Inhibition of CD44 attenuates pressure overload-induced cardiac and lung inflammation, fibrosis, and heart failure progression

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
X Weng ◽  
W Yue ◽  
L Shang ◽  
D Wang ◽  
Y Xu ◽  
...  
Keyword(s):  
Heart Failure ◽  
Lung Inflammation ◽  
Gene Knockout ◽  
Heart Association ◽  
Left Ventricular ◽  
Detectable Effect ◽  
Funding Source ◽  
Wild Type ◽  
Lymphocyte Migration ◽  
Lung Remodeling

Abstract Background Inflammation contributes to heart failure (HF) development and progression. CD44 is a member of the hyaluronate receptor family of cell adhesion molecules, which regulates tissue inflammation and fibrosis through modulating macrophage and lymphocyte migration and homing in several diseases. Here we evaluated the role and cellular mechanism of CD44 in regulating transverse aortic constriction (TAC)-induced HF development and progression in mice. Methods and results C57/B6 background CD44 KO and wild type mice (6–8 weeks) were subjected to TAC to evaluate the effect of CD44 on the development of TAC-induced LV hypertrophy and cardiac dysfunction. Due to the rapid response to TAC, Balb/c mice (6–8 weeks) were used to determine the effect of CD44 on the progression of TAC-induced congestive heart failure. We found that CD44 expression is dramatically increased in left ventricular (LV) tissues obtained from HF patients and mice. While CD44 gene knockout (KO) has no detectable effect on cardiac structure and function under control conditions, CD44 KO mice were protected from TAC-induced LV inflammation, fibrosis, hypertrophy, dysfunction, and lung remodeling as compared with wild type mice. In addition, we found that inhibition of CD44 signaling with blocking antibodies (Abs) significantly attenuated the transition from LV failure to lung remodeling, and right ventricular hypertrophy in mice with existing HF. Conclusions These data identify an important role of CD44 in attenuating cardiac and lung inflammation, fibrosis, HF development, and HF progression, suggesting that inhibition of CD44 signaling may be useful in preventing and treating HF. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Chinese National Natural Science Foundation Grants and American Heart Association

AIM2-driven inflammasome activation in chronic heart failure

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Ruppert ◽  
Z.S Onodi ◽  
P Leszek ◽  
V.E Toth ◽  
G Koncsos ◽  
...  
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Animal Models ◽  
Left Ventricular ◽  
Inflammasome Activation ◽  
Coronary Artery Ligation ◽  
Funding Source ◽  
Human Cardiomyocytes ◽  
Pannexin 1 ◽  
End Stage

Abstract Background Inflammation and cytokine release have been implicated in the pathogenesis of chronic heart failure (CHF). Of particular interest, Canakinumab, a monoclonal antibody against interleukin-1b (IL-1β), had provided benefit against cardiovascular events, suggesting that blockade of IL-1β secretion and signaling might be a promising new therapeutic target. Although, recent studies have provided evidence that inflammasome activation is the main contributor to IL-1β maturation, the role of inflammasome activation in CHF remains unknown. Objective Therefore, we aimed to assess inflammasome activation in myocardial samples from end-stage failing hearts. Methods Inflammasome activation was assessed by immunoblotting in left ventricular myocardial specimens harvested from patients with end-stage CHF. Furthermore, immunoblot measurements were also performed on translational animal models of CHF (e.g. rat models of permanent coronary artery ligation and transverse aortic constriction). Left ventricular monocyte and macrophage infiltration was detected by immunohistochemistry. To investigate the molecular background of inflammasome activation, a series of cell culture experiments were performed on AC16 human cardiomyocytes and THP-1 human monocytic cell lines. Results Out of the 4 major inflammasome sensors tested, expression of the inflammasome protein absent in melanoma 2 (AIM2) and NLR family CARD domain-containing protein 4 (NLRC4) increased in human CHF while the NLRP1 and NLRP3 (NLR family, pyrin domain containing 1 and 3) inflammasome showed no change. A similar expression pattern in AIM2 and NLRC4 was also noted in CHF animal models. Furthermore, robust infiltration of Iba1+ monocytes/macrophages was observed in human failing hearts as well as in different animal models of CHF. In vitro AIM2 inflammasome activation, as induced by transfection with double-stranded DNA [poly(deoxyadenylic-deoxythymidylic)] was reduced significantly by the pharmacological blockade of pannexin-1 channels. Conclusions AIM2 and NLRC4 inflammasome activation might contribute to chronic inflammation in CHF. Our findings suggest that pannexin-1 channels might be a promising novel target to reduce inflammasome activation. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): NVKP_16-1-2016-0017

Novel rehabilitation program after left ventricular assist device (LVAD) implantation improves functional tests and reduces levels of prognostic heart failure biomarkers

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
T Chwyczko ◽  
L Zalucka ◽  
E Smolis-Bak ◽  
I Kowalik ◽  
E Noszczak ◽  
...  
Keyword(s):  
Heart Failure ◽  
Exercise Test ◽  
Cardiopulmonary Exercise Test ◽  
Rehabilitation Program ◽  
Left Ventricular ◽  
Prognostic Biomarkers ◽  
Funding Source ◽  
Walking Test ◽  
Cardiopulmonary Exercise ◽  
Galectin 3

Abstract Background Rehabilitation after LVAD implantation is increasingly used. We developed the novel method of comprehensive rehabilitation starting directly after LVAD implantation. Study group 21 recent LVAD (15 Heart Mate III, 6 HeartWare) recipients (56.2±11.7 yrs, 100% men) were included to 5-week rehabilitation program, which included supervised endurance training on cycloergometer (5 times per week), resistance training, general fitness exercises with elements of equivalent and coordination exercises (every day). 6-minute walking test (6MWT), cardiopulmonary exercise test (CPET) and prognostic biomarkers: NT-proBNP, Galectin-3 and ST2 were investigated at the beginning and at the end of rehabilitation program. Results See Table 1. At the end of rehabilitation program, significant increase in 6MWT distance, maximum workload, peak VO2 and upward shift of anaerobic threshold in CPET were observed in all patients. Significant reductions of NTproBNP, ST2 and galectin-3 levels were observed. There were no major adverse events during rehabilitaton. Conclusions Comprehensive novel rehabilitation in LVAD recipients is safe and results in significant improvement of 6-minutes walking test distance and cardiopulmonary exercise test results. Moreover, this novel rehabilitation program reduces levels of prognostic biomarkers of heart failure: NT-proBNP, Galectin-3 and ST2. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Center for Research and Development - STRATEGMED II project

Prognostic value of global longitudinal layer specific strain for patients with heart failure with reduced ejection fraction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Johnsen ◽  
M Sengeloev ◽  
P Joergensen ◽  
N Bruun ◽  
D Modin ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Prognostic Value ◽  
Left Ventricular ◽  
Volume Index ◽  
Funding Source ◽  
Reduced Ejection Fraction ◽  
Patients With Heart Failure ◽  
All Cause Mortality ◽  
Echocardiographic Parameters

Abstract Background Novel echocardiographic software allows for layer-specific evaluation of myocardial deformation by 2-dimensional speckle tracking echocardiography. Endocardial, epicardial- and whole wall global longitudinal strain (GLS) may be superior to conventional echocardiographic parameters in predicting all-cause mortality in patients with heart failure with reduced ejection fraction (HFrEF). Purpose The purpose of this study was to investigate the prognostic value of endocardial-, epicardial- and whole wall GLS in patients with HFrEF in relation to all-cause mortality. Methods We included and analyzed transthoracic echocardiographic examinations from 1,015 patients with HFrEF. The echocardiographic images were analyzed, and conventional and novel echocardiographic parameters were obtained. A p value in a 2-sided test <0.05 was considered statistically significant. Cox proportional hazards regression models were constructed, and both univariable and multivariable hazard ratios (HRs) were calculated. Results During a median follow-up time of 40 months, 171 patients (16.8%) died. A lower endocardial (HR 1.17; 95% CI (1.11–1.23), per 1% decrease, p<0.001), epicardial (HR 1.20; 95% CI (1.13–1.27), per 1% decrease, p<0.001), and whole wall (HR 1.20; 95% CI (1.14–1.27), per 1% decrease, p<0.001) GLS were all associated with higher risk of death (Figure 1). Both endocardial (HR 1.12; 95% CI (1.01–1.23), p=0.027), epicardial (HR 1.13; 95% CI (1.01–1.26), p=0.040) and whole wall (HR 1.13; 95% CI (1.01–1.27), p=0.030) GLS remained independent predictors of mortality in the multivariable models after adjusting for significant clinical parameters (age, sex, total cholesterol, mean arterial pressure, heart rate, ischemic cardiomyopathy, percutaneous transluminal coronary angioplasty and diabetes) and conventional echocardiographic parameters (left ventricular (LV) ejection fraction, LV mass index, left atrial volume index, deceleration time, E/e', E-velocity, E/A ratio and tricuspid annular plane systolic excursion). No other echocardiographic parameters remained an independent predictors after adjusting. Furthermore, endocardial, epicardial and whole wall GLS had the highest C-statistics of all the echocardiographic parameters. Conclusion Endocardial, epicardial and whole wall GLS are independent predictors of all-cause mortality in patients with HFrEF. Furthermore, endocardial, epicardial and whole wall GLS were superior prognosticators of all-cause mortality compared with all other echocardiographic parameters. Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): Herlev and Gentofte Hospital

scholarly journals Aetiology-dependent impairment of mitochondrial function in the failing human heart

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Borger ◽  
D Scheiber ◽  
P Horn ◽  
D Pesta ◽  
U Boeken ◽  
...  
Keyword(s):  
Heart Failure ◽  
Mitochondrial Function ◽  
Human Study ◽  
Left Ventricular ◽  
Myocardial Tissue ◽  
Funding Source ◽  
Ros Production ◽  
German Research Foundation ◽  
Long Term Outcome ◽  
Tissue Specimens

Abstract Background Alterations of mitochondrial function have been identified to play a role in Heart Failure (HF) pathophysiology. Oxidative phosphorylation (OXPHOS) capacity of the myocardium was shown to be reduced in the failing heart. Ineffective mitochondrial function promotes formation of reactive oxygen species (ROS) that may affect remodelling in ischemia. Thus far, human mitochondrial function comparing dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) resembling the main aetiologies of heart failure with reduced ejection fraction (HFrEF) has not been investigated. Purpose We hypothesised that 1. ROS production is elevated in left ventricular myocardial tissue specimens of ICM patients compared to DCM. 2. Mitochondrial OXPHOS capacity is higher in left ventricular myocardial tissue specimens of DCM compared to ICM patients. Methods Myocardial tissue was obtained from the left ventricular apex from 63 patients (38 ICM, 25 DCM) with advanced HFrEF requiring implantation of a Left Ventricular Assist Device (LVAD). We performed high-resolution respirometry (HRR, OROBOROS Oxygraph-2k) in saponine-permeabilised myocardial fibres and measured ROS production fluoroscopically via the Amplex Red method. Statistical analysis was conducted using GraphPad Prism 7 and IBM SPSS v26.0. Results Groups were of comparable age (61.5±1.2 vs. 59.3±2.4 years, p=n.s.), sex (87% vs 85% male, p=n.s.), diabetic status (32% vs 38.4% type 2 diabetes mellitus, p=n.s.), and body mass index (28.1±0.8 vs. 26.3±1.1 kg/m2, p=n.s.). We detected reduced myocardial mitochondrial OXPHOS capacity in ICM under state 3 conditions by about 15% (68.7±34.0 vs. 80.9±30.5 pmol/(s*mg), p<0.05), after addition of Glutamate by 25% (78.9±38.7 vs. 104.8±41.2 pmol/(s*mg), p<0.01) as well as after Succinate (115.5±65.5 vs. 155±62.0 pmol/(s*mg), p<0.01), uncoupling agent FCCP (114.1±56.8 vs. 150.5±47.3 pmol/(s*mg), p<0.01), and by about 40% after addition of Complex I inhibitor Rotenone (55.5±25.9 vs. 96.9±28.0 pmol/(s*mg), p<0.001). We detected no difference in ROS production between ICM and DCM (0.6±0.05 vs. 0.76±0.08 pmol/(s*ml), p=n.s.). Conclusion This is the first human study deciphering distinct alterations in mitochondrial function (OXPHOS capacity) in ventricular myocardium of HFrEF patients. Future studies may address how distinct metabolic patterns at the time of implantation may relate to long-term outcome of HFrEF in terms of remodelling and recovery. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): DFG (German Research Foundation)

The effect of oestrogen withdrawal on cardiac Ca2+ regulation and the influence of GPER1

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A.J Francis ◽  
J.M Firth ◽  
N Islam ◽  
J Gorelik ◽  
K.T MacLeod
Keyword(s):  
Heart Failure ◽  
Structural Integrity ◽  
Left Ventricular ◽  
Funding Source ◽  
Hormonal Changes ◽  
Ion Conductance ◽  
Developing Heart ◽  
Rapid Stimulation ◽  
Post Menopausal

Abstract Background Post-menopausal women have an enhanced risk of developing heart failure, attributed to declining oestrogen levels during menopause. However, the signalling mechanisms remain undetermined. Purpose We aim to determine the role of G-protein coupled oestrogenic receptor 1 (GPER1) in intracellular Ca2+ regulation and the consequences of hormonal changes that may exacerbate the pathophysiology of heart failure. Methods Ovariectomy (OVx) (mimics menopausal hormone changes) or sham surgeries were conducted on female guinea pigs. Left ventricular cardiomyocytes were isolated 150-days post-operatively for experimental use. Cellular t-tubule network and structural integrity was measured using fluorescent di-8-ANEPPs staining and scanning ion conductance microscopy. GPER1 expression and localisation was measured by Western blot and immunostaining. The role of GPER1 activation was measured using selective agonist G-1 in electrophysiological and Ca2+-sensitive dye fluorescence experiments. Results Following oestrogen withdrawal, the t-tubule network density decreased by 13% and z-groove index reduced by 15%. GPER1 predominantly localised to the peri-nuclear endoplasmic reticulum and its expression increased by 32% in OVx. Action potential duration (APD) prolonged in OVx and following GPER1 activation, APD90 shortened by 11% and 25% in sham and OVx respectively. OVx cells had larger peak inward Ca2+ current (ICaL) (by 22%) and sarcoplasmic reticulum (SR) Ca2+ content (by 13%), compared with sham. While GPER1 activation had little effect on peak ICaL or SR content, it reduced Ca2+ transient amplitude (by 20%), SR fractional release (by 11%) in OVx cells. The frequency of occurrence of spontaneous Ca2+ waves evoked by periods of rapid stimulation reduced by 40% and wave-free survival time prolonged in OVx cells following GPER1 activation. Conclusions In the hearts of an animal species whose electrophysiology and intracellular Ca2+ regulation is akin to humans, we show that following oestrogen deficiency, the t-tubule network is down-regulated and becomes disorganised, GPER1 expression is increased and its activation induces negative inotropic responses in cardiomyocytes. This may limit the adverse changes to Ca2+ signalling reported in OVx that could be pro-arrhythmic and exacerbate the progression to heart failure. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): British Heart Foundation

Very early detection of low dose anti-cancer therapy-related cardiotoxicity in lymphoma patients

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y.W Liu ◽  
H.Y Chang ◽  
C.H Lee ◽  
W.C Tsai ◽  
P.Y Liu ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cancer Therapy ◽  
Cardiac Dysfunction ◽  
Systolic Dysfunction ◽  
Multivariable Analysis ◽  
Cardiopulmonary Exercise Test ◽  
Left Ventricular ◽  
Funding Source ◽  
Anti Cancer ◽  
All Cause Mortality

Abstract Background and purpose Left ventricular (LV) global peak systolic longitudinal strain (GLS) by speckle-tracking echocardiography is a sensitive modality for the detection of subclinical LV systolic dysfunction and a powerful prognostic predictor. However, the clinical implication of LV GLS in lymphoma patients receiving anti-cancer therapy remains unknown. Methods We prospectively enrolled 74 patients (57.9±17.0 years old, 57% male) with lymphoma who underwent echocardiography prior to chemotherapy, post 3rd and 6th cycle and 1 year after chemotherapy. Cancer therapy-related cardiac dysfunction (CTRCD) is defined as the reduction of absolute GLS value from baseline of ≥15%. All the eligible patients underwent a cardiopulmonary exercise test (CPET) upon completion of 3 cycles of anti-cancer therapy. The primary outcome was defined as a composite of all-cause mortality and heart failure events. Results Among 36 (49%) patients with CTRCD, LV GLS was significantly decreased after the 3rd cycle of chemotherapy (20.1±2.6% vs. 17.5±2.3%, p<0.001). In the multivariable analysis, male sex and anemia (hemoglobin <11 g/dL) were found to be independent risk factors of CTRCD. Objectively, patients with CTRCD had lower minute oxygen consumption/kg (VO2/kg) and lower VO2/kg value at anaerobic threshold in the CPET. The incidence of the primary composite outcome was higher in the CTRCD group than in the non-CTRCD group (hazard ratio 3.21; 95% CI, 1.04–9.97; p=0.03). Conclusion LV GLS is capable of detecting early cardiac dysfunction in lymphoma patients receiving anti-cancer therapy. Patients with CTRCD not only had a reduced exercise capacity but also a higher risk of all-cause mortality and heart failure events. Change of LVEF and GLS after cancer Tx Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): The Ministry of Science and Technology (MOST), Taiwan

Role of angiotensin-signalling in anthracycline-induced cardiotoxicity

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Findlay ◽  
J.H Gill ◽  
R Plummer ◽  
C.J Plummer
Keyword(s):  
Gene Expression ◽  
Heart Failure ◽  
Angiotensin Ii ◽  
Late Onset ◽  
Left Ventricular Systolic Dysfunction ◽  
Left Ventricular ◽  
Cardiomyocyte Hypertrophy ◽  
Funding Source ◽  
Study Results

Abstract   Anthracycline chemotherapy remains a key component of cancer treatment regimens in both paediatric and adult patients. A significant issue with their use is the development of anthracycline-induced cardiotoxicity (AIC), with subclinical AIC and clinical heart failure observed in 13.8% and 3.1% of patients, respectively. The major clinical complication of AIC is the development of late-onset cardiotoxicity, occurring several years after drug administration, presenting as life-threatening heart failure (HF). Determining the relationship between subclinical AIC and late-onset HF, strategies for mitigation of AIC, and impacts upon the cancer survivor population remains a complex challenge. Administration of drugs targeting the angiotensin system, specifically angiotensin converting enzyme inhibitors (ACEi), have been reported to reduce AIC in the clinic. Whilst the therapeutic effect of ACEi in management of left ventricular systolic dysfunction and consequent HF is principally through optimisation of cardiac haemodynamics, the mechanism involved with mitigation of late-onset AIC several years after anthracycline exposure are currently unknown. Using a variety of human cardiomyocyte in vitro models we have previously demonstrated induction of cardiomyocyte hypertrophy by angiotensin II and anthracyclines. Importantly, selective blockade of the angiotensin II receptor 1 (ATR1) on cardiomyocytes mitigated the anthracycline-induced hypertrophic response, implicating synergism between AIC and angiotensin signalling in cardiomyocytes. Adult human ventricular cardiac myocyte AC10 cell-line were treated in vitro with a range of clinically relevant doxorubicin doses for clinically appropriate durations, with AT1 receptor gene expression evaluated using semi-quantitative PCR. Our results confirm a positive correlation between clinically-relevant concentration of doxorubicin and induction of genetic expression of ATR1 in AC10 cells, with up to 200% increases in ATR1 expression observed. Maximal doxorubicin-induced gene expression being observed at 8 and 24-hours, respectively. These preliminary results agreeing with clinical exposure parameters for this drug with protein expression studies being optimised to support these gene expression study results. Our preliminary studies also imply patients developing AIC carry a deleted polymorphism within intron 16 of the ACE gene and increased systemic levels of the ACE product angiotensin II, both with a known association to hypertrophic cardiomyopathy. Taken together, these data support our mechanistic hypothesis that a relationship exists between AIC and modulation of the angiotensin signalling pathway in cardiomyocytes, involving structural cellular changes and asymptomatic cardiac hypertrophy. An elevation in angiotensin II levels, potentially through polymorphisms in ACE, could thereby exacerbate anthracycline-induced hypertrophy and promote the development of late-onset anthracycline-induced HF. Funding Acknowledgement Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Cancer Research UK funded PhD

Myeloid-Derived Growth Factor Protects Against Pressure Overload-Induced Heart Failure by Preserving Sarco/Endoplasmic Reticulum Ca 2+ -ATPase Expression in Cardiomyocytes

Circulation ◽  
2021 ◽  
Author(s):  
Mortimer Korf-Klingebiel ◽  
Marc R. Reboll ◽  
Felix Polten ◽  
Natalie Weber ◽  
Felix Jäckle ◽  
...  
Keyword(s):  
Heart Failure ◽  
Bone Marrow ◽  
Endoplasmic Reticulum ◽  
Growth Factor ◽  
Plasma Concentrations ◽  
Pressure Overload ◽  
Inflammatory Cells ◽  
Left Ventricular ◽  
Neonatal Rat ◽  
Wild Type

Background: Inflammation contributes to the pathogenesis of heart failure, but there is limited understanding of inflammation's potential benefits. Inflammatory cells secrete myeloid-derived growth factor (MYDGF) to promote tissue repair after acute myocardial infarction. We hypothesized that MYDGF has a role in cardiac adaptation to persistent pressure overload. Methods: We defined the cellular sources and function of MYDGF in wild-type, Mydgf -deficient ( Mydgf -/- ), and Mydgf bone marrow-chimeric or bone marrow-conditional transgenic mice with pressure overload-induced heart failure after transverse aortic constriction surgery. We measured MYDGF plasma concentrations by targeted liquid chromatography-mass spectrometry. We identified MYDGF signaling targets by phosphoproteomics and substrate-based kinase activity inference. We recorded Ca 2+ transients and sarcomere contractions in isolated cardiomyocytes. Additionally, we explored the therapeutic potential of recombinant MYDGF. Results: MYDGF protein abundance increased in the left ventricular (LV) myocardium and in blood plasma of pressure-overloaded mice. Patients with severe aortic stenosis also had elevated MYDGF plasma concentrations, which declined after transcatheter aortic valve implantation. Monocytes and macrophages emerged as the main MYDGF sources in the pressure-overloaded murine heart. While Mydgf -/- mice had no apparent phenotype at baseline, they developed more severe LV hypertrophy and contractile dysfunction during pressure overload than wild-type mice. Conversely, conditional transgenic overexpression of MYDGF in bone marrow-derived inflammatory cells attenuated pressure overload-induced hypertrophy and dysfunction. Mechanistically, MYDGF inhibited G protein coupled receptor agonist-induced hypertrophy and augmented sarco/endoplasmic reticulum Ca 2+ ATPase 2a (SERCA2a) expression in cultured neonatal rat cardiomyocytes by enhancing PIM1 serine/threonine kinase expression and activity. Along this line, cardiomyocytes from pressure-overloaded Mydgf -/- mice displayed reduced PIM1 and SERCA2a expression, greater hypertrophy, and impaired Ca 2+ cycling and sarcomere function compared to cardiomyocytes from pressure-overloaded wild-type mice. Transplanting Mydgf -/- mice with wild-type bone marrow cells augmented cardiac PIM1 and SERCA2a levels and ameliorated pressure overload-induced hypertrophy and dysfunction. Pressure-overloaded Mydgf -/- mice were similarly rescued by adenoviral Serca2a gene transfer. Treating pressure-overloaded wild-type mice subcutaneously with recombinant MYDGF enhanced SERCA2a expression, attenuated LV hypertrophy and dysfunction, and improved survival. Conclusions: These findings establish a MYDGF-based adaptive crosstalk between inflammatory cells and cardiomyocytes that protects against pressure overload-induced heart failure.

Abstract 1876: Functional Effect of Chronic Urotensin II Receptor Antagonist on L-Type Ca 2+ Current in Mouse Model of Progressive Heart Failure

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Peng Zhou ◽  
Heng-Jie Cheng ◽  
Michael Cross ◽  
Michael F Callahan ◽  
Bridget Brosnihan ◽  
...  
Keyword(s):  
Heart Failure ◽  
Receptor Antagonist ◽  
Weight Ratio ◽  
Heart Association ◽  
Cell Voltage ◽  
Fold Increase ◽  
Left Ventricular ◽  
Lv Function ◽  
List Type ◽  
Urotensin Ii

Voltage-gated Ca 2+ channels play fundamental roles in the regulation of cardiac function by various neurotransmitters. Recently, we have shown that urotensin II (UII), a potent vasoconstrictor, inhibits L-type Ca 2+ current (I Ca,L ) and produces negative inotropic action. In heart failure (HF), the UII-mediated pathway is upregulated, suggesting a therapeutic value of UII receptor antagonist (UII-ANT) for HF. However, the role and mechanism of chronic UII-ANT in HF is unclear. We tested the hypothesis that chronic UII-ANT may improve cardiac I Ca,L , preventing β-adrenergic deregulation on I Ca,L and limit HF progression. We examined plasma levels of norepinephrine (NE), left ventricular (LV) function, and myocyte I Ca,L responses to isoproterenol (ISO) in 3 age-matched groups of mice: HF (n = 7), 2 months after ISO (150 mg/kg sq for 2 days); HF/UII-ANT (n = 11), 1 month after receiving ISO, then urantide, a potent UII-ANT (10 −5 M/kg/day, sq via implanted osmotic mini pump), given for 1 month; and Controls (n = 7). I Ca,L was measured using whole-cell voltage clamp technique. Compared with controls, ISO-treated mice progressed to HF with 4.7-fold increase in plasma NE (18975 vs 4066 pg/ml) and LV dilatation associated with increased myocyte length (ML, 155 vs120 μm) and heart-to-body weight ratio (H/BW, 7.6 vs 5.5 g/kg). Stroke volume (SV, 30.3 vs 61.4 μl) and ejection fraction (EF, 39% vs 60%) were decreased. Compared with normal myocytes, in HF myocytes, I Ca,L was reduced (50%, 3.7 ± 0.2 vs 7.4 ± 0.2 pA/pF), and I Ca,L response to β-AR stimulation (ISO, 10 −8 M) was attenuated (11% vs 35%) (p < 0.01). In HF/UII-ANT mice, plasma NE (5148 pg/ml), SV (57.9 μl), and EF (57%) returned close to control levels with retained normal ML (124 μm) and H/BW (5.9 g/kg). Moreover, compared with controls, in HF/UII-ANT mice, ISO caused similar increases in the peak I Ca,L (32% vs 35%). Chronic UII-ANT treatment normalizes LV L-type Ca 2+ channel basal function and β-adrenergic regulation, leading to regression of LV and myocyte dysfunction and remodeling in mice with ISO-induced HF. This research has received full or partial funding support from the American Heart Association, AHA National Center.

Abstract 216: Left Ventricular Enlargement and Heart Failure Events: Is Bigger Better?

2012 ◽  
Vol 5 (suppl_1) ◽  
Author(s):  
Farbod Raiszadeh ◽  
Neeraja Yedlapati ◽  
Ileana L Piña ◽  
Daniel M Spevack
Keyword(s):  
Heart Failure ◽  
New York ◽  
Cox Regression ◽  
Systolic Heart Failure ◽  
Heart Association ◽  
Left Ventricular ◽  
Left Ventricular Volumes ◽  
End Diastolic Volume ◽  
New York Heart Association ◽  
The Individual

Background: Since stroke volume (SV) is a function of ejection fraction (EF) and end-diastolic volume (EDV) (SV = EF x EDV), we hypothesized that increased EDV may be advantageous in systolic heart failure (HF), allowing the left ventricle to supply increased cardiac output. Methods: Echocardiograms from 968 consecutive patients seen in our hospital’s HF clinic were reviewed. Left ventricular volumes were measured both at end systole and end diastole using the bi-plane Simpson’s method and were indexed to body surface area. EF was calculated using (EDV-ESV)/EDV. Dates of subsequent HF events (death or admission for HF exacerbation) were obtained from our database. Results: Systolic HF (EF < 50%) was found in 649 of the study subjects. Increased SV index was associated with increased EDV index. The strength of this association varied with EF, Figure. In a bivariate Cox regression model, lower SV index and higher EDV index were each independent predictors of HF events. Increase in EDV by 50 cc was associated with a 20% increase in HF events, p<0.001. Decrease in SVI by 5 cc was associated with 5% increase in HF events, p<0.001. These associations were limited to those with systolic HF. The associations between both EDVI and SVI and HF events were not confounded by patient age, sex and New York Heart Association Class. Conclusion: Increased EDV index was independently associated with increased HF events, indicating that LV enlargement in HF is not favorable. These findings underscore the individual contributions of the components of EF (SV and EDV) in predicting HF outcomes.

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