P6599Upregulation of protein and gene expression of arginase-1 in patients with ST elevation myocardial infarction

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
J Tengbom ◽  
S Cederstrom ◽  
D Verouhis ◽  
P Sorensson ◽  
F Bohm ◽  
...  

Abstract Background The mechanisms underlying rupture of a coronary atherosclerotic plaque and development of myocardial ischemia-reperfusion injury in ST-elevation myocardial infarction (STEMI) remain unknown. Increased arginase-1 activity leads to reduced nitric oxide production and increased formation of reactive oxygen species due to uncoupling of the endothelial nitric oxide synthase (eNOS). These events lead to endothelial dysfunction, plaque instability and increased susceptibility to ischemia-reperfusion injury in acute myocardial infarction. Experimental studies have shown that arginase-1 expression and activity are increased in atherosclerosis and during myocardial ischemia-reperfusion. Accordingly, inhibition of arginase-1 reduces atherosclerotic lesion development and limits the extent of infarct size during ischemia-reperfusion via an eNOS-dependent mechanism. Furthermore, arginase-1 inhibition improves endothelial function in patients with coronary artery disease but the potential role of arginase-1 in patients with STEMI is poorly understood. Purpose The purpose of the current study was to test the hypothesis that arginase-1 is upregulated and correlate to infarct size in STEMI patients. Methods and results Two independent cohorts of STEMI patients were included. In cohort 1, plasma and buffy coat leukocytes were collected from 53 STEMI patients at the time of arterial puncture for percutaneous coronary intervention, at 24–48 hours post STEMI and at 3 months post STEMI. Gene expression in leukocytes was determined in 51 patients with Affymetrix Human Transcriptome Array 2.0. In cohort 2, plasma was collected from 82 STEMI patients at admission and at 6 months for determination of plasma arginase-1. These patients underwent cardiac magnetic resonance imaging performed at day 4–7 and at 6 months post STEMI. Plasma arginase-1 levels were quantified with ELISA. Control blood samples were collected from 56 healthy age matched subjects. In cohort 1, ARG1 gene expression was four-fold higher in STEMI patients at admission compared to controls (Figure A). This expression returned to control levels within 3 months. Plasma arginase-1 levels were two times higher in STEMI patients at admission compared to controls, and remained elevated at 24–48 hours and at 3 months post STEMI (Figure B). The increase in plasma arginase-1 in STEMI patients was confirmed in cohort 2 (Figure C). Arginase-1 levels did not correlate with infarct size. Conclusions STEMI patients demonstrate increased gene expression and plasma levels of arginase-1 in the acute setting. In contrast to gene expression plasma arginase-1 levels remain significantly elevated over time. The markedly increased expression of arginase-1 already at admission may suggest a mechanistic role of arginase-1 in the development of STEMI. Further studies are needed to elucidate whether increased expression, induction and activity of arginase-1 are contributing factors for the development of STEMI.

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.


Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2134
Author(s):  
Alessandro Bellis ◽  
Ciro Mauro ◽  
Emanuele Barbato ◽  
Giuseppe Di Gioia ◽  
Daniela Sorriento ◽  
...  

During the last three decades, timely myocardial reperfusion using either thrombolytic therapy or primary percutaneous intervention (pPCI) has allowed amazing improvements in outcomes with a more than halving in 1-year ST-elevation myocardial infarction (STEMI) mortality. However, mortality and left ventricle (LV) remodeling remain substantial in these patients. As such, novel therapeutic interventions are required to reduce myocardial infarction size, preserve LV systolic function, and improve survival in reperfused-STEMI patients. Myocardial ischemia-reperfusion injury (MIRI) prevention represents the main goal to reach in order to reduce STEMI mortality. There is currently no effective therapy for MIRI prevention in STEMI patients. A significant reason for the weak and inconsistent results obtained in this field may be the presence of multiple, partially redundant, mechanisms of cell death during ischemia-reperfusion, whose relative importance may depend on the conditions. Therefore, it is always more recognized that it is important to consider a “multi-targeted cardioprotective therapy”, defined as an additive or synergistic cardioprotective agents or interventions directed to distinct targets with different timing of application (before, during, or after pPCI). Given that some neprilysin (NEP) substrates (natriuretic peptides, angiotensin II, bradykinin, apelins, substance P, and adrenomedullin) exert a cardioprotective effect against ischemia-reperfusion injury, it is conceivable that antagonism of proteolytic activity by this enzyme may be considered in a multi-targeted strategy for MIRI prevention. In this review, by starting from main pathophysiological mechanisms promoting MIRI, we discuss cardioprotective effects of NEP substrates and the potential benefit of NEP pharmacological inhibition in MIRI prevention.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Shahid Baba ◽  
Deqing zhang ◽  
David Hoetker ◽  
Yiru Guo ◽  
Aruni Bhatnagar

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.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Guangming Cheng ◽  
Sheng Ye ◽  
Magdy Girgis ◽  
Lin Zhao ◽  
Xing Chen ◽  
...  

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Min Liu ◽  
Bin Zhou ◽  
Zhong-Yuan Xia ◽  
Bo Zhao ◽  
Shao-Qing Lei ◽  
...  

Ischemia postconditioning (IpostC) is an effective way to alleviate ischemia and reperfusion injury; however, the protective effects seem to be impaired in candidates with diabetes mellitus. To gain deep insight into this phenomenon, we explored the role of DJ-1, a novel oncogene, that may exhibit powerful antioxidant capacity in postconditioning cardioprotection in a rat model of myocardial ischemia reperfusion injury. Compared with normal group, cardiac DJ-1 was downregulated in diabetes. Larger postischemic infarct size as well as exaggeration of oxidative stress was observed, while IpostC reversed the above changes in normal but not in diabetic rats. DJ-1 was increased after ischemia and postconditioning contributed to a further elevation; however, no alteration of DJ-1 was documented in all subgroups of diabetic rats. Alteration of the cardioprotective PI3K/Akt signaling proteins may be responsible for the ineffectiveness of postconditioning in diabetes. There is a positive correlation relationship between p-Akt and DJ-1 but a negative correlation between infarct size and DJ-1, which may partially explain the interaction of DJ-1 and IpostC cardioprotection. Our result indicates a beneficial role of DJ-1 in myocardial ischemia reperfusion. Downregulation of cardiac DJ-1 may be responsible for the compromised diabetic heart responsiveness to IpostC cardioprotection.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 264-264 ◽  
Author(s):  
Chintan Gandhi ◽  
David G Motto ◽  
Melissa Jensen ◽  
Steven R. Lentz ◽  
Anil K Chauhan

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.


2018 ◽  
Vol 24 (1) ◽  
pp. 18-30 ◽  
Author(s):  
Mohammed Andaleeb Chowdhury ◽  
Haden K. Sholl ◽  
Megan S. Sharrett ◽  
Steven T. Haller ◽  
Christopher C. Cooper ◽  
...  

Similar to ischemic preconditioning, high-intensity exercise has been shown to decrease infarct size following myocardial infarction. In this article, we review the literature on beneficial effects of exercise, exercise requirements for cardioprotection, common methods utilized in laboratories to study this phenomenon, and discuss possible mechanisms for exercise-mediated cardioprotection.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Xin Yu ◽  
Liang Ge ◽  
Liang Niu ◽  
Xin Lian ◽  
Haichun Ma ◽  
...  

Nitric oxide synthases (NOSs) are a family of enzymes that are responsible for the synthesis of nitric oxide (NO) from the amino acid L-arginine in the body. Among the three key NOSs, the expression of inducible NOS (iNOS) can only be induced by inflammatory stimuli and contribute to the large amount of NO production. iNOS-derived NO plays an important role in various physiological and pathophysiological conditions, including the ischemic heart disease. Nowadays, the development of specific iNOS inhibitors and the availability of iNOS knockout mice have provided substantial evidence to support the role of iNOS/NO signaling in the myocardium. Nevertheless, the role of iNOS/NO signaling in the myocardial ischemic reperfusion injury is very complex and highly perplexing; both detrimental and beneficial effects of iNOS have been described. Thus, this review will aim at providing basic insights into the current progress of the role of iNOS in myocardial ischemia reperfusion injury. A better understanding of the dual role of iNOS in details may help facilitate the development of more effective therapies for the management of ischemic heart diseases.


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