Repeated intermittent stress exacerbates myocardial ischemia-reperfusion injury

1998 ◽  
Vol 274 (2) ◽  
pp. R470-R475 ◽  
Author(s):  
Deborah A. Scheuer ◽  
Steven W. Mifflin
Keyword(s):  
Heart Disease ◽  
Myocardial Ischemia ◽  
Ischemic Heart Disease ◽  
Infarct Size ◽  
Chronic Stress ◽  
Restraint Stress ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

Chronic stress in humans has been correlated with increased risk for ischemic heart disease. Thus experiments were conducted to determine if repeated intermittent restraint stress increased infarct size in a rat model of myocardial ischemia-reperfusion injury. Male Sprague-Dawley rats were subjected to no stress (control) or to daily restraint stress for 1–1.5 h for 8–14 days (stress protocol A) or for 2 h daily for 11 or 12 days (stress protocol B). Myocardial ischemia-reperfusion (30-min ischemia, 3-h reperfusion) was performed in anesthetized rats. Average baseline arterial pressures were 111 ± 4, 120 ± 10, and 125 ± 7 mmHg in the control, stress protocol A, and stress protocol B groups, respectively. Infarct size (%area at risk) was significantly larger in both groups of stressed rats compared with control rats (58 ± 5, 78 ± 2, and 79 ± 3% in the control, stress protocol A, and stress protocol B groups, respectively). During ischemia or early reperfusion, zero of eight control, two of six protocol A stress, and two of five protocol B stress rats had at least one period of severe arrhythmia. Therefore, these results provide experimental evidence corroborating correlative studies in humans that link chronic stress with increased morbidity and mortality from ischemic heart disease.

Abstract 16598: The Role of Paraoxonase 2 in Myocardial Ischemia/Reperfusion Injury

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Jingyuan Li ◽  
Victor R Grijalva ◽  
Srinivasa T Reddy ◽  
Mansoureh Eghbali
Keyword(s):  
Myocardial Ischemia ◽  
Infarct Size ◽  
Er Stress ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Ros Production ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

Objectives: Paraoxonases (PON) gene family consists of three proteins PON1, PON2, and PON3. PON2 is an intracellular membrane-associated protein that is widely expressed in vascular cells and many tissues. At the subcellular level, PON2 is localized to both the ER and mitochondria, and protects against oxidative stress. Hypothesis: The aim of this study was to investigate the role of PON2 in myocardial ischemia reperfusion injury. Methods: PON2 deficient (PON2-/-) and WT male mice were subjected to in-vivo ischemia/reperfusion injury. The left anterior descending coronary artery was occluded for 30 min followed by 24 hr of reperfusion. The infarct size, mitochondrial calcium retention capacity (CRC) and reactive oxygen species (ROS) generation were measured. The expression of C/EBP homologous protein (CHOP), GSK3b and phosphate GSK3b protein were examined by Western Blot. The number of animals was 5-7/group and data were expressed as mean±SEM. T test were used for statistical analysis. Probability values <0.05 were considered statistically significant. Results: The infarct size was ~2 fold larger in PON2 deficient mice compared to WT mice (p<0.05). The threshold for opening of mitochondrial permeability transition pore (mPTP) in response to calcium overload was much lower in PON2-/- mice compared with WT mice (173±19 in PON2-/-, 250±41 in WT, nmol/mg-mitochondrial protein, p<0.05). The ROS production was ~2 fold higher in isolated cardiac mitochondria from PON2-/- mice compared with WT mice (p<0.05). ER stress protein CHOP increased significantly in PON2-/- mice compared to WT mice (normalized to WT: 1±0.05 in WT, 1.66±0.08 in PON2-/-, p<0.001). Phospho-GSK3b level was significantly downregulated in in PON2-/- mice compared to WT mice (pGSK3b/GSK3b normalized to WT: 1±0.06 in WT 0.67±0.08 in PON2-/-, p<0.05). Conclusions: PON2 regulates myocardial ischemia/reperfusion injury via inhibiting the opening of mPTP, which is associated with reduced mitochondria ROS production, deactivation of ER stress signaling CHOP and GSK3b.

Exosomes: promising sacks for treating ischemic heart disease?

2017 ◽  
Vol 313 (3) ◽  
pp. H508-H523 ◽  
Author(s):  
Gui-Hao Chen ◽  
Jun Xu ◽  
Yue-Jin Yang
Keyword(s):  
Heart Disease ◽  
Ischemic Heart Disease ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cardiac Regeneration ◽  
Ischemic Heart ◽  
Advantages And Disadvantages ◽  
Developing Heart ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

Ischemic heart disease(IHD) is the leading cause of death worldwide. Despite the development of continuously improving therapeutic strategies, morbidity and mortality of patients with IHD remain relatively high. Exosomes are a subpopulation of vesicles that are universally recognized as major mediators in intercellular communication. Numerous preclinical studies have shown that these tiny vesicles were protective in IHD, through such actions as alleviating myocardial ischemia-reperfusion injury, promoting angiogenesis, inhibiting fibrosis, and facilitating cardiac regeneration. Our review focused on these beneficial exosome-mediated processes. In addition, we discuss in detail how to fully exploit the therapeutic potentials of exosomes in the field of IHD. Topics include identifying robust sources of exosomes, loading protective agents into exosomes, developing heart-specific exosomes, optimizing isolation methods, and translating the cardioprotective effects of exosomes into clinical practice. Finally, both the advantages and disadvantages of utilizing exosomes in clinical settings are addressed.

Abstract 11928: Cardiospecific Overexpression of Carnosine Synthase Attenuates Myocardial Ischemia Reperfusion Injury

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Shahid Baba ◽  
Deqing zhang ◽  
David Hoetker ◽  
Yiru Guo ◽  
Aruni Bhatnagar
Keyword(s):  
Myocardial Ischemia ◽  
Infarct Size ◽  
Ischemia Reperfusion Injury ◽  
Membrane Lipids ◽  
Ischemia Reperfusion ◽  
Glycolytic Activity ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion ◽  
Underlying Mechanisms

Even though myocardial ischemia/reperfusion (I/R) remains the leading cause of death, the underlying mechanisms remain incompletely understood. Increased formation of reactive carbonyl has been shown to be a common biochemical feature of I/R injury. These carbonyls are generated from the oxidation of proteins and membrane lipids. Reactive carbonyls such as methylglyoxal are generated from increased glycolytic activity during ischemia. Previous work in our lab has shown that the endogenous dipeptide carnosine (β-alanine-histidine) quenches both protein and lipid derived carbonyls. It can also buffer changes in intracellular pH and chelate metals that catalyze ROS production. In the heart, carnosine is synthesized by the ATP grasp enzyme (ATPGD1). Hence, we examined whether overexpression of ATPGD1 could increase carnosine synthesis in the heart and attenuate I/R injury. To overexpress ATPGD1, we generated mice in which the expression of the transgene was driven by cardiospecific α-MHC promoter. Two different ATPGD1Tg mouse lines were generated, which showed 10-15 fold higher abundance of ATPGD1 protein in the heart compared with their wild-type (WT) littermates. Cardiac levels of the histidyl dipeptides anserine and carnosine were approximately 100 fold higher in the ATPGD1Tg than WT mice hearts (WT: anserine 1.8±0.3 pmoles/mg protein, carnosine 6±1 pmoles/mg protein; ATPGD1-Tg: anserine 114±15 pmoles/mg protein, carnosine 615±44 pmoles/mg protein). No changes in the levels of these dipeptides were observed in other tissues of the ATPGD1Tg mice. Echocardiographic analysis showed that ATPGD1 overexpression did not affect cardiac function. When subjected to 30 min of coronary occlusion followed by 24 h of reperfusion, the infarct size was significantly lower in ATPGD1Tg than WT mice. Infarct size as the area of risk of left ventricle was 59±3.02% in WT mice and 38±2.73% in the ATPGD1-Tg mice (p<0.05 vs WT; n=7-8), indicating that increasing carnosine levels attenuates myocardial I/R injury. These findings reveal a novel cardioprotective role of endogenous histidyl dipeptides in decreasing I/R injury and suggest that treatment with such peptides may be a potential therapy for decreasing myocardial I/R injury and its progression of heart failure.

Abstract 1000: Dichotomous Roles Of TNF-α Receptors p55 And p75 In Acute Ischemia/reperfusion Injury And Late Ischemic Preconditioning

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Michael P Flaherty ◽  
Yiru Guo ◽  
Xian-Liang Tang ◽  
Sumit Tiwari ◽  
Greg Hunt ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Infarct Size ◽  
Reperfusion Injury ◽  
Ischemic Preconditioning ◽  
Coronary Occlusion ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Acute Myocardial Ischemia ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

We have previously demonstrated that TNF-alpha signaling is critical for the development of protection afforded by the late phase of ischemic preconditioning (PC). In the current study, we investigated the roles of p55 (TNFR-I) and p75 (TNFR-II) in acute myocardial ischemia/reperfusion injury as well as late PC. Wild-type (WT, B6 and B6,129 strains), TNF-a−/−, p55−/−, p75−/−, and p55−/−/p75−/− double-knockout mice underwent a 30-min coronary occlusion followed by 4 h of reperfusion with or without six cycles of coronary occlusion/reperfusion (O/R) 24 h earlier. Six cycles of O/R reduced infarct size 24 h later in B6 as well as B6,129 WT mice, indicating a rob ust late PC effect (Figure ). This infarct-sparing effect of late PC was abolished in the absence of TNF-a, p55, p75, and both p55/p75, indicating that TNF-a signaling is critical for the development of late PC protection; and that signaling via both p55 and p75 is necessary for the development of protection. In nonpreconditioned TNF-a−/− and p75−/− mice, infarct size was similar to that observed in strain-matched WT mice (Figure ). However, infarct size in nonpreconditioned p55−/− mice was reduced compared with nonpreconditioned WT mice (46.8 ± 2.8% vs. 63.4 ± 3.2%, P < 0.05, Figure ). These observations were confirmed via linear regression analysis of myocardial risk region and infarct size. We conclude that nonredundant TNF-a signaling via both p55 and p75 is crucial for the development of late PC protection. However, the reduction in infarct size in naïve p55−/− mice indicates a deleterious role of this receptor during acute myocardial ischemia/reperfusion injury.

Abstract 15948: Inhibition of NF-kB Signaling Attenuates Age-related Aggravation of Myocardial Ischemia/Reperfusion Injury

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Guangming Cheng ◽  
Sheng Ye ◽  
Magdy Girgis ◽  
Lin Zhao ◽  
Xing Chen ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Infarct Size ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
The Elderly ◽  
Age Related ◽  
Redox Responsive ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

Introduction: Emerging evidence indicates that myocardial ischemia/reperfusion (I/R) injury is more severe in aged hearts. Although nuclear factor-kappaB (NF-kB) activity increases with aging, whether this redox-responsive transcription factor plays any role in age-related worsening of I/R injury remains unknown. Hypothesis: We hypothesized that activation of myocardial NF-kB exerts deleterious effects during I/R injury in young as well as aged hearts; and that NF-kB signaling contributes to age-related worsening of myocardial I/R injury. Methods: We used transgenic mice overexpressing a mutant IkBa that prevents NF-kB activation only in the heart. Age-matched young (10-week-old) and aged (86-week-old) male non-transgenic littermates (NTg) and IkBa transgenic (Tg) mice underwent a 30-min coronary occlusion followed by 24 h of reperfusion. Following sacrifice, infarct size was measured and molecular assays were performed. Results: The infarct size was significantly smaller in young Tg mice compared with young NTg mice (Fig), indicating a deleterious role of NF-kB signaling during myocardial I/R injury even in the young. The infarct size in aged NTg hearts was greater compared with young NTg hearts, consistent with an age-related worsening of I/R injury effects. However, infarct size in aged Tg hearts was significantly smaller than aged NTg hearts, and similar to young Tg hearts, indicating that NF-kB signaling contributes toward age-related aggravation of I/R injury. Interestingly, the levels of molecular markers of senescence, such as p16, were lower in aged Tg hearts (Fig), indicating a deleterious role of NF-kB in cardiac aging and susceptibility to I/R injury. Conclusions: We conclude that inhibition of cardiac NF-kB signaling protects against age-related aggravation of acute myocardial I/R injury. These findings suggest that modulation of NF-kB signaling may be potentially used to achieve therapeutic cardioprotection in the elderly.

scholarly journals Gene Transfer of IκBα Limits Infarct Size in a Mouse Model of Myocardial Ischemia-Reperfusion Injury

2003 ◽  
Vol 83 (8) ◽  
pp. 1097-1104 ◽  
Author(s):  
Francesco Squadrito ◽  
Barbara Deodato ◽  
Giovanni Squadrito ◽  
Paolo Seminara ◽  
Maria Passaniti ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Myocardial Ischemia ◽  
Mouse Model ◽  
Infarct Size ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

scholarly journals ADAMTS13 Deficiency Exacerbates VWF-Dependent Acute Myocardial Ischemia/Reperfusion Injury in Mice

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 264-264 ◽  
Author(s):  
Chintan Gandhi ◽  
David G Motto ◽  
Melissa Jensen ◽  
Steven R. Lentz ◽  
Anil K Chauhan
Keyword(s):  
Myocardial Infarction ◽  
Myocardial Ischemia ◽  
Infarct Size ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Neutrophil Infiltration ◽  
Adamts13 Deficiency ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocyte Apoptosis ◽  
Myocardial Ischemia Reperfusion

Abstract Abstract 264 Background and objective: ADAMTS13 (A Disintegrin And Metalloprotease with Thrombospondin type I repeats-13) cleaves von Willebrand factor (VWF), a large multimeric protein that plays an important role in thrombus formation by binding to platelets following vascular injury. Epidemiological studies suggest that elevated VWF levels and reduced ADAMTS13 activity in the plasma are risk factors for myocardial infarction. It remains unknown, however, whether the ADAMTS13-VWF axis plays a causal role in the pathophysiology of myocardial infarction. We tested the hypothesis that ADAMTS13 reduces VWF-mediated acute myocardial ischemia/reperfusion (I/R) injury in mice. Methods: Myocardial infarction was induced in male mice (8–10 weeks of age) by ligating the left anterior descending coronary artery for 30 minutes followed by 23.5 hours of reperfusion. The extent of myocardium damage was evaluated by measuring infarct size (%) in 2 mm serial sections stained with 2% triphenyl-2, 3, 4-tetrazolium-chloride. Neutrophil infiltration and myocyte apoptosis in the left ventricular area was quantified by immunohistochemistry and TUNEL staining respectively. Results: Adamts13 -/- mice exhibited significantly increased infarct size (22.2 % ± 1.1 %, P <.01) compared with WT mice (16.9 % ± 1.2 %, P<0.05). Plasma levels of cardiac troponin T (cTnT), an index of myocyte injury, were significantly higher in Adamts13−/− mice compared with WT mice (P <0.01). Adamts13+/− mice, which have a 50% reduction in ADAMTS13 activity, had similar sized infarcts (16.6 ± 1.3%) and cTnT levels compared to those in WT mice. Larger infarcts in the Adamts13−/− mice were concordant with increased neutrophil infiltration and myocyte apoptosis compared with WT mice. Because VWF remains the only known substrate of ADAMTS13 in multiple experimental models, we hypothesized that ADAMTS13 reduces myocardial injury through its proteolytic effect on hyper adhesive ULVWF and /or VWF. Vwf−/− mice exhibited significantly reduced infarct size, neutrophil infiltration, and myocyte apoptosis compared with WT mice, suggesting a detrimental role for VWF in myocardial I/R injury. VWF-deficient mice have a defect in regulation of endothelial P-selectin due to the loss of Weibel-Palade body formation. To confirm that exacerbated myocardial I/R injury in the setting of ADAMTS13 deficiency is dependent on VWF rather than P-selectin, we compared WT and Adamts13−/− mice treated with anti-VWF inhibitory antibodies. Treating WT or Adamts13−/− mice with neutralizing antibodies to VWF prior to myocardial I/R injury significantly reduced infarct size compared with control Ig-treated mice, suggesting that exacerbated myocardial I/R injury observed in Adamts13−/− mice is entirely VWF-dependent. Finally, myocardial I/R injury in Adamts13−/−/Vwf−/− mice was similar to that in Vwf−/− mice, suggesting that the exacerbated myocardial I/R injury observed in the setting of ADAMTS13 deficiency is VWF-dependent. Conclusion: These findings reveal a new role for anti-thrombotic enzyme ADAMTS13 in reducing VWF-mediated myocardial ischemia/reperfusion injury. Disclosures: Lentz: Novo Nordisk A/S: Consultancy, Investigator Other.

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