Beclin1 controls caspase-4 inflammsome activation and pyroptosis in  myocardial reperfusion-induced microvascular injury

2021 ◽  
Author(s):  
Wenjing Sun ◽  
Hongquan Lu ◽  
Shujuan Dong ◽  
Wang Nan ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Western Blot ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Myocardial Reperfusion ◽  
Beclin 1 ◽  
Blue Dye ◽  
Myocardial Infarct Size ◽  
Wild Mice ◽  
Microvascular Injury

Abstract Background Myocardial reperfusion injury is often accompanied by cell death and inflammatory reactions. Recently, pyroptosis is gradually recognized as pivotal role in cardiovascular disease. However, little is known about the regulatory role of beclin1 in the control of caspase-4 activation and pyroptosis. The present study confirmed whether beclin1 regulates caspase-4 mediated pyroptosis and thereby protects Cardiac microvascular endothelial cells (CMECs) against injury.Methods TTC and Evan's blue dye, western blot, immunofluorescence and immunohistochemistry staining were performed in wild mice and transgenic mice with overexpression of beclin-1(BECN1-Tg). CMECs were transfected with a beclin1 lentivirus. The cell cytotoxicity was analyzed by LDH-Cytotoxicity Assay Kit. The protein levels of autophagy protein (Beclin1, P62 and LC3II/LC3I) and caspase-4/GSDMD pathway were determined by western blot. Autophagic vacuoles in cells were monitored with RFP-GFP-LC3 using fluorescence microscope.Results I/R caused caspase-4 activity and gasdermin D expression increase in vivo and in vitro. Overexpression of beclin-1 in heart tissue and CMECs suppressed the caspase-4 activity and decreased the levels of gasdermin D; meanwhile beclin1 overexpression also reduced IL-1β levels, promoted autophagy (P62 expression was inhibited while LC3II expression was increased) in the heart and CMECs. Interestingly, beclin1 overexpression increased animal survival and attenuated myocardial infarct size post-myocardial ischemia reperfusion.Conclusions Induction of beclin-1 signaling can be a potential therapeutic target in myocardial reperfusion-induced microvascular injury.

Abstract 10246: Hydroxychloroquine Pretreatment Reduces Myocardial Ischemia-Reperfusion Injury: Role of Cardiac Extracellular-Signal-Regulated Kinase 5 and Autophagy

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Feiyan Yang ◽  
Chang Yin ◽  
Lei Xi ◽  
Rakesh C Kukreja
Keyword(s):  
Infarct Size ◽  
Ischemia Reperfusion Injury ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Beclin 1 ◽  
Myocardial Infarct Size ◽  
Western Blots ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Related Proteins

Background: Hydroxychloroquine (HCQ) is an antimalarial drug, which is also widely used to treat chronic rheumatologic diseases. Since HCQ was reported to inhibit cell autophagy and to activate extracellular-signal-regulated kinase 5 (ERK5) in vascular endothelial cells, we designed the current study to determine the effects of HCQ on cardiac ischemia-reperfusion (I-R) injury and post-I-R expression of ERK5 and autophagy marker proteins. Methods: Adult C57BL/6J mice of both genders were pretreated with HCQ (50 mg/kg, i.p.) 1 hour prior to isolation of the hearts, which were subjected to 30 min of no-flow global ischemia followed by 60 min of reperfusion in Langendorff mode. Ventricular function was continuously assessed and myocardial infarct size was determined at the end of I-R. Heart samples were collected following normoxic perfusion (no-ischemic controls), I-R, or I-R with HCQ for assessing ERK5 and autophagy-related proteins with Western blots. Results: HCQ pretreatment reduced infarct size significantly in the female hearts (P<0.05) as compared with the male hearts (Fig. A). Post-I-R cardiac function was better in HCQ-treated males (Fig. B). I-R resulted in a robust increase in total ERK5 (Fig. C) and phosphorylated ERK5 (Thr218/Tyr220) in both genders, which was abolished in HCQ-treated groups. Conversely, either I-R or HCQ did not affect the post-I-R cardiac expression of autophagy-related proteins (e.g., Atg5, Beclin-1, LC3II/LC3I ratio), except Beclin-1 phosphorylation was inhibited in HCQ-treated male hearts, but not females (Fig. D). Conclusions: Acute HCQ pretreatment affords cardioprotection against I-R injury in both genders. Interestingly, cardioprotective effects of HCQ are associated with a strong inhibitory effect on the induction of ERK5 following I-R in the heart, indicating a novel molecular mechanism underlying the HCQ-induced cardioprotection. However, the cardioprotective dose of HCQ has no major impact on cardiac autophagy.

scholarly journals Luteolin Exerts Cardioprotective Effects through Improving Sarcoplasmic Reticulum Ca2+-ATPase Activity in Rats during Ischemia/Reperfusion In Vivo

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Changsheng Nai ◽  
Haochen Xuan ◽  
Yingying Zhang ◽  
Mengxiao Shen ◽  
Tongda Xu ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Signaling Pathway ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Akt Signaling ◽  
Myocardial Infarct Size ◽  
Akt Signaling Pathway ◽  
Cardioprotective Effects

The flavonoid luteolin exists in many types of fruits, vegetables, and medicinal herbs. Our previous studies have demonstrated that luteolin reduced ischemia/reperfusion (I/R) injury in vitro, which was related with sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) activity. However, the effects of luteolin on SERCA2a activity during I/R in vivo remain unclear. To investigate whether luteolin exerts cardioprotective effects and to monitor changes in SERCA2a expression and activity levels in vivo during I/R, we created a myocardial I/R rat model by ligating the coronary artery. We demonstrated that luteolin could reduce the myocardial infarct size, lactate dehydrogenase release, and apoptosis during I/R injury in vivo. Furthermore, we found that luteolin inhibited the I/R-induced decrease in SERCA2a activity in vivo. However, neither I/R nor luteolin altered SERCA2a expression levels in myocardiocytes. Moreover, the PI3K/Akt signaling pathway played a vital role in this mechanism. In conclusion, the present study has confirmed for the first time that luteolin yields cardioprotective effects against I/R injury by inhibiting the I/R-induced decrease in SERCA2a activity partially via the PI3K/Akt signaling pathway in vivo, independent of SERCA2a protein level regulation. SERCA2a activity presents a novel biomarker to assess the progress of I/R injury in experimental research and clinical applications.

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.

scholarly journals Activation of Endocannabinoid Receptor 2 as a Mechanism of Propofol Pretreatment-Induced Cardioprotection against Ischemia-Reperfusion Injury in Rats

2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Hai-Jing Sun ◽  
Yan Lu ◽  
Hao-Wei Wang ◽  
Hao Zhang ◽  
Shuang-Ran Wang ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Ischemia Reperfusion Injury ◽  
Culture Media ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
In Vivo Model ◽  
Myocardial Infarct Size ◽  
Cb2 Receptor

Propofol pretreatment before reperfusion, or propofol conditioning, has been shown to be cardioprotective, while its mechanism is unclear. The current study investigated the roles of endocannabinoid signaling in propofol cardioprotection in an in vivo model of myocardial ischemia/reperfusion (I/R) injury and in in vitro primary cardiomyocyte hypoxia/reoxygenation (H/R) injury. The results showed that propofol conditioning increased both serum and cell culture media concentrations of endocannabinoids including anandamide (AEA) and 2-arachidonoylglycerol (2-AG) detected by LC-MS/MS. The reductions of myocardial infarct size in vivo and cardiomyocyte apoptosis and death in vitro were accompanied with attenuations of oxidative injuries manifested as decreased reactive oxygen species (ROS), malonaldehyde (MDA), and MPO (myeloperoxidase) and increased superoxide dismutase (SOD) production. These effects were mimicked by either URB597, a selective endocannabinoids degradation inhibitor, or VDM11, a selective endocannabinoids reuptake inhibitor. In vivo study further validated that the cardioprotective and antioxidative effects of propofol were reversed by selective CB2 receptor antagonist AM630 but not CB1 receptor antagonist AM251. We concluded that enhancing endogenous endocannabinoid release and subsequent activation of CB2 receptor signaling represent a major mechanism whereby propofol conditioning confers antioxidative and cardioprotective effects against myocardial I/R injury.

Nogo-A mediated endoplasmic reticulum stress during myocardial ischemic-reperfusion injury in diabetic rats

2021 ◽  
Author(s):  
yonghong xiong ◽  
yan leng ◽  
wei li ◽  
wenyuan li ◽  
rong chen ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Molecular Mechanisms ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Myocardial Damage ◽  
Diabetic Rats ◽  
Myocardial Infarct Size ◽  
Sprague Dawley

Abstract Background: Diabetic myocardial ischemia reperfusion (MI/R) injury is aggravated after myocardial infarction, which leads to myocardial damage. Molecular mechanisms associated with the diabetic ischemia-related cardiac diseases are not yet fully understood. Nogo-A is an endoplasmic reticulum (ER) protein ubiquitously expressed in tissues including in the heart. However, the mechanisms that account for the Nogo-A in MI/R injury remain unknown. Methods: SD (Sprague Dawley) rats were subjected to 45 min of ischemia, followed by 3 h reperfusion. Rats were injection with streptozotocin (60mg/kg), tauroursodeoxycholic acid injection (100mg/kg) or corresponding controls just prior to MI/R. Blood and heart samples were collected at 3 h post-reperfusion. Serum LDH and CK-MB, myocardial infarct size, histopathologic changes, apotosis and ER stress were analyzed to evaluate MI/R injury. Signaling pathways were also investigated in vitro using embryonic rat cardiomyocyte-derived H9c2 cells cultures to identify underlying mechanisms for Nogo-A in diabetic MI/R injury. Results: TUDCA treatment significantly reduced Nogo-A, GRP78 and CHOP levels, diminished myocardial infarct areas, attenuated ER stress and decreased myocardial apoptosis after MI/R. ER stress signaling was significantly decreased in the TUDCA-treated MI/R group compared with controls. The effect of Nogo-A was abrogated by pretreatment with knockdown CHOP. A positive feedback loop between Nogo-A and CHOP was found leading to an enhanced ER stress in diabetic MI/R injure. Conclusions: Our data suggest that Nogo-A mediated ER stress plays a major role in diabetic MI/R injury and Nogo-A might be a key regulator of ER stress.

Sex differences in myocardial infarct size are abolished by sarcolemmal KATP channel blockade in rat

2006 ◽  
Vol 290 (6) ◽  
pp. H2644-H2647 ◽  
Author(s):  
Micah S. Johnson ◽  
Russell L. Moore ◽  
David A. Brown
Keyword(s):  
At Risk ◽  
Sex Differences ◽  
Infarct Size ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Female Rats ◽  
Male Rats ◽  
Myocardial Infarct Size ◽  
Sprague Dawley

This study was conducted to examine the relationship between myocardial ATP-sensitive potassium (KATP) channels and sex differences in myocardial infarct size after in vitro ischemia-reperfusion (I/R). Hearts from adult male and female Sprague-Dawley rats were excised and exposed to an I/R protocol (1 h of ischemia, followed by 2 h of reperfusion) on a modified Langendorff apparatus. Hearts from female rats showed significantly smaller infarct sizes than hearts from males (23 ± 4 vs. 40 ± 5% of the zone at risk, respectively; P < 0.05). Administration of HMR-1098, a sarcolemmal KATP channel blocker, abolished the sex difference in infarct size (42 ± 4 vs. 45 ± 5% of the zone at risk in hearts from female and male rats, respectively; P = not significant). Further experiments showed that blocking the KATP channels in ischemia, and not reperfusion, was sufficient to increase infarct size in female rats. These data demonstrate that sarcolemmal KATP channels are centrally involved in mechanisms that underlie sex differences in the susceptibility of the intact heart to I/R injury.

Expression of SERCA isoform with faster Ca2+ transport properties improves postischemic cardiac function and Ca2+ handling and decreases myocardial infarction

2007 ◽  
Vol 293 (4) ◽  
pp. H2418-H2428 ◽  
Author(s):  
M. A. Hassan Talukder ◽  
Anuradha Kalyanasundaram ◽  
Xue Zhao ◽  
Li Zuo ◽  
Poornima Bhupathy ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Myocardial Salvage ◽  
Myocardial Infarct Size ◽  
Intracellular Ca ◽  
Developed Pressure

Myocardial ischemia-reperfusion (I/R) injury is associated with contractile dysfunction, arrhythmias, and myocyte death. Intracellular Ca2+ overload with reduced activity of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) is a critical mechanism of this injury. Although upregulation of SERCA function is well documented to improve postischemic cardiac function, there are conflicting reports where pharmacological inhibition of SERCA improved postischemic function. SERCA2a is the primary cardiac isoform regulating intracellular Ca2+ homeostasis; however, SERCA1a has been shown to substitute SERCA2a with faster Ca2+ transport kinetics. Therefore, to further address this issue and to evaluate whether SERCA1a expression could improve postischemic cardiac function and myocardial salvage, in vitro and in vivo myocardial I/R studies were performed on SERCA1a transgenic (SERCA1a+/+) and nontransgenic (NTG) mice. Langendorff-perfused hearts were subjected to 30 min of global ischemia followed by reperfusion. Baseline preischemic coronary flow and left ventricular developed pressure were significantly greater in SERCA1a+/+ mice compared with NTG mice. Independent of reperfusion-induced oxidative stress, SERCA1a+/+ hearts demonstrated greatly improved postischemic (45 min) contractile recovery with less persistent arrhythmias compared with NTG hearts. Morphometry showed better-preserved myocardial structure with less infarction, and electron microscopy demonstrated better-preserved myofibrillar and mitochondrial ultrastructure in SERCA1a+/+ hearts. Importantly, intraischemic Ca2+ levels were significantly lower in SERCA1a+/+ hearts. The cardioprotective effect of SERCA1a was also observed during in vivo regional I/R with reduced myocardial infarct size after 24 h of reperfusion. Thus SERCA1a+/+ hearts were markedly protected against I/R injury, suggesting that expression of SERCA 1a isoform reduces postischemic Ca2+ overload and thus provides potent myocardial protection.

scholarly journals Luteolin Modulates SERCA2a Leading to Attenuation of Myocardial Ischemia/ Reperfusion Injury via Sumoylation at Lysine 585 in Mice

2018 ◽  
Vol 45 (3) ◽  
pp. 883-898 ◽  
Author(s):  
Yinping Du ◽  
Ping Liu ◽  
Tongda Xu ◽  
Defeng Pan ◽  
Hong Zhu ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Infarct Size ◽  
Ischemia Reperfusion Injury ◽  
Heart Function ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Myocardial Infarct Size ◽  
Myocardial Ischemia Reperfusion

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.

scholarly journals Effect of eNOS on Ischemic Postconditioning-Induced Autophagy against Ischemia/Reperfusion Injury in Mice

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jun Shao ◽  
Chen Miao ◽  
Zhi Geng ◽  
Maohong Gu ◽  
Yanhu Wu ◽  
...  
Keyword(s):  
Ischemia Reperfusion Injury ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Critical Role ◽  
Ischemic Postconditioning ◽  
Coronary Artery Ligation ◽  
Myocardial Infarct Size ◽  
Protective Effects ◽  
H9c2 Cells

Autophagy is involved in the development of numerous illnesses, including ischemia/reperfusion (I/R). Endothelial nitric oxide synthase (eNOS) participates in the protective effects of ischemic postconditioning (IPostC). However, it remains unclear whether eNOS-mediated autophagy serves as a critical role in IPostC in the hearts of mice, in protecting against I/R injury. In the present study, the hearts of mice with left anterior descending coronary artery ligation were studied as I/R models. H9c2 cells underwent exposure to hypoxia/reoxygenation (H/R) and were examined as in vitro model. IPostC reduced mice myocardial infarct size and improved the structure of the heart. IPostC increased the formation of autophagosomes and increased the phosphorylation of eNOS and adenosine monophosphate-activated protein kinase (AMPK). Autophagy and eNOS inhibition suppressed the cardioprotective effects of IPostC. AMPK or eNOS inhibition abolished the improvement effect of IPostC on autophagy. AMPK inhibition decreased eNOS phosphorylation in the heart. Additionally, H9c2 cells suffering hypoxia were used as in vitro model. Autophagy or eNOS inhibition abolished the protective effects of hypoxic postconditioning (HPostC) against H/R injury. AMPK and eNOS inhibition/knockout decreased autophagic activity in the HPostC group. These results indicated that IPostC protects the heart against I/R injury, partially via promoting AMPK/eNOS-mediated autophagy.

scholarly journals MiR-31 Downregulation Protects Against Cardiac Ischemia/Reperfusion Injury by Targeting Protein Kinase C Epsilon (PKCe) Directly

2015 ◽  
Vol 36 (1) ◽  
pp. 179-190 ◽  
Author(s):  
Yongyi Wang ◽  
Min Men ◽  
Wengang Yang ◽  
Hui Zheng ◽  
Song Xue
Keyword(s):  
Reperfusion Injury ◽  
Target Gene ◽  
Ischemia Reperfusion Injury ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Cardiac Ischemia ◽  
Cardioprotective Effect ◽  
Myocardial Infarct Size

Background: Various miRNAs have been shown to participate in cardiac ischemia/reperfusion injury (I/R). miR-31 was identified as the most strikingly upregulated miRNA after acute myocardial infarction; therefore, the underlying role and mechanism of miR-31 in cardiac I/R was investigated. Methods: miR-31 expression was detected after cardiac I/R in mice. The cardioprotective effect of miR-31 downregulation was assessed in vitro and in vivo. The functional target gene and its downstream molecule were determined. Results: miR-31 expression increased after I/R. miR-31 downregulation increased cell viability and SOD activity and decreased LDH activity and MDA content in vitro. Additionally, miR-31 downregulation alleviated myocardial infarct size in vivo. PKCe was identified as the functional target gene of miR-31, and NFκB was identified as its downstream molecule that was involved in the miR-31-mediated cardioprotective effect. Conclusion: miR-31 expression increased throughout the cardiac I/R process, and miR-31 downregulation induced a cardioprotective effect via a miR-31/PKCe/NFκB-dependent pathway.

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