Abstract 48: Myelopoiesis Following Myocardial Ischemia (MI) Involves Activation of the Nlrp3 Inflammasome by Neutrophil-Derived S100a8/a9

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Prabhakara R Nagareddy ◽  
Rahul Annabathula ◽  
Shaojing Ye ◽  
Yuri M Klaychkin ◽  
Ahmed Abdel-Latif ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Ventricular Remodeling ◽  
Cardiac Fibroblasts ◽  
Myocardial Damage ◽  
Extramedullary Hematopoiesis ◽  
Heart Cell ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Hematopoietic Stem ◽  
Coronary Syndrome

Ischemic myocardial damage triggers leukocytosis, particularly the production of monocytes and neutrophils from the bone marrow and spleen (myelopoiesis). These cells infiltrate the evolving myocardial wound, degrade extracellular matrix, and aid in the clearance of dead cardiac myocytes and their debris. Although this inflammatory process is a prerequisite for tissue healing, it is non-specific and often blunt. If unchecked, excessive production of monocytes and neutrophils may result in abnormal ventricular remodeling and heart failure. The myocardial cellular and molecular events that orchestrate with the BM/spleen to regulate myelopoiesis remain unclear. We report here that the number of circulating monocytes and neutrophils peak within 24 hours following coronary artery ligation (LAD) in mice. This is due to expansion and proliferation of hematopoietic stem and multi-potential progenitor cells (HSPC) in the BM as well as extramedullary hematopoiesis in the spleen. MI induced-myelopoiesis was associated with a dramatic increase in the expression of S100a8/a9 (a damage associated molecular pattern), its receptor (Tlr4), the Nlrp3 inflammasome, and pro-IL1β in the heart. Cell separation studies revealed that the infiltrating neutrophils and cardiac fibroblasts are the predominant source of S100a8/a9 and the Nlrp3 inflammasome respectively in the heart. Furthermore, deletion of S100a8/a9 not only reduced MI-induced myelopoiesis but also significantly improved the mortality and cardiac function in mice following LAD. These data supports our hypothesis that neutrophil-derived S100a8/a9 interact with Tlr4 on cardiac fibroblasts to induce the Nlrp3 inflammasome and produce IL1β, which in turn stimulates IL-1R on HSPCs to promote myelopoiesis. Pharmacological strategies aimed at inhibition of S100a8a/9 or the Nlrp3 inflammasome-mediated production of IL1β may be a promising approach to limit inflammation following acute coronary syndrome.

Abstract 116: Myelopoiesis Following Myocardial Ischemia (MI) Involves Activation of the Nlrp3 Inflammasome by Neutrophil-derived S100a8/a9

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Prabhakara R Nagareddy ◽  
Rahul Annabathula ◽  
Saojing Ye ◽  
Yuri Klyachkin ◽  
Ahmed Abdel-Latif ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Ventricular Remodeling ◽  
Cardiac Fibroblasts ◽  
Myocardial Damage ◽  
Heart Cell ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Hematopoietic Stem ◽  
Coronary Syndrome ◽  
Molecular Events

Ischemic myocardial damage triggers leukocytosis particularly the production of monocytes and neutrophils from the bone marrow and spleen (myelopoiesis). These cells infiltrate the evolving myocardial wound, degrade extracellular matrix and aid in the clearance of dead cardiac myocytes and their debris. Although this inflammatory process is a prerequisite for tissue healing, it is non-specific and often blunt. If unchecked, excessive production of monocytes and neutrophils may result in abnormal ventricular remodeling and heart failure. The myocardial cellular and molecular events that orchestrate with the BM/spleen to regulate myelopoiesis remain unclear. We report here that the number of circulating monocytes and neutrophils peak within 24 hours following coronary artery ligation (LAD) in mice. This is due to expansion and proliferation of hematopoietic stem and multi-potential progenitor cells (HSPC) in the BM as well as extra medullary hematopoiesis in the spleen. MI induced -myelopoiesis was associated with a dramatic increase in the expression of S100a8/a9 (a damage associated molecular pattern), its receptor (Tlr4), the Nlrp3 inflammasome and pro-IL1β in the heart. Cell separation studies revealed that the infiltrating neutrophils and cardiac fibroblasts are the predominant source of S100a8/a9 and the Nlrp3 inflammasome respectively in the heart. Further, deletion of s100a8/a9 not only reduced MI -induced myelopoiesis but also significantly improved the mortality and cardiac function in mice following LAD. These data supports our hypothesis that neutrophil-derived S100a8/a9 interact with Tlr4 on cardiac fibroblasts to induce the Nlrp3 inflammasome and produce IL1β, which in turn stimulates IL-1R on HSPCs to promote myelopoiesis. Pharmacological strategies aimed at inhibition of S100a8a/9 or the Nlrp3 inflammasome-mediated production of IL1β may be a promising approach to limit inflammation following acute coronary syndrome.

Abstract 16163: Hydrogen Sulfide Reduces Inflammasome Formation in Mice With Ischemic HFrEF

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Adolfo G Mauro ◽  
Juan Valle Raleigh ◽  
Khoa Nguyen ◽  
David E Durrant ◽  
Erica Kim ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Nlrp3 Inflammasome ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Saline Control ◽  
Lv Function ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Reduced Ejection Fraction ◽  
Fractional Shortening

Background: Hydrogen sulfide (H2S) has been shown to attenuate myocardial ischemia/reperfusion injury via suppression of NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome. Whether the H2S donor, Na2S, protects against ischemic heart failure with reduced ejection fraction (HFrEF) when treatment is initiated after development of LV dysfunction is unknown. Methods and Results: Adult male mice underwent myocardial infarction (MI) by permanent coronary artery ligation after baseline echocardiography. Repeat echocardiography was performed at day 3 post MI and surviving mice with fractional shortening (FS) less than 25% were treated with either Na2S (100 μg/kg, ip) or saline (volume matched, ip) for 25 days. LV fractional shortening remained unchanged at 7 and 28 days post-MI in the saline group, but improved significantly with Na2S at both time points (Fig. A). Moreover, LV infarct scar size, assessed by trichrome staining, was smaller in Na2S group (14.8 ± 2.1%) as compared to control (28.8 ± 4.8%, P<0.05) at 7 days post MI. Immunofluorescence staining for apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), a component of the inflammasome, showed significant increase at 3 days post MI with sustained elevation at 7 days in the saline-treated group, whereas treatment with Na2S starting on day 3 post-MI significantly attenuated ASC 4 days later (Fig. B). Survival rate was 2-fold higher in Na2S group compared to saline control at 28 days post MI (P<0.05, Fig. C). Conclusion: Treatment with Na2S in mice with ischemic HFrEF improves LV function and survival up to 28 days post MI, possibly through suppression of ASC and prevention of further NLRP3 inflammasome formation. We propose that H2S donors can be promising therapeutic tools for ischemic HF.

Abstract 363: In Situ Cardiac Cellular Reprogramming Using Adenoviral Vectors: Implication for Clinical Myocardial Regeneration

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Megumi Mathison ◽  
Vivek P Singh ◽  
Maria J Chiuchiolo ◽  
Deepthi Sanagasetti ◽  
Yun Mao ◽  
...  
Keyword(s):  
Cardiac Fibroblasts ◽  
Lentiviral Vectors ◽  
Adenoviral Vectors ◽  
Cellular Reprogramming ◽  
Expression Vectors ◽  
Coronary Artery Ligation ◽  
Sprague Dawley ◽  
Artery Ligation ◽  
Lentivirus Vectors

Objective: The reprogramming of cardiac fibroblasts into induced cardiomyocytes (iCMs) improves ventricular function in myocardial infarction models. Only integrating chronic expression vectors have thus far been used to administer reprogramming genes, potentially limiting clinical applicability. We hypothesized that reprogramming could be achieved using non-integrating, acute expression adenoviral vectors. Methods: Adenoviral (Ad) and lentiviral vectors encoding Gata4 (G), Mef2c (M) and Tbx5 (T) were validated in vitro . Sprague Dawley rats then underwent coronary artery ligation and Ad-mediated administration of vascular endothelial growth factor to provide infarct prevascularization. Three weeks later, Ad or lentivirus encoding G, M, or T or an equivalent dose of a null vector was administered. Outcomes were analyzed by serial echocardiography, and by terminal MRI and histology. Results: Ad and lentivirus vectors provided equivalent in vitro GMT expression by Western blotting and AdGMT induced expression of the cardiomyocyte marker cTnT in approximately 7% of cardiac fibroblasts, compared to 4% of cells infected with LentiGMT. Sections of infarcted myocardium from rats that had been treated with AdGMT or LentiGMT demonstrated higher density of cells expressing the cardiomyocyte marker MHY7 compared to AdNull treated animals (p<0.05). Echocardiography demonstrated that AdGMT significantly increased ejection fraction compared to AdNull (AdGMT: 21% ± 3%, LentiGMT: 14% ± 5%, AdNull: -0.4% ± 2%; p<0.05). Conclusions: Adenoviral vectors are at least as effective as lentiviral vectors in inducing cardiac fibroblast transdifferentiation into iCMs and improving cardiac function in post-infarct rat hearts. The utility of short-term expression Ad vectors represents an important potential tool in inducing cardiac cellular reprogramming clinically.

Effects of carbon nanotube-mediated Caspase3 gene silencing on cardiomyocyte apoptosis and cardiac function during early acute myocardial infarction

Nanoscale ◽  
2020 ◽  
Vol 12 (42) ◽  
pp. 21599-21604
Author(s):  
Yi Li ◽  
Hong Yu ◽  
Liang Zhao ◽  
Yuting Zhu ◽  
Rui Bai ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Gene Silencing ◽  
Ventricular Remodeling ◽  
Myocardial Cell ◽  
Coronary Artery Ligation ◽  
Protective Effects ◽  
Sprague Dawley ◽  
Artery Ligation ◽  
Sd Rats

Caspase3 gene silencing based on the gene transfer carrier F-CNT-siCas3 had obvious protective effects on myocardial cell apoptosis, ventricular remodeling, and cardiac function in Sprague-Dawley (SD) rats after coronary artery ligation.

scholarly journals Progression of heart failure after myocardial infarction in the rat

2001 ◽  
Vol 281 (5) ◽  
pp. R1734-R1745 ◽  
Author(s):  
J. Francis ◽  
R. M. Weiss ◽  
S. G. Wei ◽  
A. K. Johnson ◽  
R. B. Felder
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Ventricular Remodeling ◽  
Systolic Function ◽  
Left Ventricular Remodeling ◽  
Plasma Renin ◽  
Left Ventricular Systolic Function ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Artery Ligation

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.

scholarly journals Integrative System Biology Analyses Identify Seven MicroRNAs to Predict Heart Failure

2019 ◽  
Vol 5 (1) ◽  
pp. 22 ◽  
Author(s):  
Henri Charrier ◽  
Marie Cuvelliez ◽  
Emilie Dubois-Deruy ◽  
Paul Mulder ◽  
Vincent Richard ◽  
...  
Keyword(s):  
Heart Failure ◽  
Systems Biology ◽  
Ventricular Remodeling ◽  
Left Ventricular Remodeling ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Mirna Signature ◽  
Artery Ligation ◽  
Proteomic Data

Heart failure (HF) has several etiologies including myocardial infarction (MI) and left ventricular remodeling (LVR), but its progression remains difficult to predict in clinical practice. Systems biology analyses of LVR after MI provide molecular insights into this event such as modulation of microRNA (miRNA) that could be used as a signature of HF progression. To define a miRNA signature of LVR after MI, we use 2 systems biology approaches, integrating either proteomic data generated from LV of post-MI rat induced by left coronary artery ligation or multi-omics data (proteins and non-coding RNAs) generated from plasma of post-MI patients from the REVE-2 study. The first approach predicted that 13 miRNAs and 3 of these miRNAs would be validated to be associated with LVR in vivo: miR-21-5p, miR-23a-3p and miR-222-3p. The second approach predicted that 24 miRNAs among 1310 molecules and 6 of these miRNAs would be selected to be associated with LVR in silico: miR-17-5p, miR-21-5p, miR-26b-5p, miR-222-3p, miR-335-5p and miR-375. We identified a signature of 7 microRNAs associated with LVR after MI that support the interest of integrative systems biology analyses to define a miRNA signature of HF progression.

scholarly journals Febuxostat Modulates MAPK/NF-κBp65/TNF-α Signaling in Cardiac Ischemia-Reperfusion Injury

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Sana Irfan Khan ◽  
Rajiv Kumar Malhotra ◽  
Neha Rani ◽  
Anil Kumar Sahu ◽  
Ameesha Tomar ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Myocardial Damage ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Morphological Alterations ◽  
Treatment Groups ◽  
Antiapoptotic Proteins ◽  
Male Wistar Rats

Xanthine oxidase and xanthine dehydrogenase have been implicated in producing myocardial damage following reperfusion of an occluded coronary artery. We investigated and compared the effect of febuxostat and allopurinol in an experimental model of ischemia-reperfusion (IR) injury with a focus on the signaling pathways involved. Male Wistar rats were orally administered vehicle (CMC) once daily (sham and IR + control), febuxostat (10 mg/kg/day; FEB10 + IR), or allopurinol (100 mg/kg/day; ALL100 + IR) for 14 days. On the 15th day, the IR-control and treatment groups were subjected to one-stage left anterior descending (LAD) coronary artery ligation for 45 minutes followed by a 60-minute reperfusion. Febuxostat and allopurinol pretreatment significantly improved cardiac function and maintained morphological alterations. They also attenuated oxidative stress and apoptosis by suppressing the expression of proapoptotic proteins (Bax and caspase-3), reducing TUNEL-positive cells, and increasing the level of antiapoptotic proteins (Bcl-2). The MAPK-based molecular mechanism revealed suppression of active JNK and p38 proteins concomitant with the rise in ERK1/ERK2, a prosurvival kinase. Additionally, a reduction in the level of inflammatory markers (TNF-α, IL-6, and NF-κB) was also observed. The changes observed with febuxostat were remarkable in comparison with those observed with allopurinol. Febuxostat protects relatively better against IR injury than allopurinol by suppressing inflammation and apoptosis mediating the MAPK/NF-κBp65/TNF-α pathway.

Abstract 15058: Disruption of Extracellular Cytotoxic Chromatin by Acute DNase1 Administration Improves Left Ventricular Remodeling after Myocardial Infarction

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Benjamin Vogel ◽  
Hisahito Shinagawa ◽  
Ullrich Hofmann ◽  
Georg Ertl ◽  
Stefan Frantz
Keyword(s):  
Myocardial Infarction ◽  
Ventricular Remodeling ◽  
Left Ventricular Remodeling ◽  
Left Ventricular ◽  
Pcr Analysis ◽  
Coronary Artery Ligation ◽  
Protective Effects ◽  
Artery Ligation ◽  
High Concentrations

Rationale: Myocardial infarction (MI) leads to necrosis of multinucleated and polyploid myocytes. This causes uncontrolled release of cellular content like chromatin to the infarct area. Chromatin is mainly comprised of histones which are essential for controlling and packing of DNA but paradoxically are also known to be cytotoxic. This makes free chromatin a toxic DNA polymer creating local high concentrations of hazardous histones. Objective: We hypothesized that chromatin from necrotic cells accumulates in ischemic myocardium, creates local high concentrations of cytotoxic histones, and thereby potentiates ischemic damage to the heart after MI. The endonuclease DNase1 is capable of dispersing extracellular chromatin through linker DNA digestion and could decrease local histone concentrations and cytotoxicity. Methods and Results: After permanent coronary artery ligation in mice we found extracellular histones accumulated within the infarcted myocardium. Histone cytotoxicity towards isolated myocytes was confirmed in vitro. To reduce histone related cytotoxicity in vivo DNase1 was injected within the first 6 hours after induction of MI. DNase1 accumulated in the infarcted region of the heart, effectively disrupted extracellular cytotoxic chromatin and thereby reduced high local histone concentration. Animals acutely treated with DNase1 revealed significantly improved left ventricular remodeling as measured by serial echocardiography up to 28 days after MI (e.g. NaCl vs DNase1, papillary end diastolic area [mm 2 ]: 23.26 ± 2.06 vs 18.90 ± 1.24, n=9 vs 10, p<0,05). Treatment did not influence mortality, infarct size or inflammatory parameters as determined by neutrophil infiltration and RTQ-PCR analysis of characteristic cytokines. However improved myocyte survival was discovered within the infarct region which might account for the protective effects in DNase1 treated animals (NaCl vs DNase1: 3.0 ± 0.7% vs 8.3 ± 2.3%; p<0.05; n=7 vs 8). Conclusions: Targeting extracellular cytotoxic chromatin within the infarcted heart by DNase1 is a promising approach to preserve myocytes from histone induced cell death and to conserve left ventricular function after MI. The efficacy of other chromatin degrading agents is now under investigation.

Abstract 368: Biomechanical Properties of Scar ECM: from the Acute to Chronic Stages of Myocardial Infarction

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Bryn Brazile ◽  
J. R Butler ◽  
Sourav Patnaik ◽  
Yanyi Xu ◽  
Andrew Claude ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Function ◽  
Sodium Dodecyl ◽  
Longitudinal Direction ◽  
Biomechanical Properties ◽  
Circumferential Direction ◽  
Heart Cell ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Biaxial Behavior

Introduction: Myocardial infarction (MI) affects more than 8 million Americans, causing massive heart cell death and heart function decrease. To better understand the scar biomechanics, we characterized the mechanical properties of pure scar ECM, obtained by decellularizing the MI tissues. Materials and Methods: Infarcted rat hearts were generated by a permanent left coronary artery ligation (PLCAL) and harvested at 15 min, 1, 2, and 4 weeks (per acute to chronic stages of MI)(N = 6 each). Scar ECM were obtained by decellularizing the infarcted hearts in 0.1% sodium dodecyl sulfate (SDS) solution for 3 weeks. Scar ECM specimens were trimmed into square shape, and then subjected to biaxial testing with one edge aligned with the circumferential direction and the other edge aligned with the longitudinal direction of the rat heart. After 10 cycle preconditioning, an equibiaxial tension protocol of T circ : T rad = 30:30 N/m was performed to capture the tissue biaxial behavior. Results and Discussion: Scar ECM 15 minutes through 4 weeks post infarction showed a stiffening biaxial behavior along with the time (Fig.1). The decrease of extensibility along longitudinal direction was more noticeable than circumferential direction, which led to a decrease in degree of anisotropy. Conclusions: Scar ECM biomechanics showed a stiffening behavior with a marked reduction in extensibility (longitudinal) with time. This change in biomechanical properties can be correlated to the collagen structure changes with progression of MI. Knowledge of the structural-mechanical relationship of scar ECM will help us understand MI progression and help formulate regenerative therapies.

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