Abstract 18942: Inhibition of β-arrestin 1 Prevents post-MI Maladaptive Ventricular Remodeling

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Md Abdur Razzaque ◽  
Xianyao Xu ◽  
Abbasali Badami ◽  
Peter Klepacz ◽  
Mei Han ◽  
...  

Remote (non-infarct) territory fibrosis is a significant cause of post-myocardial infarction (MI) heart failure (HF). We have previously shown that increased activity of β-arrestin 1 in adult human cardiac fibroblasts (CF) isolated from failing hearts is an important mechanism of cardiac fibrosis. This study investigates the potential therapeutic role of β-arrestin 1 inhibition on CF biology in vivo. Adult male rats underwent LAD ligation to induce post-MI HF. β-arrestin 1 was inhibited by intra-coronary adenoviral-mediated delivery of a β-arrestin 1 inhibitor (Ad-Barr1ct) immediately following LAD ligation (n=11). Ad-Barr1ct contains a rat β-arrestin 1 C-terminal fragment (aa. 369-418). Control rats received a null adenovirus (n=10). Animals were studied prior to and up to 8 weeks (wks) post-MI and adenoviral delivery. There was a significant decline in LV function at 8 wks post-MI in Ad-null rats vs. pre-MI. Remote territory (non-infarct area) fibrosis increased by 8 wks post-MI consistent with adverse remodeling. Intra-coronary delivery of Ad-Barr1ct following LAD ligation significantly inhibited post-MI LV dysfunction vs. Ad-Null as measured by improved fractional shortening and ejection fraction. Ad-Barr1ct also decreased peri-infarct and remote territory fibrosis. Consistent with these findings, Ad-arr1ct resulted in decreased α-SMA, collagen I, collegen III and fibronectin expression in CF isolated 8 wks post-MI vs. Ad-Null providing evidence of decreased post-MI CF activation and myofibroblast transformation with Ad-Barr1ct. Targeted inhibition of β-arrestin 1 in the heart may represent a novel therapeutic approach to prevent pathological fibrosis and maladaptive remodeling post-MI.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jennifer L Philip ◽  
Xianyao Xu ◽  
Mei Han ◽  
Jinju Li ◽  
Abdur Razzaque ◽  
...  

Remote (non-infarct) territory fibrosis is a significant cause of post-myocardial infarction (MI) heart failure (HF). We have previously shown that increased activity of G protein-coupled receptor kinase-2 (GRK2) in adult human cardiac fibroblasts (CF) isolated from failing hearts is an important mechanism of cardiac fibrosis. This study investigates the potential therapeutic role of GRK2 inhibition on CF biology in vivo. Adult male rats underwent LAD ligation to induce post-MI HF. GRK2 was inhibited by intra-coronary adenoviral-mediated delivery of a GRK2 inhibitor (Ad-GRK2ct) immediately following LAD ligation (n=11). Control rats received a null adenovirus (n=10). Animals were studied prior to and up to 12 weeks (wks) post-MI and adenoviral delivery. There was a significant decline in LV function at 2 wks post-MI which was present through 12 wks [Fractional shortening: 0.35±0.01 vs. 0.52±0.01, p<0.01] in Ad-null rats vs. pre-MI. Remote territory (non-infarct area) fibrosis increased by 2 wks post-MI [6±1% vs. 2±1% fibrosis, p<0.01] progressing by 12 wks to 12% fibrosis [p<0.01], consistent with adverse remodeling. Collagen synthesis was upregulated 2.9-fold in CF isolated 12 wks post-MI [p<0.03] and GRK2 activity was increased 1.4-fold [p=0.002]. There was a 42% decrease in intracellular cAMP [p<0.05] and loss of β-agonist-stimulated inhibition of collagen synthesis characteristic of normal CF [3969±1058 vs. 708±95 cmp/mg protein, p<0.01]. Intra-coronary delivery of Ad-GRK2ct following LAD ligation significantly inhibited post-MI LV dysfunction vs. Ad-Null as measured by improved fractional shortening [0.42±0.01 vs. 0.30±0.02, p<0.01] and ejection fraction [72±1% vs. 57±2%, p<0.01]. Ad-GRK2ct also decreased peri-infarct and remote territory fibrosis by 60% [p<0.001]. Consistent with these findings, Ad-GRK2ct resulted in decreased a-SMA, collagen I, and collegen III expression in CF isolated 12 wks post-MI vs. Ad-Null providing evidence of decreased post-MI CF activation and myofibroblast transformation with Ad-GRK2ct. Targeted inhibition of GRK2 and restoration of β-adrenergic signaling/cAMP production in CF may represent a novel therapeutic approach to prevent pathological fibrosis and maladaptive remodeling post-MI.


Circulation ◽  
2018 ◽  
Vol 138 (5) ◽  
pp. 513-526 ◽  
Author(s):  
Kevin J. Morine ◽  
Xiaoying Qiao ◽  
Sam York ◽  
Peter S. Natov ◽  
Vikram Paruchuri ◽  
...  

Background: Heart failure is a growing cause of morbidity and mortality worldwide. Transforming growth factor beta (TGF-β1) promotes cardiac fibrosis, but also activates counterregulatory pathways that serve to regulate TGF-β1 activity in heart failure. Bone morphogenetic protein 9 (BMP9) is a member of the TGFβ family of cytokines and signals via the downstream effector protein Smad1. Endoglin is a TGFβ coreceptor that promotes TGF-β1 signaling via Smad3 and binds BMP9 with high affinity. We hypothesized that BMP9 limits cardiac fibrosis by activating Smad1 and attenuating Smad3, and, furthermore, that neutralizing endoglin activity promotes BMP9 activity. Methods: We examined BMP9 expression and signaling in human cardiac fibroblasts and human subjects with heart failure. We used the transverse aortic constriction–induced model of heart failure to evaluate the functional effect of BMP9 signaling on cardiac remodeling. Results: BMP9 expression is increased in the circulation and left ventricle (LV) of human subjects with heart failure and is expressed by cardiac fibroblasts. Next, we observed that BMP9 attenuates type I collagen synthesis in human cardiac fibroblasts using recombinant human BMP9 and a small interfering RNA approach. In BMP9 –/– mice subjected to transverse aortic constriction, loss of BMP9 activity promotes cardiac fibrosis, impairs LV function, and increases LV levels of phosphorylated Smad3 (pSmad3), not pSmad1. In contrast, treatment of wild-type mice subjected to transverse aortic constriction with recombinant BMP9 limits progression of cardiac fibrosis, improves LV function, enhances myocardial capillary density, and increases LV levels of pSmad1, not pSmad3 in comparison with vehicle-treated controls. Because endoglin binds BMP9 with high affinity, we explored the effect of reduced endoglin activity on BMP9 activity. Neutralizing endoglin activity in human cardiac fibroblasts or in wild-type mice subjected to transverse aortic constriction–induced heart failure limits collagen production, increases BMP9 protein levels, and increases levels of pSmad1, not pSmad3. Conclusions: Our results identify a novel functional role for BMP9 as an endogenous inhibitor of cardiac fibrosis attributable to LV pressure overload and further show that treatment with either recombinant BMP9 or disruption of endoglin activity promotes BMP9 activity and limits cardiac fibrosis in heart failure, thereby providing potentially novel therapeutic approaches for patients with heart failure.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Zeping Qiu ◽  
Jingwen Zhao ◽  
Fanyi Huang ◽  
Luhan Bao ◽  
Yanjia Chen ◽  
...  

AbstractMyocardial fibrosis and ventricular remodeling were the key pathology factors causing undesirable consequence after myocardial infarction. However, an efficient therapeutic method remains unclear, partly due to difficulty in continuously preventing neurohormonal overactivation and potential disadvantages of cell therapy for clinical practice. In this study, a rhACE2-electrospun fibrous patch with sustained releasing of rhACE2 to shape an induction transformation niche in situ was introduced, through micro-sol electrospinning technologies. A durable releasing pattern of rhACE2 encapsulated in hyaluronic acid (HA)—poly(L-lactic acid) (PLLA) core-shell structure was observed. By multiple in vitro studies, the rhACE2 patch demonstrated effectiveness in reducing cardiomyocytes apoptosis under hypoxia stress and inhibiting cardiac fibroblasts proliferation, which gave evidence for its in vivo efficacy. For striking mice myocardial infarction experiments, a successful prevention of adverse ventricular remodeling has been demonstrated, reflecting by improved ejection fraction, normal ventricle structure and less fibrosis. The rhACE2 patch niche showed clear superiority in long term function and structure preservation after ischemia compared with intramyocardial injection. Thus, the micro-sol electrospun rhACE2 fibrous patch niche was proved to be efficient, cost-effective and easy-to-use in preventing ventricular adverse remodeling.


Endocrinology ◽  
2012 ◽  
Vol 153 (8) ◽  
pp. 3692-3700 ◽  
Author(s):  
Hui-Ping Gu ◽  
Sen Lin ◽  
Ming Xu ◽  
Hai-Yi Yu ◽  
Xiao-Jun Du ◽  
...  

Myocardial fibrosis is a key pathological change in a variety of heart diseases contributing to the development of heart failure, arrhythmias, and sudden death. Recent studies have shown that relaxin prevents and reverses cardiac fibrosis. Endogenous expression of relaxin was elevated in the setting of heart disease; the extent of such up-regulation, however, is insufficient to exert compensatory actions, and the mechanism regulating relaxin expression is poorly defined. In the rat relaxin-1 (RLN1, Chr1) gene promoter region we found presence of repeated guanine (G)-rich sequences, which allowed formation and stabilization of G-quadruplexes with the addition of a G-quadruplex interactive ligand berberine. The G-rich sequences and the G-quadruplexes were localized adjacent to the binding motif of signal transducer and activator of transcription (STAT)3, which negatively regulates relaxin expression. Thus, we hypothesized that the formation and stabilization of G-quadruplexes by berberine could influence relaxin expression. We found that berberine-induced formation of G-quadruplexes did increase relaxin gene expression measured at mRNA and protein levels. Formation of G-quadruplexes significantly reduced STAT3 binding to the promoter of relaxin gene. This was associated with consequent increase in the binding of RNA polymerase II and STAT5a to relaxin gene promoter. In cardiac fibroblasts and rats treated with angiotensin II, berberine was found to suppress fibroblast activation, collagen synthesis, and extent of cardiac fibrosis through up-regulating relaxin. The antifibrotic action of berberine in vitro and in vivo was similar to that by exogenous relaxin. Our findings document a novel therapeutic strategy for fibrosis through up-regulating expression of endogenous relaxin.


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Masataka Nishiga ◽  
Takahiro Horie ◽  
Yasuhide Kuwabara ◽  
Osamu Baba ◽  
Tetsushi Nakao ◽  
...  

Background: A highly conserved microRNA, miR-33 is considered as a potential therapeutic target for atherosclerosis, because recent reports, including ours, indicated miR-33 has atherogenic effects by reducing HDL-C. However, the functions of miR-33 in heart failure remain to be elucidated. Methods and results: To clarify the functions of miR-33 involved in cardiac hypertrophy and fibrosis in vivo, we investigated the responses to pressure overload by transverse aortic constriction (TAC) in miR-33 deficient (KO) mice. When subjected to TAC, miR-33 expression level was significantly up-regulated in wild-type (WT) left ventricles, whereas miR-33 KO hearts displayed no less hypertrophic responses than WT hearts. However, interestingly, histological and gene expression analyses showed ameliorated cardiac fibrosis in miR-33 KO hearts compared to WT hearts. Furthermore, we generated cardiac fibroblast specific miR-33 deficient mice, which also showed ameliorated cardiac fibrosis when they were subjected to TAC. We also found that cardiac fibroblasts were mainly responsible for miR-33 expression in the heart, because its expression was about 4-folds higher in isolated primary cardiac fibroblasts than cardiomyocytes. Deficiency of miR-33 impaired cell proliferation in primary fibroblasts, which was considered due to altered lipid raft cholesterol content by up-regulated ATP-binding cassette transporter A1/G1. Conclusion: Deficiency of miR-33 impaired fibroblast proliferation in vitro, and ameliorated cardiac fibrosis induced by pressure overload in vivo.


Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Shuang Li ◽  
Dong Han ◽  
Dachun Yang

Background: Hypertensive ventricular remodeling is a common cause of heart failure. Activation and accumulation of cardiac fibroblasts is the key contributors to this progression. Our previous studies indicate that transient receptor potential ankyrin 1 (TRPA1), a Ca 2+ channel necessary and sufficient, play a prominent role in ventricular remodeling. However, the molecular mechanisms regulating remain poorly understood. Methods: We used TRPA1 agonists cinnamaldehyde (CA) pretreatment and TRPA1 knockout mice to understand the role of TRPA1 in ventricular remodeling of hypertensive heart. We also examine the mechanisms through gene transfection and in vitro experiments. Results: TRPA1 overexpression fully activated myofibroblast transformation, while fibroblasts lacking TRPA1 were refractory to transforming growth factor β (TGF-β) -induced transdifferentiation. TRPA1 knockout mice showed hypertensive ventricular remodeling reversal following pressure overload. We found that the TGF-β induced TRPA1 expression through calcineurin-NFAT-Dyrk1A signaling pathway via the TRPA1 promoter. Once induced, TRPA1 activates the Ca 2+ -responsive protein phosphatase calcineurin, which itself induced myofibroblast transdifferentiation. Moreover, inhibition of calcineurin prevented TRPA1-dependent transdifferentiation. Conclusion: Our study provides the first evidence that TRPA1 regulation in cardiac fibroblasts transformation in response to hypertensive stimulation. The results suggesting a comprehensive pathway for myofibroblast formation in conjunction with TGF-β, Calcineurin, NFAT and Dyrk1A. Furthermore, these data indicate that negative modulation of cardiac fibroblast TRPA1 may represent a therapeutic strategy against hypertensive cardiac remodeling.


2016 ◽  
Vol 64 (4) ◽  
pp. 912.1-912
Author(s):  
M Razzaque ◽  
JL Philip ◽  
X Xu ◽  
M Han ◽  
J Li ◽  
...  

ObjectivesRemote (non-infarct) territory fibrosis is a significant cause of post-infarction heart failure (HF). We have previously shown that increased G protein-coupled receptor kinase-2 (GRK2) activity in adult human cardiac fibroblasts (CF) isolated from failing hearts is an important mechanism of cardiac fibrosis through uncoupling β-adrenergic receptor (β-AR) signaling. This study investigates the potential therapeutic role of GRK2 inhibition on CF biology in vivo.MethodsAdult male rats underwent LAD ligation to induce post-MI HF. Left ventricular (LV) function was assessed by echocardiography. Myocardial fibrosis was quantitated by histologic staining. LV CF were isolated and cultured. GRK2 was inhibited by intra-coronary adenoviral-mediated delivery of a GRK2 inhibitor (Ad-GRK2ct) immediately following LAD ligation (n=11). Control rats received a null adenovirus (n=10). Animals were studied prior to and 12 weeks post-MI and adenoviral delivery.ResultsThere was a significant decline in LV function at 12 weeks post-MI which [Fractional shortening: 0.35±0.01 vs. 0.52±0.01, p<0.01]. There was significant increase in remote territory (non-infarct area) fibrosis at 12 weeks post-MI compared to control [12±1% vs. 2±1% fibrosis, p<0.05], consistent with adverse remodeling. Additionally, collagen synthesis was significantly upregulated in isolated CF 12 weeks post-MI compared to control CF [3559±760 vs. 1029±45 cmp/mg protein, p<0.02]. At 12 weeks post-MI, GRK2 activity was increased 1.4-fold [p<0.01]. There was a 42% decrease in intracellular cAMP [p<0.05] and loss of b-agonist (isoproterenol)-stimulated inhibition of collagen synthesis characteristic of normal CF, indicating uncoupling of β-AR signaling post-MI. Adenoviral mediated overexpression of GRK2ct, GRK2 inhibitor, in vitro in the cultured CF post-MI led to a 50% decrease in aSMA expression (p<0.01) as well as a significant decreased collagen expression and synthesis compared to null adenovirus (Ad-Null) control [1928±126 vs. 2611±213 cmp/mg protein, p<0.05], restoring the control CF phenotype. Intra-coronary delivery of Ad-GRK2ct following MI significantly reduced post-MI LV dysfunction vs. Ad-Null as measured by improved fractional shortening [0.42±0.01 vs. 0.30±0.02, p<0.01] and ejection fraction [72±1% vs. 57±2%, p<0.03]. Ad-GRK2ct also decreased peri-infarct and remote territory fibrosis by 60% [p<0.03]. Consistent with these findings, Ad-GRK2ct resulted in an over 25% decreased in α-SMA, collagen I, and collagen III expression in CF isolated 12 weeks post-MI vs. Ad-Null [p<0.04] providing evidence of decreased post-MI CF activation and myofibroblast transformation with Ad-GRK2ct.ConclusionsUncoupling of β-adrenergic signaling in CF via increased GRK2 appears to be a key mechanism of post-MI fibrosis. Targeted inhibition of GRK2 and restoration of b-adrenergic signaling/cAMP production in CF may represent a novel therapeutic approach to prevent pathological fibrosis and maladaptive remodeling.


2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Sundaravadivel Balasubramanian ◽  
Harinath Kasiganesan ◽  
Lakeya Quinones ◽  
Yuhua Zhang ◽  
Amy Bradshaw ◽  
...  

During prolonged hypertrophic insult to the myocardium, while the function of cardiomyocytes needs to be protected, the hyperactivation of cardiac fibroblasts has to be curbed to prevent fibrosis. Previously, we showed that integrin-mediated non-receptor tyrosine kinase (NRTK) activation is required for normal functioning of both cardiac fibroblasts and cardiomyocytes. We hypothesized that inhibition of NRTKs in cardiac fibroblasts without affecting cardiomyocytes would be beneficial to the stressed myocardium. Our initial studies using kinase inactive forms of Src, Pyk2 and FAK expressed adenovirally in isolated primary cardiac fibroblasts showed that the pro-fibrotic signaling events as studied by fibronectin and collagen deposition are downregulated. Our in vivo studies in mouse transverse aortic constriction (TAC) model suggest that dasatinib, a multikinase NRTK inhibitor administration via a peritoneally implanted mini-osmotic pump is able to preserve ventricular geometry and function and reduce the accumulation of fibrotic extracellular matrix (ECM) proteins upon 4 wk pressure overload. Data obtained from cell culture experiments with kinase inactive NRTKs and dasatinib suggest that NRTK inhibition is able to reduce the proliferation, migration and mitogenic signaling in cardiac fibroblasts without affecting the cell survival pathways in cardiomyocytes. These data indicate that NRTKs play a significant pro-fibrotic role in cardiac fibroblasts and curbing the activity of NRTKs could be a potential therapeutic approach to treat fibrosis in hypertrophic heart diseases.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Shuin Park ◽  
Sara Ranjbarvaziri ◽  
Fides Lay ◽  
Peng Zhao ◽  
Aldons J Lusis ◽  
...  

Fibroblasts are a heterogeneous population of cells that function within the injury response mechanisms across various tissues. Despite their importance in pathophysiology, the effects of different genetic backgrounds on fibroblast contribution to the development of disease has yet to be addressed. It has previously been shown that mice in the Hybrid Mouse Diversity Panel, which consists of 110 inbred mouse strains, display a spectrum in severity of cardiac fibrosis in response to chronic treatment of isoproterenol (ISO). Here, we characterized cardiac fibroblasts (CFbs) from three different mouse strains (C57BL/6J, C3H/HeJ, and KK/HIJ) which exhibited varying degrees of fibrosis after ISO treatment. The select strains of mice underwent sham or ISO treatment via intraperitoneally-implanted osmotic pumps for 21 days. Masson’s Trichrome staining showed significant differences in fibrosis in response to ISO, with KK/HIJ mice demonstrating the highest levels, C3H/HeJ exhibiting milder levels, and C57BL/6J demonstrating little to no fibrosis. When CFbs were isolated and cultured from each strain, the cells demonstrated similar traits at the basal level but responded to ISO stimuli in a strain-specific manner. Likewise, CFbs demonstrated differential behavior and gene expression in vivo in response to ISO. ISO treatment caused CFbs to proliferate similarly across all strains, however, immunofluorescence staining showed differential levels of CFb activation. Additionally, RNA-sequencing analysis revealed unique gene expression profiles of all three strains upon ISO treatment. Our study depicts the phenotypic heterogeneity of CFbs across different strains of mice and our results suggest that ISO-induced cardiac fibrosis is a complex process that is independent of fibroblast proliferation and is mainly driven by the activation/inhibition of genes involved in pro-fibrotic pathways.


Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1667 ◽  
Author(s):  
Lara Matilla ◽  
Vanessa Arrieta ◽  
Eva Jover ◽  
Amaia Garcia-Peña ◽  
Ernesto Martinez-Martinez ◽  
...  

Circulating levels of soluble interleukin 1 receptor-like 1 (sST2) are increased in heart failure and associated with poor outcome, likely because of the activation of inflammation and fibrosis. We investigated the pathogenic role of sST2 as an inductor of cardiac fibroblasts activation and collagen synthesis. The effects of sST2 on human cardiac fibroblasts was assessed using proteomics and immunodetection approaches to evidence the upregulation of neuropilin-1 (NRP-1), a regulator of the profibrotic transforming growth factor (TGF)-β1. In parallel, sST2 increased fibroblast activation, collagen and fibrosis mediators. Pharmacological inhibition of nuclear factor-kappa B (NF-κB) restored NRP-1 levels and blocked profibrotic effects induced by sST2. In NRP-1 knockdown cells, sST2 failed to induce fibroblast activation and collagen synthesis. Exogenous NRP-1 enhanced cardiac fibroblast activation and collagen synthesis via NF-κB. In a pressure overload rat model, sST2 was elevated in association with cardiac fibrosis and was positively correlated with NRP-1 expression. Our study shows that sST2 induces human cardiac fibroblasts activation, as well as the synthesis of collagen and profibrotic molecules. These effects are mediated by NRP-1. The blockade of NF-κB restored NRP-1 expression, improving the profibrotic status induced by sST2. These results show a new pathogenic role for sST2 and its mediator, NRP-1, as cardiac fibroblast activators contributing to cardiac fibrosis.


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