Role of Membrane Dysfunction and Altered Calcium Homeostasis in the Pathogenesis of Irreversible Myocardial Injury

1989 ◽  
pp. 551-559
Author(s):  
L. Maximilian Buja ◽  
James T. Willerson
2021 ◽  
Vol 22 (2) ◽  
pp. 722
Author(s):  
Yukino Ogura ◽  
Kazuko Tajiri ◽  
Nobuyuki Murakoshi ◽  
DongZhu Xu ◽  
Saori Yonebayashi ◽  
...  

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.


2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Ahmed Ayuna ◽  
Nik Abidin

Abstract Background Anthracycline-induced cardiotoxicity has been classified based on its onset into acute, early, and late. It may have a significant burden on the quality and quantity of life of those exposed to this class of medication. Currently, there are several ongoing debates on the role of different measures in the primary prevention of cardiotoxicity in cancer survivors. Our article aims to focus on the role of neurohormonal blockers in the primary prevention of anthracycline-induced cardiotoxicity, whether it is acute, early, or late onset. Main body of the abstract PubMed and Google Scholar database were searched for the relevant articles; we reviewed and appraised 15 RCTs, and we found that angiotensin-converting enzyme inhibitors (ACEI) and B-blockers were the most commonly used agents. Angiotensin II receptor blockers (ARBs) and mineralocorticoid receptor antagonists (MRAs) were used in a few other trials. The follow-up period was on the range of 1–156 weeks (mode 26 weeks). Left ventricular ejection fraction (LVEF), left ventricular diameters, and diastolic function were assessed by either echocardiogram or occasionally by cardiac magnetic resonance imaging (MRI). The occurrence of myocardial injury was assessed by troponin I. It was obvious that neurohormonal blockers reduced the occurrence of LVEF and myocardial injury in 14/15 RCTs. Short conclusion Beta-blockers, especially carvedilol and ACEI, especially enalapril, should be considered for the primary prevention of acute- and early-onset cardiotoxicity. ARB and MRA are suitable alternatives when patients are intolerant to ACE-I and B-blockers. We recommend further studies to explore and establish the role of neurohormonal blockers in the primary prevention of the acute-, early-, and late-onset cardiotoxicity.


Author(s):  
Kang Zhou ◽  
Yan Xu ◽  
Qiong Wang ◽  
Lini Dong

Abstract Myocardial injury is still a serious condition damaging the public health. Clinically, myocardial injury often leads to cardiac dysfunction and, in severe cases, death. Reperfusion of the ischemic myocardial tissues can minimize acute myocardial infarction (AMI)-induced damage. MicroRNAs are commonly recognized in diverse diseases and are often involved in the development of myocardial ischemia/reperfusion injury. However, the role of miR-431 remains unclear in myocardial injury. In this study, we investigated the underlying mechanisms of miR-431 in the cell apoptosis and autophagy of human cardiomyocytes in hypoxia/reoxygenation (H/R). H/R treatment reduced cell viability, promoted cell apoptotic rate, and down-regulated the expression of miR-431 in human cardiomyocytes. The down-regulation of miR-431 by its inhibitor reduced cell viability and induced cell apoptosis in the human cardiomyocytes. Moreover, miR-431 down-regulated the expression of autophagy-related 3 (ATG3) via targeting the 3ʹ-untranslated region of ATG3. Up-regulated expression of ATG3 by pcDNA3.1-ATG3 reversed the protective role of the overexpression of miR-431 on cell viability and cell apoptosis in H/R-treated human cardiomyocytes. More importantly, H/R treatments promoted autophagy in the human cardiomyocytes, and this effect was greatly alleviated via miR-431-mimic transfection. Our results suggested that miR-431 overexpression attenuated the H/R-induced myocardial damage at least partly through regulating the expression of ATG3.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Pei-Ling I Hsu ◽  
Fan-E Mo

Introduction: Matricellular protein CCN1 is expressed in myocardial infarction, pressure overload, and ischemia in mice, and in patients with a failing heart. Despite its well-documented angiogenic activities, CCN1 promotes fibroblast apoptosis in some contexts. The role of CCN1 in an injured heart was not clear. We assessed the hypothesis that CCN1 plays a detrimental role and mediates cardiac injury through its proapoptotic activities. Methods and Results: To test the role of CCN1 in cardiac injury, we employed two different myocardial injury models in mice, including a work-overload-induced injury created by isoproterenol treatment (ISO; 100 mg/kg/day; s.c. for 5 days; n= 6 for each group) and an injury induced by the cardiotoxicity of doxorubicin (DOX, single dose of 15 mg/kg; i.p. sacrificed after 14 days). Ccn1 expression was induced in the damaged myocardium in both injury models. A line of knock-in mice carrying an apoptosis-defective Ccn1 mutant allele, Ccn1-dm , which has disrupted integrin α 6 β 1 binding sites, were tested in the ISO- or DOX -induced cardiac injury. Myocardial damage was seen in tissues from wile-type (WT) hearts after receiving ISO. Ccn1 dm/dm (DM) mice possessed remarkable resistance against ISO or DOX treatments and exhibited no tissue damage or fibrosis compared to WT mice after H&E or Masson’s trichrome stainings. DM mice were resistant to both ISO- and DOX-induced cardiac cell apoptosis, indicating that CCN1 is critically mediating cardiomyocyte apoptotic death in cardiac injury. Moreover, we found that death factor Fas ligand (FasL) and its receptor Fas were upregulated in WT mice receiving ISO or DOX treatments by immunohistochemical staining, compared with the PBS-control. 8-OHdG-positive, a marker for oxidative stress, cardiomyocytes were increased by ISO or DOX treatments as well. In contrast, the expression of Fas/FasL, and the 8-OHdG-positive cardiomyocytes in the myocardium of DM mice were not changed by ISO or DOX. Conclusions: We identify CCN1 as a novel pathophysiological regulator of cardiomyocyte apoptosis in cardiac injury. Blocking apoptotic function of CCN1 effectively prevents myocardial injury in mice. CCN1 and its receptor α 6 β 1 represent promising future therapeutic targets in cardiac injury.


2008 ◽  
Vol 45 (3) ◽  
pp. 420-428 ◽  
Author(s):  
Thomas J. Hund ◽  
Keith F. Decker ◽  
Evelyn Kanter ◽  
Peter J. Mohler ◽  
Penelope A. Boyden ◽  
...  

2011 ◽  
Vol 2011 ◽  
pp. 1-21 ◽  
Author(s):  
Yan Feng ◽  
Wei Chao

Toll-like receptors (TLRs) are a member of the innate immune system. TLRs detect invading pathogens through the pathogen-associated molecular patterns (PAMPs) recognition and play an essential role in the host defense. TLRs can also sense a large number of endogenous molecules with the damage-associated molecular patterns (DAMPs) that are produced under various injurious conditions. Animal studies of the last decade have demonstrated that TLR signaling contributes to the pathogenesis of the critical cardiac conditions, where myocardial inflammation plays a prominent role, such as ischemic myocardial injury, myocarditis, and septic cardiomyopathy. This paper reviews the animal data on (1) TLRs, TLR ligands, and the signal transduction system and (2) the important role of TLR signaling in these critical cardiac conditions.


Aging ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 4463-4473
Author(s):  
Ying Li ◽  
Youguang Zhao ◽  
Chenming Qiu ◽  
Yuanrui Yang ◽  
Guihua Liao ◽  
...  

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