Protective effect of C5 shRNA on myocardial ischemia–reperfusion injury in rats

2012 ◽  
Vol 90 (10) ◽  
pp. 1394-1402 ◽  
Author(s):  
Kai Tang ◽  
Yunjiu Cheng ◽  
Suhua Wu ◽  
Lijuan Liu ◽  
Lingli Cheng

Myocardial ischemia and reperfusion (MI/R) injury is associated with activation of the complement system. Complement activation generates a series of bioactive substances, including early (C3a, C3b) and terminal (C5a, C5b-9) components. The terminal complement components are key mediators of MI/R injury. This study investigated whether C5 shRNA preconditioning has protective effects following MI/R injury and its potential mechanism. Rats were injected with C5 shRNA 2 days before induction of ischemia. The effects of C5 shRNA were evaluated by the assessment of heart function, infarct size, histopathology, inflammatory cytokine levels, and the plasma level of troponin T. Akt phosphorylation was assessed by immunoblotting. C5 shRNA efficiently inhibited C5 expression both in vitro and in vivo, and attenuated MI/R injury. C5 shRNA preconditioning significantly decreased the level of troponin T and the production of pro-inflammatory cytokine. The infarct size was decreased by 40% in C5 shRNA treated rats. Akt phosphorylation increased after C5 shRNA preconditioning. These results suggest that C5 shRNA preconditioning in rats has protective effects following MI/R injury; this may be partly effected by mediating the activation of the PI3K pathway and by phosphorylation of Akt.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Bernhard J Haubner ◽  
Julia Schwaighofer ◽  
Florian Huber ◽  
Greg Neely ◽  
Keiji Kuba ◽  
...  

Introduction - Phosphoinositide 3-Kinase gamma (PI3Kγ) is a well-known key enzyme in inflammation pathways. Emerging data demonstrate that PI3Kγ plays a distinct role in cardiomyocytes, but its influence in the setting of myocardial ischemia and reperfusion is still an enigma. To clarify these effects we examined the morphology and contractility of PI3Kγ−/−hearts after ischemia and reperfusion. Methods - PI3Kγ knock out (KO) mice and C57 Bl6 wild type (WT) mice were subjected to 30 minutes of ischemia followed by 3 hours, 1 week and 3 weeks of reperfusion. We therefore reversibly ligated the left anterior descending artery (LAD) in an in vivo model and harvested the myocardium after the defined time of reperfusion. Histological sections were stained with H&E and Masson Trichrome in order to measure the area of infartion and the amount of interstitial fibrosis. Furthermore, Troponin T serum levels were determined and transthoracic echocardiography was performed for measuring the differences in myocardial contractiliy. Results - Comparing PI3Kγ KO mice with WT mice, we found a significant decrement of Troponin T serum levels in the transgenic group 3 hours after reperfusion (0.77±0.28 vs. 1.28±0.48 ng/ml, p<0.001). In addition, a distinct reduction of myocardial infarction was observed in the KO group compared to the WT mice (3 hours: 1.18±0.31 vs. 1.78±0.45 mm 2 , p=0.001; 1 week: 0.88±0.32 vs. 1.29±0.34 mm 2 , p=0.001; 3 weeks: 0.62±0.18 vs. 1.87±0.59 mm 2 , p<0.001). Furthermore, we showed a matching smaller quantity of myocardial fibrosis in the transgenic cohort (1 week: score 1.23±0.6 vs. 2.13±0.74, p=0.005; 3 weeks: score 1.08±0.79 vs. 2±0.71, p=0.014). Fractional shortening (FS) analysis determined by echocardiography revealed significantly enhanced myocardial contractility in PI3Kγ lacking mice after ischemia and reperfusion (1 week: 37.85±7.71 vs. 23.75±8.78 %FS, p=0.007; 3 weeks: 30.67±4.87 vs. 23.7±7.47 %FS, p=0.043). Conclusions - Our data provide the first evidence for the crucial role of PI3Kγ signalling in myocardial ischemia/reperfusion injury: PI3Kγ deficient mice show a significantly better outcome concerning infarction area, Troponin T elevation, scar size, fibrosis, and contractility at all stages of reperfusion (3 hours to 3 weeks).


2018 ◽  
Vol 45 (3) ◽  
pp. 883-898 ◽  
Author(s):  
Yinping Du ◽  
Ping Liu ◽  
Tongda Xu ◽  
Defeng Pan ◽  
Hong Zhu ◽  
...  

Background/Aims: The myocardial sarcoplasmic reticulum calcium ATPase (SERCA2a) is a pivotal pump responsible for calcium cycling in cardiomyocytes. The present study investigated the effect of luteolin (Lut) on restoring SERCA2a protein level and stability reduced by myocardial ischemia/reperfusion (I/R) injury. We verified a hypothesis that Lut protected against myocardial I/R injury by regulating SERCA2a SUMOylation. Methods: The hemodynamic data, myocardial infarct size of intact hearts, apoptotic analysis, mitochondrial membrane potential (ΔΨm), the level of SERCA2a SUMOylation, and the activity and expression of SERCA2a were examined in vivo and in vitro to clarify the cardioprotective effects of Lut after SUMO1 was knocked down or over-expressed. The putative SUMO conjugation sites in mouse SERCA2a were investigated as the possible regulatory mechanism of Lut. Results: Initially, we found that Lut reversed the SUMOylation and stability of SERCA2a as well as the expression of SUMO1, which were reduced by I/R injury in vitro. Furthermore, Lut increased the expression and activity of SERCA2a partly through SUMO1, thus improving ΔΨm and reducing apoptotic cells in vitro and promoting the recovery of heart function and reducing infarct size in vivo. We also demonstrated that SUMO acceptor sites in mouse SERCA2a involving lysine 585, 480 and 571. Among the three acceptor sites, Lut enhanced SERCA2a stability via lysine 585. Conclusions: Our results suggest that Lut regulates SERCA2a through SUMOylation at lysine 585 to attenuate myocardial I/R injury.


2015 ◽  
Vol 43 (06) ◽  
pp. 1083-1097 ◽  
Author(s):  
Wei Zhang ◽  
Baichun Xing ◽  
Linlin Yang ◽  
Jialun Shi ◽  
Xinmin Zhou

Icaritin (ICT) is a traditional Chinese medicinal herb proved to be neuroprotective and exerts promoting effects on cardiac differentiation. However, its role in cardioprotection against myocardial ischemia/reperfusion (MI/R) injury remains largely unknown. This study aimed to investigate the effects of ICT treatment on MI/R injury and the underlying mechanisms. Rats were subjected to 30 min of myocardial ischemic insult followed by 3 h of reperfusion. ICT (3, 10, and 30 mg/kg) was administered intraperitoneally 10 min before reperfusion. ICT treatment at the dose of 10 and 30 mg/kg improved cardiac function and limited infarct size following MI/R. Meanwhile, ICT reduced plasma creatine kinase (CK), lactate dehydrogenase (LDH) activities and cardiomyocyte apoptosis in I/R heart tissue. Moreover, ICT treatment not only inhibited the pro-inflammatory cytokine TNF-α production and increased the anti-inflammatory cytokine IL-10 level in myocardium but also reduced the increase in the generation of superoxide content and malondialdehyde (MDA) formation and simultaneously increased the anti-oxidant capability in I/R hearts. Furthermore, ICT treatment increased Akt phosphorylation and inhibited PTEN expression in I/R hearts. PI3K inhibitor wortmannin inhibited ICT-enhanced Akt phosphorylation, and blunted ICT-mediated anti-oxidative and anti-inflammatory effects and cardioprotection. Our study indicated for the first time that ICT reduces inflammation and oxidative stress and protects against MI/R injury in rats, which might be via a PI3K–Akt-dependent mechanism.


2017 ◽  
Vol 42 (6) ◽  
pp. 2295-2306 ◽  
Author(s):  
Waleed Al-Herz ◽  
Fawzi Babiker

Background/Aims: To investigate the cardioprotective effects of intravenous immunoglobulins (IVIG) in rats subjected to regional myocardial ischemia reperfusion (I/R). Methods: Langendorff-perfused rat hearts were used in this study. Hearts subjected to regional ischemia served as a negative untreated control. The effects of IVIG pre- and post-ischemic treatment on left ventricular function, coronary vascular dynamics and contractility were assessed. IVIG were administered in either a low or high dose. The infarct size was determined using triphenyltetrazolium chloride and through biochemical assays using the measured creatine kinase and lactate dehydrogenase levels. Apoptosis was evaluated by the TUNEL assay, and the caspase-3 expression level was assessed by immunoblotting. The cytokine levels were measured by ELISA. Results: Low and high doses of immunoglobulins administered 2 hours before sacrifice, before the ischemic insult or at reperfusion resulted in a significant improvement in cardiac hemodynamics, coronary vascular dynamics and heart contractility. A significant decrease in the infarct size and cardiac enzymes was also evident compared to those in the control. IVIG administered as an infusion at reperfusion or pre-treatment resulted in a marked decrease in myocyte apoptosis, which was associated with decreased levels of caspase-3 expression in the supernatants of homogenized left ventricles. Infusion of IVIG both pre-ischemia and at reperfusion did not show the same protective effects. Conclusions: This study demonstrates a novel protection to the heart by low and high doses of IVIG given either pre- or post-ischemia.


2011 ◽  
pp. 709-714 ◽  
Author(s):  
H. ŘÍHA ◽  
J. NECKÁŘ ◽  
F. PAPOUŠEK ◽  
I. NETUKA ◽  
J. PIRK ◽  
...  

Inhalational anesthetic-induced preconditioning (APC) has been shown to reduce infarct size and attenuate contractile dysfunction caused by myocardial ischemia. Only a few studies have reported the effects of APC on arrhythmias during myocardial ischemia-reperfusion injury, focusing exclusively on reperfusion. Accordingly, the aim of the present study was to examine the influence of APC on ventricular arrhythmias evoked by regional no-flow ischemia. APC was induced in adult male Wistar rats by 12-min exposures to two different concentrations (0.5 and 1.0 MAC) of isoflurane followed by 30-min wash-out periods. Ventricular arrhythmias were assessed in the isolated perfused hearts during a 45-min regional ischemia and a subsequent 15-min reperfusion. Myocardial infarct size was determined after an additional 45 min of reperfusion. The incidence, severity and duration of ventricular arrhythmias during ischemia were markedly reduced by APC. The higher concentration of isoflurane had a larger effect on the incidence of ventricular fibrillation than the lower concentration. The incidence of ventricular tachycardia and reversible ventricular fibrillation during reperfusion was also significantly reduced by APC; the same was true for myocardial infarct size. In conclusion, we have shown that preconditioning with isoflurane confers profound protection against myocardial ischemia- and reperfusion-induced arrhythmias and lethal myocardial injury.


2020 ◽  
Author(s):  
Xinhao Liu ◽  
Hui Chen ◽  
Zhibing Yan ◽  
Lei Du ◽  
Dou Huang ◽  
...  

Abstract BACKGROUND: Diabetes mellitus (DM) exhibits a higher sensitivity to myocardial ischemia/reperfusion(I/R)injury and may compromise the effectiveness of cardioprotective interventions, including ischemic preconditioning. We previously found that liver ischemic preconditioning(RLIPC) could limit infarct size post I/R in normal rat hearts and further exerted anti-arrhythmic effects in diabetic or non-diabetic rats after myocardial I/R, however, little is known regarding the effect of RLIPC on infarct-sparing in diabetic hearts. In this study, we evaluated the protective effects of RLIPC on I/R injury in streptozotocin (STZ)-induced type 1 diabetic rats.METHODS:Type 1 diabetes mellitus was induced by one-time intraperitoneal injection of streptozotocin in Sprague–Dawley rats. Rats were exposed to 45 min of left anterior descendin(LAD) coronary artery occlusion, followed by 3 h of reperfusion. For liver ischemic preconditioning, four cycles of 5 min of liver I/R stimuli were performed before LAD occlusion. the cardioprotective effect of RLIPC was determined in diabetic rats.RESULTS: Compared to non-RLIPC treated DM rats, RLIPC treatment significantly reduced infarct size in diabetic hearts post I/R. RLIPC also improved cardiac functions including LVESP, LVEDP, dp/dtmax, and -dp/dtmax. In addition, RLIPC could largely preserved cardiac morphology by reducing the pathological score post I/R in diabetic hearts. Finally, western blotting analysis showed that RLIPC stimulated phosphorylation of ventricular GSK-3β and STAT-5, which are key components of RISK and SAFE signaling pathways.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Hui-Yong Chen ◽  
Ze-Zhou Xiao ◽  
Xiao Ling ◽  
Rong-Ning Xu ◽  
Peng Zhu ◽  
...  

Abstract Aims Myocardial ischemia is the most common form of cardiovascular disease and the leading cause of morbidity and mortality. Understanding the mechanisms is very crucial for the development of effective therapy. Therefore, this study aimed to investigate the functional roles and mechanisms by which ELAVL1 regulates myocardial ischemia and reperfusion (I/R) injury. Methods Mouse myocardial I/R model and cultured myocardial cells exposed to hypoxia/reperfusion (H/R) were used in this study. Features of ferroptosis were evidenced by LDH activity, GPx4 activity, cellular iron, ROS, LPO, and GSH levels. The expression levels of autophagy markers (Beclin-1, p62, LC3), ELAVL1 and FOXC1 were measured by qRT-PCR, immunostaining and western blot. RIP assay, biotin-pull down, ChIP and dual luciferase activity assay were employed to examine the interactions of ELAVL1/Beclin-1 mRNA and FOXC1/ELAVL1 promoter. CCK-8 assay was used to examine viability of cells. TTC staining was performed to assess the myocardial I/R injury. Results Myocardial I/R surgery induced ferroptosis and up-regulated ELAVL1 level. Knockdown of ELAVL1 decreased ferroptosis and ameliorated I/R injury. Si-ELAVL1 repressed autophagy and inhibition of autophagy by inhibitor suppressed ferroptosis and I/R injury in myocardial cells. Increase of autophagy could reverse the effects of ELAVL1 knockdown on ferroptosis and I/R injury. ELAVL1 directly bound with and stabilized Beclin-1 mRNA. Furthermore, FOXC1 bound to ELAVL1 promoter region and activated its transcription upon H/R exposure. Conclusion FOXC1 transcriptionally activated ELAVL1 may promote ferroptosis during myocardial I/R by modulating autophagy, leading to myocardial injury. Inhibition of ELAVL1-mediated autophagic ferroptosis would be a new viewpoint in the treatment of myocardial I/R injury.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Jingyuan li ◽  
Zoltan Pierre Arany ◽  
Mansoureh Eghbali

Angiogenesis plays an important role in the pathogenesis of cardiovascular disease. Pro-angiogenic and anti-angiogenic treatments have provided new insights into the impact of angiogenesis-based approaches on coronary artery disease. We have recently reported that the hearts of late pregnant (LP) mice are more prone to ischemia/reperfusion (I/R) injury compared to non pregnant(NP) mice. Provided the significant change of angiogenesis status in pregnancy, here we explored whether stimulating the angiogenesis with VEGF is able to protect the heart against I/R injury in late pregnancy, and whether anti-antigenic treatment with soluble endoglin(sENG), an anti-angiogenic factor, aggravates cardiac I/R injury in NP. Pregnant mice at day 12 either received daily injection of VEGF (100 ug/kg daily subcutaneous injection) or PBS(LP CTRL) for 7 days, and at day 19 the LP mice hearts were subjected to 20 min ischemia followed by 40 min reperfusion in Langendorff. NP mice either received a single adenovirus sENG(2х10 8particles via tail vein injection) or vehicle(NP CTRL), and 10 days later NP mice were subjected to 20 min ischemia followed by 40 min reperfusion in Langendorff. The heart function was recorded throughout the experiments, and the infarct size was measured by TTC staining at the end of experiments. Exogenous VEGF treatment significantly improved the cardiac function of LP mice after ischemia. The rate pressure product (RPP) at the end of reperfusion was improved from 1617±287 mmHg*beats/min (n=6) in LP CTRL to 11287±1783 mmHg*beats/min (n=3) in the VEGF group(p<0.01). The infarct size was also significantly reduced by VEGF treatment to 25.0±4.3% (n=3) from 57.4±5.2%(n=6) in CTRL (p<0.01). While sENG aggravated the cardiac I/R injury in NP, as the RPP at the end of reperfusion in the sENG group (4523±1281 mmHg*beats/min, n=4) was significantly lower compared with NP CTRL group(12818±1213 mmHg*beats/min, n=6)(p<0.01). Furthermore, the infarct size in the sENG group was markedly higher compared with NP CTRL group (34.0±3.3% (n=4) vs. 16.3±1.4%(n=6) in NP CTRL, p<0.05). In conclusion, anti-angiogenic treatment aggravates the cardiac I/R injury in NP, while angiogenic therapy protects the heart against I/R injury in LP.


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