Abstract 15863: Macrophage Foxp1 is a Regulator of Pathologic Cardiac Hypertrophy

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Shuichi Yoneda ◽  
Saptarsi M Haldar ◽  
Jessica Jenkins ◽  
Yunmei Wang ◽  
Teruo Inoue ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Molecular Mechanisms ◽  
Interstitial Fibrosis ◽  
Systolic Dysfunction ◽  
Disease Process ◽  
Left Ventricular ◽  
Negative Regulator ◽  
Control Male ◽  
Pathologic Cardiac Hypertrophy

Introduction: Pathologic cardiac hypertrophy is a maladaptive response to neurohormonal and hemodynamic stress that is a hallmark of human heart failure. While inflammation has been implicated in pathologic hypertrophy, the molecular mechanisms underlying innate immune dysregulation in this disease process are incompletely defined. We have previously demonstrated that the forkhead transcription factor Foxp1 controls monocyte differentiation and suppresses inflammatory activation of macrophages. In this study, we hypothesized that monocyte/macrophage Foxp1 regulates pathologic cardiac hypertrophy. Methods: Macrophage-specific Foxp1 over-expressing (macFoxp1tg=anti-inflammatory) vs. non-tg controls, as well as macrophage-specific Foxp1 knockdown (macFoxp1ko=pro-inflammatory) vs. Cre-control male mice were subject to chronic angiotensin II (AII) infusion (1.8 mcg/kg/min via subcutaneous osmotic mini-pump) for 4 weeks. Results: AII-mediated cardiac hypertrophy (heart mass and cardiomyocyte cross-sectional area), left ventricular (LV) systolic dysfunction, LV dilation, interstitial fibrosis and macrophage (Mac-3+ cells) accumulation were significantly attenuated in macFoxp1tg mice compared to non-tg controls. In contrast, AII-mediated cardiac hypertrophy, LV systolic dysfunction and cavity dilation were significantly exacerbated in macFoxp1ko mice compared to Cre controls. There were no differences in systemic blood pressure between these groups, corroborating a load-independent role for macrophage Foxp1 in cardiac hypertrophy. Conclusion: These studies identify macrophage Foxp1 as a novel negative regulator of pathologic cardiac hypertrophy in vivo. Modulation of Foxp1 signaling may provide a novel strategy for prevention and treatment of heart failure.

Abstract 1342: The NF-kappaB P50 Subunit Protects Against Remodeling and Cardiac Dysfunction Following Myocardial Infarction

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Leo Timmers ◽  
J Karlijn van Keulen ◽  
Imo I Hoefer ◽  
Joost P Sluijter ◽  
Marie Jose Goumans ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Molecular Mechanisms ◽  
Interstitial Fibrosis ◽  
Systolic Dysfunction ◽  
Protective Role ◽  
Left Ventricular ◽  
Lv Remodeling ◽  
Nf Kappab

Introduction Left ventricular (LV) remodeling leads to congestive heart failure and is a main determinant of morbidity and mortality following myocardial infarction (MI). To further improve the treatment of post infarct LV remodeling, a better understanding of the molecular mechanisms involved in this complicated process is required. The nuclear factor (NF)- κB family (p50, p52, p65) usually forms dimers that regulate DNA transcription in response to a variety of stimuli including pro-inflammatory cytokines, oxidative stress and also ischemia. Inhibition of NF- κB has been shown to reduce heart failure following MI in rats. The specific role of the different NF- κB subunits during LV remodeling, however, has not been clarified thus far. In this study, we elucidate the role of the NF- κB p50 subunit in post infarct LV remodeling. Methods and Results MI was induced in wild type C57Bl6 mice and NF- κB p50 KO mice. Without affecting infarct size (45.4 ± 4.3 vs. 42.5 ± 4.6%; p=0.461), the absence of NF- κB p50 increased the extent of LV remodeling (EDV: 175 ± 13 vs. 107 ± 11 μl; p=0.005) and aggravated systolic dysfunction (LVEF: 16.1 ± 1.5 % vs. 24.7 ± 3.7%; p=0.045) 28 days following MI as assessed by magnetic resonance imaging (9.4 T). In the non-infarcted myocardium, interstitial fibrosis (1.53 ± 0.28 vs. 1.05 ± 0.15 grayvalue/μm 2 ; p=0.042) and hypertrophy (426 ± 51 vs. 251 ± 12 μm 2 /cardiomyocyte; p=0.018) were increased in NF-κB p50 KO mice. In the infarct area, however, collagen density was decreased (15.11 ± 1.16 vs. 27.28 ± 4.93 grayvalue/μm 2 ; p=0.028), which was accompanied by increased TNF-alpha mRNA expression (0.086 ± 0.04 vs. 0.026 ± 0.015; p=0.046) and increased MMP9 activity (0.31 ± 0.03 vs. 0.19 ± 0.03; p=0.049) Conclusion These data provide evidence for a protective role of NF- κB p50 in post infarct maladaptive LV remodeling, most likely by reducing inflammatory cytokine production and matrix degradation.

Abstract 4876: LAMP2 Cardiomyopathy is a Particularly Adverse Phenocopy of Sarcomeric Hypertrophic Cardiomyopathy

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Barry Maron ◽  
William C Roberts ◽  
Michael Arad ◽  
Carolyn Y Ho ◽  
Tammy S Haas ◽  
...  
Keyword(s):  
Heart Failure ◽  
Hypertrophic Cardiomyopathy ◽  
Sudden Death ◽  
Heart Transplantation ◽  
Systolic Dysfunction ◽  
Ventricular Tachyarrhythmia ◽  
Young Patients ◽  
Disease Process ◽  
Left Ventricular ◽  
Asymptomatic Patients

Mutations in the X-linked lysosome-associated membrane protein gene (LAMP2; Danon disease) produce a morphologic phenocopy of sarcomeric hypertrophic cardiomyopathy (HCM) in young patients, characterized by extreme left ventricular (LV) hypertrophy and pre-excitation. However, the natural history of this newly recognized cardiomyopathy is incompletely resolved. Seven young asymptomatic patients with LAMP2 cardiomyopathy were identified at ages 8 to 15 years; 6 were male. LV hypertrophy was particularly marked (septal thickness 25– 65 mm; mean 42±17) in the presence of nondilated LV cavity. On each ECG, Wolff-Parkinson-White pre-excitation pattern was associated with markedly increased voltages (74±38mm for R- or S-wave). Over the 7±3 year follow-up from initial cardiac diagnosis, all 7 patients experienced particularly adverse disease consequences associated with progressive LV wall thinning and cavity dilatation and systolic dysfunction (ejection fraction, 29±7%) by the ages of 12 – 24 years (mean 20). Of the 7 patients, 5 either died of progressive heart failure, had heart transplantation or were considered for a donor heart; 2 others had sudden death events, including one fatal ventricular tachyarrhythmia refractory to defibrillator therapy and one appropriate defibrillator shock in an asymptomatic female survivor. Pathologic examination of hearts at autopsy showed histopathologic findings compatible with both HCM due to sarcomere protein mutations (i.e., extensive myocyte disarray, intramural small vessel disease, myocardial replacement scarring), and also evidence of a storage disease process (i.e., clusters of myocytes with vacuolated sarcoplasm within fibrotic areas). Heart weights, 1266 and 1425 grams, are the most substantial recorded for hypertrophic cardiomyopathies. LAMP2 cardiomyopathy is a uniformly profound, and particularly deleterious disease entity, causing refractory heart failure with systolic dysfunction as well as sudden death in young patients < 25 years of age. This novel phenocopy of sarcomeric HCM underscores the power of molecular diagnosis for predicting prognosis, and should also raise consideration for intervention with early heart transplantation.

Microarray analysis of Akt1 activation in transgenic mouse hearts reveals transcript expression profiles associated with compensatory hypertrophy and failure

2006 ◽  
Vol 27 (2) ◽  
pp. 156-170 ◽  
Author(s):  
Stephan Schiekofer ◽  
Ichiro Shiojima ◽  
Kaori Sato ◽  
Gennaro Galasso ◽  
Yuichi Oshima ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Molecular Mechanisms ◽  
Interstitial Fibrosis ◽  
Expression Profiles ◽  
Active Form ◽  
Heart Tissue ◽  
Compensatory Hypertrophy ◽  
Transcript Expression ◽  
Heart Size

To investigate molecular mechanisms involved in the development of cardiac hypertrophy and heart failure, we developed a tetracycline-regulated transgenic system to conditionally switch a constitutively active form of the Akt1 protein kinase on or off in the adult heart. Short-term activation (2 wk) of Akt1 resulted in completely reversible hypertrophy with maintained contractility. In contrast, chronic Akt1 activation (6 wk) induced extensive cardiac hypertrophy, severe contractile dysfunction, and massive interstitial fibrosis. The focus of this study was to create a transcript expression profile of the heart as it undergoes reversible Akt1-mediated hypertrophy and during the transition from compensated hypertrophy to heart failure. Heart tissue was analyzed before transgene induction, 2 wk after transgene induction, 2 wk of transgene induction followed by 2 days of repression, 6 wk after transgene induction, and 6 wk of transgene induction followed by 2 wk of repression. Acute overexpression of Akt1 (2 wk) leads to changes in the expression of 826 transcripts relative to noninduced hearts, whereas chronic induction (6 wk) led to changes in the expression of 1,611, of which 65% represented transcripts that were regulated during the pathological phase of heart growth. Another set of genes identified was uniquely regulated during heart regression but not growth, indicating that nonoverlapping transcription programs participate in the processes of cardiac hypertrophy and atrophy. These data define the gene regulatory programs downstream of Akt that control heart size and contribute to the transition from compensatory hypertrophy to heart failure.

Cacao Bean Polyphenols Inhibit Cardiac Hypertrophy and Systolic Dysfunction in Pressure Overload-induced Heart Failure Model Mice

Planta Medica ◽  
2020 ◽  
Vol 86 (17) ◽  
pp. 1304-1312
Author(s):  
Nurmila Sari ◽  
Yasufumi Katanasaka ◽  
Hiroki Honda ◽  
Yusuke Miyazaki ◽  
Yoichi Sunagawa ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Gene Transcription ◽  
Binding Protein ◽  
Systolic Dysfunction ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Cardiomyocyte Hypertrophy ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

AbstractPathological stresses such as pressure overload and myocardial infarction induce cardiac hypertrophy, which increases the risk of heart failure. Cacao bean polyphenols have recently gained considerable attention for their beneficial effects on cardiovascular diseases. This study investigated the effect of cacao bean polyphenols on the development of cardiac hypertrophy and heart failure. Cardiomyocytes from neonatal rats were pre-treated with cacao bean polyphenols and then stimulated with 30 µM phenylephrine. C57BL/6j male mice were subjected to sham or transverse aortic constriction surgery and then orally administered with vehicle or cacao bean polyphenols. Cardiac hypertrophy and function were examined by echocardiography. In cardiomyocytes, cacao bean polyphenols significantly suppressed phenylephrine-induced cardiomyocyte hypertrophy and hypertrophic gene transcription. Extracellular signal-regulated kinase 1/2 and GATA binding protein 4 phosphorylation induced by phenylephrine was inhibited by cacao bean polyphenols treatment in the cardiomyocytes. Cacao bean polyphenols treatment at 1200 mg/kg significantly ameliorated left ventricular posterior wall thickness, fractional shortening, hypertrophic gene transcription, cardiac hypertrophy, cardiac fibrosis, and extracellular signal-regulated kinase 1/2 phosphorylation induced by pressure overload. In conclusion, these findings suggest that cacao bean polyphenols prevent pressure overload-induced cardiac hypertrophy and systolic dysfunction by inhibiting the extracellular signal-regulated kinase 1/2-GATA binding protein 4 pathway in cardiomyocytes. Thus, cacao bean polyphenols may be useful for heart failure therapy in humans.

scholarly journals Atrial Electrophysiological Remodeling and Fibrillation in Heart Failure

2016 ◽  
Vol 10s1 ◽  
pp. CMC.S39713 ◽  
Author(s):  
Sandeep V. Pandit ◽  
Antony J. Workman
Keyword(s):  
Heart Failure ◽  
Molecular Mechanisms ◽  
Left Ventricular Systolic Dysfunction ◽  
Systolic Dysfunction ◽  
Left Ventricular ◽  
Calcium Handling ◽  
Ion Currents ◽  
Multiple Variables ◽  
The Individual ◽  
And Function

Heart failure (HF) causes complex, chronic changes in atrial structure and function, which can cause substantial electrophysiological remodeling and predispose the individual to atrial fibrillation (AF). Pharmacological treatments for preventing AF in patients with HF are limited. Improved understanding of the atrial electrical and ionic/molecular mechanisms that promote AF in these patients could lead to the identification of novel therapeutic targets. Animal models of HF have identified numerous changes in atrial ion currents, intracellular calcium handling, action potential waveform and conduction, as well as expression and signaling of associated proteins. These studies have shown that the pattern of electrophysiological remodeling likely depends on the duration of HF, the underlying cardiac pathology, and the species studied. In atrial myocytes and tissues obtained from patients with HF or left ventricular systolic dysfunction, the data on changes in ion currents and action potentials are largely equivocal, probably owing mainly to difficulties in controlling for the confounding influences of multiple variables, such as patient's age, sex, disease history, and drug treatments, as well as the technical challenges in obtaining such data. In this review, we provide a summary and comparison of the main animal and human electrophysiological studies to date, with the aim of highlighting the consistencies in some of the remodeling patterns, as well as identifying areas of contention and gaps in the knowledge, which warrant further investigation.

Heart failure due to chronic experimental aortic regurgitation

1994 ◽  
Vol 267 (2) ◽  
pp. H556-H562 ◽  
Author(s):  
N. M. Magid ◽  
G. Opio ◽  
D. C. Wallerson ◽  
M. S. Young ◽  
J. S. Borer
Keyword(s):  
Heart Failure ◽  
Aortic Regurgitation ◽  
Systolic Dysfunction ◽  
Disease Process ◽  
Experimental Models ◽  
Left Ventricular ◽  
Sham Operation ◽  
Systolic Performance ◽  
Baseline Values ◽  
Chronic Aortic Regurgitation

Previously reported experimental models of aortic regurgitation generally have manifested normal systolic performance and have not developed heart failure [Magid et al. Am. J. Physiol. 263 (Heart Circ. Physiol. 32): H226–H233, 1992]. To determine whether more severe chronic experimental aortic regurgitation would generate systolic malperformance, heart failure, and emulate the human disease process, 11 New Zealand White rabbits underwent surgical induction of aortic regurgitation and 5 control animals underwent sham operation. Doppler echocardiography was performed serially for up to 3 yr, and pathological studies were performed at necropsy. Left ventricular internal dimension at end diastole increased 80% (P < 0.00002) and left ventricular weight increased 250% (P < 0.0002) in aortic regurgitant rabbits (regurgitant fraction 52 +/- 13%) compared with baseline values. Six of 11 aortic regurgitant animals died with pathological evidence of congestive heart failure at 1.5 +/- 0.8 yr postoperatively; 2 of these developed severe systolic malperformance, manifest as fractional shortenings of 15 and 19% at 1.6 and 1.7 yr, respectively. Five of 11 aortic regurgitant animals survived until killed at 2.9 +/- 0.1 yr. Thus moderate-to-severe chronic aortic regurgitation in rabbits frequently results in heart failure and systolic dysfunction and may usefully model chronic aortic regurgitation and heart failure in humans.

scholarly journals Rubicon-regulated beta-1 adrenergic receptor recycling protects the heart from pressure overload

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Yasuhiro Akazawa ◽  
Manabu Taneike ◽  
Hiromichi Ueda ◽  
Rika Kitazume-Taneike ◽  
Tomokazu Murakawa ◽  
...  
Keyword(s):  
Heart Failure ◽  
Adrenergic Receptor ◽  
Systolic Function ◽  
Systolic Dysfunction ◽  
Pressure Overload ◽  
Developed Countries ◽  
Left Ventricular ◽  
Negative Regulator ◽  
High Morbidity ◽  
Deficient Mice

AbstractHeart failure has high morbidity and mortality in the developed countries. Autophagy is important for the quality control of proteins and organelles in the heart. Rubicon (Run domain Beclin-1-interacting and cysteine-rich domain-containing protein) has been identified as a potent negative regulator of autophagy and endolysosomal trafficking. The aim of this study was to investigate the in vivo role of Rubicon-mediated autophagy and endosomal trafficking in the heart. We generated cardiomyocyte-specific Rubicon-deficient mice and subjected the mice to pressure overload by means of transverse aortic constriction. Rubicon-deficient mice showed heart failure with left ventricular dilatation, systolic dysfunction and lung congestion one week after pressure overload. While autophagic activity was unchanged, the protein amount of beta-1 adrenergic receptor was decreased in the pressure-overloaded Rubicon-deficient hearts. The increases in heart rate and systolic function by beta-1 adrenergic stimulation were significantly attenuated in pressure-overloaded Rubicon-deficient hearts. In isolated rat neonatal cardiomyocytes, the downregulation of the receptor by beta-1 adrenergic agonist was accelerated by knockdown of Rubicon through the inhibition of recycling of the receptor. Taken together, Rubicon protects the heart from pressure overload. Rubicon maintains the intracellular recycling of beta-1 adrenergic receptor, which might contribute to its cardioprotective effect.

Abstract 559: Diacylglycerol Kinase-ζ Rescues Gαq-induced Heart Failure

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Takeshi Niizeki ◽  
Yasuchika Takeishi ◽  
Yo Koyama ◽  
Tatsuro Kitahara ◽  
Satoshi Suzuki ◽  
...  
Keyword(s):  
Heart Failure ◽  
Transgenic Mice ◽  
Cardiac Hypertrophy ◽  
Critical Role ◽  
Weight Ratio ◽  
Left Ventricular ◽  
Negative Regulator ◽  
Heart Weight ◽  
Type I ◽  
Gpcr Signaling

Background: It has been reported that the expression of a constitutively active mutant of the G protein αq subunit in the hearts of transgenic mice (Gαq-TG) induces cardiac hypertrophy and lethal heart failure. Thus, the Gαq protein-coupled receptor (GPCR) signaling pathway, which includes diacylglycerol (DAG) and protein kinase C (PKC), plays a critical role in the development of cardiac hypertrophy and heart failure. DAG kinase (DGK) catalyzes DAG and controls cellular DAG levels, and thus may act as a negative regulator of GPCR signaling. In this study, we tested the hypothesis that DGKζ rescues Gαq-TG mice from developing heart failure. Methods and Results: We generated double transgenic mice (Gαq/DGKζ-TG) with cardiac-specific overexpression of both DGKζ and constitutive active Gαq by crossing Gαq-TG mice with transgenic mice with cardiac-specific overexpression of DGKζ (DGKζ-TG), and the pathophysiological consequences were analyzed. DGKζ inhibited cardiac hypertrophy and progression to heart failure in Gαq-TG mice (Table ). DGKζ prevented dilatation of left ventricular dimension and reduction of left ventricular fractional shortening in Gαq-TG mice. Markedly increased left ventricular end-diastolic pressure in Gαq-TG mice was normalized in Gαq/DGKζ-TG mice. Increases in heart weight/body weight ratio and cardiomyocyte cross sectional area were attenuated in Gαq/DGKζ-TG mice. Translocation of PKC α and ε isoforms, activation of JNK and p38 MAPK induced by Gαq were attenuated by DGKζ. DGKζ reduced fibrotic changes and concomitant upregulation of fibrosis-related genes such as collagen type I and type III induced by Gαq. DGKζ improved the survival rate of Gαq-TG mice. Conclusions: These results demonstrate the first evidence that DGKζ prevents cardiac dysfunction and heart failure by activated Gαq without detectable adverse effects in in vivo hearts and suggest that DGKζ represents a novel therapeutic target for cardiac hypertrophy and heart failure. Summary of the results

Abstract P478: Farnesyl Transferase Inhibitor Tipifarnib Reduces Circulating Exosomes And Protects Against Pressure Overload-mediated Cardiac Hypertrophy

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Vandana Mallaredy
Keyword(s):  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Cardiac Remodeling ◽  
Molecular Mechanisms ◽  
Cell Communication ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Farnesyl Transferase ◽  
Farnesyl Transferase Inhibitor

Clinically, Hypertrophic cardiomyopathy (HCM) in response to pathophysiological stress is one of the major initiating factors for the onset of cardiac remodeling leading to heart failure. Studies have revealed that HCM characterized by left ventricular hypertrophy, hypercontractility, and impaired relaxation is mainly driven by an intricate crosstalk among the multiple cellular and molecular mechanisms, which leads to heart failure. In agreement with this observation, we investigated if the Tipifarnib-mediated reduction/alteration of circulating exosomes mediates cardiac cell communication during HCM. Several studies have shown Tipifarnib as a potential Farnesyl transferase inhibitor. However, in recent past Tipifarnib has been shown to target exosomes biogenesis by several mechanisms such as inhibiting Ras pathway, ESCRT complex etc. Tipifarnib treatment in mice significantly reduced the number of circulating plasma exosomes. We examined the response of Tipifarnib treatment (10 mg/kg body weight) in C57BL6J male mice subjected to transverse aortic constriction (TAC) surgery. Untreated TAC mice had worsening of systolic Left Ventricular function at 4 weeks that further deteriorated at 8 weeks, while the treatment with Tipifarnib substantially improved cardiac functions by reducing cardiac hypertrophy and fibrosis. Exosomes isolated from the serum of sham and TAC mice with or without tipifarnib were used for in vitro cell based analyses. We observed that the exosomes isolated from Tipifarnib treated TAC mice reduced isoproterenol (ISO)-induced cardiomyoblast hypertrophy and fibrosis-associated genes in adult cardiac fibroblasts. Taken together, our studies suggest Tipifarnib protects against pressure overload induced cardiac remodeling and dysfunction by altering hypertrophic and fibrotic gene expression, by potentially reducing circulating exosomes or by altering exosome contents. Ongoing studies will clarify the molecular mechanisms of these observations.

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