scholarly journals Reperfusion Therapy with Rapamycin Attenuates Myocardial Infarction through Activation of AKT and ERK

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Scott M. Filippone ◽  
Arun Samidurai ◽  
Sean K. Roh ◽  
Chad K. Cain ◽  
Jun He ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Infarct Size ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Mammalian Target Of Rapamycin ◽  
Reperfusion Therapy ◽  
Myocardial Infarct Size ◽  
Ribosomal Protein S6 ◽  
Cardioprotective Effects ◽  
Fractional Shortening

Prompt coronary reperfusion is the gold standard for minimizing injury following acute myocardial infarction. Rapamycin, mammalian target of Rapamycin (mTOR) inhibitor, exerts preconditioning-like cardioprotective effects against ischemia/reperfusion (I/R) injury. We hypothesized that Rapamycin, given at the onset of reperfusion, reduces myocardial infarct size through modulation of mTOR complexes. Adult C57 male mice were subjected to 30 min of myocardial ischemia followed by reperfusion for 1 hour/24 hours. Rapamycin (0.25 mg/kg) or DMSO (7.5%) was injected intracardially at the onset of reperfusion. Post-I/R survival (87%) and cardiac function (fractional shortening, FS:28.63±3.01%) were improved in Rapamycin-treated mice compared to DMSO (survival: 63%, FS:17.4±2.6%). Rapamycin caused significant reduction in myocardial infarct size (IS:26.2±2.2%) and apoptosis (2.87±0.64%) as compared to DMSO-treated mice (IS:47.0±2.3%; apoptosis:7.39±0.81%). Rapamycin induced phosphorylation of AKT S473 (target of mTORC2) but abolished ribosomal protein S6 phosphorylation (target of mTORC1) after I/R. Rapamycin induced phosphorylation of ERK1/2 but inhibited p38 phosphorylation. Infarct-limiting effect of Rapamycin was abolished with ERK inhibitor, PD98059. Rapamycin also attenuated Bax and increased Bcl-2/Bax ratio. These results suggest that reperfusion therapy with Rapamycin protects the heart against I/R injury by selective activation of mTORC2 and ERK with concurrent inhibition of mTORC1 and p38.

scholarly journals Nod-like Receptor Protein 3 (Nlrp3) Inflammasomes Inhibition by Metformin Limits Myocardial Ischemia/reperfusion Injury

2020 ◽  
Author(s):  
Jing Zhang ◽  
Liu Yang ◽  
Qin Zhang ◽  
Xing Shi ◽  
Fuzhou Hua ◽  
...  
Keyword(s):  
Infarct Size ◽  
Nlrp3 Inflammasome ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Inflammasome Activation ◽  
Myocardial Infarct Size ◽  
Ampk Phosphorylation ◽  
Nlrp3 Inflammasome Activation ◽  
Cardioprotective Effects

Abstract Background Ischemia/reperfusion (I/R) injury is a life-threatening vascular emergency following myocardial infarction. Our previous study showed cardioprotective effects of metformin against myocardial I/R injury. In this study, we further examined the involvement of AMPK mediated activation of NLRP3 inflammasome in this cardioprotective effect of metformin. Methods Myocardial I/R injury was simulated in a rat heart Langendorff model and neonatal rat ventricle myocytes (NRVMs) were subjected to hypoxi/reoxygenation (H/R) to establish an in vitro model. Outcome measures included myocardial infarct size, hemodynamic monitoring, myocardial tissue injury, myocardial apoptotic index and the inflammatory response. myocardial infarct size and cardiac enzyme activities. Results First, we found that metformin postconditioning can not only significantly alleviated myocardial infarct size, attenuated cell apoptosis, and inhibited myocardial fibrosis. Furthermore, metformin activated phosphorylated AMPK, decreased pro-inflammatory cytokines, TNF-α, IL-6 and IL-1β, and decreased NLRP3 inflammasome activation. In isolated NRVMs metformin increased cellular viability, decreased LDH activity and inhibited cellular apoptosis and inflammation. Importantly, inhibition of AMPK phosphorylation by Compound C (CC) resulted in decreased survival of cardiomyocytes mainly by inducing the release of inflammatory cytokines and increasing NLRP3 inflammasome activation. Finally, in vitro studies revealed that the NLRP3 activator nigericin abolished the anti-inflammatory effects of metformin in NRVMs, but it had little effect on AMPK phosphorylation. Conclusions Collectively, our study confirmed that metformin exerts cardioprotective effects by regulating myocardial I/R injury-induced inflammatory response, which was largely dependent on the enhancement of the AMPK pathway, thereby suppressing NLRP3 inflammasome activation.

Abstract 13498: Reperfusion Therapy With Rapamycin Prevents Myocardial Ischemic Injury, Through Activation of AKT and ERK

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Scott M Filippone ◽  
Sean K Roh ◽  
Fadi N Salloum ◽  
Rakesh C Kukreja ◽  
Anindita Das
Keyword(s):  
Infarct Size ◽  
Map Kinases ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Reperfusion Therapy ◽  
Tunel Staining ◽  
Coronary Artery Ligation ◽  
Myocardial Infarct Size ◽  
Artery Ligation ◽  
Tetrazolium Chloride

Background: The selective inhibitor of mammalian target of rapamycin (mTOR), rapamycin (RAPA), has been shown to exert preconditioning-like cardioprotective effects against ischemia/reperfusion (I/R) injury. Two distinct mTOR complexes (mTORC1 and mTORC2) differentially regulate cardiomyocyte apoptosis and tissue damage following myocardial infarction. We hypothesized that reperfusion therapy with RAPA would reduce myocardial infarct size through differential modulation of mTOR complexes and MAP kinases. Methods and Results: Adult C57BL mice were subjected to 30 min of ischemia via left anterior descending coronary artery ligation followed by reperfusion for 24 hr. RAPA (0.25 mg/kg) or 10% DMSO (volume-matched control) was administered via intra-cardiac injection at the onset of reperfusion. Post I/R survival (90%) and cardiac function (fractional shortening, FS: 26.9±2.6%) were improved in RAPA-treated mice compared to control (survival: 60%, FS:16.7±3.2%). Additionally, RAPA caused significant reduction in myocardial infarct size (Fig. 1A), measured by tetrazolium chloride staining, and apoptosis (Fig. 1B) in peri-infarct regions, assessed by TUNEL staining. Western blot analysis revealed that RAPA restored Akt473 phosphorylation (target of mTORC2), but reduced ribosomal protein S6 phosphorylation (target of mTORC1) following I/R injury (Fig. 1C). The protective effect of RAPA was associated with increased phosphorylation of ERK1/2 and decreased phosphorylation of P38 (Fig. 1D). RAPA also attenuated pro-apoptotic protein Bax, in concert with increased pro-survival Bcl2 to Bax ratio (Fig. 1E). Conclusion: Reperfusion therapy with RAPA protects hearts against I/R injury by selective activation of mTORC2 and ERK with concurrent inhibition of mTOC1 and P38. We propose that RAPA could be a novel treatment strategy to modulate mTOR complexes and MAP kinase signaling for attenuation of reperfusion injury in the heart.

Endothelial nitric oxide synthase overexpression attenuates myocardial reperfusion injury

2004 ◽  
Vol 286 (1) ◽  
pp. H276-H282 ◽  
Author(s):  
Steven P. Jones ◽  
James J. M. Greer ◽  
Aman K. Kakkar ◽  
P. Derek Ware ◽  
Richard H. Turnage ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Myocardial Infarction ◽  
Infarct Size ◽  
Myocardial Infarct ◽  
Left Ventricular ◽  
Myocardial Reperfusion ◽  
Enos Gene ◽  
Myocardial Infarct Size ◽  
Endothelial Nitric Oxide ◽  
Fractional Shortening

Previous studies indicate that deficiency of endothelial nitric oxide (NO) synthase (eNOS)-derived NO exacerbates myocardial reperfusion injury. We hypothesized that overexpression of eNOS would reduce the extent of myocardial ischemia-reperfusion (MI/R) injury. We investigated two distinct strains of transgenic (TG) mice overexpressing the eNOS gene (eNOS TG). Bovine eNOS was overexpressed in one strain (eNOS TG-Kobe), whereas the human eNOS gene was overexpressed in the other strain (eNOS TG-RT). Non-TG (NTG) and eNOS TG mice were subjected to 30 min of coronary artery occlusion followed by 24 h of reperfusion, and the extent of myocardial infarction was determined. Myocardial infarct size was reduced by 33% in the eNOS TG-Kobe strain ( P < 0.05 vs. NTG) and by 32% in the eNOS TG-RT strain ( P < 0.05 vs. NTG). However, postischemic cardiac function (cardiac output, fractional shortening) was not improved in the eNOS TG-Kobe mouse at 24 h of reperfusion [ P = not significant (NS) vs. NTG]. In additional studies, eNOS TG-Kobe mice were subjected to 30 min of myocardial infarction and 7 days of reperfusion. Fractional shortening and the first derivative of left ventricular pressure were measured in eNOS TG-Kobe and NTG mice, and no significant differences in contractility were observed ( P = NS) between the eNOS TG mice and NTG controls. Left ventricular end-diastolic pressure was significantly ( P < 0.05 vs. NTG) reduced in the eNOS TG-Kobe strain at 7 days of reperfusion. The cardioprotective effects of eNOS overexpression on myocardial infarct size were ablated by Nω-nitro-l-arginine methyl ester (300 mg/kg) pretreatment. Thus genetic overexpression of eNOS in mice attenuates myocardial infarction after MI/R but fails to significantly protect against postischemic myocardial contractile dysfunction in mice.

scholarly journals Ophiopogonin D Reduces Myocardial Ischemia-Reperfusion Injury via Upregulating CYP2J3/EETs in Rats

2018 ◽  
Vol 49 (4) ◽  
pp. 1646-1658 ◽  
Author(s):  
Xiaoyan Huang ◽  
Yuguang Wang ◽  
Yi Wang ◽  
Liang Yang ◽  
Jia Wang ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Cardiac Function ◽  
Infarct Size ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Myocardial Infarct Size ◽  
Protective Effects ◽  
Cardioprotective Effects ◽  
Myocardial Ischemia Reperfusion ◽  
Apoptotic Effects

Background/Aims: Epoxyeicosatrienoic acids (EETs) are cytochrome P450 epoxygenase (CYP) metabolites of arachidonic acid and have multiple cardiovascular effects. Ophiopogonin D (OP-D) is an important effective monomeric component in Shenmai injection (SM-I). Both have been reported to have a variety of biological functions, including anti-inflammatory, anti-oxidant, and anti-apoptotic effects. We previously demonstrated that OP-D–mediated cardioprotection involves activation of CYP2J2/3 and enhancement of circulating EETs levels in vitro and can be developed as a novel drug for the therapy of myocardial ischemia-reperfusion (MI/R) injury. We therefore hypothesized that the protective effects of OP-D and SM-I against MI/R injury are associated with increased expression of CYP2J3 and enhanced circulating 11,12-EET levels in vivo. Methods: A rat model of MI/R injury was generated by ligation of the left anterior descending coronary artery for 40 min, followed by reperfusion for 2 h to determine the protective effects and potential mechanisms of OP-D and SM-I. Electrocardiogram and ultrasonic cardiogram were used to evaluate cardiac function; 2,3,5-triphenyltetrazolium chloride was used to measure myocardial infarct size; hematoxylin and eosin staining and transmission electron microscopy were used to observe the morphology of myocardial tissue; and the expression of related proteins in the mechanistic study was observed by western blot analysis. Results: We found that OP-D and SM-I exert protective effects on MI/R injury, including regulation of cardiac function, reduction of lactate dehydrogenase and creatine kinase production, attenuation of myocardial infarct size, and improvement of the recovery of damaged myocardial structures. We found that OP-D and SM-I activate CYP2J3 expression and increase levels of circulating 11,12-EET in MI/R-injured rats. Conclusion: We tested the hypothesis that the cardioprotective effects of OP-D and SM-I on MI/R injury are associated with increased expression of CYP2J3 and enhanced circulating 11,12-EET levels in rats. Taken together, our results show that the effects of OP-D and SM-I were also mediated by the activation of the PI3K/Akt/eNOS signaling pathway, while inhibition of the NF-κB signaling pathway and antioxidant and anti-apoptotic effects were involved in the cardioprotective effects of OP-D and SM-I.

scholarly journals Phosphatidylserine Supplementation as a Novel Strategy for Reducing Myocardial Infarct Size and Preventing Adverse Left Ventricular Remodeling

2021 ◽  
Vol 22 (9) ◽  
pp. 4401
Author(s):  
David Schumacher ◽  
Adelina Curaj ◽  
Mareike Staudt ◽  
Franziska Cordes ◽  
Andreea R. Dumitraşcu ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Infarct Size ◽  
Ventricular Remodeling ◽  
Heart Function ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Myocardial Infarct Size ◽  
Novel Strategy

Phosphatidylserines are known to sustain skeletal muscle activity during intense activity or hypoxic conditions, as well as preserve neurocognitive function in older patients. Our previous studies pointed out a potential cardioprotective role of phosphatidylserine in heart ischemia. Therefore, we investigated the effects of phosphatidylserine oral supplementation in a mouse model of acute myocardial infarction (AMI). We found out that phosphatidylserine increases, significantly, the cardiomyocyte survival by 50% in an acute model of myocardial ischemia-reperfusion. Similar, phosphatidylserine reduced significantly the infarcted size by 30% and improved heart function by 25% in a chronic model of AMI. The main responsible mechanism seems to be up-regulation of protein kinase C epsilon (PKC-ε), the main player of cardio-protection during pre-conditioning. Interestingly, if the phosphatidylserine supplementation is started before induction of AMI, but not after, it selectively inhibits neutrophil’s activation, such as Interleukin 1 beta (IL-1β) expression, without affecting the healing and fibrosis. Thus, phosphatidylserine supplementation may represent a simple way to activate a pre-conditioning mechanism and may be a promising novel strategy to reduce infarct size following AMI and to prevent myocardial injury during myocardial infarction or cardiac surgery. Due to the minimal adverse effects, further investigation in large animals or in human are soon possible to establish the exact role of phosphatidylserine in cardiac diseases.

scholarly journals ω-3 Polyunsaturated Fatty Acid Postconditioning Protects the Isolated Perfused Rat Heart from Ischemia-Reperfusion Injury

2018 ◽  
Vol 8 (3) ◽  
pp. 173-182 ◽  
Author(s):  
Fu-wei Zhang ◽  
Jian Tong ◽  
Yu-sheng Yan ◽  
Qun-qing Chen ◽  
Xiao-ping Zhao
Keyword(s):  
Infarct Size ◽  
Rat Heart ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Mitochondrial Damage ◽  
Myocardial Infarct Size ◽  
Perfused Rat Heart ◽  
Isolated Perfused Rat Heart ◽  
Cardioprotective Effects

Aims: This study aimed to evaluate the cardioprotective effects of ω-3 polyunsaturated fatty acids (PUFAs) postconditioning against ischemia-reperfusion (I/R) injury. Methods: Sixty Sprague-Dawley rats were randomly divided into 4 groups (n = 15 for each) and used to generate the Langendorff isolated perfused rat heart model. The sham group received a continuous perfusion of 150 min. The remaining three I/R-treated groups sequentially received a 30-min perfusion, a 30-min cardioplegia, and a 90-min reperfusion. The I/R-ischemic preconditioning (IP) group additionally received three cycles of 20-s reperfusion and 20-s coronary reocclusion preceded the 90 min of reperfusion. The I/R-ω group were perfused with ω-3 PUFAs for 15 min before the 90 min of reperfusion. The myocardial infarct size, the degree of mitochondrial damage, the antioxidant capacity of the myocardium, and the cardiac functions during reperfusion were compared among groups. Results: Compared with the I/R group, the I/R-ω group had significantly reduced myocardial infarct size, reduced levels of lactate dehydrogenase and malondialdehyde, elevated superoxide dismutase level, and elevated rising (+dp/dtmax) and descending (–dp/dtmax) rate of left ventricular pressure. The I/R-ω group had a significantly lower rate of mitochondrial damage in myocardial tissue compared with the I/R and I/R-IP groups. Conclusion: ω-3 PUFA postconditioning possesses good cardioprotective effects and may be developed into a therapeutic strategy for myocardial I/R injury.

scholarly journals New Interventional Therapies beyond Stenting to Treat ST-Segment Elevation Acute Myocardial Infarction

2021 ◽  
Vol 8 (9) ◽  
pp. 100
Author(s):  
Pablo Vidal-Calés ◽  
Pedro L. Cepas-Guillén ◽  
Salvatore Brugaletta ◽  
Manel Sabaté
Keyword(s):  
Myocardial Infarction ◽  
Infarct Size ◽  
Ischemia Reperfusion Injury ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Myocardial Damage ◽  
Left Ventricular ◽  
Myocardial Infarct Size ◽  
St Segment Elevation ◽  
St Segment

Myocardial infarction remains the principal cause of death in Europe. In patients with ST-segment-elevation myocardial infarction (STEMI), a promptly revascularization with primary percutaneous intervention (PCI) has transformed prognosis in the last decades. However, despite increasing successful PCI procedures, mortality has remained unchanged in recent years. Also, due to an unsatisfactory reperfusion, some patients have significant myocardial damage and suffer left ventricular adverse remodeling with reduced function—all that resulting in the onset of heart failure with all its inherent clinical and socioeconomic burden. As a consequence of longer ischemic times, distal thrombotic embolization, ischemia-reperfusion injury and microvascular dysfunction, the resultant myocardial infarct size is the major prognostic determinant in STEMI patients. The improved understanding of all the pathophysiology underlying these events has derived to the development of several novel therapies aiming to reduce infarct size and to improve clinical outcomes in these patients. In this article, based on the mechanisms involved in myocardial infarction prognosis, we review the new interventional strategies beyond stenting that may solve the suboptimal results that STEMI patients still experience.

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