DNAzyme Targeting Transcription Factor c-Jun Inhibits Myocardial Inflammation, ROS Generation and Infarct Size after Ischemia–reperfusion Injury

2009 ◽  
Vol 18 ◽  
pp. S112
Author(s):  
Xiao Luo ◽  
Hong Cai ◽  
Harry C. Lowe ◽  
Colin N. Chesterman ◽  
Levon M. Khachigian
RSC Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 4173-4173
Author(s):  
Laura Fisher

Retraction of ‘Chrysin attenuates myocardial ischemia–reperfusion injury by inhibiting myocardial inflammation’ by Jingguo Wu et al., 2018, 8, 13739–13746, DOI: 10.1039/C8RA00590G.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Chi K Lam ◽  
Wen Zhao ◽  
Wenfeng Cai ◽  
Guansheng Liu ◽  
Phil Bidwell ◽  
...  

Sarcoplasmic reticulum (SR) calcium handling is central not only in the control of heart function during excitation-contraction coupling but also in mitochondrial energetics and apoptosis. Recent studies have identified the anti-apoptotic protein, HS-1 associated protein X-1 (HAX-1) as a novel regulator of SR calcium cycling. Although HAX-1 has been shown to localize to mitochondria in various tissues, we found out that it also localizes to SR through its interaction with phospholamban (PLN) in cardiac muscle. Acute or chronic overexpression of HAX-1 in cardiomyocytes promoted PLN inhibition on the calcium ATPase (SERCA) and decreased cardiomyocyte calcium kinetics and contractile parameters. Accordingly, ablation of HAX-1 significantly enhanced SERCA activity and calcium kinetics. Furthermore, the HAX-1/PLN interaction appeared to also regulate cardiomyocyte survival. Indeed, overexpression of HAX-1 and the associated depressed SR Ca-load attenuated endoplasmic reticulum stress induced apoptosis, as evidenced by reduction of both caspase-12 activation and pro-apoptotic transcription factor C/EBP homologous protein induction during ischemia/reperfusion injury. In addition, the depressed SR Ca-cycling by HAX-1 overexpression was associated with reduced mitochondrial Ca-load as reflected by: a) hyper-phosphorylation of pyruvate dehydrogenase (PDH) and decreases in its activity, to diminish ATP production consistent with the attenuated energetic demand in these hearts; and b) reduced levels of reactive oxygen species, indicating protection from oxidative damage and preserved mitochondrial integrity. These findings suggest that HAX-1 is a key regulator of Ca-cycling, apoptosis and energetics in the heart. Thus, decreases in HAX-1 levels, observed during ischemia/reperfusion injury, may contribute to the deteriorated function and progression to heart failure development.


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Jingyuan Li ◽  
Negar Motayagheni ◽  
Neusha Barakati ◽  
Mansoureh Eghbali

The prevalence of coronary artery disease in late pregnancy (LP) has increased recently due to significant changes in women’s lifestyle patterns (age, stress, smoking, diabetes and chronic hypertension). Myocardial infarction during LP and the peripartum is associated with significant maternal mortality and morbidity compared to non pregnant women for unclear reasons. We have recently demonstrated that cardiac vulnerability to I/R injury drastically increases in LP rodents, leading to myocardial infarct size ~4 fold greater than in non-pregnant controls. We also discovered that administration of intralipid (an emulsion of soy bean oil, egg yolk phospholipids and glycerol) at reperfusion resulted in ~60% reduction in infarct size of the heart in LP rat subjected to I/R injury. However, the molecular mechanisms underlying intralipid-induced cardioprotection in late pregnancy is not clear. Here we hypothesized that intralipid protects the heart in late pregnancy by regulating the levels of specific microRNAs. The left anterior descending coronary artery was occluded in LP rats (21-22 days of pregnancy) for 45 min followed by 3 hr of reperfusion. One single bolus of PBS (control group) or 20% intralipid (intralipid group) was applied through the femoral vein 5 min before the reperfusion. The hearts of control and intralipid groups were used for microRNA microarray analysis (Ocean Ridge Biosciences). MicroRNA-microarray analysis identified MiR122 as a novel micro-RNA which its expression was strikingly upregulated more than 10 fold in the heart of LP rats in intralipid group compared to control group. miR122 regulates apoptosis in cardiomyocytes subjected to hypoxia/reoxygenation since miR122-overexpression resulted in reduced apoptosis, whereas knockdown of miR122 enhanced apoptosis. Pyruvate kinase isoform M2 (PKM2), which is known to regulate cell apoptosis in the liver, is a direct target of miR122. Our data show that PKM2 and caspase 3 are two targets of miR122 since the expression of PKM2 and capase-3 in the heats subjected to I/R was significantly lower in intralipid group compared to control group in LP. In conclusion intralipid protects the heart in late pregnancy against ischemia/reperfusion injury via inducing miR122 by targeting PKM2.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Jingyuan Li ◽  
Victor R Grijalva ◽  
Srinivasa T Reddy ◽  
Mansoureh Eghbali

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.


2001 ◽  
Vol 281 (6) ◽  
pp. H2398-H2409 ◽  
Author(s):  
Jianzhong An ◽  
Srinivasan G. Varadarajan ◽  
Amadou Camara ◽  
Qun Chen ◽  
Enis Novalija ◽  
...  

We determined in intact hearts whether inhibition of Na+/H+ exchange (NHE) decreases intracellular Na+ and Ca2+ during ischemia and reperfusion, improves function during reperfusion, and reduces infarct size. Guinea pig isolated hearts were perfused with Krebs-Ringer solution at 37°C. Left ventricular (LV) free wall intracellular Na+ concentration ([Na+]i) and intracellular Ca2+ concentration ([Ca2+]i) were measured using fluorescence dyes. Hearts were exposed to 30 min of ischemia with or without 10 μM of benzamide (BIIB-513), a selective NHE-1 inhibitor, infused for 10 min just before ischemia or for 10 min immediately on reperfusion. At 2 min of reperfusion, BIIB-513 given before ischemia decreased peak increases in [Na+]i and [Ca2+]i, respectively, from 2.5 and 2.3 times (controls) to 1.6 and 1.3 times preischemia values. At 30 min of reperfusion, BIIB-513 increased systolic-diastolic LV pressure (LVP) from 49 ± 2% (controls) to 80 ± 2% of preischemia values. BIIB-513 reduced ventricular fibrillation by 54% and reduced infarct size from 64 ± 1% to 20 ± 3%. First derivative of the LVP, O2 consumption, and cardiac efficiency were also improved by BIIB-513. Similar results were obtained with BIIB-513 given on reperfusion. These data show that Na+ loading is a marker of reperfusion injury in intact hearts in that inhibiting NHE reduces Na+ and Ca2+ loading during reperfusion while improving function. These results clearly implicate the ionic basis by which inhibiting NHE protects the guinea pig intact heart from ischemia-reperfusion injury.


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