scholarly journals A Peptide of the Amino-Terminus of GRK2 Induces Hypertrophy and Yet Elicits Cardioprotection after Pressure Overload

2020 ◽  
Author(s):  
Sarah M. Schumacher ◽  
Kamila M. Bledzka ◽  
Jessica Grondolsky ◽  
Rajika Roy ◽  
Erhe Gao ◽  
...  

AbstractG protein-coupled receptor (GPCR) kinase 2 (GRK2) expression and activity are elevated early on in response to several forms of cardiovascular stress and are a hallmark of heart failure. Interestingly, though, in addition to its well-characterized role in regulating GPCRs, mounting evidence suggests a GRK2 “interactome” that underlies a great diversity in its functional roles. Several such GRK2 interacting partners are important for adaptive and maladaptive myocyte growth; therefore, an understanding of domain-specific interactions with signaling and regulatory molecules could lead to novel targets for heart failure therapy. While elevated cardiac levels and activity of GRK2 contribute to adverse heart remodeling and contractile dysfunction, inhibition of GRK2 via overexpression of a carboxyl-terminal peptide, βARKct, or its amino-terminal domain Regulator of G protein Signaling (RGS) homology domain (βARKrgs) can enhance cardiac function and can prevent heart failure development via Gβγ or Gαq sequestration, respectively. Previously, our lab investigated cardiac-specific transgenic expression of a fragment of this RGS domain (βARKnt) (residues 50-145). In contrast to βARKrgs this fragment did not alter acute hypertrophy after pressure overload or demonstrate RGS activity in vivo against Gq-mediated signaling. Herein, we subjected these transgenic mice to pressure overload and found that unlike their littermate controls or previous GRK2 fragments, they exhibited an increased left ventricular wall thickness and mass prior to cardiac stress that underwent proportional hypertrophic growth to controls after acute pressure overload. Importantly, despite this enlarged heart, βARKnt mice did not undergo the expected transition to heart failure observed in controls. Further, βARKnt expression limited adverse left ventricular remodeling and increased cell survival signaling. These data support the idea that the βARKnt peptide embodies a distinct functional interaction and novel means of cardioprotection during pressure-overload induced heart failure.

2011 ◽  
Vol 301 (5) ◽  
pp. C1046-C1056 ◽  
Author(s):  
Serban P. Georgescu ◽  
Mark J. Aronovitz ◽  
Juan L. Iovanna ◽  
Richard D. Patten ◽  
John M. Kyriakis ◽  
...  

Left ventricular remodeling, including the deposition of excess extracellular matrix, is key to the pathogenesis of heart failure. The stress-inducible transcriptional regulator p8 is increased in failing human hearts and is required both for agonist-stimulated cardiomyocyte hypertrophy and for cardiac fibroblasts matrix metalloprotease-9 (MMP9) induction. In the heart, upregulation of autophagy is an adaptive response to stress and plays a causative role in cardiomyopathies. We have recently shown that p8 ablation in cardiac cells upregulates autophagy and that, in vivo, loss of p8 results in a decrease of cardiac function. Here we investigated the effects of p8 genetic deletion in mediating adverse myocardial remodeling. Unstressed p8−/− mouse hearts manifested complex alterations in the expression of fibrosis markers. In addition, these mice displayed elevated autophagy and apoptosis compared with p8+/+ mice. Transverse aortic constriction (TAC) induced left ventricular p8 expression in p8+/+ mice. Pressure overload caused left ventricular remodeling in both genotypes, however, p8−/− mice showed less cardiac fibrosis induction. Consistent with this, although MMP9 induction was attenuated in the p8−/− mice, induction of MMP2 and MMP3 were strikingly upregulated while TIMP2 was downregulated. Left ventricular autophagy increased after TAC and was significantly higher in the p8−/− mice. Thus p8-deletion results in reduced collagen fibrosis after TAC, but in turn, is associated with a detrimental higher increase in autophagy. These findings suggest a role for p8 in regulating in vivo key signaling pathways involved in the pathogenesis of heart failure.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Sarah M Schumacher ◽  
Erhe Gao ◽  
J. Kurt Chuprun ◽  
Walter J Koch

During heart failure (HF), cardiac levels and activity of the G protein-coupled receptor (GPCR) kinase (GRK) GRK2 are elevated and contribute to adverse remodeling and contractile dysfunction, while inhibition via a carboxyl-terminal peptide, βARKct, enhances heart function and can prevent HF development. Mounting evidence supports the idea of a dynamic “interactome” in which GRK2 can uncouple GPCRs via novel protein-protein interactions. Several GRK2 interacting partners are important for adaptive and maladaptive myocyte growth; therefore, an understanding of domain-specific interactions with signaling and regulatory molecules could lead to novel targets for HF therapy. For instance, GRK2 contains a putative amino-terminal Regulator of G protein Signaling (RGS) domain (βARK-RGS) that directly interacts with Gq and appears to inhibit signaling without altering Gq enzymatic activity. Previously, our lab investigated cardiac-specific transgenic (Tg) expression of a fragment of this RGS domain (βARKnt). This fragment did not alter acute hypertrophy after pressure overload or demonstrate RGS activity in vivo against Gq-mediated signaling. In contrast, βARKnt induced hypertrophy and elevated β-adrenergic receptor (βAR) density without altering agonist-induced contractility or adenylyl cyclase activity, due to a compensatory increase in GRK2 activity. Importantly, though, βAR downregulation in response to chronic agonist administration was attenuated by βARKnt expression, indicating a novel regulation of βAR receptor density. Given these findings we have recently investigated the effect of βARKnt expression during chronic pressure overload post trans-aortic constriction (TAC). Echocardiographic analysis revealed increased posterior wall thickness and left-ventricular mass 4 weeks post-TAC compared to non-transgenic littermate controls (NLC). Importantly, despite enhanced hypertrophy, the progression to HF was inhibited in βARKnt mice 14 weeks post-TAC (%LV Ejection Fraction of 36.1 ± 0.2 in NLC versus 56.6 ± 0.9 in Tg mice). While mechanistic characterization is underway, these data indicate that βARKnt-mediated regulation of βAR density may provide a novel means of cardioprotection during pressure-overload induced HF.


2019 ◽  
Vol 5 (1) ◽  
pp. 22 ◽  
Author(s):  
Henri Charrier ◽  
Marie Cuvelliez ◽  
Emilie Dubois-Deruy ◽  
Paul Mulder ◽  
Vincent Richard ◽  
...  

Heart failure (HF) has several etiologies including myocardial infarction (MI) and left ventricular remodeling (LVR), but its progression remains difficult to predict in clinical practice. Systems biology analyses of LVR after MI provide molecular insights into this event such as modulation of microRNA (miRNA) that could be used as a signature of HF progression. To define a miRNA signature of LVR after MI, we use 2 systems biology approaches, integrating either proteomic data generated from LV of post-MI rat induced by left coronary artery ligation or multi-omics data (proteins and non-coding RNAs) generated from plasma of post-MI patients from the REVE-2 study. The first approach predicted that 13 miRNAs and 3 of these miRNAs would be validated to be associated with LVR in vivo: miR-21-5p, miR-23a-3p and miR-222-3p. The second approach predicted that 24 miRNAs among 1310 molecules and 6 of these miRNAs would be selected to be associated with LVR in silico: miR-17-5p, miR-21-5p, miR-26b-5p, miR-222-3p, miR-335-5p and miR-375. We identified a signature of 7 microRNAs associated with LVR after MI that support the interest of integrative systems biology analyses to define a miRNA signature of HF progression.


2021 ◽  
Vol 14 (676) ◽  
pp. eabb5968
Author(s):  
Ryan C. Coleman ◽  
Akito Eguchi ◽  
Melissa Lieu ◽  
Rajika Roy ◽  
Eric W. Barr ◽  
...  

Aberrant changes in gene expression underlie the pathogenesis and progression of pressure-overload heart failure, leading to maladaptive cardiac hypertrophy, ventricular remodeling, and contractile dysfunction. Signaling through the G protein Gq triggers maladaptation and heart failure, in part through the activation of G protein–coupled receptor kinase 5 (GRK5). Hypertrophic stimuli induce the accumulation of GRK5 in the nuclei of cardiomyocytes, where it regulates pathological gene expression through multiple transcription factors including NFAT. The nuclear targeting of GRK5 is mediated by an amino-terminal (NT) domain that binds to calmodulin (CaM). Here, we sought to prevent GRK5-mediated pathology in pressure-overload maladaptation and heart failure by expressing in cardiomyocytes a peptide encoding the GRK5 NT (GRK5nt) that encompasses the CaM binding domain. In cultured cardiomyocytes, GRK5nt expression abrogated Gq-coupled receptor–mediated hypertrophy, including attenuation of pathological gene expression and the transcriptional activity of NFAT and NF-κB. We confirmed that GRK5nt bound to and blocked Ca2+-CaM from associating with endogenous GRK5, thereby preventing GRK5 nuclear accumulation after pressure overload. We generated mice that expressed GRKnt in a cardiac-specific fashion (TgGRK5nt mice), which exhibited reduced cardiac hypertrophy, ventricular dysfunction, pulmonary congestion, and cardiac fibrosis after chronic transverse aortic constriction. Together, our data support a role for GRK5nt as an inhibitor of pathological GRK5 signaling that prevents heart failure.


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Sarah M Schumacher ◽  
Erhe Gao ◽  
J. Kurt Chuprun ◽  
Walter J. Koch

During heart failure (HF), cardiac levels and activity of the G protein-coupled receptor (GPCR) kinase (GRK) GRK2 are elevated and contribute to adverse remodeling and contractile dysfunction, while inhibition via a carboxyl-terminal peptide, βARKct, enhances heart function and can prevent HF. Mounting evidence supports the idea of a dynamic “interactome” in which GRK2 can uncouple GPCRs via novel protein-protein interactions. Several GRK2 interacting partners are important for adaptive and maladaptive myocyte growth; therefore, an understanding of domain-specific interactions with signaling and regulatory molecules could lead to novel targets for HF therapy. For instance, GRK2 contains a putative amino-terminal R egulator of G protein S ignaling (RGS) domain (βARKrgs) that directly interacts with Gαq and inhibits signaling. Previously, our lab investigated cardiac-specific transgenic expression of a fragment of this RGS domain (βARKnt), that did not reduce acute hypertrophy after pressure overload or demonstrate RGS activity in vivo against Gαq-mediated signaling. In contrast, βARKnt induced hypertrophy and elevated β-adrenergic receptor (βAR) density without altering agonist-induced contractility or adenylyl cyclase activity, due to a compensatory increase in GRK2 activity. Importantly, βAR downregulation in response to chronic agonist administration was attenuated by βARKnt expression, indicating a novel regulation of βAR receptor density. Herein, we investigated the effect of βARKnt expression during chronic pressure overload post trans-aortic constriction (TAC). Echocardiographic analysis revealed increased posterior wall thickness and left-ventricular mass 4 weeks post-TAC compared to non-transgenic littermate controls. Importantly, despite enhanced hypertrophy, the progression to HF was inhibited in βARKnt mice 14 weeks post-TAC. Histological analysis of interstitial fibrosis and cross-sectional area is underway to determine alterations in maladaptive remodeling. Further, cardiomyocyte signaling and βARKnt protein-binding partners are a focus, since our data indicate that βARKnt-mediated regulation of βAR density may provide a novel means of cardioprotection during pressure-overload induced HF.


Author(s):  
Henri Charrier ◽  
Marie Cuvelliez ◽  
Emilie Dubois-Deruy ◽  
Paul Mulder ◽  
Vincent Richard ◽  
...  

Heart failure (HF) has several etiologies including myocardial infarction (MI) and left ventricular remodeling (LVR), but its progression remains difficult to predict in clinical practice. Systems biology analyses of LVR after MI predict molecular insights of this event such as modulation of microRNA (miRNA) that could be used as a signature of HF progression. To define a miRNA signature of LVR after MI, we use 2 systems biology approaches integrating either proteomic data generated from LV of post-MI rat induced by left coronary artery ligation or multi-omics data (proteins and non-coding RNAs) generated from plasma of post-MI patients from the REVE-2 study. The first approach predicts 13 miRNAs and 3 of these miRNAs were validated to be associated with LVR in vivo: miR-21-5p, miR-23a-3p and miR-222-3p. The second approach predicts 24 miRNAs among 1310 molecules and 6 of these miRNAs were selected to be associated with LVR in silico: miR-17-5p, miR-21-5p, miR-26b-5p, miR-222-3p, miR-335-5p and miR-375. We identified a signature of 7 microRNAs associated with LVR after MI that support the interest of integrative systems biology analyses to define a miRNA signature of HF progression.


Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 256-OR ◽  
Author(s):  
JAGDEEP S.S. SINGH ◽  
IFY MORDI ◽  
MOHAPRADEEP MOHAN ◽  
STEPHEN J. GANDY ◽  
EWAN PEARSON ◽  
...  

2019 ◽  
Vol 4 (3) ◽  
pp. 120-123
Author(s):  
Ioana Cîrneală ◽  
Diana Opincariu ◽  
István Kovács ◽  
Monica Chițu ◽  
Imre Benedek

Abstract Heart failure is a clinical syndrome that appears as a consequence of a structural disease, and the most common cause of left ventricular systolic dysfunction results from myocardial ischemia. Cardiac remodeling and neuroendocrine activation are the major compensatory mechanisms in heart failure. The main objective of the study is to identify the association between serum biomarkers illustrating the extent of myocardial necrosis (highly sensitive troponin as-says), left ventricular dysfunction (NT-proBNP), and systemic inflammatory response (illustrated via serum levels of hsCRP and interleukins) during the acute phase of a myocardial infarction, and the left ventricular remodeling process at 6 months following the acute event, quantified via speckle tracking echocardiography. The study will include 400 patients diagnosed with acute myocardial infarction without signs and symptoms of heart failure at the time of enrollment that will undergo a complex clinical examination and speckle tracking echocardiography. Serum samples from the peripheral blood will be collected in order to determine the inflammatory serum biomarkers. After 6 months, patients will be divided into 2 groups according to the development of ventricular remodeling, quantified by speckle tracking echocardiography: group 1 will consist of patients with a remodeling index lower than 15%, and group 2 will consist of patients with a remodeling index higher than 15%. All clinical and imaging data obtained at the baseline will be compared between these two groups in order to determine the features associated with a higher risk of deleterious ventricular remodeling and heart failure.


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