Abstract 17065: Cardiac Progenitor Cell-mediated Cardiac Regeneration in the Poastnatal Mammalian Heart

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Yuan-Hung Liu ◽  
Ling-Ping Lai ◽  
Shih-Yun Huang ◽  
Yi-Shuan Lin ◽  
Hsing-Yu Huang ◽  
...  

The massive loss of cardiomyocytes after myocardial infarction often results in cardiac fibrosis, chamber dilatation and heart failure. Several studies have shown that inflammation contributes to adverse left ventricular remodeling, however, anti-inflammatory therapy with NSAID during the acute phase of myocardial infarction augments the adverse cardiac remodeling and increases mortality. We hypothesized that inflammation in the acute phase of myocardial infarction might trigger the activation of cardiac progenitors and that anti-inflammatory therapy might attenuate the repair by the cardiac progenitors. We confirmed that Nkx2.5 enhancer-expressing cells existed in the postnatal mouse heart and could differentiate into striated cardiomyocytes in vitro. Using the Nkx2.5 enhancer-eGFP transgenic mice, we found the number of eGFP+ cells and inflammatory cells (marked by Gr1. Mac1, B220, CD45) increased remarkably and significantly after coronary artery ligation. The activated Nkx2.5 enhancer expressing cells expressed up-regulated cardiogenesis genes and could differentiate into cardiomyocytes in vivo by lineage tracing. To prove that anti-inflammatory therapy might attenuate the repair by the cardiac progenitors, we added NSAID (ibuprofen) to the feeding water after coronary ligation on the Nkx2.5-eGFP transgenic mice and found the activated level of progenitor cells was decreased by 73% after the mice were treated with ibuprofen. We further lineage-traced the post-inury inducible Nkx2.5-Cre; ROSA26-LacZ double transgenic mice with ibuprofen or water and found the LacZ+ positive area was decreased by 80% in the heart sections of ibuprofen-treated mice. We concluded that the inflammatory signaling enhances the cardiac progenitor cells to proliferate and differentiate into cardiomyocytes. Understanding the factors regulating cardiac regeneration helps us treat the patients with myocardial infarction or heart failure.

2004 ◽  
Vol 286 (1) ◽  
pp. H381-H387 ◽  
Author(s):  
Ling Chen ◽  
Chang Xun Chen ◽  
Xiaohong Tracey Gan ◽  
Norbert Beier ◽  
Wolfgang Scholz ◽  
...  

Sodium/hydrogen exchange (NHE) inhibitors show promise as potential therapeutic agents for the treatment of heart failure, but it is not known whether they can reverse the maladaptive remodeling that results in heart failure. We sought to determine the effect of the NHE-1-specific inhibitor EMD-87580 (EMD) on heart failure produced by myocardial infarction in the rat and to assess whether up to 4 wk of treatment delay results in beneficial effects. Male Sprague-Dawley rats were subjected to coronary artery ligation (or a sham procedure) and followed for up to 3 mo, at which time hypertrophy and hemodynamics were determined. EMD was provided in the diet, and treatment commenced immediately or 2–4 wk after ligation. EMD significantly reduced hemodynamic abnormalities, including the elevation in left ventricular end-diastolic pressure, and diminished the loss of systolic function with all treatment protocols. Left ventricular dilatation and hypertrophy, as assessed by heart weight, cell size, and atrial natriuretic peptide (ANP) expression, were similarly reversed to sham or near-sham levels. In addition, the increased plasma ANP and pro-ANP values were reversed to levels not significantly different from sham. Surprisingly, virtually all beneficial effects were identical with all treatment protocols. These effects were observed in the absence of infarct size reduction or blood pressure-lowering effects. Our results suggest that NHE-1 inhibition attenuates and reverses postinfarction remodeling and heart failure with a treatment delay of up to 4 wk after infarction. The effect is independent of infarct size or afterload reduction, indicating a direct effect on the myocardium.


2018 ◽  
Vol 123 (6) ◽  
pp. 686-699 ◽  
Author(s):  
Subba Rao Mekala ◽  
Philipp Wörsdörfer ◽  
Jochen Bauer ◽  
Olga Stoll ◽  
Nicole Wagner ◽  
...  

Rationale: Regeneration of lost cardiomyocytes is a fundamental unresolved problem leading to heart failure. Despite several strategies developed from intensive studies performed in the past decades, endogenous regeneration of heart tissue is still limited and presents a big challenge that needs to be overcome to serve as a successful therapeutic option for myocardial infarction. Objective: One of the essential prerequisites for cardiac regeneration is the identification of endogenous cardiomyocyte progenitors and their niche that can be targeted by new therapeutic approaches. In this context, we hypothesized that the vascular wall, which was shown to harbor different types of stem and progenitor cells, might serve as a source for cardiac progenitors. Methods and Results: We describe generation of spontaneously beating mouse aortic wall-derived cardiomyocytes without any genetic manipulation. Using aortic wall-derived cells (AoCs) of WT (wild type), αMHC (α-myosin heavy chain), and Flk1 (fetal liver kinase 1)-reporter mice and magnetic bead-associated cell sorting sorting of Flk1 + AoCs from GFP (green fluorescent protein) mice, we identified Flk1 + CD (cluster of differentiation) 34 + Sca-1 (stem cell antigen-1)-CD44 − AoCs as the population that gives rise to aortic wall-derived cardiomyocytes. This AoC subpopulation delivered also endothelial cells and macrophages with a particular accumulation within the aortic wall-derived cardiomyocyte containing colonies. In vivo, cardiomyocyte differentiation capacity was studied by implantation of fluorescently labeled AoCs into chick embryonic heart. These cells acquired cardiomyocyte-like phenotype as shown by αSRA (α-sarcomeric actinin) expression. Furthermore, coronary adventitial Flk1 + and CD34 + cells proliferated, migrated into the myocardium after mouse myocardial infarction, and expressed Isl-1 + (insulin gene enhancer protein-1) indicative of cardiovascular progenitor potential. Conclusions: Our data suggest Flk1 + CD34 + vascular adventitia-resident stem cells, including those of coronary adventitia, as a novel endogenous source for generating cardiomyocytes. This process is essentially supported by endothelial cells and macrophages. In summary, the therapeutic manipulation of coronary adventitia-resident cardiac stem and their supportive cells may open new avenues for promoting cardiac regeneration and repair after myocardial infarction and for preventing heart failure.


2001 ◽  
Vol 281 (5) ◽  
pp. R1734-R1745 ◽  
Author(s):  
J. Francis ◽  
R. M. Weiss ◽  
S. G. Wei ◽  
A. K. Johnson ◽  
R. B. Felder

This study examined the early neurohumoral events in the progression of congestive heart failure (CHF) after myocardial infarction (MI) in rats. Immediately after MI was induced by coronary artery ligation, rats had severely depressed left ventricular systolic function and increased left ventricular end-diastolic volume (LVEDV). Both left ventricular function and the neurohumoral indicators of CHF underwent dynamic changes over the next 6 wk. LVEDV increased continuously over the study interval, whereas left ventricular stroke volume increased but reached a plateau at 4 wk. Plasma renin activity (PRA), arginine vasopressin, and atrial natriuretic factor all increased, but with differing time courses. PRA declined to a lower steady-state level by 4 wk. Six to 8 wk after MI, CHF rats had enhanced renal sympathetic nerve activity and blunted baroreflex regulation. These findings demonstrate that the early course of heart failure is characterized not by a simple “switching on” of neurohumoral drive, but rather by dynamic fluctuations in neurohumoral regulation that are linked to the process of left ventricular remodeling.


1987 ◽  
Vol 253 (6) ◽  
pp. H1449-H1455 ◽  
Author(s):  
R. E. Mendez ◽  
J. M. Pfeffer ◽  
F. V. Ortola ◽  
K. D. Bloch ◽  
S. Anderson ◽  
...  

To study the role of atrial natriuretic peptide (ANP) in chronic heart failure, ANP synthesis, storage, and release were examined by measuring atrial ANP messenger ribonucleic acid (mRNA) levels and atrial and plasma ANP concentrations in rats with myocardial infarction produced by coronary artery ligation. Three groups were defined as the following: 1) controls, sham-operated, or operated, but noninfarcted; 2) moderate infarcts, involving 5-30% of the left ventricular circumference; and 3) large infarcts (greater than or equal to 30%). In addition, to determine a possible modulation by dietary Na intake on ANP levels in heart failure, plasma immunoreactive ANP (iANP) levels were measured in rats with and without infarcts given low, regular, or high Na intake for 2 wk, by which time all groups were in neutral balance. Plasma iANP levels varied directly with increasing infarct and atrial sizes, irrespective of Na intake. In contrast, atrial ANP concentration varied inversely with increasing infarct size. The ANP mRNA content index, a measure of total atrial ANP mRNA, was significantly increased in rats with large infarcts compared with control rats. These results indicate that in rats with myocardial infarction, the severity of left ventricular dysfunction, as inferred from infarct size, but not chronic Na intake, is the primary determinant of the extent of activation of the ANP system. Elevated circulating ANP levels are maintained through enhanced atrial synthesis and release. ANP may thus play an important role in the hemodynamic and renal adaptations to chronic heart failure.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jerome Thireau ◽  
Charlotte Farah ◽  
Muriel Bouly ◽  
Jerome Roussel ◽  
Alain Lacampagne ◽  
...  

Introduction: Targeting leaky cardiac ryanodine receptors (RyR2) to prevent diastolic Ca2+ release from the sarcoplasmic reticulum (SR) is a promising pharmacological approach, to rescue the impaired cardiac contraction and prevent Ca2+-dependent arrhythmias in heart failure (HF) and disease. Hypothesis: Based on prior work from the Marks group, the Rycal S44121 (also known as ARM036) is an experimental small molecule stabilizer of RyR. We investigated the effects of S44121 in a post-myocardial infarction (PMI) mouse model of HF. Methods and results: Mice were randomly assigned to 3 groups: Sham, PMI (subjected to left coronary artery ligation), and PMI-S (treated for 3 weeks with S44121 by subcutaneous osmotic pumps on day 7 post-MI, 10 mg/kg/day). Intracellular Ca2+ was measured on single left ventricular myocytes. PMI mice exhibited a 4-fold increase in the frequency of spontaneous Ca2+ release events, Ca2+ sparks, as measured in quiescent cells using the fluorescent Ca2+ indicator Fluo-4. PMI mice also exhibited higher global diastolic Ca2+, measured with the ratiometric fluorescent probe, Indo-1 AM, and increased the occurrence of ectopic diastolic Ca2+ waves. Acute application of S44121 (10 μM for 15 min) reduced Ca2+ sparks frequency. Chronic treatment of mice with S44121 also normalized the frequency of Ca2+ sparks and of ectopic Ca2+ waves, and corrected diastolic cellular Ca2+ overload. Effects were maximal at 20 mg/kg/day. Furthermore, treatment with S44121 abolished Ca2+ waves promoted by β-adrenergic challenge (acute application of isoproterenol, 10 nM). The potential anti-arrhythmic benefit of S44121 was assessed in vivo using telemetric surface electrocardiograms. S44121 had no effect on ECG intervals and did not alter the heart rate. However, anti-arrhythmic effects were confirmed by observation of a dose-dependent reduction of spontaneous ventricular extrasystoles and ventricular tachycardia. Near maximum benefits were observed at 10 mg/kg/day, both in basal conditions or following a challenge with acute treatment of isoproterenol (0.5 mg/kg, dosed ip). Conclusion: In mice with post-ischemic HF, treatment with S44121 prevented the abnormal diastolic SR Ca2+ leak and ectopic Ca2+ waves, and reduced ventricular arrhythmias.


2007 ◽  
Vol 293 (3) ◽  
pp. H1609-H1616 ◽  
Author(s):  
Margaret P. Chandler ◽  
Eric E. Morgan ◽  
Tracy A. McElfresh ◽  
Theodore A. Kung ◽  
Julie H. Rennison ◽  
...  

Clinical studies have shown a greater incidence of myocardial infarction in diabetic patients, and following an infarction, diabetes is associated with an increased risk for the development of left ventricular (LV) dysfunction and heart failure. The goal of this study was to determine if the progression of heart failure following myocardial infarction in type 2 diabetic (T2D) rats is accelerated compared with nondiabetic rats. Male nondiabetic Wistar-Kyoto (WKY) and T2D Goto-Kakizaki (GK) rats underwent coronary artery ligation or sham surgery to induce heart failure. Postligation (8 and 20 wk), two-dimensional echocardiography and LV pressure measurements were made. Heart failure progression, as assessed by enhanced LV remodeling and contractile dysfunction, was accelerated 8 wk postligation in the T2D animals. LV remodeling was evident from increased end-diastolic and end-systolic diameters and areas in the GK compared with the WKY infarcted group. Furthermore, enhanced LV contractile dysfunction was evident from a greater deterioration in fractional shortening and enhanced myocardial performance index (an index of global LV dysfunction) in the GK infarcted group. This accelerated progression was accompanied by greater increases in atrial natriuretic factor and skeletal α-actin (gene markers of heart failure and hypertrophy) mRNA levels in GK infarcted hearts. Despite similar decreases in metabolic gene expression (i.e., peroxisome proliferator-activated receptor-α-regulated genes associated with fatty acid oxidation) between infarcted WKY and GK rat hearts, myocardial triglyceride levels were elevated in the GK hearts only. These results, demonstrating enhanced remodeling and LV dysfunction 8 wk postligation provide evidence of an accelerated progression of heart failure in T2D rats.


2007 ◽  
Vol 79 (2) ◽  
pp. 250-259 ◽  
Author(s):  
Daniel C. Trindade ◽  
Raquel C. Trindade ◽  
Michelle P. Marassi ◽  
Ornélia P.P.R. Martins ◽  
Ricardo H. Costa-e-Sousa ◽  
...  

We investigated the morphologic and functional changes of infarcted rat hearts under a paradigm of angiotensinconverting enzyme inhibition. Myocardial infarction was induced by left coronary artery ligation and a control group (SHAM) underwent sham-operation. Infarcted rats received normal drinking water with (CAP group) or without (INF group) captopril. Functional assessment was performed by electro (ECG) and echocardiogram (ECHO) just before and 21 days after surgery. The ECG of INF and CAP showed similar values and resembled healed infarct after surgery. The most outstanding differences between INF and CAP were the prevention of the increase of P-wave and attenuation both in rightward deviation of the QRS axis and Q-wave amplitude in CAP compared with INF. The ECHO showed that captopril treatment improved the diastolic filling more than systolic performance. Cardiac dilatation and left congestive heart failure were observed only in INF. Both infarcted groups showed a scar tissue in the left ventricular wall, but the INF showed a higher scar area than CAP (49.7 ± 5.24 vs. 22.33 ± 6.19 respectively). These data suggest that the renin-angiotensin system induces morphologic and functional changes in post-infarcted rat hearts and which can be assessed by non-invasive exams.


2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Anna Frey ◽  
Sandy Popp ◽  
Antonia Post ◽  
Marc Lehmann ◽  
Anna-Leena Sirén ◽  
...  

Objective: Anxiety and depression are common and independently predict mortality in patients with heart failure. The mechanisms of these interrelations are still unclear. Consequently, we developed a model in C57BL/6 mice with experimental myocardial infarction (MI) and heart failure to study anxiety- or depression-like behavior. Methods: Heart failure was achieved after coronary artery ligation in 13 mice; 16 sham operated mice acted as controls. Left ventricular (LV) remodeling was assessed by echocardiography, infarct size by histology. Sucrose preference test was performed over a period of 8 weeks to assess depression-like behavior. The elevated plus maze (EPM), the light-dark box (LDB) and the open field (OF) tests were subsequently applied to determine general disinterest and anxiety-like behavior. Finally, the histological and immunohistochemical evaluation of the brain was performed. Results: Mice with MI size of at least 30% of LV (averaged 50±3%; increase in diastolic LV diameter from 0.40±0.02 cm to 0.62±0.03 cm) showed diminished intake (p=0.029) and preference (p=0.029) for sucrose solution. Besides, MI mice exhibited reduced exploratory behavior and markedly lower interest in unfamiliar environments, indicated by an increase in center time (p=0.016) and a reduced number of vertical rears (p=0.037) in the EPM. An increased latency to the first rear (p=0.018), covered shorter distances (p=0.048) and spent less time moving (p=0.028) in the OF were found in MI mice. MI did not affect anxiety-related measures in all three tests (all p>0.05). MI mice showed normal brain morphology with normal neuronal morphology and neuropil structure, also confirmed by normal expression of selected neuronal markers. Markers for neurodegeneration, apoptosis or inflammation showed no abnormalities in MI mice. Conclusions: Mice with MI exhibited anhedonia-like behavior, which was accompanied by other characteristics of depression-like behavior, such as decreased exploratory activity and interest in novelty. Hence, MI caused distinct behavioral changes in mice comparable to symptoms observed in humans with heart failure and comorbid depression, but did not affect anxiety-like behavior. The model is suitable for further mechanistic studies.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Manisha Gupte ◽  
Hind Lal ◽  
Firdos Ahmad ◽  
Lin Zhong ◽  
Douglas B Sawyer ◽  
...  

Aim: Neuregulin-1β (NRG-1β), a growth factor critical for cardiac development as well as maintenance of heart function after injury has been shown to significantly improve heart function in preclinical rodent models. Importantly, number of studies are ongoing to test the efficacy of NRG-1β as a treatment for patients with chronic heart failure. However, the efficacy of recombinant NRG-1β in a typ1 diabetic model of heart failure due to myocardial infarction (MI) has not been investigated. The aim of the present study was to determine the efficacy of exogenous NRG-1β to improve residual cardiac function after MI in type1 diabetic rats. Methods and Results: Sprague Dawley rats were induced type 1 diabetes by a single injection of streptozotocin (STZ) (65 mg/kg). Two weeks after induction of type 1 diabetes, rats underwent left coronary artery ligation to induce MI. STZ-diabetic rats were treated with saline or NRG-1β (100 ug/kg) twice a week for 7 weeks, starting two weeks prior to experimental MI. Residual left ventricular (LV) function was significantly greater in the NRG-1β-treated STZ-diabetic MI group compared to the vehicle-treated STZ-diabetic MI group 5 weeks after MI as assessed by high-resolution echocardiography. Furthermore, NRG-1β treatment in STZ-diabetic MI rats reduced myocardial fibrosis and apoptosis as well as decreased gene expression of key oxidant-producing enzymes. Conclusion: This study demonstrates that augmentation of NRG-1β signaling in STZ-diabetic post-MI rats via therapy with exogenous recombinant NRG-1β will alleviate subsequent HF through improvements in residual LV function via protection against adverse remodeling and apoptosis.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Kiyotake Ishikawa ◽  
Jaume Aguero ◽  
Kenneth Fish ◽  
Lauren Leonardson ◽  
Roger J Hajjar

Background: Hypertension (HT) increases cardiac afterload and is one of the risk factors of poor prognosis after myocardial infarction (MI). However, there is little information on how HT impacts the healing processes during sub-acute phase MI. We investigated the role of an increased afterload on left ventricular (LV) performance and remodeling shortly after MI. Methods: Anterior MIs were created in 15 Yorkshire pigs via percutaneous access. To mimic HT condition, 7 pigs (Banding, n=7) underwent surgical banding of the ascending aorta 10 days after the MI, and were compared to the remaining pigs (Control, n=8). LV remodeling and function were assessed one month after MI using 3-D echocardiography and invasive hemodynamic measurements. Results: Echocardiographic assessment at day 10 revealed no significant differences in LV ejection fraction (EF) or LV volumes. One month after MI, aortic banding increased the systemic vascular resistance index, but was not statistically significant (1658±282 dyn/s/cm5/m 2 vs 1153±658 dyn/s/cm5/m 2 , P=0.08). Banding group presented with significantly impaired LVEF (Figure, P=0.002), larger end systolic volume (Figure, P=0.045), lower cardiac index (3.1±0.9 L/min/m 2 vs 4.4±0.6 L/min/m 2 , P=0.01), and elevated LV end diastolic pressure (22.4±5.0 mmHg vs 14.4±7.5 mmHg: P=0.04, Banding vs Control, respectively). Reduced EF was associated with remote myocardial dysfunction and histological analysis revealed increased interstitial fibrosis in this area. Conclusion: Increased afterload in sub-acute phase of MI induces more severely impaired cardiac function and LV remodeling, and was associated with worse heart failure status.


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