scholarly journals MicroRNA-145 Protects against Myocardial Ischemia Reperfusion Injury via CaMKII-Mediated Antiapoptotic and Anti-Inflammatory Pathways

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Zhebo Liu ◽  
Bo Tao ◽  
Suzhen Fan ◽  
Yong Pu ◽  
Hao Xia ◽  
...  

MicroRNA-145 (miR-145) has been shown to play an important role in cardiovascular system disorders; however, the underlying mechanism is not completely understood. The purpose of this study was aimed at elucidating the cardioprotective effects of miR-145 against myocardial ischemia/reperfusion (I/R) injury. We established a rat myocardial I/R model with 45 min left anterior descending coronary artery (LAD) occlusion and 2 h reperfusion. The levels of myocardial enzymes, apoptotic, inflammatory, and oxidative indices were determined. The arrhythmia score was assessed by programmed electrical stimulation (PES). Quantitative real-time PCR and western blot were applied to evaluate the expression levels of miR-145 and related target proteins, respectively. I/R injury decreased the expression of miR-145; however, upregulated miR-145 markedly reduced the elevation of ST segment, decreased corrected QT (QTc) intervals, and attenuated I/R-induced electrophysiological instability. Furthermore, miR-145 suppressed myocardium apoptotic, inflammatory, and oxidative response as well as the phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII), ryanodine receptor2 (RyR2 Ser2814), apoptosis signal-regulating kinase 1 (ASK1), c-Jun NH2-terminal kinases (JNK), and nuclear translocation of nuclear factor kappa-B (NF-κB) p65. In summary, overexpression of miR-145 alleviates I/R-induced myocardial electrophysiological instability and apoptotic and inflammatory response via inhibition of the CaMKII-mediated ASK1 antiapoptotic pathway and NF-κB p65 anti-inflammatory pathways.

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Xuejun Wang ◽  
Erin J Terpstra ◽  
Eduardo Callegari ◽  
Chengjun Hu ◽  
Hanming Zhang ◽  
...  

Cardiac proteasome functional insufficiency is implicated in a large subset of heart disease and has been experimentally demonstrated to play an essential role in cardiac proteotoxicity, including desmin-related cardiomyopathy and myocardial ischemia-reperfusion (I-R) injury. Pharmacological inhibition of phosphodiesterase 5 (PDE5) via sildenafil for example, which can stabilize cGMP and thereby increase cGMP-dependent protein kinase (PKG) activity, is consistently reported to protect against I-R injury; however, the underlying mechanism is not fully understood. We have recently discovered that PKG activation enhances proteasomal degradation of misfolded proteins (Ranek, et al. Circulation 2013), prompting us to hypothesize that proteasome-priming may contribute to cardioprotection-induced by PDE5 inhibition. Here we used a cardiomyocyte-restricted proteasome inhibition transgenic mouse line (Tg) and non-Tg (Ntg) littermates to interrogate the action of sildenafil on I-R injury created by left anterior descending artery (LAD) ligation (30 min) and release (24 hr). Sildenafil was administered 30 min before LAD ligation. Results showed that (1) the 26S proteasome activity of the Ntg I-R hearts was significantly elevated by sildenafil but this elevation was blocked in the Tg line; (2) the infarct size reduction by sildenafil treatment in Ntg mice was completely abolished in the Tg mice with the same treatment; and (3) systolic and diastolic function impairment after I/R was markedly attenuated in sildenafil-treated Ntg mice, but not in the sildenafil-treated Tg mice. Additionally, immunoprecipitation assays show that PKG interacted with the proteasome in cultured cardiomyocytes, and this interaction appeared to be augmented by sildenafil treatment. Moreover, in vitro incubation of active PKG with purified human 26S proteasomes increased proteasome peptidase activities and the phosphorylation at specific serine residues of a 19S proteasome subunit as revealed by “gel-free” nano-LC-MS/MS. We conclude that active PKG directly interacts with, phosphorylates, and increases the activities of, the proteasome and that proteasome priming mediates to cardioprotection of PDE5 inhibition against I-R injury.


2019 ◽  
Vol 39 (7) ◽  
Author(s):  
WenHua Li ◽  
Yong Li ◽  
Ying Chu ◽  
WeiMin Wu ◽  
QiuHua Yu ◽  
...  

Abstract Myocardial ischemia–reperfusion (I/R) injury is a major contributor to the morbidity and mortality associated with coronary artery disease. How to ensure the recovery of blood supply to ischemic myocardial tissue while avoiding or reducing I/R injury remains a critical problem in clinical practice. In the present study, we examined the function of phospholipase C ϵ-1 (PLCE1) by an H9c2 H/R (H/R, hypoxia–reoxygenation) model and a rat myocardial I/R injury model. The expression of PLCE1 and its effect on I/R injury-induced inflammatory response as well as its possible underlying mechanism were investigated. Our results have shown that PLCE1 was progressively increased along with the increase in hypoxia time in the H/R H9c2 and HL-1 cells. In myocardial I/R rats, PLCE1 presented a low expression level in the sham group, however, it was increased sharply in the I/R group. Overexpression of PLCE1 promoted the expression of IL-6, TNF-α, and IL-1α, and decreased the expression of IL-10. Knockdown of PLCE1 decreased the expression of IL-6, TNF-α, and IL-1α, and increased the expression of IL-10. Furthermore, overexpression of PLCE1 increased the phosphorylation of p38, ERK1/2, and nuclear factor-κ B (NF-κB) P65 while knockdown of PLCE1 inhibited their phosphorylation. In conclusion, the present study provided evidence that PLCE1 was up-regulated in H/R H9c2 cell and I/R rat. Overexpression of PLCE1 promoted the inflammatoion via activation of the NF-κB signaling pathway.


Blood ◽  
2012 ◽  
Vol 120 (26) ◽  
pp. 5217-5223 ◽  
Author(s):  
Simon F. De Meyer ◽  
Alexander S. Savchenko ◽  
Michael S. Haas ◽  
Daphne Schatzberg ◽  
Michael C. Carroll ◽  
...  

Abstract Coronary heart disease is a major cause of death in the western world. Although essential for successful recovery, reperfusion of ischemic myocardium is inevitably associated with reperfusion injury. To investigate a potential protective role of ADAMTS13, a protease cleaving von Willebrand factor multimers, during myocardial ischemia/reperfusion, we used a mouse model of acute myocardial infarction. We found that Adamts13−/− mice developed larger myocardial infarctions than wild-type control mice, whereas treatment of wild-type mice with recombinant human ADAMTS13 (rhADAMTS13) led to smaller infarctions. The protective effect of ADAMTS13 was further confirmed by a significant reduction of cardiac troponin-I release and less myocardial apoptosis in mice that received rhADAMTS13 compared with controls. Platelets adherent to the blood vessel wall were observed in few areas in the heart samples from mice treated with vehicle and were not detected in samples from mice treated with rhADAMTS13. However, we observed a 9-fold reduction in number of neutrophils infiltrating ischemic myocardium in mice that were treated with rhADAMTS13, suggesting a potent anti-inflammatory effect of ADAMTS13 during heart injury. Our data show that ADAMTS13 reduces myocardial ischemia/reperfusion injury in mice and indicate that rhADAMTS13 could be of therapeutic value to limit myocardial ischemia/reperfusion injury.


2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Bin Zhang ◽  
Mengen Zhai ◽  
Buying Li ◽  
Zhenhua Liu ◽  
Kaifeng Li ◽  
...  

Reducing oxidative stress is a crucial therapeutic strategy for ameliorating diabetic myocardial ischemia/reperfusion (MI/R) injury. Honokiol (HKL) acts as an effective cardioprotective agent for its strong antioxidative activity. However, its roles and underlying mechanisms against MI/R injury in type 1 diabetes (T1D) remain unknown. Since SIRT1 and Nrf2 are pivotal regulators in diabetes mellitus patients suffering from MI/R injury, we hypothesized that HKL ameliorates diabetic MI/R injury via the SIRT1-Nrf2 signaling pathway. Streptozotocin-induced T1D rats and high-glucose-treated H9c2 cells were exposed to HKL, with or without administration of the SIRT1 inhibitor EX527, SIRT1 siRNA, or Nrf2 siRNA, and then subjected to I/R operation. We found that HKL markedly improved the postischemic cardiac function, decreased the infarct size, reduced the myocardial apoptosis, and diminished the reactive oxygen species generation. Intriguingly, HKL remarkably activated SIRT1 signaling, enhanced Nrf2 nuclear translocation, increased antioxidative signaling, and decreased apoptotic signaling. However, these effects were largely abolished by EX527 or SIRT1 siRNA. Additionally, our cellular experiments showed that Nrf2 siRNA blunted the cytoprotective effects of HKL, without affecting SIRT1 expression and activity. Collectively, these novel findings indicate that HKL abates MI/R injury in T1D by ameliorating myocardial oxidative damage and apoptosis via the SIRT1-Nrf2 signaling pathway.


2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Liming Yu ◽  
Qing Li ◽  
Bo Yu ◽  
Yang Yang ◽  
Zhenxiao Jin ◽  
...  

Berberine (BBR) exerts potential protective effect against myocardial ischemia/reperfusion (MI/R) injury. Activation of silent information regulator 1 (SIRT1) signaling attenuates MI/R injury by reducing oxidative damage and inflammation response. This study investigated the antioxidative and anti-inflammatory effects of BBR treatment in MI/R condition and elucidated its potential mechanisms. Sprague-Dawley rats were treated with BBR in the absence or presence of the SIRT1 inhibitor sirtinol (Stnl) and then subjected to MI/R injury. BBR conferred cardioprotective effects by improving postischemic cardiac function, decreasing infarct size, reducing apoptotic index, diminishing serum creatine kinase and lactate dehydrogenase levels, upregulating SIRT1, Bcl-2 expressions, and downregulating Bax and caspase-3 expressions. Stnl attenuated these effects by inhibiting SIRT1 signaling. BBR treatment also reduced myocardium superoxide generation, gp91phoxexpression, malondialdehyde (MDA) level, and cardiac inflammatory markers and increased myocardium superoxide dismutase (SOD) level. However, these effects were also inhibited by Stnl. Consistently, BBR conferred similar antioxidative and anti-inflammatory effects against simulated ischemia reperfusion injury in cultured H9C2 cardiomyocytes. SIRT1 siRNA administration also abolished these effects. In summary, our results demonstrate that BBR significantly improves post-MI/R cardiac function recovery and reduces infarct size against MI/R injury possibly due to its strong antioxidative and anti-inflammatory activity. Additionally, SIRT1 signaling plays a key role in this process.


2021 ◽  
Vol 12 ◽  
Author(s):  
Haijian Zhang ◽  
Yifei Liu ◽  
Xiaoqing Cao ◽  
Wenmiao Wang ◽  
Xiaohong Cui ◽  
...  

Cardiomyocyte apoptosis in response to inflammation is a primary cause of myocardial ischemia-reperfusion injury (IRI). Nuclear factor erythroid 2 like 2 (Nrf2) reportedly plays an important role in myocardial IRI, but the underlying mechanism remains obscure. Expression data from the normal heart tissues of mice or heart tissues treated with reperfusion for 6 h after ischemia (IR6h) were acquired from the GEO database; changes in biological function and infiltrating immune cells were analyzed. The binding between the molecules was verified by chromatin immunoprecipitation sequencing. Based on confirmation that early myocardial ischemia-reperfusion (myocardial ischemia/reperfusion for 6 hours, IR6h) promoted myocardial apoptosis and inflammatory response, we found that Nrf2, cooperating with Programmed Cell Death 4, promoted transcription initiation of C-C Motif Chemokine Ligand 3 (Ccl3) in myocardial tissues of mice treated with IR6h. Moreover, Ccl3 contributed to the high signature score of C-C motif chemokine receptor 1 (Ccr1)-positive macrophages. The high signature score of Ccr1-positive macrophages leads to the release of pro-inflammatory factors interleukin 1 beta and interleukin 6. This study is the first to elucidate the damaging effect of Nrf2 via remodeling of the immune microenvironment in early myocardial ischemia-reperfusion, which provides us with new perspectives and treatment strategies for myocardial ischemia-reperfusion.


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