Inhibition of mitochondrial fission as a novel therapeutic strategy to reduce mortality upon myocardial infarction

2018 ◽  
Vol 132 (20) ◽  
pp. 2163-2167 ◽  
Author(s):  
Hannah A. Cooper ◽  
Satoru Eguchi

Ischemia reperfusion (I/R) injury is a common event following myocardial infarction (MI) resulting in excessive oxidative stress, calcium overload, inflammation, and cardiomyocyte death. Mitochondrial homeostasis including their dynamics are imbalanced in cardiac I/R injury in favor of increased mitochondrial fission. Inhibition of mitochondrial fission prior to I/R injury is protective and improves cardiac function following MI. Clinically, patients with MI often receive treatment following initiation of the ischemic event. Thus, treatments with more realistic timing would have better translational value and are important to research. In a recent study published in Clinical Science, Maneechote et al. [Clin. Sci. (2018) 132, 1669–1683] examined the effect of inhibiting mitochondrial fission using the mitochondrial division inhibitor (Mdivi-1) at different time points, pre-ischemia, during-ischemia, and upon onset of reperfusion, in a rat cardiac I/R model. The findings showed the greatest cardiac function improvement with pre-ischemia treatment along with decreased mitochondrial fragmentation and increased mitochondrial function. Mdivi-1 given during ischemia and at onset of reperfusion also improved cardiac function, but to a lesser extent than pre-ischemia intervention. Maneechote et al. postulated that the LV protection by Mdivi-1 in cardiac I/R could be due to an improvement in mitochondrial dysfunction through attenuating excessive mitochondrial fission which then reduces apoptotic myocytes. Their findings provide new insights into future treatment of patients suffering acute MI which could consider targetting the excessive mitochondrial fission during cardiac ischemia or at onset of reperfusion. Here, we will further discuss the background of the study, potential molecular mechanisms of mitochondrial fission, consequences of the fission, and future research directions.

1989 ◽  
Vol 7 (4) ◽  
pp. 527-540 ◽  
Author(s):  
E G Levine ◽  
R A King ◽  
C D Bloomfield

Heredity is generally felt to play a minor role in the development of cancer. This review critically examines this assumption. Topics discussed include evidence for heritable predisposition in animals and humans; the potential importance of genetic-environmental interactions; approaches that are being used to successfully locate genes responsible for heritable predisposition; comparability of genetic findings among heritable and corresponding sporadic malignancies; and future research directions. Breast, colon, and lung cancer are used to exemplify clinical and research activity in familial cancer; clinical phenotypes, segregation and linkage analyses, models for environmental interactions with inherited traits, and molecular mechanisms of tumor development are discussed. We conclude that the contribution of heredity to the cancer burden is greater than generally accepted, and that study of heritable predisposition will continue to reveal carcinogenic mechanisms important to the development of all cancers.


2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Lanfang Li ◽  
Heng Zeng ◽  
Jian-xiong Chen

Background: Apelin is an endogenous ligand for the angiotensin-like 1 receptor (APJ) and is emerging as a key player in the regulation of angiogenesis as well as ischemia/reperfusion injury. So far, little is known about the functional role of apelin in myocardial ischemia. We investigated the potential intracellular molecular mechanisms and protective role of apelin during myocardial ischemic injury. Methods and Results: Myocardial ischemia was achieved by ligation of the left anterior descending coronary artery (LAD) for 24 hours and 14 days. Myocardial apoptosis was detected by TUNEL staining. Akt, endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), SDF-1 and CXCR4 expression were measured by western blot. The CD133+/cKit+/Sca1+, CD133/SDF-1+ and cKit/CXCR4+ cells were determined by immunostaining. Myocardial capillary and arteriole densities were analyzed in the border zone of infarcted myocardium at 14 d of ischemia. Treatment of C57BL/6J mice with apelin-13 (1 mg/Kg.d) by i.p. injection for 3 days before surgery results in significant decreases in TUNEL positive cells and myocardial infarct size at 24 hours of ischemia. Treatment with apelin increases the phosphorylation of AKT and eNOS and upregulates VEGF expression in the ischemic heart. Furthermore, treatment with apelin leads to the expression of SDF-1 and CXCR4 and increases in the number of CD133+/cKit+/Sca1+, CD133/SDF-1+ and cKit/CXCR4+ cells in ischemic hearts. Treatment with apelin also significantly increases myocardial capillary densities and arteriole formation together with a significant decrease in the ratio of heart weight to body weight at 14 days of ischemia. This is accompanied by a significant improvement of cardiac function after 14 days of ischemia. Conclusions: Our data demonstrate that apelin contributes to the protection of myocardial infarction and angiogenesis by the mechanisms involving in upregulation of SDF-1/CXCR4 and AKT/eNOS/VEGF pathways.


2009 ◽  
Vol 24 (9) ◽  
pp. 1064-1084 ◽  
Author(s):  
Michael A. Babcock ◽  
Felina V. Kostova ◽  
Donna M. Ferriero ◽  
Michael V. Johnston ◽  
Jan E. Brunstrom ◽  
...  

2019 ◽  
Vol 133 (3) ◽  
pp. 497-513 ◽  
Author(s):  
Chayodom Maneechote ◽  
Siripong Palee ◽  
Sasiwan Kerdphoo ◽  
Thidarat Jaiwongkam ◽  
Siriporn C. Chattipakorn ◽  
...  

Abstract An uncontrolled balance of mitochondrial dynamics has been shown to contribute to cardiac dysfunction during ischemia/reperfusion (I/R) injury. Although inhibition of mitochondrial fission could ameliorate cardiac dysfunction, modulation of mitochondrial fusion by giving a fusion promoter at different time-points during cardiac I/R injury has never been investigated. We hypothesized that giving of a mitochondrial fusion promoter at different time-points exerts cardioprotection with different levels of efficacy in rats with cardiac I/R injury. Forty male Wistar rats were subjected to a 30-min ischemia by coronary occlusion, followed by a 120-min reperfusion. The rats were then randomly divided into control and three treated groups: pre-ischemia, during-ischemia, and onset of reperfusion. A pharmacological mitochondrial fusion promoter-M1 (2 mg/kg) was used for intervention. Reduced mitochondrial fusion protein was observed after cardiac I/R injury. M1 administered prior to ischemia exerted the highest level of cardioprotection by improving both cardiac mitochondrial function and dynamics regulation, attenuating incidence of arrhythmia, reducing infarct size and cardiac apoptosis, which led to the preservation of cardiac function and decreased mortality. M1 given during ischemia and on the onset of reperfusion also exerted cardioprotection, but with a lower efficacy than when given at the pre-ischemia time-point. Attenuating a reduction in mitochondrial fusion proteins during myocardial ischemia and at the onset of reperfusion exerted cardioprotection by attenuating mitochondrial dysfunction and dynamic imbalance, thus reducing infarct size and improving cardiac function. These findings indicate that it could be a promising intervention with the potential to afford cardioprotection in the clinical setting of acute myocardial infarction.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2693-2693
Author(s):  
Larissa Verda ◽  
Kehuan Luo ◽  
Xiaoqiang Han ◽  
Andrew Wasserstrom ◽  
Jon Lomasney ◽  
...  

Abstract Recent studies suggest that primitive stem cells derived from bone marrow (BM) possess greater functional plasticity that was expected previously. It has been shown that bone marrow stem cells (BMSC) promote repairing mechanisms within myocardium following ischemia/reperfusion models of myocardial infarction (MI). Although it remains unclear whether BMSC transdifferentiate into or just fuse with cardiomyocytes, hemodynamic improvement after intramyocardial BMSC injection as well as after G-CSF injection has been demonstrated. Here, we investigated the contribution of BMSC versus G-CSF administration in myocardial repair following MI. Ten weeks old C57BL/6J mice were irradiated and transplanted with green fluorescent protein (GFP) positive bone marrow cells. Three months later, these mice underwent ligation of left anterior descending branch (LAD) of coronary artery and subsequently divided into three groups. One group (n=7) received G-CSF administration at 200ug/kg for 10 consecutive days. Another group (n=9) was injected with GFP+ marrow cells directly into ischemic heart. The third group was held as control (n=7). One month after coronary ligation we found significant improvement in cardiac function determined as a cardiac output, maximum power and dP/dt, in the G-CSF group compared to control. We evaluated the phenotype of GFP+ cells within myocardium in each treatment group by 488 nm laser-scanning confocal miscroscopy (of whole heart and slides) 35 days after LAD ligation. We found no evidence of myocardial transdifferentiation or cardiomyocyte cell fusion. Instead GFP+ capillaries were present and exclusively located in infarct border zones in both the G-CSF and bone marrow implantation groups, confirmed by anti-factor VIII staining. G-CSF administration and to a lesser extent marrow injection resulted in improved post infarct cardiac function indices. This beneficial effect is not due to transdifferentiation but could be explained by marrow injected or G-CSF mobilized endothelial progenitor cells (EPC) and/or cytokine mediated neo-vasculogenesis.


2016 ◽  
Vol 213 (7) ◽  
pp. 1353-1374 ◽  
Author(s):  
Anta Ngkelo ◽  
Adèle Richart ◽  
Jonathan A. Kirk ◽  
Philippe Bonnin ◽  
Jose Vilar ◽  
...  

Acute myocardial infarction (MI) is a severe ischemic disease responsible for heart failure and sudden death. Inflammatory cells orchestrate postischemic cardiac remodeling after MI. Studies using mice with defective mast/stem cell growth factor receptor c-Kit have suggested key roles for mast cells (MCs) in postischemic cardiac remodeling. Because c-Kit mutations affect multiple cell types of both immune and nonimmune origin, we addressed the impact of MCs on cardiac function after MI, using the c-Kit–independent MC-deficient (Cpa3Cre/+) mice. In response to MI, MC progenitors originated primarily from white adipose tissue, infiltrated the heart, and differentiated into mature MCs. MC deficiency led to reduced postischemic cardiac function and depressed cardiomyocyte contractility caused by myofilament Ca2+ desensitization. This effect correlated with increased protein kinase A (PKA) activity and hyperphosphorylation of its targets, troponin I and myosin-binding protein C. MC-specific tryptase was identified to regulate PKA activity in cardiomyocytes via protease-activated receptor 2 proteolysis. This work reveals a novel function for cardiac MCs modulating cardiomyocyte contractility via alteration of PKA-regulated force–Ca2+ interactions in response to MI. Identification of this MC-cardiomyocyte cross-talk provides new insights on the cellular and molecular mechanisms regulating the cardiac contractile machinery and a novel platform for therapeutically addressable regulators.


2019 ◽  
Vol 11 (12) ◽  
pp. 305-315 ◽  
Author(s):  
Rafael Vidal-Perez ◽  
Charigan Abou Jokh Casas ◽  
Rosa Maria Agra-Bermejo ◽  
Belén Alvarez-Alvarez ◽  
Julia Grapsa ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Niek J. Pluijmert ◽  
Cindy I. Bart ◽  
Wilhelmina H. Bax ◽  
Paul H. A. Quax ◽  
Douwe E. Atsma

Abstract Many novel therapies to treat myocardial infarction (MI), yielding promising results in animal models, nowadays failed in clinical trials for several reasons. The most used animal MI model is based on permanent ligation of the left anterior descending (LAD) coronary artery in healthy mice resulting in transmural MI, while in clinical practice reperfusion is usually accomplished by primary percutaneous coronary interventions (PCI) limiting myocardial damage and inducing myocardial ischemia–reperfusion (MI-R) injury. To evaluate a more similar murine MI model we compared MI-R injury to unreperfused MI in hypercholesterolemic apolipoprotein (APO)E*3-Leiden mice regarding effects on cardiac function, left ventricular (LV) remodeling and inflammation. Both MI-R and MI resulted in significant LV dilation and impaired cardiac function after 3 weeks. Although LV dilation, displayed by end-diastolic (EDV) and end-systolic volumes (ESV), and infarct size (IS) were restricted following MI-R compared to MI (respectively by 27.6% for EDV, 39.5% ESV, 36.0% IS), cardiac function was not preserved. LV-wall thinning was limited with non-transmural LV fibrosis in the MI-R group (66.7%). Two days after inducing myocardial ischemia, local leucocyte infiltration in the infarct area was decreased following MI-R compared to MI (36.6%), whereas systemic circulating monocytes were increased in both groups compared to sham (130.0% following MI-R and 120.0% after MI). Both MI-R and MI models against the background of a hypercholesterolemic phenotype appear validated experimental models, however reduced infarct size, restricted LV remodeling as well as a different distributed inflammatory response following MI-R resemble the contemporary clinical outcome regarding primary PCI more accurately which potentially provides better predictive value of experimental therapies in successive clinical trials.


Sign in / Sign up

Export Citation Format

Share Document