Browsing by Author "Koch, Walter J"

Now showing 1 - 16 of 16
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    A (Alpha1-Adrenergic Receptors), B (Blocking Alpha1-Adrenergic Receptors), C (Catecholamines): On the Road to Heart Failure
    (JACC: Basic to Translational Science, 2024-01-01) Roy, Rajika; Koch, Walter J
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    A peptide of the amino-terminus of GRK2 induces hypertrophy and yet elicits cardioprotection after pressure overload
    (Journal of Molecular and Cellular Cardiology, 2021-05) Bledzka, Kamila M; Manaserh, Iyad H; Grondolsky, Jessica; Pfleger, Jessica; Roy, Rajika; Gao, Erhe; Chuprun, J Kurt; Koch, Walter J; Schumacher, Sarah M
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    A peptide of the N terminus of GRK5 attenuates pressure-overload hypertrophy and heart failure
    (Science Signaling, 2021-03-30) Coleman, Ryan C; Eguchi, Akito; Lieu, Melissa; Roy, Rajika; Barr, Eric W; Ibetti, Jessica; Lucchese, Anna-Maria; Peluzzo, Amanda M; Gresham, Kenneth; Chuprun, J Kurt; Koch, Walter J
    GRK5 does not mediate pathological signaling in the heart if its nuclear translocation is disrupted.
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    Adding another GRK to the fire of heart failure
    (European Heart Journal, 2021-04-07) Roy, Rajika; Koch, Walter J
    Abstract
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    Characterization of βARKct engineered cellular extracellular vesicles and model specific cardioprotection
    (American Journal of Physiology-Heart and Circulatory Physiology, 2021-04-01) Kwon, Jin-Sook; Schumacher, Sarah M; Gao, Erhe; Chuprun, J Kurt; Ibetti, Jessica; Roy, Rajika; Khan, Mohsin; Kishore, Raj; Koch, Walter J
    βARKct, the peptide inhibitor of GRK2, improves survival and metabolic functions of cardiac-derived progenitor cells. As any benefit of stem cells in the ischemic and injured heart suggests paracrine mechanisms via secreted EVs, we investigated whether CDC-βARKct engineered EVs would show any benefit over control CDC-EVs. Compared with control EVs, βARKct-containing EVs displayed some unique beneficial properties that may be due to altered pro- and anti-inflammatory cytokines within the vesicles.
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    Diabetes impairs cardioprotective function of endothelial progenitor cell-derived extracellular vesicles via H3K9Ac inhibition
    (Theranostics, 2022) Huang, Grace; Cheng, Zhongjian; Hildebrand, Alycia; Wang, Chunlin; Cimini, Maria; Roy, Rajika; Lucchese, Anna Maria; Benedict, Cindy; Mallaredy, Vandana; Magadum, Ajit; Joladarashi, Darukeshwara; Thej, Charan; Gonzalez, Carolina; Trungcao, May; Garikipati, Venkata Naga Srikanth; Elrod, John W; Koch, Walter J; Kishore, Raj
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    Enhanced NCLX-dependent mitochondrial Ca2+ efflux attenuates pathological remodeling in heart failure
    (Journal of Molecular and Cellular Cardiology, 2022-06) Garbincius, Joanne F; Luongo, Timothy S; Jadiya, Pooja; Hildebrand, Alycia N; Kolmetzky, Devin W; Mangold, Adam S; Roy, Rajika; Ibetti, Jessica; Nwokedi, Mary; Koch, Walter J; Elrod, John W
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    G protein-coupled receptor kinase 5 (GRK5) contributes to impaired cardiac function and immune cell recruitment in post-ischemic heart failure
    (Cardiovascular Research, 2022-01-07) de Lucia, Claudio; Grisanti, Laurel A; Borghetti, Giulia; Piedepalumbo, Michela; Ibetti, Jessica; Lucchese, Anna Maria; Barr, Eric W; Roy, Rajika; Okyere, Ama Dedo; Murphy, Haley Christine; Gao, Erhe; Rengo, Giuseppe; Houser, Steven R; Tilley, Douglas G; Koch, Walter J
    Abstract Aims  Myocardial infarction (MI) is the most common cause of heart failure (HF) worldwide. G protein-coupled receptor kinase 5 (GRK5) is upregulated in failing human myocardium and promotes maladaptive cardiac hypertrophy in animal models. However, the role of GRK5 in ischemic heart disease is still unknown. In this study, we evaluated whether myocardial GRK5 plays a critical role post-MI in mice and included the examination of specific cardiac immune and inflammatory responses. Methods and results  Cardiomyocyte-specific GRK5 overexpressing transgenic mice (TgGRK5) and non-transgenic littermate control (NLC) mice as well as cardiomyocyte-specific GRK5 knockout mice (GRK5cKO) and wild type (WT) were subjected to MI and, functional as well as structural changes together with outcomes were studied. TgGRK5 post-MI mice showed decreased cardiac function, augmented left ventricular dimension and decreased survival rate compared to NLC post-MI mice. Cardiac hypertrophy and fibrosis as well as fetal gene expression were increased post-MI in TgGRK5 compared to NLC mice. In TgGRK5 mice, GRK5 elevation produced immuno-regulators that contributed to the elevated and long-lasting leukocyte recruitment into the injured heart and ultimately to chronic cardiac inflammation. We found an increased presence of pro-inflammatory neutrophils and macrophages as well as neutrophils, macrophages and T-lymphocytes at 4-days and 8-weeks respectively post-MI in TgGRK5 hearts. Conversely, GRK5cKO mice were protected from ischemic injury and showed reduced early immune cell recruitment (predominantly monocytes) to the heart, improved contractility and reduced mortality compared to WT post-MI mice. Interestingly, cardiomyocyte-specific GRK2 transgenic mice did not share the same phenotype of TgGRK5 mice and did not have increased cardiac leukocyte migration and cytokine or chemokine production post-MI. Conclusions  Our study shows that myocyte GRK5 has a crucial and GRK-selective role on the regulation of leucocyte infiltration into the heart, cardiac function and survival in a murine model of post-ischemic HF, supporting GRK5 inhibition as a therapeutic target for HF.
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    Genomic Binding Patterns of Forkhead Box Protein O1 Reveal Its Unique Role in Cardiac Hypertrophy
    (Circulation, 2020-09) Pfleger, Jessica; Coleman, Ryan C; Ibetti, Jessica; Roy, Rajika; Kyriazis, Ioannis D; Gao, Erhe; Drosatos, Konstantinos; Koch, Walter J
    Background: Cardiac hypertrophic growth is mediated by robust changes in gene expression and changes that underlie the increase in cardiomyocyte size. The former is regulated by RNA polymerase II (pol II) de novo recruitment or loss; the latter involves incremental increases in the transcriptional elongation activity of pol II that is preassembled at the transcription start site. The differential regulation of these distinct processes by transcription factors remains unknown. Forkhead box protein O1 (FoxO1) is an insulin-sensitive transcription factor that is also regulated by hypertrophic stimuli in the heart. However, the scope of its gene regulation remains unexplored. Methods: To address this, we performed FoxO1 chromatin immunoprecipitation–deep sequencing in mouse hearts after 7 days of isoproterenol injections (3 mg·kg −1 ·mg −1 ), transverse aortic constriction, or vehicle injection/sham surgery. Results: Our data demonstrate increases in FoxO1 chromatin binding during cardiac hypertrophic growth, which positively correlate with extent of hypertrophy. To assess the role of FoxO1 on pol II dynamics and gene expression, the FoxO1 chromatin immunoprecipitation–deep sequencing results were aligned with those of pol II chromatin immunoprecipitation–deep sequencing across the chromosomal coordinates of sham- or transverse aortic constriction–operated mouse hearts. This uncovered that FoxO1 binds to the promoters of 60% of cardiac-expressed genes at baseline and 91% after transverse aortic constriction. FoxO1 binding is increased in genes regulated by pol II de novo recruitment, loss, or pause-release. In vitro, endothelin-1– and, in vivo, pressure overload–induced cardiomyocyte hypertrophic growth is prevented with FoxO1 knockdown or deletion, which was accompanied by reductions in inducible genes, including Comtd1 in vitro and Fstl1 and Uck2 in vivo. Conclusions: Together, our data suggest that FoxO1 may mediate cardiac hypertrophic growth via regulation of pol II de novo recruitment and pause-release; the latter represents the majority (59%) of FoxO1-bound, pol II–regulated genes after pressure overload. These findings demonstrate the breadth of transcriptional regulation by FoxO1 during cardiac hypertrophy, information that is essential for its therapeutic targeting.
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    Interleukin-10 Deficiency Alters Endothelial Progenitor Cell–Derived Exosome Reparative Effect on Myocardial Repair via Integrin-Linked Kinase Enrichment
    (Circulation Research, 2020-01-31) Yue, Yujia; Wang, Chunlin; Benedict, Cindy; Huang, Grace; Truongcao, May; Roy, Rajika; Cimini, Maria; Garikipati, Venkata Naga Srikanth; Cheng, Zhongjian; Koch, Walter J; Kishore, Raj
    Rationale: Systemic inflammation compromises the reparative properties of endothelial progenitor cell (EPC) and their exosomes on myocardial repair, although the underlying mechanism of loss of function of exosomes from inflamed EPCs is still obscure. Objective: To determine the mechanisms of IL-10 (interleukin-10) deficient-EPC–derived exosome dysfunction in myocardial repair and to investigate if modification of specific exosome cargo can rescue reparative activity. Methods and Results: Using IL-10 knockout mice mimicking systemic inflammation condition, we compared therapeutic effect and protein cargo of exosomes isolated from wild-type EPC and IL-10 knockout EPC. In a mouse model of myocardial infarction (MI), wild-type EPC-derived exosome treatment significantly improved left ventricle cardiac function, inhibited cell apoptosis, reduced MI scar size, and promoted post-MI neovascularization, whereas IL-10 knockout EPC-derived exosome treatment showed diminished and opposite effects. Mass spectrometry analysis revealed wild-type EPC-derived exosome and IL-10 knockout EPC-derived exosome contain different protein expression pattern. Among differentially expressed proteins, ILK (integrin-linked kinase) was highly enriched in both IL-10 knockout EPC-derived exosome as well as TNFα (tumor necrosis factor-α)-treated mouse cardiac endothelial cell–derived exosomes (TNFα inflamed mouse cardiac endothelial cell–derived exosome). ILK-enriched exosomes activated NF-κB (nuclear factor κB) pathway and NF-κB–dependent gene transcription in recipient endothelial cells and this effect was partly attenuated through ILK knockdown in exosomes. Intriguingly, ILK knockdown in IL-10 knockout EPC-derived exosome significantly rescued their reparative dysfunction in myocardial repair, improved left ventricle cardiac function, reduced MI scar size, and enhanced post-MI neovascularization in MI mouse model. Conclusions: IL-10 deficiency/inflammation alters EPC-derived exosome function, content and therapeutic effect on myocardial repair by upregulating ILK enrichment in exosomes, and ILK-mediated activation of NF-κB pathway in recipient cells, whereas ILK knockdown in exosomes attenuates NF-κB activation and reduces inflammatory response. Our study provides new understanding of how inflammation may alter stem cell-exosome–mediated cardiac repair and identifies ILK as a target kinase for improving progenitor cell exosome-based cardiac therapies.
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    Level of beta-adrenergic receptor kinase 1 inhibition determines degree of cardiac dysfunction after chronic pressure overload-induced heart failure.
    (Circulation, 2005-02-08) Tachibana, Hideo; Naga Prasad, Sathyamangla V; Lefkowitz, Robert J; Koch, Walter J; Rockman, Howard A
    BACKGROUND: Heart failure is characterized by abnormalities in beta-adrenergic receptor (betaAR) signaling, including increased level of myocardial betaAR kinase 1 (betaARK1). Our previous studies have shown that inhibition of betaARK1 with the use of the Gbetagamma sequestering peptide of betaARK1 (betaARKct) can prevent cardiac dysfunction in models of heart failure. Because inhibition of betaARK activity is pivotal for amelioration of cardiac dysfunction, we investigated whether the level of betaARK1 inhibition correlates with the degree of heart failure. METHODS AND RESULTS: Transgenic (TG) mice with varying degrees of cardiac-specific expression of betaARKct peptide underwent transverse aortic constriction (TAC) for 12 weeks. Cardiac function was assessed by serial echocardiography in conscious mice, and the level of myocardial betaARKct protein was quantified at termination of the study. TG mice showed a positive linear relationship between the level of betaARKct protein expression and fractional shortening at 12 weeks after TAC. TG mice with low betaARKct expression developed severe heart failure, whereas mice with high betaARKct expression showed significantly less cardiac deterioration than wild-type (WT) mice. Importantly, mice with a high level of betaARKct expression had preserved isoproterenol-stimulated adenylyl cyclase activity and normal betaAR densities in the cardiac membranes. In contrast, mice with low expression of the transgene had marked abnormalities in betaAR function, similar to the WT mice. CONCLUSIONS: These data show that the level of betaARK1 inhibition determines the degree to which cardiac function can be preserved in response to pressure overload and has important therapeutic implications when betaARK1 inhibition is considered as a molecular target.
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    Loss of dynamic regulation of G protein-coupled receptor kinase 2 by nitric oxide leads to cardiovascular dysfunction with aging.
    (American journal of physiology. Heart and circulatory physiology, 2020-05) Lieu, Melissa; Traynham, Christopher J; de Lucia, Claudio; Pfleger, Jessica; Piedepalumbo, Michela; Roy, Rajika; Petovic, Jennifer; Landesberg, Gavin; Forrester, Steven J; Hoffman, Matthew; Grisanti, Laurel A; Yuan, Ancai; Gao, Erhe; Drosatos, Konstantinos; Eguchi, Satoru; Scalia, Rosario; Tilley, Douglas G; Koch, Walter J
    Nitric oxide (NO) and S-nitrosothiol (SNO) are considered cardio- and vasoprotective substances. We now understand that one mechanism in which NO/SNOs provide cardiovascular protection is through their direct inhibition of cardiac G protein-coupled receptor (GPCR) kinase 2 (GRK2) activity via S-nitrosylation of GRK2 at cysteine 340 (C340). This maintains GPCR homeostasis, including β-adrenergic receptors, through curbing receptor GRK2-mediated desensitization. Previously, we have developed a knockin mouse (GRK2-C340S) where endogenous GRK2 is resistant to dynamic S-nitrosylation, which led to increased GRK2 desensitizing activity. This unchecked regulation of cardiac GRK2 activity resulted in significantly more myocardial damage after ischemic injury that was resistant to NO-mediated cardioprotection. Although young adult GRK2-C340S mice show no overt phenotype, we now report that as these mice age, they develop significant cardiovascular dysfunction due to the loss of SNO-mediated GRK2 regulation. This pathological phenotype is apparent as early as 12 mo of age and includes reduced cardiac function, increased cardiac perivascular fibrosis, and maladaptive cardiac hypertrophy, which are common maladies found in patients with cardiovascular disease (CVD). There are also vascular reactivity and aortic abnormalities present in these mice. Therefore, our data demonstrate that a chronic and global increase in GRK2 activity is sufficient to cause cardiovascular remodeling and dysfunction, likely due to GRK2's desensitizing effects in several tissues. Because GRK2 levels have been reported to be elevated in elderly CVD patients, GRK2-C340 mice can give insight into the aged-molecular landscape leading to CVD.NEW & NOTEWORTHY Research on G protein-coupled receptor kinase 2 (GRK2) in the setting of cardiovascular aging is largely unknown despite its strong established functions in cardiovascular physiology and pathophysiology. This study uses a mouse model of chronic GRK2 overactivity to further investigate the consequences of long-term GRK2 on cardiac function and structure. We report for the first time that chronic GRK2 overactivity was able to cause cardiac dysfunction and remodeling independent of surgical intervention, highlighting the importance of GRK activity in aged-related heart disease.
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    MAP Kinase Phosphatase-5 Deficiency Protects Against Pressure Overload-Induced Cardiac Fibrosis
    (Frontiers in Immunology) Zhong, Chao; Min, Kisuk; Zhao, Zhiqiang; Zhang, Cheng; Gao, Erhe; Huang, Yan; Zhang, Xinbo; Baldini, Margaret; Roy, Rajika; Yang, Xiaofeng; Koch, Walter J; Bennett, Anton M; Yu, Jun
    Cardiac fibrosis, a pathological condition due to excessive extracellular matrix (ECM) deposition in the myocardium, is associated with nearly all forms of heart disease. The processes and mechanisms that regulate cardiac fibrosis are not fully understood. In response to cardiac injury, macrophages undergo marked phenotypic and functional changes and act as crucial regulators of myocardial fibrotic remodeling. Here we show that the mitogen-activated protein kinase (MAPK) phosphatase-5 (MKP-5) in macrophages is involved in pressure overload-induced cardiac fibrosis. Cardiac pressure overload resulting from transverse aortic constriction (TAC) leads to the upregulation of Mkp-5 gene expression in the heart. In mice lacking MKP-5, p38 MAPK and JNK were hyperactivated in the heart, and TAC-induced cardiac hypertrophy and myocardial fibrosis were attenuated. MKP-5 deficiency upregulated the expression of the ECM-degrading matrix metalloproteinase-9 (Mmp-9) in the Ly6Clow (M2-type) cardiac macrophage subset. Consistent with in vivo findings, MKP-5 deficiency promoted MMP-9 expression and activity of pro-fibrotic macrophages in response to IL-4 stimulation. Furthermore, using pharmacological inhibitors against p38 MAPK, JNK, and ERK, we demonstrated that MKP-5 suppresses MMP-9 expression through a combined effect of p38 MAPK/JNK/ERK, which subsequently contributes to the inhibition of ECM-degrading activity. Taken together, our study indicates that pressure overload induces MKP-5 expression and facilitates cardiac hypertrophy and fibrosis. MKP-5 deficiency attenuates cardiac fibrosis through MAPK-mediated regulation of MMP-9 expression in Ly6Clow cardiac macrophages.
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    Not All β-Receptors Appear the Same in Heart Failure: Emergence of β3-Agonists as a Therapeutic Option
    (Circulation: Heart Failure, 2022-07) Roy, Rajika; Koch, Walter J
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    Podoplanin neutralization improves cardiac remodeling and function after acute myocardial infarction.
    (JCI insight, 2019-07) Cimini, Maria; Garikipati, Venkata Naga Srikanth; de Lucia, Claudio; Cheng, Zhongjian; Wang, Chunlin; Truongcao, May M; Lucchese, Anna Maria; Roy, Rajika; Benedict, Cindy; Goukassian, David A; Koch, Walter J; Kishore, Raj
    Podoplanin, a small mucine-type transmembrane glycoprotein, has been recently shown to be expressed by lymphangiogenic, fibrogenic and mesenchymal progenitor cells in the acutely and chronically infarcted myocardium. Podoplanin binds to CLEC-2, a C-type lectin-like receptor 2 highly expressed by CD11bhigh cells following inflammatory stimuli. Why podoplanin expression appears only after organ injury is currently unknown. Here, we characterize the role of podoplanin in different stages of myocardial repair after infarction and propose a podoplanin-mediated mechanism in the resolution of post-MI inflammatory response and cardiac repair. Neutralization of podoplanin led to significant improvements in the left ventricular functions and scar composition in animals treated with podoplanin neutralizing antibody. The inhibition of the interaction between podoplanin and CLEC-2 expressing immune cells in the heart enhances the cardiac performance, regeneration and angiogenesis post MI. Our data indicates that modulating the interaction between podoplanin positive cells with the immune cells after myocardial infarction positively affects immune cell recruitment and may represent a novel therapeutic target to augment post-MI cardiac repair, regeneration and function.
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    Restricting mitochondrial GRK2 post-ischemia confers cardioprotection by reducing myocyte death and maintaining glucose oxidation
    (Science Signaling, 2018-12-11) Sato, Priscila Y; Chuprun, J Kurt; Grisanti, Laurel A; Woodall, Meryl C; Brown, Brett R; Roy, Rajika; Traynham, Christopher J; Ibetti, Jessica; Lucchese, Anna M; Yuan, Ancai; Drosatos, Konstantinos; Tilley, Doug G; Gao, Erhe; Koch, Walter J
    Preventing GRK2 from localizing to mitochondria lessens the damage induced by myocardial infarction.