scholarly journals Effect of Wenxin Granules on Gap Junction and MiR-1 in Rats with Myocardial Infarction

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Aiming Wu ◽  
Mingjing Zhao ◽  
Lixia Lou ◽  
Jianying Zhai ◽  
Dongmei Zhang ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Gap Junctions ◽  
Gap Junction ◽  
High Dose ◽  
Coronary Artery Ligation ◽  
Sprague Dawley ◽  
Artery Ligation ◽  
Ventricular Fibrillation Threshold ◽  
Transmission Electron ◽  
Lethal Arrhythmia

Myocardial infarction (MI) patients are at high risk of potential lethal arrhythmia. Gap junction and microRNA-1 (miR-1) are both arrhythmia generating conditions. The present study investigated whether Wenxin Granules (Wenxin-Keli, WXKL) could prevent potential lethal arrhythmia by improving gap junctions and miR-1 following MI. Male Sprague-Dawley rats were divided randomly into control, model, metoprolol, low dose WXKL, and high dose WXKL groups. The MI rat model was created by coronary artery ligation. Treatments were administrated intragastrically to the rats for 4 weeks. Conventional transmission electron microscopy was performed to observe the ultrastructure of gap junctions. Quantitative real-time PCR and western blotting were used to detect the expression of miR-1, protein kinase C (PKC), and related proteins. Additionally, a programmatic electrophysiological stimulation test was performed to detect the ventricular fibrillation threshold (VFT). WXKL protected the ultrastructure of the gap junctions and their constituent Cx43 by regulating miR-1 and PKC mediated signal transduction and increased the VFT significantly in the rat MI model. The results suggested that WXKL is an effective alternative medicine to prevent potentially lethal arrhythmia following MI.

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.

Abstract 17179: Uremic Toxins Contribute to Cardiac Fibrosis after Myocardial Infarction: Role of MicroRNAs

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Indrajeet Rana ◽  
Andrew Kompa ◽  
Joanna Skommer ◽  
Suree Lekawanvijit ◽  
Darren J Kelly ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Cardiac Fibrosis ◽  
Uremic Toxins ◽  
Coronary Artery Ligation ◽  
Uremic Toxin ◽  
Sprague Dawley ◽  
Artery Ligation ◽  
Tgf Β1

Introduction: A decline in renal function is a common consequence of myocardial infarction (MI) resulting in increased cardiovascular events, known as cardiorenal syndrome (CRS). Although molecular mechanisms contributing to CRS are not well understood, a role for elevated plasma levels of the uremic toxin indoxyl sulphate (IS) and increased fibrosis have been described. MicroRNAs are small endogenously transcribed regulatory RNAs that modulate gene expression and regulate many cardiac processes involved in cardiac dysfunction. Aim: Using a rat model we investigated whether MI leads to changes in expression of cardiac microRNA-21 and microRNA-29, both known to contribute to fibrosis. We also investigated the effect of lowering plasma uremic toxins on cardiac expression of these microRNAs. Methods: MI was induced by coronary artery ligation in male Sprague-Dawley rats. At 16 weeks cardiac function was measured prior to sacrifice. Cardiac tissues were assessed for molecular changes using real-time PCR, western blot analysis and histological methods. Results: MI significantly increased cardiac microRNA-21, collagen1A1, fibronectin-1 and TGFβ1 mRNA expression, as well as cardiac fibrosis and collagen 1 protein expression. Conversely, microRNA-29 expression was reduced in the heart (Table). Treatment with the AST-120 significantly reversed all these changes (Table). MicroRNA-21 levels significantly correlated with mRNA for TGF-β1 (P=0.049; r2=0.17) and its target genes collagen1A1 (P=0.004; r2=0.35) and fibronectin-1 (P=0.003; r2=0.52). MicroRNA-29b levels negatively and significantly correlated with TGF-β1 (P=0.017; r2=0.26) and collagen1A1 (P=0.048; r2=0.18) and fibronectin-1 (P=0.013; r2=0.29). Conclusions: We report a link between the beneficial effects of lowering circulating uremic toxins and microRNAs changes in the heart. Targeting microRNA’s may provide a therapeutic target for the treatment of CRS.

scholarly journals Preservation of Functional Microvascular Bed Is Vital for Long-Term Survival of Cardiac Myocytes Within Large Transmural Post-Myocardial Infarction Scar

2017 ◽  
Vol 66 (2) ◽  
pp. 99-120 ◽  
Author(s):  
Colleen Nofi ◽  
Yevgen Bogatyryov ◽  
Eduard I. Dedkov
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Myocyte ◽  
Coronary Artery Ligation ◽  
Sprague Dawley ◽  
Artery Ligation ◽  
Term Survival ◽  
Long Term Survival ◽  
Thebesian Veins ◽  
Transverse Area

This study was aimed to understand the mechanism of persistent cardiac myocyte (CM) survival in myocardial infarction (MI) scars. A transmural MI was induced in 12-month-old Sprague–Dawley rats by permanent coronary artery ligation. The hearts were collected 3 days, 1, 2, 4, 8, and 12 weeks after MI and evaluated with histology, immunohistochemistry, and quantitative morphometry. Vasculature patency was assessed in 4-, 8-, and 12-week-old scars by infusion of 15-micron microspheres into the left ventricle before euthanasia. The infarcted/scarred area has a small continually retained population of surviving CMs in subendocardial and subepicardial regions. Surprisingly, whereas the transverse area of subepicardial CMs remained relatively preserved or even enlarged over 12 post-MI weeks, subendocardial CMs underwent progressive atrophy. Nevertheless, the fractional volume of viable CMs remained comparable in mature scars 4, 8, and 12 weeks after MI (3.6 ± 0.4%, 3.4 ± 0.5%, and 2.5 ± 0.3%, respectively). Despite the opposite dynamics of changes in size, CMs of both regions displayed sarcomeres and gap junctions. Most importantly, surviving CMs were always accompanied by patent microvessels linked to a venous network composed of Thebesian veins, intramural sinusoids, and subepicardial veins. Our findings reveal that long-term survival of CMs in transmural post-MI scars is sustained by a local microcirculatory bed.

scholarly journals Prevention of AMI Induced Ventricular Remodeling: Inhibitory Effects of Heart-Protecting Musk Pill on IL-6 and TNF-Alpha

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Wei Cen ◽  
Zhiliang Chen ◽  
Ning Gu ◽  
Ralph Hoppe
Keyword(s):  
Inflammatory Cytokines ◽  
Ventricular Remodeling ◽  
Ultrastructural Changes ◽  
Coronary Artery Ligation ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Artery Ligation ◽  
Necrosis Factor Alpha ◽  
Transmission Electron ◽  
Factor Alpha

Heart-Protecting Musk Pill (HMP) is a Traditional Chinese Medicine (TCM) that has been used for the prevention and treatment of coronary heart disease in clinic. The current study investigated the effect of HMP on the concentrations of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) and observed the relationship between level changes of inflammatory cytokines and ventricular remodeling in rats with acute myocardial infarction (AMI). Animal models of AMI were made by coronary artery ligation in Sprague-Dawley (SD) rats. AMI rats showed increased levels of IL-6 and TNF-α. Treatment with HMP decreases IL-6 and TNF-αconcentrations in rats with AMI. Histopathological and transmission electron microscopic findings were also essentially in agreement with biochemical findings. The results of our study revealed that inflammatory cytokines IL-6 and TNF-αinduce cardiac remodeling in rats after AMI; HMP improves cardiac function and ameliorates ventricular remodeling by downregulating the expression of IL-6 and TNF-αand further suppressing the ultrastructural changes of myocardial cells.

Cardiac adaptations to endurance training in rats with a chronic myocardial infarction

1989 ◽  
Vol 66 (2) ◽  
pp. 712-719 ◽  
Author(s):  
T. I. Musch ◽  
R. L. Moore ◽  
P. G. Smaldone ◽  
M. Riedy ◽  
R. Zelis
Keyword(s):  
Myocardial Infarction ◽  
Endurance Training ◽  
Left Ventricular ◽  
Treadmill Running ◽  
Coronary Artery Ligation ◽  
Maximal Heart Rate ◽  
Chronic Myocardial Infarction ◽  
Artery Ligation ◽  
Training Paradigm ◽  
Myosin Isozyme

The hemodynamic response to maximal exercise was determined in sedentary and trained rats with a chronic myocardial infarction (MI) produced by coronary artery ligation and in rats that underwent sham operations (SHAM). Infarct size in the MI groups of rats comprised 28–29% of the total left ventricle and resulted in both metabolic and hemodynamic changes that suggested that these animals had moderate compensated heart failure. The training regimen used in the present study produced significant increases in maximal O2 uptake (VO2max) when expressed in absolute terms (ml/min) or when normalized for body weight (ml.min-1.kg-1) and consisted of treadmill running at work loads that were equivalent to 70–80% of the animal's VO2max for a period of 60 min/day, 5 days/wk over an 8- to 10-wk interval. This training paradigm produced two major cardiocirculatory adaptations in the MI rat that had not been elicited previously when using a training paradigm of a lower intensity. First, the decrement in the maximal heart rate response to exercise (known as “chronotropic incompetence”) found in the sedentary MI rat was completely reversed by endurance training. Second, the downregulation of cardiac myosin isozyme composition from the fast ATPase V1 isoform toward the slower ATPase (V2 and V3) isoforms in the MI rat was partially reversed by endurance training. These cardiac adaptations occurred without a significant increase in left ventricular pump function as an increase in maximal cardiac output (Qmax) and maximal stroke volume (SVmax) did not occur in the trained MI rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of Myocardial Infarction with Sequential Ligation of the Left Anterior Descending Artery and Its Diagonal Branch in Dogs and Sheep

2003 ◽  
Vol 26 (4) ◽  
pp. 351-357 ◽  
Author(s):  
W.G. Kim ◽  
Y.C. Shin ◽  
S.W. Hwang ◽  
C. Lee ◽  
C.Y. Na
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Pulmonary Artery ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Suitable Model ◽  
Artery Ligation ◽  
Diagonal Branch ◽  
Left Anterior Descending Artery ◽  
Arterial Blood

We report a comparison of the effects of myocardial infarction in dogs and sheep using sequential ligation of the left anterior descending artery (LAD) and its diagonal branch (DA), with hemodynamic, ultrasonographic and pathological evaluations. Five animals were used in each group. After surgical preparation, the LAD was ligated at a point approximately 40% of the distance from the apex to the base of the heart, and after one hour, the DA was ligated at the same level. Hemodynamic and ultrasonographic measurements were performed preligation, 30 minutes after LAD ligation, and 1 hour after DA ligation. As a control, two animals in each group were used for the simultaneous ligation of the LAD and the DA. Two months after the coronary ligation, the animals were evaluated as previously, and killed for postmortem examination of their hearts. All seven animals in the dog group survived the experimental procedures, while in the sheep group only animals with sequential ligation of the LAD and DA survived. Statistically significant decreases in systemic arterial blood pressure and cardiac output, and an increase in the pulmonary artery capillary wedge pressure (PACWP) were observed one hour after sequential ligation of the LAD and its DA in the sheep, while only systemic arterial pressures decreased in the dog. Ultrasonographic analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all sheep, but in no dogs. Data two months after coronary artery ligation showed significant increases in central venous pressure, pulmonary artery pressure, and PACWP in the sheep, but not in the dog. Left ventricular end-diastolic dimension and left ventricular end-systolic dimension in ultrasonographic studies were also increased only in the sheep. Pathologically, the well-demarcated thin-walled transmural anteroseptal infarcts with chamber enlargement were clearly seen in all specimens of sheep, and only-mild-to-moderate chamber enlargements with endocardial fibrosis were observed in the dog hearts. In conclusion, this study confirms that the dog is not a suitable model for myocardial infarction with failure by coronary artery ligation despite negligent operative mortality, when compared directly with an ovine model.

Infarct size is increased in female post-MI rats treated with rapamycin

2009 ◽  
Vol 87 (6) ◽  
pp. 460-470 ◽  
Author(s):  
Claude Lajoie ◽  
Viviane El-Helou ◽  
Cindy Proulx ◽  
Robert Clément ◽  
Hugues Gosselin ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Female Rats ◽  
Coronary Artery Ligation ◽  
Female Rat ◽  
Sprague Dawley ◽  
Ischemic Insult ◽  
Fibrotic Response ◽  
Artery Ligation ◽  
Sprague Dawley Rats ◽  
Scar Healing

Rapamycin represents a recognized drug-based therapeutic approach to treat cardiovascular disease. However, at least in the female heart, rapamycin may suppress the recruitment of putative signalling events conferring cardioprotection. The present study tested the hypothesis that rapamycin-sensitive signalling events contributed to the cardioprotective phenotype of the female rat heart after an ischemic insult. Rapamycin (1.5 mg/kg) was administered to adult female Sprague–Dawley rats 24 h after complete coronary artery ligation and continued for 6 days. Rapamycin abrogated p70S6K phosphorylation in the left ventricle of sham rats and the noninfarcted left ventricle (NILV) of 1-week postmyocardial-infarcted (MI) rats. Scar weight (MI 0.028 ± 0.006, MI+rapamycin 0.064 ± 0.004 g) and surface area (MI 0.37 ± 0.08, MI+rapamycin 0.74 ± 0.03 cm2) were significantly larger in rapamycin-treated post-MI rats. In the NILV of post-MI female rats, rapamycin inhibited the upregulation of eNOS. Furthermore, the increased expression of collagen and TGF-β3 mRNAs in the NILV were attenuated in rapamycin-treated post-MI rats, whereas scar healing was unaffected. The present study has demonstrated that rapamycin-sensitive signalling events were implicated in scar formation and reactive fibrosis. Rapamycin-mediated suppression of eNOS and TGF-β3 mRNA in post-MI female rats may have directly contributed to the larger infarct and attenuation of the reactive fibrotic response, respectively.

Abstract 12648: Deletion of 12/15 Lipoxygenase Improves Left Ventricle Function and Survival by Resolving Inflammation Post Myocardial Infarction

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Vasundhara Kain ◽  
Kevin A Ingle ◽  
Janusz Kabarowski ◽  
Sumanth D Prabhu ◽  
Ganesh V Halade
Keyword(s):  
Myocardial Infarction ◽  
Left Ventricle ◽  
Survival Rates ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Lv Remodeling ◽  
Early Expression ◽  
Cox 2

12/15 lipoxygenase (LOX) is crucial in the inflammatory process leading to diabetes and atherosclerosis. However, the role of 12/15 LOX in myocardial infarction (MI) and left ventricle (LV) remodeling is unclear. We assessed the role of 12/15 LOX in resolving inflammation in post-MI LV remodeling. 8-12 weeks old C57BL/6J wild-type (WT; n=67) and 12/15 LOX (LOX –/– ; n=78) male mice were subjected to permanent coronary artery ligation surgery and monitored through day (d)1 and d5. No MI surgery mice were maintained as d0 naïve controls. LOX -/- mice showed higher survival rate, improved fractional shortening with reduced remodeling and edema index than WT at d1 and d5 post-MI (all p<0.05). LOX -/- mice showed increased Cxcl5 expression at d1 post-MI, consistent with stimulated neutrophil recruitment in the infarct region that was decreased at d5 compared to WT. LOX -/- mice infarct had increased expression of Ccl2 and Cxcl1, that stimulated an earlier recruitment of monocytes with increased macrophages population at d5 (all p<0.05) compared to WT. The altered kinetics of immune cells post-MI indicates a rapid resolving phase, through increase in alternative macrophage phenotypes with reduced collagen density in LOX -/- mice compared to WT mice at d5 post-MI. LOX -/- mice showed a coordinated COX-1 and COX-2 response at d1 post MI, leading to an evident increase in 5-LOX and hemoxygenase-1 (HO-1) at d5 post-MI. 12/15 LOX deletion enhanced the recruitment of alternative macrophages with secretion of HO-1 to resolve inflammation. In-vitro addition of LOX metabolite 12 hydroxyeicosatetraenoic acid to LOX -/- fibroblast induced early expression of COX-2 and 5-LOX compared to WT, indicating 5LOX role in resolution of inflammation. Post-MI increased expression of TIMP-1 and decrease in MMP-9 at d1 and α-SMA at d5 in LOX -/- mice suggested controlled differentiation of fibroblast-to-myofibroblast which is key event during ventricular tissue repair and resolving phase. This change is supported by increased expression of tgf-βi, ctgf and admats-2 (all P<0.05) at d5 post MI. In conclusion, absence of 12/15 LOX improves post-MI survival rates and attenuates LV dysfunction by resolving inflammation through coordination of 5-LOX and HO-1 as key inflammation resolving enzymes.

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