arginine vasopressin‐induced cardiac fibroblast proliferation

Abstract

Cardiac fibrosis is a pathological feature commonly found in hearts exposed to haemodynamic orneurohormonal stress. Elevated levels of arginine vasopressin (AVP) are closely associated with the progression of heart failure and could be an underlying cause of cardiac fibrosis. The aim of this study is to characterize the effect of AVP on neonatal rat cardiac fibroblasts (NRCFs) and to illustrate its signalling mechanism. The proliferative effect of AVP was assessed by methylthiazolyldiphenyl-tetrazolium assay and 5-bromo-2'-deoxyuridine (BrdU) incorporation assay, and the amounts of cellular signalling proteins α-smooth muscle actin (α-SMA), matrix metalloproteinase (MMP) 2, MMP9, and phosphorylated ERK were determined by western blotting. AVP, in a time- and concentration-dependent manner, promoted NRCF proliferation and the expression of MMP2 and MMP9. Inhibition of G protein-coupled receptor kinase2 (GRK2) by the inhibitory peptide GRK2-Ct or knock-down of GRK2 suppressed AVP-induced BrdU incorporation and the expression of MMP2 and α-SMA in NRCFs. Moreover, shRNA-mediated silencing of β-arrestin1 or β-arrestin 2 abolished AVP-induced BrdU incorporation and MMP2 expression. AVP-induced NRCF proliferation depended on the phosphorylation of ERK , and inhibition of GRK2 or silencing of β-arrestins blocked AVP-induced ERK phosphorylation. The effects of AVP on NRCF proliferation and α-SMA expression were blocked by SR45059, a vasopressin receptor type1A (V R) selective antagonist. In conclusion, AVP promotes NRCF proliferation through V R-mediated GRK2/β-arrestin/ERK signalling.

GRK2 Mediates Arginine Vasopressin-Induced Interleukin-6 Production via Nuclear Factor-κB Signaling Neonatal Rat Cardiac Fibroblast

“…V 1A R Mediates AVP-Induced Inflammation. To determine which subtypes functionally mediate AVP-induced IL-6 production, mRNAs for V 1A receptor were detected only by reverse transcription-PCR in NRCFS (Chen et al, 2017). More importantly, the V 1A receptor selective inhibitor SR49059 efficiently blocked the AVP-induced IL-6 expression with 2.35 6 0.46 nM, IC 50 (n 5 3, Fig.…”

“…GRK in inflammation and inflammatory disease is an evolving area of research (Packiriswamy and Parameswaran, 2015), but there is little information on the inflammatory regulation of GRK2 in hearts. Our previous study has shown that AVP enhances the survival of H9c2 myoblasts (Zhu et al, 2013), proliferation of rat smooth muscle (Zhang et al, 2016), and cardiac fibroblasts (Chen et al, 2015(Chen et al, , 2017) via a GRK2/b-arrestin1/ERK 1/2 -dependent pathway. The present study investigated the effect of AVP on IL-6 production in neonatal rat cardiac fibroblasts (NRCFs) and the relative impact of the GRK2-dependent signaling on this effect.…”

“…All three subtypes belong to the G proteincoupled receptor (GPCR) superfamily (Carmichael and Kumar, 1994;Thibonnier et al, 2002). Among the three subtypes of the vasopressin receptors, only V 1A R is expressed in cardiac myocytes (Hiroyama et al, 2007) and in cardiac fibroblasts (Chen et al, 2017). Administration of AVP increases cell hypertrophy in neonatal mouse cardiomyocytes (Hiroyama et al, 2007), and either constitutive or controlled overexpression of V 1A Rin cardiac myocytes induces hypertrophy and dilation of the left ventricles, diminishes contractile performance of the myocardium, and reprograms the heart failure gene profile in transgenic mice; its effects are mediated primarily via Ga q protein-dependent signaling (Li et al, 2011).…”

“…Although Ga q -coupled V 1A R typically induces protein kinase C, an activator of the myocardial hypertrophic gene programs (Li et al, 2011), it also interacts with GPCR kinase (GRK) isoforms (Tilley et al, 2014), primarily GRK2 (Chen et al, 2015(Chen et al, , 2017Zhang et al, 2016). Besides their well defined roles in receptor desensitization, GRKs also activate the G protein-independent signaling pathways (Moore et al, 2007;Huang et al, 2011).…”

A Chinese Perspective on Receptors and Receptor Regulation

“…In addition to b-arrestin, increasing nontraditional functions of GPCR kinases (GRKs) have also been discovered beyond their original function for GPCR desensitization. Zhu et al (2012) found that Gi-biased b 2 -adrenergic receptor signaling links GRK2 upregulation to heart failure, and that GRK2/b-arrestin signaling mediates the proliferation of cardiac fibroblast induced by arginine vasopressin (Chen et al, 2017) and cell survival evoked by hypoxia (Zhu et al, 2013). In this special issue, Dr. Weizhong Zhu's laboratory found that GRK2 mediates arginine vasopressin-induced interleukin-6 production via nuclear factor kB p65 signaling in neonatal rat cardiac fibroblasts (Xu et al, 2017).…”