Abstract 208: The Interaction of Neutrophils and Interferon Gamma Promotes Post-infarct Survival in a Mouse Model of Myocardial Infarction

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Stefanie Finger ◽  
Maike Knorr ◽  
Sabine Kossmann ◽  
Tanja Schoenfelder ◽  
Susanne Karbach ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Mrna Expression ◽  
Healing Process ◽  
Cardiac Injury ◽  
Flow Cytometric Analysis ◽  
Left Ventricular ◽  
Infarcted Myocardium ◽  
Inflammatory Monocytes ◽  
Initial Injury

Background: Myelomonocytic cells are involved in both the initial injury phase and the healing process of myocardial infarction (MI). However, the exact interaction of inflammatory myeloid cells and prominent cytokines remains only partly understood. Objective: The goal of the study was to investigate the either cardioprotective or in part adverse role of lysozyme M positive (LysM+) and granulocyte-receptor 1 positive (Gr-1+) immune cells on cardiac injury and healing in a murine model of MI. Methods and results: MI was induced in 8 to 12 week-old male mice (C57BL/6 background) by ligation of the left anterior descending (LAD) coronary artery. Compared to LysMCre controls, LysM+ cell depleted LysMiDTR transgenic mice (depletion 3d prior MI by diphtheria toxin application, 25 ng/g body weight) showed a decreased influx of CD45.2+/CD3-/CD11b+/Gr-1high neutrophils into infarcted myocardium 1d post MI (measured by flow cytometric analysis). Additionally cardiac mRNA expression levels of inflammatory cytokines like INFγ and TNFα were decreased 7d post MI. To more specifically assess the role of neutrophils, we depleted C57BL/6 mice with a monoclonal anti-Gr-1 antibody and found increased mortality early after MI as well as a decrease in INFγ mRNA expression 1d and 7d post MI. MCP-1 (CCL2) and CCR2 mRNA were reduced 3d after MI according to decreased amount of CD11b+/Ly6G-/Ly6Chigh inflammatory monocytes in the infarcted myocardium of anti-Gr-1 treated mice. LAD ligated INFγ-/- mice displayed a significantly reduced survival, worsening of left ventricular function and an impaired inflammatory cell infiltration compared to C57BL/6 controls. Conclusion: We provide evidence that neutrophils and INFγ play an essential role in survival and cardiac remodeling following MI. Our data indicate that neutrophils are required for monocyte chemotaxis. We conclude, that strategies to combat the inflammatory injury in MI must consider a potentially beneficial effect of early neutrophil influx into infarcted myocardium.

Effect of simvastatin on collagen I deposition in non-infarcted myocardium: role of NF-κB and osteopontin

2010 ◽  
Vol 88 (11) ◽  
pp. 1026-1034 ◽  
Author(s):  
Jianhua Zhang ◽  
Yan Xu ◽  
Lingxin Pan ◽  
Ting Chen ◽  
Zhiwu Chen ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Myocardial Fibrosis ◽  
Left Ventricular ◽  
Collagen I ◽  
Pyrrolidine Dithiocarbamate ◽  
Maximal Rate ◽  
Over Expression ◽  
Infarcted Myocardium ◽  
Infarcted Region

The novel biological effect of statins in alleviating myocardium fibrosis following infarction has been increasingly recognized, yet the underlying mechanisms are not fully understood. The purpose of this study was to characterize the effect of simvastatin on myocardial fibrosis and collagen I deposition in the non-infarcted region after myocardial infarction (MI) and to identify the role of NF-κB and osteopontin in simvastatin-mediated inhibition of post-MI collagen over-expression. A rat model of MI was generated by ligating the left anterior descending coronary artery. The rats surviving the MI operation were randomly divided into the following 3 groups: myocardial infarction (MI, vehicle), simvastatin (Sim, 30 mg·kg–1·day–1), and pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB, 100 mg·kg–1·day–1). Four weeks after MI, cardiac function, mRNAs, and protein expression in non-infarcted myocardium were analyzed. Myocardial fibrosis and collagen I over-expression were observed following MI, accompanied by an increase of NF-κB and osteopontin. Simvastatin improved post-MI left ventricular dysfunction and ameliorated post-MI associated changes to several cardiac parameters, including the left ventricular end diastolic pressure (LVEDP), the maximal rate of pressure development (+dP/dtmax), and the maximal rate of pressure decline (–dP/dtmax). Concurrently, simvastatin significantly suppressed the over-expression of NF-κB, osteopontin, and collagen I in the non-infarcted region following MI. Inhibition of NF-κB by PDTC also reduced osteopontin over-expression and excessive collagen I production and improved the above functional myocardial parameters. These results show that post-MI myocardial fibrosis and collagen I over-expression in the non-infarcted region is associated with activation of NF-κB and osteopontin up-regulation. The anti-fibrotic effect of simvastatin following MI is associated with the attenuation of the expression of osteopontin and NF-κB. The inhibition of NF-κB activation could be the process upstream of osteopontin suppression in the simvastatin-mediated effect.

scholarly journals Neutrophil Elastase Deficiency Ameliorates Myocardial Injury Post Myocardial Infarction in Mice

2021 ◽  
Vol 22 (2) ◽  
pp. 722
Author(s):  
Yukino Ogura ◽  
Kazuko Tajiri ◽  
Nobuyuki Murakoshi ◽  
DongZhu Xu ◽  
Saori Yonebayashi ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Neutrophil Elastase ◽  
Myocardial Injury ◽  
Flow Cytometric Analysis ◽  
Akt Signaling ◽  
Border Zone ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Deficient Mice

Neutrophils are recruited into the heart at an early stage following a myocardial infarction (MI). These secrete several proteases, one of them being neutrophil elastase (NE), which promotes inflammatory responses in several disease models. It has been shown that there is an increase in NE activity in patients with MI; however, the role of NE in MI remains unclear. Therefore, the present study aimed to investigate the role of NE in the pathogenesis of MI in mice. NE expression peaked on day 1 in the infarcted hearts. In addition, NE deficiency improved survival and cardiac function post-MI, limiting fibrosis in the noninfarcted myocardium. Sivelestat, an NE inhibitor, also improved survival and cardiac function post-MI. Flow cytometric analysis showed that the numbers of heart-infiltrating neutrophils and inflammatory macrophages (CD11b+F4/80+CD206low cells) were significantly lower in NE-deficient mice than in wild-type (WT) mice. At the border zone between intact and necrotic areas, the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cells was lower in NE-deficient mice than in WT mice. Western blot analyses revealed that the expression levels of insulin receptor substrate 1 and phosphorylation of Akt were significantly upregulated in NE-knockout mouse hearts, indicating that NE deficiency might improve cardiac survival by upregulating insulin/Akt signaling post-MI. Thus, NE may enhance myocardial injury by inducing an excessive inflammatory response and suppressing Akt signaling in cardiomyocytes. Inhibition of NE might serve as a novel therapeutic target in the treatment of MI.

Role of oxidative stress in left ventricular remodeling and heart failure after myocardial infarction

1999 ◽  
Vol 5 (3) ◽  
pp. 79
Author(s):  
Shintaro Kinugawa ◽  
Hiroyuki Tsutsui ◽  
Tomomi Ide ◽  
Hideo Ustumi ◽  
Nobuhiro Suematsu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Heart Failure ◽  
Ventricular Remodeling ◽  
Left Ventricular Remodeling ◽  
Left Ventricular

Involvement of monocytes/macrophages as key factors in the development and progression of cardiovascular diseases

2014 ◽  
Vol 458 (2) ◽  
pp. 187-193 ◽  
Author(s):  
María Fernández-Velasco ◽  
Silvia González-Ramos ◽  
Lisardo Boscá
Keyword(s):  
Myocardial Infarction ◽  
Immune System ◽  
Cardiovascular Diseases ◽  
Cardiac Tissue ◽  
Initial Period ◽  
Cardiac Injury ◽  
Key Factors ◽  
Cardiac Damage ◽  
Inflammatory Profile

Emerging evidence points to the involvement of specialized cells of the immune system as key drivers in the pathophysiology of cardiovascular diseases. Monocytes are an essential cell component of the innate immune system that rapidly mobilize from the bone marrow to wounded tissues where they differentiate into macrophages or dendritic cells and trigger an immune response. In the healthy heart a limited, but near-constant, number of resident macrophages have been detected; however, this number significantly increases during cardiac damage. Shortly after initial cardiac injury, e.g. myocardial infarction, a large number of macrophages harbouring a pro-inflammatory profile (M1) are rapidly recruited to the cardiac tissue, where they contribute to cardiac remodelling. After this initial period, resolution takes place in the wound, and the infiltrated macrophages display a predominant deactivation/pro-resolution profile (M2), promoting cardiac repair by mediating pro-fibrotic responses. In the present review we focus on the role of the immune cells, particularly in the monocyte/macrophage population, in the progression of the major cardiac pathologies myocardial infarction and atherosclerosis.

Abstract 814: Atorvastatin Attenuates Oxidative Stress And Improves Neuronal Nitric Oxide Synthase In The Brain Stem Of Heart Failure Mice

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Joseph Francis ◽  
Li Yu ◽  
Anuradha Guggilam ◽  
Srinivas Sriramula ◽  
Irving H Zucker
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Myocardial Infarction ◽  
Heart Failure ◽  
Brain Stem ◽  
Mrna Expression ◽  
Natriuretic Peptide ◽  
Left Ventricular ◽  
Neuronal Nos ◽  
The Brain

3-Hydroxyl-3-methylglutaryl coenzyme A reductase inhibitors (statins) have been shown to reduce the incidence of myocardial infarction independent of their lipid-lowering effects. Nitric oxide (NO) in the central nervous system contributes to cardiovascular regulatory mechanisms. Imbalance between nitric oxide (NO) and superoxide anion (O 2 . − ) in the brain may contribute to enhanced sympathetic drive in heart failure (HF). This study was done to determine whether treatment with atorvastatin (ATS) ameliorates the imbalance between NO and O 2 . − production in the brain stem and contributes to improvement of left ventricular (LV) function. Methods and Results: Myocardial infarction (MI) was induced by ligation of the left coronary artery or sham surgery. Subsequently, mice were treated with ATS (10 μg/kg) (MI + ATS), or vehicle (MI + V). After 5 weeks, echocardiography revealed left ventricular dilatation in MI mice. Realtime RT-PCR indicated an increase in the mRNA expression of the LV hypertrophy markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). Neuronal NOS (nNOS) and endothelial NOS (eNOS) mRNA expression were significantly reduced, while that of NAD(P)H oxidase subunit (gp91phox) expression was elevated in the brain stem of MI mice. Compared with sham-operated mice, ATS-treated mice showed reduced cardiac dilatation, decreased ANP and BNP in the LV. ATS also reduced gp91phox expression and increased nNOS mRNA expression in the brain stem, while no changes in eNOS and iNOS were observed. Conclusion: These findings suggest that ATS reduces oxidative stress and increases neuronal NOS in the brain stem, and improves left ventricular function in heart failure.

Role of Left Ventricular Dyssynchrony in Predicting Remodeling after ST Elevation Myocardial Infarction

2011 ◽  
Vol 29 (2) ◽  
pp. 165-172 ◽  
Author(s):  
Burak Turan ◽  
Fatih Yilmaz ◽  
Tansu Karaahmet ◽  
Kursat Tigen ◽  
Bulent Mutlu ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Left Ventricular ◽  
St Elevation Myocardial Infarction ◽  
Left Ventricular Dyssynchrony ◽  
Ventricular Dyssynchrony ◽  
St Elevation

Novel role of platelet reactivity in adverse left ventricular remodelling after ST-segment elevation myocardial infarction: The REMODELING Trial

2017 ◽  
Vol 117 (05) ◽  
pp. 911-922 ◽  
Author(s):  
Yongwhi Park ◽  
Udaya Tantry ◽  
Jin-Sin Koh ◽  
Jong-Hwa Ahn ◽  
Min Kang ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Platelet Reactivity ◽  
Left Ventricular ◽  
Ventricular Remodelling ◽  
Left Ventricular Remodelling ◽  
St Segment Elevation ◽  
Segment Elevation Myocardial Infarction ◽  
St Segment ◽  
Hs Crp

SummaryThe role of platelet-leukocyte interaction in the infarct myocardium still remains unveiled. We aimed to determine the linkage of platelet activation to post-infarct left ventricular remodelling (LVR) process. REMODELING was a prospective, observational, cohort trial including patients (n = 150) with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. Patients were given aspirin plus clopidogrel therapy (600 mg loading and 75 mg daily). Platelet reactivity (PRU: P2Y12 Reaction Units) was assessed with VerifyNow P2Y12 assay on admission. Transthoracic echocardiography was performed on admission and at one-month follow-up. The primary endpoint was the incidence of LVR according to PRU-based quartile distribution. LVR was defined as a relative ≥ 20 % increase in LV end-diastolic volume (LVEDV) between measurements. Adverse LVR was observed in 36 patients (24.0 %). According to PRU quartile, LVR rate was 10.8 % in the first, 23.1 % in the second, 27.0 % in the third, and 35.1 % in the fourth (p = 0.015): the optimal cut-off of PRU was ≥ 248 (area under curve: 0.643; 95 % confidence interval: 0.543 to 0.744; p = 0.010). LVR rate also increased proportionally according to the level of high sensitivity-C reactive protein (hs-CRP) (p = 0.012). In multivariate analysis, the combination of PRU (≥ 248) and hs-CRP (≥ 1.4 mg/l) significantly increased the predictive value for LVR occurrence by about 21-fold. In conclusion, enhanced levels of platelet activation and inflammation determined the incidence of adverse LVR after STEMI. Combining the measurements of these risk factors increased risk discrimination of LVR. The role of intensified antiplatelet or anti-inflammatory therapy in post-infarct LVR process deserves further study.

scholarly journals Troponin: the biomarker of choice for the detection of cardiac injury

2005 ◽  
pp. 1191-1202
Author(s):  
Luciano Babuin ◽  
Allan S. Jaffe
Keyword(s):  
Myocardial Infarction ◽  
Cardiovascular Disease ◽  
Acute Myocardial Infarction ◽  
Troponin I ◽  
Cardiac Injury ◽  
Transaminase Activity ◽  
Elevated Troponin ◽  
Critical Issues ◽  
European Society Of Cardiology

It has been known for 50 years that transaminase activity increases in patients with acute myocardial infarction. With the development of creatine kinase (CK), biomarkers of cardiac injury began to take a major role in the diagnosis and management of patients with acute cardiovascular disease. In 2000 the European Society of Cardiology and the American College of Cardiology recognized the pivotal role of biomarkers and made elevations in their levels the “cornerstone” of diagnosis of acute myocardial infarction. At that time, they also acknowledged that cardiac troponin I and T had supplanted CK-MB as the analytes of choice for diagnosis. In this review, we discuss the science underlying the use of troponin biomarkers, how to interpret troponin values properly and how to apply these measurements to patients who present with possible cardiovascular disease. Troponin is the biomarker of choice for the detection of cardiac injury. To use it properly, one must understand how sensitive the specific assay being used is for detecting cardiac injury, the fact that elevated troponin levels are highly specific for cardiac injury and some critical issues related to the basic science of the protein and its measurement. In this article, we review the biology of troponin, characteristics of assays that measure serum troponin levels and how to apply these measurements to patients who present with possible cardiovascular disease. We also discuss other clinical situations in which troponin levels may be elevated.

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