Myocardial Ischemia-reperfusion Injury Model Research Articles

The therapeutic effect of Jiawei Danshen Decoction on myocardial ischemia-reperfusion injury by inhibiting H2S-mediated autophagy signaling pathway

ObjectiveTo investigate the protective effects of Jiawei Danshen Decoction (加味丹参饮, JWDSD) on myocardial ischemia-reperfusion injury (MIRI) via the regulation of serum Hydrogen sulfide (H2S) and cardiac Beclin1, light Chain 3A/B (LC3A/B), p62, and autophagy protein5 (ATG5). MethodsSeventy specific pathogen free (SPF) Sprague-Dawley (SD) rats were randomly assigned to seven groups (n = 10 in each group), including normal control, sham operation, MIRI model (model), ischemic preconditioning, NaHS, JWDSD, and JWDSD +CSE inhibitor (JWDSD + PPG) groups, and orally administered the indicated drugs for 14 d. Two hours after the last administration, the left anterior decreased branch of the coronary artery of each rat in model, NaHS, JWDSD, and JWDSD + PPG groups was ligated for 30 min and subsequently reperfused for 90 min to establish the MIRI model, and the rats in the sham operation group were only exposed to the thorax after surgery without coronary ligation. Blood samples were collected to detect H2S levels using an enzyme-linked immunosorbent assay (ELISA). Heart tissues were harvested for histopathological and immunohistochemical examination and quantitative reverse transcription polymerase chain reaction analysis of Beclin1 and ATG5 mRNA expression and Western blot analysis of Beclin1, LC3A/B, and p62 protein expression. Results(1) The serum H2S content in model group rats was significantly reduced (P < 0.01), JWDSD significantly increased the serum H2S content of model group rats (P < 0.01), and the CSE inhibitor (PPG) significantly reduced H2S levels in the JWDSD group rats (P < 0.01). (2) Compared with the normal control group, the myocardial tissue necrosis and cell destruction occurred in the MIRI model group, and JWDSD could alleviate the myocardial tissue necrosis of model rats, but the ameliorative effect of JWDSD could be reversed by PPG. (3) Beclin1, LC3A/B, and p62 expression levels in the heart tissues of the model group were significantly increased (P < 0.001), whereas decreased by JWDSD (P < 0.05, P < 0.01, and P < 0.001, respectively), and the inhibitory effects of JWDSD on Beclin1, LC3A/B, and p62 expression were partially reversed by PPG (P < 0.01, P < 0.05, and P < 0.01, respectively). (4) The expression levels of autophagy-related genes Beclin1 and ATG5 were significantly increased in the model group (P < 0.001). JWDSD clearly downregulated the expression levels of Beclin1 and ATG5 (P < 0.05 and P < 0.001, respectively), which were reversed by PPG (P < 0.001). ConclusionOur experimental data show that JWDSD can exhibit an anti-MIRI role by increasing endogenous H2S generation, and downregulating the expression of Beclin1, LC3A/B, p62 and ATG5, which are related to inhibiting autophagy signaling.

Retraction.

Retraction: "Anti-Apoptotic Effect of MicroRNA-30b in Early Phase of Rat Myocardial Ischemia-Reperfusion Injury Model," Chun-Li Song, Bin Liu, Jin-Peng Wang, Bei-Lin Zhang, Ji-Chang Zhang, Li-Yan Zhao, Yong-Feng Shi, Yang-Xue Li, Guan Wang, Hong-Ying Diao, Qian Li, Xin Xue, Jun-Duo Wu, Jia Liu, Yun-Peng Yu, Dan Cai, and Zhi-Xian Liu, J Cell Biochem. 2015; 2610-2619: The above article, published online on 28 April 2015 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/10.1002/jcb.25208) has been retracted by agreement between the authors, the journal's Editor in Chief, Prof. Dr. Christian Behl, and Wiley Periodicals LLC. The retraction has been agreed because the authors stated that unintentional errors occurred during the research process, and the experimental results cannot be verified. Thus, the conclusions are considered to be invalid. The authors apologize for the unintentional errors.

Upregulation of Small Ubiquitin-Like Modifier 2 and Protein SUMOylation as a Cardioprotective Mechanism Against Myocardial Ischemia-Reperfusion Injury

Background: Small ubiquitin-like modifier (SUMO) proteins modify proteins through SUMOylation as an essential protein post-translational modification (PTM) for regulating redox status, inflammation, and cardiac fibrosis in myocardial infarction. This study aimed to investigate whether natural product puerarin could alleviate myocardial ischemia/reperfusion injury (MI-RI) by targeting protein SUMOylation.Methods: Mouse MI-RI model was induced by ligating the left anterior descending (LAD) coronary artery and subsequently treated with puerarin at the dose of 100 mg/kg. Rat cardiomyocyte H9c2 cells were challenged by hypoxia/reoxygenation and treated with puerarin at concentrations of 10, 20, and 40 μM. The infarction area of mouse hearts was assessed by 2% TTC staining. Cell damage was analyzed for the release of lactate dehydrogenase (LDH) in serum and cell culture medium. Western blot technique was employed to detect the expression of SUMO2, phospho-ERK, pro-inflammatory biomarker COX2, fibrosis index galectin-3, apoptosis-related protein cleaved PARP-1. The activation of the estrogen receptor (ER) pathway was assayed by the dual-luciferase reporter system.Results: The present study validated that puerarin effectively reduced myocardial infarct size and LDH release in the mouse MI-RI model. In the cell culture system, puerarin effectively decreased the release of LDH and the protein level of COX2, galectin-3, and cleaved PARP-1. Mechanistic studies revealed that puerarin increased the expression of SUMO2, SUMOylation of proteins and the activation of ER/ERK pathway in cardiomyocytes. ER, ERK and SUMO2 inhibitors attenuated the cardioprotective effects of puerarin.Conclusion: Puerarin may alleviate myocardial injury by promoting protein SUMOylation through ER/ERK/SUMO2-dependent mechanism.

Effect of electroacupuncture preconditioning on neuronal activities in lateral hypothalamus area of myocardial ischemia reperfusion injury rats

To observe the effect of electroacupuncture (EA) preconditioning of "Shenmen" (HT7)-"Tongli" (HT5) segment of the Heart Meridian on neuronal electrical activities of lateral hypothalamus area (LHA) in rats with myocardial ischemia reperfusion injury (MIRI), so as to investigate its possible mechanism underlying improvement of MIRI. Twenty-four SD rats were randomly divided into sham, model, EA and damage + EA (D+EA) groups, with 6 rats in each group. The MIRI model was established by occlusion of the anterior descending branch (ADB) of the left coronary artery for 30 min, followed by reperfusion for 2 h. In the sham operation group, the ADB was only threaded beneath the artery without ligation. EA (2 Hz, 1 V) was applied to bilateral HT7-HT5 for 20 min, once daily for 7 days. In the D+EA group, FN was injected with 0.4 μL of 1 g/L kainic acid solution. Electrocardiogram (ECG) of the neck-thoracic lead was recorded by using PowerLab. The electrical activities of the LHA region were recorded by the implanted microelectrode array (2×4) and Plexon multi-channel acquisition system. Cluster analysis of neuronal signals was carried out by Offline Sorter software. The discharge waveforms, autocorrelation and cross-correlation of neuronal activities were analyzed by using Neuro Explorer software. Compared with the sham group, the ECG-ST height was significantly increased (P<0.05), the discharge frequency of pyramidal neurons was significantly reduced (P<0.01), while the discharge frequency of interneurons was increased (P<0.01) in the model group. After EA treatment, the ECG-ST height was significantly decreased (P<0.05), the discharge frequency of pyramidal neurons was significantly increased (P<0.01) relevant to the model group. In comparison with the EA group, the ECG-ST height in the D+EA group was significantly elevated (P<0.05), whereas the discharge frequency of pyramidal neurons was significantly decreased (P<0.01). The discharge frequency of interneurons was kept increasing after MIRI. Real-time spectrum analysis showed that the local field potential spectrum energy of the EA group was significantly lower than that of the model group and the D+EA group. EA preconditioning of Heart Meridian can significantly increase the discharge frequency of LHA excitatory pyramidal neurons and reduce the energy of the local field potential spectrum, which maybe one of the important mechanisms of EA in anti -MIRI.

Aesculin suppresses the NLRP3 inflammasome-mediated pyroptosis via the Akt/GSK3β/NF-κB pathway to mitigate myocardial ischemia/reperfusion injury

BackgroundAesculin (AES), an effective component of Cortex fraxini, is a hydroxycoumarin glucoside that has diverse biological properties. The nucleotide-binding domain leucine-rich repeat-containing receptor, pyrin domain-containing 3 (NLRP3) inflammasome has been heavily interwoven with the development of myocardial ischemia/reperfusion injury (MIRI). Nevertheless, it remains unclear whether AES makes a difference to the changes of the NLRP3 inflammasome in MIRI. PurposeWe used rats that were subjected to MIRI and neonatal rat cardiomyocytes (NRCMs) that underwent oxygen-glucose deprivation/restoration (OGD/R) process to investigate what impacts AES exerts on MIRI and the NLRP3 inflammasome activation. MethodsThe establishment of MIRI model in rats was conducted using the left anterior descending coronary artery ligation for 0.5 h ischemia and then untying the knot for 4 h of reperfusion. After reperfusion, AES were administered intraperitoneally using 10 and 30 mg/kg doses. We evaluated the development of reperfusion ventricular arrhythmias, hemodynamic changes, infarct size, and the biomarkers in myocardial injury. The inflammatory mediators and pyroptosis were also assessed. AES at the concentrations of 1, 3, and 10 μM were imposed on the NRCMs immediately before the restoration process. We also determined the cell viability and cell death in the NRCMs exposed to OGD/R insult. Furthermore, we also analyzed the levels of proteins that affect the NLRP3 inflammasome activation, pyroptosis, and the AKT serine/threonine kinase (Akt)/glycogen synthase kinase 3 beta (GSK3β)/nuclear factor-kappa B (NF-κB) signaling pathway via western blotting. ResultsWe found that AES notably attenuated reperfusion arrhythmias and myocardia damage, improved the hemodynamic function, and ameliorated the inflammatory response and pyroptosis of cardiomyocytes in rats and NRCMs. Additionally, AES reduced the NLRP3 inflammasome activation in rats and NRCMs. AES also enhanced the phosphorylation of Akt and GSK3β, while suppressing the phosphorylation of NF-κB. Moreover, the allosteric Akt inhibitor, MK-2206, abolished the AES-mediated cardioprotection and the NLRP3 inflammasome suppression. ConclusionsThese findings indicate that AES effectively protected cardiomyocytes against MIRI by suppressing the NLRP3 inflammasome-mediated pyroptosis, which may relate to the upregulated Akt activation and disruption of the GSK3β/NF-κB pathway.

Propofol protects cardiomyocytes from hypoxia/reoxygenation injury via regulating MALAT1/miR-206/ATG3 axis.

Previous studies have shown that propofol (PPF) plays a protective role in ischemia-reperfusion (I/R) in multiple organs and tissues. This study was aimed to explore the mechanism of PPF in ameliorating myocardial ischemia-reperfusion injury (MIRI). MIRI model was established with Sprague-Dawley rats, and PPF pretreatment was performed before reperfusion. Creatine kinase isoform (CK-MB), lactate dehydrogenase (LDH), and hematoxylin and eosin stain were used to evaluate the severity of MIRI. H9c2 cells were treated with hypoxia/reoxygenation (H/R) to simulate I/R injury in vitro. Real-time quantitative polymerase chain reaction (qPCR) was employed to assess MALAT1 and microRNA (miR)-206 expressions. Autophagy-related 3 (ATG3), LC3BⅡ/LC3BⅠ, and Beclin-1 expression were examined by western blot. Apoptosis was monitored using flow cytometry. Interaction between MALAT1 and miR-206 was determined by bioinformatics analysis, dual-luciferase reporter gene assay, RIP assay, and RNA pull-down assay. PPF pretreatment remarkably reduced CK-MB level, LDH level, myocardial infarct size, and LC3BⅡ/LC3BⅠ ratio and Beclin-1 expression in the rats with MIRI, and repressed the apoptosis of H9c2 cells exposed to H/R. PPF pretreatment markedly suppressed MALAT1 expression and enhanced miR-206 expression in both in vivo and in vitro models. MiR-206 was identified as a target of MALAT1 in cardiomyocytes, and MALAT1 could increase the expression of ATG3. Additionally, the upregulation of MALAT1 partially reversed the protective effect of PPF on cardiomyocytes in vitro. PPF modulated MALAT1/miR-206/ATG3 axis to protect cardiomyocytes against I/R injury.

Pharmacological postconditioning with sappanone A ameliorates myocardial ischemia reperfusion injury and mitochondrial dysfunction via AMPK-mediated mitochondrial quality control

Pharmacological postconditioning (PPC), drug intervention before or during the early minutes of reperfusion, could stimulate cardioprotection as ischemic postconditioning. In this study, we examined whether PPC with sappanone A (SA), a homoisoflavanone with potent antioxidant and anti-inflammatory activity, has a protective effect on myocardial ischemia reperfusion injury (MIRI), and explored the underlying mechanism. A MIRI model was established using the Langendorff method. After 30 min of ischemia, isolated rat hearts were treated with SA at the onset of reperfusion to stimulate PPC. The changes in myocardial infarct size, mitochondrial function, mitochondrial biogenesis, mitophagy, and mitochondrial fission and fusion were detected. The results showed that SA postconditioning decreased the myocardial infarct size, inhibited the release of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), and cardiac troponin (cTnI), as well as improved cardiac function, enhanced myocardial ATP content and mitochondrial complex activity, and prevented the loss of mitochondrial membrane potential and opening of mitochondrial permeability transition pore (mPTP). Mechanistically, we found that SA was an AMP-activated protein kinase (AMPK) activator, and SA postconditioning could facilitate mitochondrial biogenesis by increasing mitochondrial DNA (mtDNA) copy number and the expression of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α). In addition, it balanced mitochondrial dynamics by decreasing fission and increasing fusion, and enhanced mitophagy in an AMPK-dependent manner. Moreover, AMPK silencing abolished the cardioprotection of SA postconditioning. Collectively, our study demonstrated that SA postconditioning ameliorated MIRI and mitochondrial dysfunction by regulation of mitochondrial quality control via activating AMPK. This finding provides a new insight into pharmacological action and clinical use of SA.

DL-3-n-butylphthalide protects H9c2 cardiomyoblasts from ischemia/reperfusion injury by regulating HSP70 expression via PI3K/AKT pathway activation.

DL-3-n-butylphthalide (NBP) is commonly used to treat ischemic strokes due to its antioxidative and anti-inflammatory effects. The present study aimed to examine the protective effects of NBP on myocardial ischemia-reperfusion injury (MIRI) by establishing a MIRI model in H9c2 cells. Cell viability assay using Cell Counting Kit-8, lactate dehydrogenase (LDH) cytotoxicity and lipid peroxidation malondialdehyde (MDA) content were assessed to detect cell activity, degree of cell injury and oxidative stress reaction. Reverse transcription-quantitative PCR was used to quantify the expression of inflammatory factors in H9c2 cells. Western blotting and immunofluorescence staining were used to detect the protein expression of PI3K/AKT and heat shock protein 70 (HSP70). The present results indicated that NBP significantly increased cell viability during ischemia-reperfusion. Moreover, NBP inhibited the release of LDH and the production of MDA. NBP treatment also significantly decreased the expression of inflammatory factors at the mRNA level. Additionally, NBP activated the PI3K/AKT pathway and upregulated the expression of HSP70 compared with cells in the MIRI model. LY294002, a PI3K inhibitor, reversed the protective effects of NBP and suppressed the expression of HSP70. The present study demonstrated that NBP protected H9c2 cells from MIRI by regulating HSP70 expression via PI3K/AKT pathway activation.

Up-regulation of CTRP12 ameliorates hypoxia/re-oxygenation-induced cardiomyocyte injury by inhibiting apoptosis, oxidative stress, and inflammation via the enhancement of Nrf2 signaling.

C1q/TNF-related protein 12 (CTRP12) has been reported to play a key role in coronary artery disease. However, whether CTRP12 plays a role in the regulation of myocardial ischemia-reperfusion injury is not fully understood. The goals of this work were to assess the possible relationship between CTRP12 and myocardial ischemia-reperfusion injury. Here, we exposed cardiomyocytes to hypoxia/re-oxygenation (H/R) to establish an in vitro cardiomyocyte injury model of myocardial ischemia-reperfusion injury. Our results showed that H/R treatment resulted in a decrease in CTRP12 expression in cardiomyocytes. The up-regulation of CTRP12 ameliorated H/R-induced cardiomyocyte injury via the down-regulation of apoptosis, oxidative stress, and inflammation. In contrast, the knockdown of CTRP12 enhanced cardiomyocyte sensitivity to H/R-induced cardiomyocyte injury. Further investigation showed that CTRP12 enhanced the levels of nuclear Nrf2 and increased the expression of Nrf2 target genes in cardiomyocytes exposed to H/R. However, the inhibition of Nrf2 markedly diminished CTRP12-overexpression-mediated cardioprotective effects against H/R injury. Overall, these data indicate that CTRP12 protects against H/R-induced cardiomyocyte injury by inhibiting apoptosis, oxidative stress, and inflammation via the enhancement of Nrf2 signaling. This work suggests a potential role of CTRP12 in myocardial ischemia-reperfusion injury and proposes it as an attractive target for cardioprotection.

Effect of electroacupuncture preconditioning on myocyte apoptosis in myocardial ischemia-reperfusion injury rats based on FXR/SHP pathway

To observe the effect of electroacupuncture (EA) preconditioning on left-cardiac function, contents of serum TNF-α and IL-6 and expression of myocardial farnesoid X receptor(FXR), small heterodimer partner (SHP), apoptosis inducing factor (AIF) and heat shock proteins 70 (HSP70) genes in myocardial ischemia-reperfusion injury (MIRI) rats, so as to explore its mechanisms underlying improvement of ischemic myocardial injury. Forty male Wistar rats were randomly divided into normal control, sham operation, MIRI model and EA pretreatment groups, with 10 rats in each group. Rats of the sham operation group received exposure of the thorax and heart. The MIRI model was established by occlusion of the anterior descending branch of the left coronary artery (LAD). EA (2 Hz/100 Hz and 1 mA) was applied to bilateral "Neiguan" (PC6), "Zusanli" (ST36) and "Guanyuan" (CV4) for 20 min, once a day for 7 days. The left ventricular end-diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP)and maximal rates of rise and fall of left ventricular pressure (±dp/dtmax) were detected, the contents of serum TNF-α and IL-6 were detected by using enzyme-linked immunosorbent assay (ELISA), and the expression of FXR, SHP, AIF and HSP70 apoptotic genes in the myocardial tissue were measured by fluorescent quantitative RT-PCR. Compared with the normal control group, the LVEDP, contents of serum TNF-α and IL-6, and the expression levels of myocardial FXR, SHP, AIF and HSP70 mRNAs were significantly increased (P<0.05), while LVSP and ±dp/dtmax levels were obviously decreased in the model group (P<0.05). In comparison with the model group, MIRI-induced increases of LVEDP, TNF-α and IL-6 contents, and FXR, SHP and AIF mRNA expression and decreases of ±dp/dtmax and LVSP levels were reversed(P<0.05), except HSP70 mRNA expression with significantly increased (P<0.05) in the EA pretreatment group. EA pretreatment can protect the left ventricular function of the ischemic heart in MIRI rats, which may be related to its effects in reliving peripheral inflammation and regulating the expression levels of apoptosis-related factors FXR, SHP, AIF and HSP70 in the myocardium.

Platelet-rich plasma alleviates myocardial ischemia-reperfusion injury in rats

To investigate the protective effect of platelet-rich plasma (PRP) against acute myocardial ischemiareperfusion (IR) injury and the possible mechanism. Aortic blood samples were collected from 10 SD rats to prepare PRP, in which the concentrations of platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-β1 (TGF-β1) were measured. Cell models of IR injury were established in primary cultures of neonatal SD rat cardiomyocytes by exposing the cells to 3 h of hypoxia. The cells were then reoxygenated and co-cultured with 1%, 5%, 10%, and 20% volume of PRP for 12 h, and the changes in cell viability was assessed. Immunofluorescence staining of the cardiomyocytes was performed, and the cellular expression of AMPK and its phosphorylation level were detected. The effects of PRP on the proliferation and migration of rat aortic endothelial cells (RAOECs) were examined. In a SD rat model of myocardial IR injury, 100 μL of PRP (n= 20) or normal saline (n=20) was injected at 4 sites around the ligation site immediately after cardiac reperfusion. One day after the injection, 6 rats were selected from each group for TTC staining of the myocardial tissues and measurement of troponin Ⅰ content. One week later, the cardiac function of the remaining rats was assessed by echocardiography, and HE staining of the myocardial tissues was performed. The effect of PRP treatment for 24 h on polarization of M1 and M2 macrophages was also examined by flow cytometry in RAW264.7 cells after hypoxic exposure for 3 h. The concentrations of PDGF-BB and TGF-β1 were significantly higher in PRP than in whole blood. Addition of 1% volume of PRP significantly reduced death of the cardiomyocytes following reoxygenation, and this effect was closely related with the activation of AMPK. Treatment with PRP obviously promoted the proliferation and migration of RAOECs. In rat models of acute myocardial IR injury, injections of PRP significantly reduced the infarct size and troponin Ⅰ concentration as compared with saline injection (P < 0.001). One week after PRP injection, the rats showed significantly improved cardiac function with a lowered level of inflammatory response in comparison with the rats with saline injection. In RAW264.7 cells with hypoxic exposure, treatment with PRP obviously decreased the number of M1 macrophages and increase the number of M2 macrophages. PRP can improve acute myocardial IR injury in rats by phosphorylating AMPK and regulating macrophage polarization, which produces a protective immunomodulatory effect on the ischemic myocardial tissues.

EGCG decreases myocardial infarction in both I/R and MIRI rats through reducing intracellular Ca2+ and increasing TnT levels in cardiomyocytes.

Myocardial ischemia/reperfusion injury (MIRI) usually induces serious health problems. This study attempted to explore protective effects of (-)-epigallocatechin-3-gallate (EGCG) on MIRI and the associated mechanism. Ischemia/reperfusion of an isolated rat heart (I/R model) and the MIRI model were used in this study. Myocardial infarction was measured with staining with 2,3,5-triphenyltetrazolium chloride (TTC). Ca2+ and troponin T (TnT) concentrations in coronary perfusion fluid were evaluated using the chromatometry method. Ca2+ concentration in cardiomyocytes was determined with detecting Ca2+ fluorescence intensity. The ultrastructure of cardiomyocytes was observed using transmission electron microscopy (TEM). β-nicotinamide adenine dinucleotide (NAD+) of cardiomyocytes was also determined. The EGCG (I/R+EGCG) significantly reduced myocardial infarction size of isolated rat heart compared to I/R rats (p < 0.05), remarkably increased Ca2+ and decreased TnT concentrations in coronary perfusion fluid of I/R rats compared to the I/R model (p < 0.05), as well as markedly decreased intracellular Ca2+ concentration and promoted NAD+ concentration in cardiomyocytes compared to I/R rats (p < 0.05). It also obviously maintained the mitochondrial structure in cardiomyocytes of I/R rats and improved the ultrastructure of cardiomyocytes of MIRI rats. Lonidamine (LND) treatment (I/R+EGCG+LND group) significantly blocked the effects of EGCG on I/R injury compared to the I/R+EGCG group (p < 0.05). The EGCG (MIRI+EGCG) significantly decreased myocardial infarction size compared to MIRI rats (p < 0.05) and remarkably enhanced Ca2+ and reduced TnT concentrations in the pulmonary artery compared to that of MIRI rats (p < 0.05). The EGCG decreased myocardial infarction size in both I/R models and MIRI models by reducing intracellular Ca2+ concentration, increasing TnT concentration, promoting NAD+ concentration, and improving the ultrastructure of cardiomyocytes.

Cardioprotective effects of azilsartan compared with that of telmisartan on an in vivo model of myocardial ischemia‐reperfusion injury

Azilsartan is found to be more potent than other angiotensin receptor blockersin reducing blood pressure. However, its effect on the heart following myocardial infarction remains to be established. For the first time, we investigated the peroxisome proliferator-activated receptor-γ(PPAR-γ) agonistic and cardioprotective properties of azilsartan. Computational modeling studies of interactions between azilsartan and PPAR-γ revealed azilsartan as an agonist of PPAR-γ and showed the mechanism of azilsartan in cardioprotection. Our study compared the cardioprotective potential of telmisartan to that of azilsartan in a murine model of myocardial ischemia-reperfusion injuryby comparing their antioxidant, ant apoptotic, anti-inflammatory, mitogen-activated protein kinase (MAPK)-modulating ability, and PPAR-γ agonistic activity. Male Wistar rats were grouped into four to receive vehicle (dimethyl sulfoxide [0.05%] 2 ml/kg) telmisartan (10 mg/kg p.o.), azilsartan (10 mg/kg p.o.) or azilsartan with specific PPAR-γ blocker, GW 9662 for 28 days. Ischemia was induced for 45 min on the 29th day followed by 60 min of reperfusion. Telmisartan and azilsartan pretreatment significantly nearly normalized cardiac parameters and preserved structural changes. Both drugs inhibited oxidative burst, inflammation, as well as cell death by modulating apoptotic protein expression along with reduction in 4',6-diamidino-2-phenylindole/terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. An increment in pro-survival kinase ERK paralleled with a reduction in p38 and JNK was also revealed by MAPK pathway studies, after administration of these drugs. Interestingly, the aforementioned changes induced by both drugs were reversed by administration of the specific PPAR-γ antagonist, GW9662. However, we found that azilsartan upregulated PPAR-γ to a lesser extent as compared to telmisartan and the latter may be preferred in hypertensive patients at risk of myocardial infarction.

Bortezomib alleviates myocardial ischemia reperfusion injury via enhancing of Nrf2/HO-1 signaling pathway

Bortezomib is a classical proteasome inhibitor and previous researches have reported its roles of anti-oxidation and anti-inflammatory functions in various diseases. However, the role of Bortezomib in myocardial ischemia reperfusion injury (MIRI) is unclear. Thus, our research seeks to reveal the protective effects of Bortezomib pretreatment in the mice model of MIRI. First, by the optimization of Bortezomib concentration and pretreatment timepoints, we found that 0.5 mg/kg Bortezomib pretreatment 2 h before MIRI significantly attenuated pathological damage and neutrophil infiltration. Then we found that pretreatment with Bortezomib obviously increased myocardial systolic function ((left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS)) and decreased infarct size, as well as serum Troponin T levels. Meanwhile, Bortezomib pretreatment also remarkably augmented oxidative stress related protein levels of Superoxide dismutase [Cu–Zn] (SOD1), Catalase (CAT) and Glutathione (GSH), while reactive oxygen species (ROS) contents and Malonaldehyde (MDA) protein level were significantly reduced. Mechanistically, Bortezomib pretreatment significantly promoted nuclear translocation of transcriptional factor nuclear factor erythroid 2-related factor 2(Nrf2) and Heme Oxygenase 1(HO-1) expression. Interestingly, co-treatment with ML-385, a new type and selective Nrf2 inhibitor, counteracted antioxidative effects induced by Bortezomib pretreatment. In conclusion, Bortezomib pretreatment mitigates MIRI by inhibiting oxidative damage which is regulated by Nrf2/HO-1 signaling pathway.

ROS MEDIATED MYOCARDIAL ISCHEMIA-REPERFUSION INJURY ATTENUATION BY MORIN: REGULATION OF RISK/SAPK PATHWAYS

Abstract Objective: Morin, a bioflavonoid, has demonstrated anti-oxidant, anti-inflammatory and other diverse pharmacological protective activities in various experimental models. Oxidative stress plays an important role in the pathogenesis of myocardial ischemia reperfusion (IR) injury. Thus, this study aimed to evaluate the effect of Morin in Myocardial IR injury model and its underlying mechanism. Design and method: Male albino Wistar rats were divided into 5 groups. Sham; IR-Control; 2 Morin pre-treated groups (40 and 80 mg/kg; p.o.) and Morin perse group. The morin were administered for 28 days in respective group. On 29th day, rats were experienced 45 min myocardial ischemia following 60 min reperfusion except Sham and Morin perse groups. The cardioprotective potential was investigated via hemodynamic, biochemical, inflammatory marker investigations, cytokines levels, morphological analysis, immuno-histochemical analysis and protein expression estimation through multiplexed Immuno-blotting. The apoptotic markers were also investigate to analysed the programmed cell death due to oxidative stress. Results: With respect to IR-control group, Morin pre-treatment significantly normalized hemodynamic parameters, restored antioxidant status, improved pathological changes, reduced the release of cardiac injury markers, inhibited inflammation (TNF-alpha/IL-6/NF (kappa)B/IKK (beta) and apoptosis (increased Bcl-2, decreased Bax/Caspase-3 and TUNEL positivity) in the myocardium. This improvement in antioxidant, inflammation and anti-apoptosis markers could be due to downregulation of SAPK (p38/JNK) pathway and upregulation of survival kinase i.e. RISK pathway (ERK/eNOS) in the myocardium. Conclusions: IR induced oxidative stress leads to production of free radicals is attenuated by morin pretreatment for 28 days in rats which further reduced inflammation and apoptosis in the myocardium. This is the first experimental study which highlighted the role of SAPK/RISK pathways in morin induced cardio-protection in IR injury.

HOTAIR/miR-17-5p Axis is Involved in the Propofol-Mediated Cardioprotection Against Ischemia/Reperfusion Injury.

BackgroundPropofol (PPF) ameliorates ischemia/reperfusion (I/R) injury in multiple organs by reducing apoptosis and release of pro-inflammatory cytokines. This study aims to explore the mechanism of PPF in attenuating myocardial ischemia-reperfusion injury (MIRI).Materials and MethodsRat MIRI model was established, and PPF pre-treatment was performed 10 min before I/R. H9c2 cardiomyocytes treated with hypoxia/reoxygenation (H/R) were used to establish an in vitro model. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to evaluate HOTAIR and miR-17-5p expression levels. Flow cytometry was employed to detect the apoptosis of H9c2 cells. The interaction between HOTAIR and miR-17-5p was determined by bioinformatics analysis, luciferase reporter gene analysis, and RNA immunoprecipitation experiments. STAT3 and p-STAT3 expressions were detected by Western blot.ResultsPPF pre-treatment significantly reduced creatine kinase isoenzyme (CK-MB) and serum lactate dehydrogenase (LDH) levels in the serum of the rats with MIRI. PPF pre-treatment remarkably up-regulated HOTAIR expression and down-regulated miR-17-5p expression in both in vivo and in vitro models. HOTAIR adsorbed miR-17-5p to repress the expression of miR-17-5p. PPF pre-treatment markedly inhibited cardiomyocyte apoptosis induced by I/R or H/R. HOTAIR knockdown could partially reverse the protective effects of PPF on MIRI. HOTAIR could activate STAT3 signaling via repressing miR-17-5p expression.ConclusionPPF protects the MIRI by modulating the HOTAIR/miR-17-5p/STAT3 axis.

The Protective Role of Bmal1-Regulated Autophagy Mediated by HDAC3/SIRT1 Pathway in Myocardial Ischemia/Reperfusion Injury of Diabetic Rats

Histone deacetylase 3 (HDAC3) and silent information regulator 1 (SIRT1) are histone deacetylases that regulate important metabolic pathways and play important roles in diabetes and myocardial ischemia/reperfusion (IR) injury. In this study, we explored the protective mechanism of Bmal1-regulated autophagy mediated by the HDAC3/SIRT1 pathway in myocardial IR injury of diabetic rats. Type 1 diabetes was established by administering an intraperitoneal injection of streptozotocin. After 8 weeks, the left anterior descending coronary artery was ligated for 30 min and reperfused for 120 min to establish a myocardial IR injury model in diabetic rats. H9c2 cardiomyocytes were exposed to high glucose concentration (30 mM) and hypoxia/reoxygenation (H/R) stimulation in vitro. The myocardial infarct size and levels of serum cTn-I, CK-MB, and LDH in diabetic rats subjected to myocardial IR injury were significantly higher. Upregulated HDAC3 and downregulated SIRT1 expression were observed in diabetic and IR hearts, along with a lower Bmal1 level. Autophagy was rapidly increased in the hearts of diabetic or non-diabetic rats in the IR group compared with the sham group, but significantly attenuated in the hearts of diabetic rats compared with the hearts of non-diabetic rats after IR insult. Consistent with decreased autophagy, we observed increased HDAC3 expression and decreased SIRT1 and Bmal1 levels in the myocardial tissue of diabetic rats after IR. Inhibition of HDAC3 by the inhibitor RGFP966 and activation of SIRT1 by the agonist SRT1720 could significantly attenuate myocardial IR injury in diabetic rats by restoring Bmal1-regulated autophagy. Based on these findings, the disordered HDAC3/SIRT1 circuit (upregulated HDAC3 and downregulated SIRT1 levels) plays an important role in aggravating myocardial IR injury in diabetic rats by downregulating Bmal1-mediated autophagy. Treatments targeting HDAC3/SIRT1 to activate the autophagy may represent a novel strategy to alleviate myocardial IR injury in diabetes.

Characterization of novel lncRNAs in upper thoracic spinal cords of rats with myocardial ischemia-reperfusion injuries.

Myocardial ischemia-reperfusion injury (MIRI) is a significant problem in clinical cardiology, and refers to a more serious myocardial injury caused by blood recanalization after a period of myocardial ischemia, as compared with injury caused by vascular occlusion. The spinal cord, as the primary afferent and efferent center of cardiac sensory and sympathetic nerve fibres, has received increased attention in recent years with regards to the regulation of MIRIs. Previous studies have revealed that MIRI has a strong correlation with the abnormal expression of long non-coding (lnc)RNAs in the myocardium; however, there are limited reports on the effects of the altered expression of lncRNAs in the spinal cord following MIRI. To investigate the expression patterns of lncRNAs in the spinal cord after MIRI and their potential role in the early stage of reperfusion, a MIRI model was established in rats. After 30 min of myocardial ischemia and 2 h of reperfusion, the upper thoracic spinal cord tissues were immediately dissected and isolated. lncRNAs and mRNAs in spinal cord tissues were screened using transcriptome sequencing technology, and the expression of several highly deregulated mRNAs, including Frs3, Zfp52, Dnajc6, Nedd4l, Tep1, Myef2, Tgfbr1, Fgf12, Mef2c, Tfdp1 and lncRNA, including ENSRNOT00000080713, ENSRNOT00000090564, ENSRNOT00000082588, ENSRNOT00000091080, ENSRNOT00000091570, ENSRNOT00000087777, ENSRNOT00000082061, ENSRNOT00000091108, ENSRNOT00000087028, ENSRNOT00000086475, were further validated via reverse transcription-quantitative PCR. The number of altered expressed lncRNAs was 126, among which there were 41 upregulated probe sets and 85 downregulated sets. A total of 470 mRNAs were differentially expressed, in which 231 probe sets were upregulated and 239 were downregulated. Gene Ontology analysis indicated that dysregulated transcripts related to biological processes were mainly associated with ‘cell-cell signaling’. Moreover, pathway analysis demonstrated significant changes in the ‘PI3K/Akt signaling pathway’ and the ‘p53 signaling pathway’. Thus, the altered expression of lncRNAs in the spinal cord may be of considerable importance in the process of MIRI. The present results could provide an insight into the potential roles and mechanism of lncRNAs during the early stage of reperfusion.

Sufentanil preconditioning protects against myocardial ischemia/reperfusion injury via miR-125a/DRAM2 axis

ABSTRACT This project aimed to investigate the protective mechanism of sufentanil pretreatment on myocardial ischemia-reperfusion injury (IRI). An in vivo rat model of myocardial IRI and an in vitro cultured cardiomyocyte model of hypoxia-reoxygenation (H/R) were used to confirm the anti-oxidation and anti-autophagy effects of sufentanil. The interaction between miR-125a and damage-regulated autophagy regulator 2 (DRAM2) was verified by luciferase reporter assay. We showed that pretreatment with sufentanil suppressed myocardial damage caused by IRI in rats by inhibiting oxidative stress and mitochondrial autophagy. Furthermore, the cardioprotective mechanism of sufentanil was mediated by miR-125a. MiR-125a targeted DRAM2 to ameliorate cardiomyocyte autophagy and oxidative injury following H/R treatment. In conclusion, our results demonstrated that sufentanil pretreatment produced a protective effect against myocardial IRI via regulating miR-125a/DRAM2 signaling axis.

Preclinical Evidence onthe Cardio Protective Activity of Prisniparni (Desmodium Gangeticum (L.) Dc) in Myocardial Ischemia Reperfusion Injury: A Narrative Review.

Heart failure developed by Myocardial Ischemia and Ischemia reperfusion injury has been a major challenge for medical science with its mortality and morbidity rate, worldwide. The need of the hour is medical interventions that can reduce injury from myocardial ischemia and reperfusion. It’s here where herbal medicines can play a pivotal role, as it is used in invention of many commercial drugs. Prisniparni (Desmodium gangeticum (L.) DC is a widely used medicinal plant in Ayurvedafor various ailments especially in cardiac diseases. Medicated milk prepared from Prisniparniis advised in Vatika hridroga chikitsa. This review highlights the cardio protective activity of Desmodium gangeticum (L.) DC) seen in several preclinical models of MyocardialIschemia reperfusion injury. A thorough literature search lead to 6 studies that met the inclusion criteria .Results of these studies pointed out the free radical scavenging activity of the plant Desmodium gangeticum (L.) DCduring Ischemia and Ischemia reperfusion. Which majorly helped in cardio protection by preserving mitochondrial respiratory enzymes.