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Ischemic heart disease is the most prevalent cause of death worldwide affecting both the gender of all age groups. The high mortality rate is due to damage of myocardial tissue that emanates at the time of myocardial ischemia and re-oxygenation, thus averting reperfusion injury is recognized as a potential way to reduce acute cardiac injury and subsequent mortality. Flavonoids are polyphenol derivatives of plant origin and empirical shreds of evidence substantiate their numerous activities such as antioxidant, anti-inflammatory, anti-apoptotic, and anti-thrombotic activity, leading to their role in cardio protection. Recent investigations have unveiled the capacity of flavonoids to impede pivotal regulatory enzymes, signaling molecules, and transcription factors that orchestrate the mediators participating in the inflammatory cascade. The present comprehensive review, dwells on the preclinical studies on the effectiveness of flavonoids from the year 2007 to 2023, for the prevention and therapeutics for myocardial ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect and mechanism of the activation of nuclear factor κB (NF-κB) on myocardial ischemia-reperfusion (IR) injury under hyperglycemic condition. Methods Forty-eight male C57BL/6J mice were acclimated for one week and were randomly assigned into six groups： non-diabetic sham-operated group (NG-Sham group), non-diabetic ischemia-reperfusion group (NG-IR group), diabetic sham-operated group (DM-Sham group), diabetic ischemia-reperfusion group (DM-IR group), diabetic ischemia-reperfusion negative control group (DM-IR-NC group), and diabetic ischemia-reperfusion NF- κB recombinant protein intervention group (DM-IR-NF- κB group), with eight mice in each group. Mice in the NG-Sham and NG-IR groups were fed the normal diet. Mice in the NG-IR group underwent myocardial infarction (MI) modeling by ligation of the left anterior descending (LAD) coronary artery, while mice in the NG-Sham group had the LAD artery exposed but not ligated. Mice in the DM-IR group received intraperi‑ toneal injections of streptozotocin (STZ) at 40 mg/kg for four consecutive days to induce diabetes mellitus (DM) . One week after the establishment of the DM model, MI was induced by LAD ligation. Mice in the DM-Sham group underwent the same procedure for DM induction and had the LAD artery exposed but not ligated. Mice in the DM-IR-NF-κB and DM-IR-NC groups underwent the same DM induction procedure and MI modeling. Mice in the DM-IR-NF- κB group received an intravenous injection of NF-κB recombinant protein at 0. 5 mg/kg via the tail vein 30 minutes before chest opening, while mice in the DM-IR-NC group did not receive the NF-κB recombinant protein. The myocardial infarct area in the NG-IR and DM-IR groups was assessed by TTC staining. The mRNA expression levels of NF-κB, IL-6, IL-1β, and TNF-α in the myocardial tissues were measured by RT-qPCR. The mitochondrial membrane potential in the NG-Sham, NG-IR, DM-Sham, and DM-IR groups was evaluated using JC-1 staining, and mitochondrial reactive oxygen species (ROS) content was assessed using MitoSOX staining. AMPK and p-AMPK protein expression levels in the myocardial tis‑ sues were determined by Western blotting. Serum AST and LDH activities in the DM-IR-NC and DM-IR-NF-κB groups were measured by colorimetric assays, and the content of serum CK-MB was determined using double-antibody sandwich ELISA. Results Compared with the NG-IR group, the myocardial infarct area increased (P<0. 05) and the mRNA expression of NF-κB in the myocardial tissues was up-regulated (P<0. 05), while the mRNA expression levels of IL-6, IL-1β, and TNF- α did not show significant changes in the DM-IR group (all P>0. 05) . Compared with the NG-Sham group, the NG-IR and DM-Sham groups exhibited decreased mitochondrial membrane potential and increased ROS content (both P<0. 05) ； compared with the NG-IR group, the DM-IR group showed further decreased mitochondrial membrane potential and increased ROS content (both P<0. 05) . Pearson correlation analysis showed that there was a significant posi‑ tive correlation between the NF-κB mRNA level and mitochondrial membrane potential in the myocardial tissues of IR mice (r=0. 496, P<0. 05) . Compared with the NG-IR group, the DM-IR group exhibited up-regulated AMPK protein expres‑ sion, down-regulated p-AMPK protein expression, and decreased p-AMPK/AMPK ratio (all P<0. 05) . Compared with the DM-IR-NC group, the content of serum AST, LDH, and CK-MB increased (all P<0. 05), the relative expression levels of p-AMPK protein and p-AMPK/AMPK in the myocardial tissues decreased (all P<0. 05), while the relative expression of AMPK protein did not change significantly in the DM-IR-NF-κB group (P>0. 05) . Conclusion The activation of NF-κB can promote the susceptibility of the myocardium to IR injury under hyperglycemic condition, and the mechanism may be that NF-κB induces the inactivation of the AMPK signaling pathway and disorder of mitochondrial quality control. [ABSTRACT FROM AUTHOR]

At present, the incidence rate of acute myocardial infarction is increasing year by year. Patients with acute myocardial infarction may experience myocardial ischemia-reperfusion injury (MIRI) after reperfusion of coronary blood flow, which further exacerbates the injury and leads to a decrease in the patient' s quality of life. Therefore, reducing MIRI has become one of the urgent issues that need to be addressed in the treatment of cardiovascular diseases. Traditional Chinese medicine has the advantages of multiple pathways and targets in the treatment of MIRI, which can provide new ideas for alleviating MIRI. The Wnt signaling pathway is closely related to the occurrence and development of MIRI, and it can improve MIRI by regulating inflammatory response, cell apoptosis, oxidative stress, autophagy, and other factors. The article reviews the research progress of traditional Chinese medicine in alleviating MIRI by regulating the Wnt signaling pathway, in order to provide a theoretical basis for the treatment of MIRI. [ABSTRACT FROM AUTHOR]

Background: Myocardial ischemia–reperfusion injury (MIRI) refers to severe damage to the ischemic myocardium following the restoration of blood flow, and it is a major complication of reperfusion therapy for myocardial infarction. Notably, drugs such as metoprolol have been utilized to reduce ischemia–reperfusion injury. Tanshinone IIA is a major constituent extracted from Salvia miltiorrhiza Bunge. Recently, tanshinone IIA has been studied extensively in animal models for controlling MIRI. Therefore, we conducted a meta-analysis on the application of tanshinone IIA in rat models with MIRI to evaluate the therapeutic effects of tanshinone IIA. Methods: A comprehensive search was conducted across PubMed, Web of Science, Embase, the Cochrane Library, the China National Knowledge Infrastructure database, the Wanfang database, and the Chinese Scientific Journal Database to gather studies on tanshinone IIA intervention in rat models with MIRI.We employed SYRCLE's risk of bias tool to assess study quality. The primary outcome indicators were superoxide dismutase (SOD) and malondialdehyde (MDA). Myocardial infarction area was a secondary outcome indicator. This study was registered at PROSPERO (registration number CRD 42022344447). Results: According to the inclusion and exclusion criteria, 15 eligible studies were selected from 295 initially identified studies. In rat models with MIRI, tanshinone IIA significantly increased SOD levels while reducing MDA levels and myocardial infarction area. Moreover, the duration of myocardial ischemia influenced the effectiveness of tanshinone IIA. However, additional high-quality research studies are needed to establish the efficacy and definitive guidelines for the use of tanshinone IIA. Animal studies demonstrated that tanshinone IIA exerted a significant therapeutic effect when the ischemia duration was less than 40 minutes. Tanshinone IIA was found to be more effective when administered via intravenous, intraperitoneal, and intragastric routes at doses above 5 mg/kg. Additionally, treatment with tanshinone IIA at all stages—prior to myocardial ischemia, after ischemia but before reperfusion, prior to ischemia and after reperfusion, and after reperfusion—showed satisfactory results. Conclusions: Tanshinone IIA enhanced SOD activity and reduced MDA levels, thereby ameliorating oxidative stress damage during MIRI. Additionally, it reduced the myocardial infarction area, indicating its effectiveness in mitigating MIRI-induced damage in rats and demonstrating a myocardial protective effect. These findings contribute valuable insights for developing MIRI treatment strategies. [ABSTRACT FROM AUTHOR]

Myocardial ischemia‐reperfusion injury (MIRI) represents a critical pathology in acute myocardial infarction (AMI), which is characterized by high mortality and morbidity. Cardiac microvascular dysfunction contributes to MIRI, potentially culminating in heart failure (HF). Pigment epithelium‐derived factor (PEDF), which belongs to the non‐inhibitory serpin family, exhibits several physiological effects, including anti‐angiogenesis, anti‐inflammatory and antioxidant properties. Our study aims to explore the impact of PEDF and its functional peptide 34‐mer on both cardiac microvascular perfusion in MIRI rats and human cardiac microvascular endothelial cells (HCMECs) injury under hypoxia reoxygenation (HR). It has been shown that MIRI is accompanied by ferroptosis in HCMECs. Furthermore, we investigated the effect of PEDF and its 34‐mer, particularly regarding the Nrf2/HO‐1 signalling pathway. Our results demonstrated that PEDF 34‐mer significantly ameliorated cardiac microvascular dysfunction following MIRI. Additionally, they exhibited a notable suppression of ferroptosis in HCMECs, and these effects were mediated through activation of Nrf2/HO‐1 signalling. These findings highlight the therapeutic potential of PEDF and 34‐mer in alleviating microvascular dysfunction and MIRI. By enhancing cardiac microvascular perfusion and mitigating endothelial ferroptosis, PEDF and its derivative peptide represent promising candidates for the treatment of AMI. [ABSTRACT FROM AUTHOR]

Reperfusion therapy is critical for saving heart muscle after myocardial infarction, but the process of restoring blood flow can itself exacerbate injury to the myocardium. This phenomenon is known as myocardial ischemia-reperfusion injury (MIRI), which includes oxidative stress, inflammation, and further cell death. microRNA-146a (miR-146a) is known to play a significant role in regulating the immune response and inflammation, and has been studied for its potential impact on the improvement of heart function after myocardial injury. However, the delivery of miR-146a to the heart in a specific and efficient manner remains a challenge as extracellular RNAs are unstable and rapidly degraded. Milk exosomes (MEs) have been proposed as ideal delivery platform for miRNA-based therapy as they can protect miRNAs from RNase degradation. In this study, the effects of miR-146a containing MEs (MEs-miR-146a) on improvement of cardiac function were examined in a rat model of MIRI. To enhance the targeting delivery of MEs-miR-146a to the site of myocardial injury, the ischemic myocardium-targeted peptide IMTP was modified onto the surfaces, and whether the modified MEs-miR-146a could exert a better therapeutic role was examined by echocardiography, myocardial injury indicators and the levels of inflammatory factors. Furthermore, the expressions of miR-146a mediated NF-κB signaling pathway-related proteins were detected by western blotting and qRT-PCR to further elucidate its mechanisms. MiR-146 mimics were successfully loaded into the MEs by electroporation at a square wave 1000 V voltage and 0.1 ms pulse duration. MEs-miR-146a can be up-taken by cardiomyocytes and protected the cells from oxygen glucose deprivation/reperfusion induced damage in vitro. Oral administration of MEs-miR-146a decreased myocardial tissue apoptosis and the expression of inflammatory factors and improved cardiac function after MIRI. The miR-146a level in myocardium tissues was significantly increased after the administration IMTP modified MEs-miR-146a, which was higher than that of the MEs-miR-146a group. In addition, intravenous injection of IMTP modified MEs-miR-146a enhanced the targeting to heart, improved cardiac function, reduced myocardial tissue apoptosis and suppressed inflammation after MIRI, which was more effective than the MEs-miR-146a treatment. Moreover, IMTP modified MEs-miR-146a reduced the protein levels of IRAK1, TRAF6 and p-p65. Therefore, IMTP modified MEs-miR-146a exerted their anti-inflammatory effect by inhibiting the IRAK1/TRAF6/NF-κB signaling pathway. Taken together, our findings suggested miR-146a containing MEs may be a promising strategy for the treatment of MIRI with better outcome after modification with ischemic myocardium-targeted peptide, which was expected to be applied in clinical practice in future. [ABSTRACT FROM AUTHOR]

Background: Myocardial ischemia-reperfusion injury (I/R) has been improved with drugs and effective reperfusion, but it still cannot be prevented. Methods: To investigate whether renal denervation (RDN) reduces cardiomyocyte apoptosis by ameliorating endoplasmic reticulum stress, 60 male specific pathogen-free (SPF) Wistar rats were randomly divided into 6 groups (n = 6). We established the I/R rat model by ligating the left anterior descending artery. The I/R+ angiotensin receptor neprilysin inhibitors (ARNI) group received ARNIs for 2 weeks until euthanasia. Results: The I/R+RDN and I/R+ARNI groups have signifiantly ameliorated left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) and reversed expansion of the left ventricular end-systolic diameter (LVSD) and left ventricular end diastolic diameter (LVDD) compared to the I/R group. The levels of norepinephrine (NE), angiotensin II, and aldosterone (ALD) increased signifiantly in the I/R group, but decreased signifiantly after RDN and ARNI intervention. In the I/R+RDN and I/R+ARNI groups, the myocardial tissue edema was alleviated. The infarct size was smaller in the I/R+RDN and I/R+ARNI groups compared to the I/R group. Apoptosis of cardiomyocytes and fib oblasts in myocardial tissue increased signifiantly in the I/R group, which was greatly diminished by RDN and ARNI. The expression of Bax, caspase-3, CHOP, PERK, and ATF4 protein was signifiantly increased in the I/R group, which compared to other groups, and the level of CHOP, PERK, and ATF4 gene expression increased. After RDN intervention, these expression levels recovered to varying degrees. Conclusion: The effect of RDN may be associated with regulating the endoplasmic reticulum stress PERK/ATF4 signaling pathway. [ABSTRACT FROM AUTHOR]

Objective: To investigate the potential role of Tongxinluo (TXL) in attenuating myocardial fibrosis after myocardial ischemia-reperfusion injury (MIRI) in mice. Methods: A MIRI mouse model was established by left anterior descending coronary artery ligation for 45 min. According to a random number table, 66 mice were randomly divided into 6 groups (n=11 per group): the sham group, the model group, the LY-294002 group, the TXL group, the TXL+LY-294002 group and the benazepril (BNPL) group. The day after modeling, TXL and BNPL were administered by gavage. Intraperitoneal injection of LY-294002 was performed twice a week for 4 consecutive weeks. Echocardiography was used to measure cardiac function in mice. Masson staining was used to evaluate the degree of myocardial fibrosis in mice. Qualitative and quantitative analysis of endothelial mesenchymal transition (EndMT) after MIRI was performed by immunohistochemistry, immunofluorescence staining and flow cytometry, respectively. The protein expressions of platelet endothelial cell adhesion molecule-1 (CD31), α-smoth muscle actin (α-SMA), phosphatidylinositol-3-kinase (PI3K) and phospho protein kinase B (p-AKT) were assessed using Western blot. Results: TXL improved cardiac function in MIRI mice, reduced the degree of myocardial fibrosis, increased the expression of CD31 and inhibited the expression of α-SMA, thus inhibited the occurrence of EndMT (P<0.05 or P<0.01). TXL significantly increased the protein expressions of PI3K and p-AKT (P<0.05 or P<0.01). There was no significant difference between TXL and BNPL group (P>0.05). In addition, the use of the PI3K/AKT pathway-specific inhibitor LY-294002 to block this pathway and combination with TXL intervention, eliminated the protective effect of TXL, further supporting the protective effect of TXL. Conclusion: TXL activated the PI3K/AKT signaling pathway to inhibit EndMT and attenuated myocardial fibrosis after MIRI in mice. [ABSTRACT FROM AUTHOR]

This research is concentrated on investigating the role and mechanism of miR-652-3p in the protective effects of isoflurane (ISO) against myocardial ischemia–reperfusion (I/R) injury. H9c2 cells underwent pretreatment with varying concentrations of ISO, and subsequently, a hypoxia/reoxygenation (H/R) model was constructed. The levels of miR-652-3p, ISL LIM homeobox 1 (ISL1), and inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) were evaluated through reverse transcription polymerase chain reaction (RT-qPCR). Enzyme-linked immunosorbent assay was employed to investigate concentrations of myocardial injury markers, such as creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI). Cell counting kit-8 was used to evaluate cell viability, while flow cytometry was utilized to measure apoptosis. Additionally, a dual luciferase reporter assay was conducted to validate the targeting relationship between ISL1 and miR-652-3p. Herein, we confirmed that the level of miR-652-3p was gradually increased with prolonged hypoxia; nevertheless, this increase was suppressed by ISO pretreatment (P < 0.05). Additionally, ISO pretreatment prevented the decrease in cell viability, increase in apoptosis, and overproduction of IL-6, TNF-α, CK-MB, and cTnI induced by H/R (P < 0.05). However, the inhibitory effects of ISO were counteracted by the increased levels of miR-652-3p (P < 0.05). ISL1 is a potential target of miR-652-3p. H/R induction suppressed ISL1 levels compared to the control, but ISO treatment increased its expression (P < 0.05). Overexpression of ISL1 inhibited the elimination of the protective effect of ISO on myocardial damage induced by the elevation of miR-652-3p (P < 0.05). The findings of this research confirm that miR-652-3p attenuated the protective effect of ISO on cardiomyocytes in myocardial ischemia by targeting ISL1. [ABSTRACT FROM AUTHOR]

Zhuohua Zhang,1,2 Yan Liu,2 Da Huang,2 Zhaohe Huang1,3,4 1Department of Cardiology, First Affiliated Hospital of Jinan University, Guangzhou, 510630, People’s Republic of China; 2Department of Cardiology, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, 533000, People’s Republic of China; 3Affiliated Southwest Hospital, Youjiang Medical University for Nationalities, Baise, 533000, People’s Republic of China; 4Graduate School, Youjiang Medical University for Nationalities, Baise, 533000, People’s Republic of ChinaCorrespondence: Zhaohe Huang, Department of Cardiology, First Affiliated Hospital of Jinan University, Guangzhou, 510630, People’s Republic of China, Tel +86 13977691455, Fax +86 776-2853272, Email bshuangzhaohe@163.comPurpose: Myocardial ischemia-reperfusion injury (MIRI) is characterized by inflammation and ferroptosis, but the precise mechanisms remain unknown. This study used single-cell transcriptomics technology to investigate the changes in various cell subtypes during MIRI and the regulatory network of ferroptosis-related genes and immune infiltration.Methods: Datasets GSE146285, GSE83472, GSE61592, and GSE160516 were obtained from Gene Expression Omnibus. Each cell subtype in the tissue samples was documented. The Seurat package was used for data preprocessing, standardization, and clustering. Cellphonedb was used to investigate the ligand-receptor interactions between cells. The hdWGCNA analysis was used to create a gene co-expression network. GSVA and GSEA were combined to perform functional enrichment and pathway analysis on the gene set. Furthermore, characteristic genes of the disease were identified using Lasso regression and SVM algorithms. Immune cell infiltration analysis was also performed. MIRI rat models were created, and samples were taken for RT-qPCR and Western blot validation.Results: The proportion of MIRI samples in the C2, C6, and C11 subtypes was significantly higher than that of control samples. Three genes associated with ferroptosis (CD44, Cfl1, and Zfp36) were identified as MIRI core genes. The expression of these core genes was significantly correlated with mast cells and monocyte immune infiltrating cells. The experimental validation confirmed the upregulation of Cd44 and Zfp36 expression levels in MIRI, consistent with current study trends.Conclusion: This study used single-cell transcriptomics technology to investigate the molecular mechanisms underpinning MIRI. Numerous important cell subtypes, gene regulatory networks, and disease-associated immune infiltration were also discovered. These findings provide new information and potential therapeutic targets for MIRI diagnosis and treatment.Keywords: myocardial ischemia-reperfusion injury, ferroptosis, immune cell infiltration, single-cell transcriptome sequencing, WGCNA

Abstract Ischemic heart disease is the most prevalent cause of death worldwide affecting both the gender of all age groups. The high mortality rate is due to damage of myocardial tissue that emanates at the time of myocardial ischemia and re-oxygenation, thus averting reperfusion injury is recognized as a potential way to reduce acute cardiac injury and subsequent mortality. Flavonoids are polyphenol derivatives of plant origin and empirical shreds of evidence substantiate their numerous activities such as antioxidant, anti-inflammatory, anti-apoptotic, and anti-thrombotic activity, leading to their role in cardio protection. Recent investigations have unveiled the capacity of flavonoids to impede pivotal regulatory enzymes, signaling molecules, and transcription factors that orchestrate the mediators participating in the inflammatory cascade. The present comprehensive review, dwells on the preclinical studies on the effectiveness of flavonoids from the year 2007 to 2023, for the prevention and therapeutics for myocardial ischemia-reperfusion injury. Graphical Abstract

Abstract Reperfusion therapy is critical for saving heart muscle after myocardial infarction, but the process of restoring blood flow can itself exacerbate injury to the myocardium. This phenomenon is known as myocardial ischemia-reperfusion injury (MIRI), which includes oxidative stress, inflammation, and further cell death. microRNA-146a (miR-146a) is known to play a significant role in regulating the immune response and inflammation, and has been studied for its potential impact on the improvement of heart function after myocardial injury. However, the delivery of miR-146a to the heart in a specific and efficient manner remains a challenge as extracellular RNAs are unstable and rapidly degraded. Milk exosomes (MEs) have been proposed as ideal delivery platform for miRNA-based therapy as they can protect miRNAs from RNase degradation. In this study, the effects of miR-146a containing MEs (MEs-miR-146a) on improvement of cardiac function were examined in a rat model of MIRI. To enhance the targeting delivery of MEs-miR-146a to the site of myocardial injury, the ischemic myocardium-targeted peptide IMTP was modified onto the surfaces, and whether the modified MEs-miR-146a could exert a better therapeutic role was examined by echocardiography, myocardial injury indicators and the levels of inflammatory factors. Furthermore, the expressions of miR-146a mediated NF-κB signaling pathway-related proteins were detected by western blotting and qRT-PCR to further elucidate its mechanisms. MiR-146 mimics were successfully loaded into the MEs by electroporation at a square wave 1000 V voltage and 0.1 ms pulse duration. MEs-miR-146a can be up-taken by cardiomyocytes and protected the cells from oxygen glucose deprivation/reperfusion induced damage in vitro. Oral administration of MEs-miR-146a decreased myocardial tissue apoptosis and the expression of inflammatory factors and improved cardiac function after MIRI. The miR-146a level in myocardium tissues was significantly increased after the administration IMTP modified MEs-miR-146a, which was higher than that of the MEs-miR-146a group. In addition, intravenous injection of IMTP modified MEs-miR-146a enhanced the targeting to heart, improved cardiac function, reduced myocardial tissue apoptosis and suppressed inflammation after MIRI, which was more effective than the MEs-miR-146a treatment. Moreover, IMTP modified MEs-miR-146a reduced the protein levels of IRAK1, TRAF6 and p-p65. Therefore, IMTP modified MEs-miR-146a exerted their anti-inflammatory effect by inhibiting the IRAK1/TRAF6/NF-κB signaling pathway. Taken together, our findings suggested miR-146a containing MEs may be a promising strategy for the treatment of MIRI with better outcome after modification with ischemic myocardium-targeted peptide, which was expected to be applied in clinical practice in future.

Abstract Background Diabetes is a predominant driver of coronary artery disease worldwide. This study aims to unravel the distinct characteristics of oral and gut microbiota in diabetic coronary heart disease (DCHD). Simultaneously, we aim to establish a causal link between the diabetes-driven oral-gut microbiota axis and increased susceptibility to diabetic myocardial ischemia–reperfusion injury (MIRI). Methods We comprehensively investigated the microbial landscape in the oral and gut microbiota in DCHD using a discovery cohort (n = 183) and a validation chohort (n = 68). Systematically obtained oral (tongue-coating) and fecal specimens were subjected to metagenomic sequencing and qPCR analysis, respectively, to holistically characterize the microbial consortia. Next, we induced diabetic MIRI by administering streptozotocin to C57BL/6 mice and subsequently investigated the potential mechanisms of the oral-gut microbiota axis through antibiotic pre-treatment followed by gavage with specific bacterial strains (Fusobacterium nucleatum or fecal microbiota from DCHD patients) to C57BL/6 mice. Results Specific microbial signatures such as oral Fusobacterium nucleatum and gut Lactobacillus, Eubacterium, and Roseburia faecis, were identified as potential microbial biomarkers in DCHD. We further validated that oral Fusobacterium nucleatum and gut Lactobacillus are increased in DCHD patients, with a positive correlation between the two. Experimental evidence revealed that in hyperglycemic mice, augmented Fusobacterium nucleatum levels in the oral cavity were accompanied by an imbalance in the oral-gut axis, characterized by an increased coexistence of Fusobacterium nucleatum and Lactobacillus, along with elevated cardiac miRNA-21 and a greater extent of myocardial damage indicated by TTC, HE, TUNEL staining, all of which contributed to exacerbated MIRI. Conclusion Our findings not only uncover dysregulation of the oral-gut microbiota axis in diabetes patients but also highlight the pivotal intermediary role of the increased abundance of oral F. nucleatum and gut Lactobacillus in exacerbating MIRI. Targeting the oral-gut microbiota axis emerges as a potent strategy for preventing and treating DCHD. Oral-gut microbial transmission constitutes an intermediate mechanism by which diabetes influences myocardial injury, offering new insights into preventing acute events in diabetic patients with coronary heart disease. Graphic Abstract

Ischemic heart disease, associated with high morbidity and mortality, represents a major challenge for the development of drug-based strategies to improve its prognosis. Results of pre-clinical studies suggest that agonists of cannabinoid CB2 receptors and multitarget cannabidiol might be potential cardioprotective strategies against ischemia-reperfusion injury. The aim of our study was to reevaluate the cardioprotective effects of cannabinoids against ischemiareperfusion injury according to the IMproving Preclinical Assessment of Cardioprotective Therapies (IMPACT) criteria published recently by the European Union (EU) CARDIOPROTECTION COST ACTION. To meet the minimum criteria of those guidelines, experiments should be performed (i) on healthy small animals subjected to ischemia with reperfusion lasting for at least 2 hours and (ii) confirmed in small animals with comorbidities and comedications and (iii) in large animals. Our analysis revealed that the publications regarding cardioprotective effects of CB2 receptor agonists and cannabidiol did not meet all three strict steps of IMPACT. Thus, additional experiments are needed to confirm the cardioprotective activities of (endo) cannabinoids mainly on small animals with comorbidities and on large animals. Moreover, our publication underlines the significance of the IMPACT criteria for a proper planning of preclinical experiments regarding cardiac ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

Previous research has identified intravascular platelet thrombi in regions affected by myocardial ischemia-reperfusion (MI/R) injury and neighbouring areas. However, the occurrence of arterial thrombosis in the context of MI/R injury remains unexplored. This study utilizes intravital microscopy to investigate carotid artery thrombosis during MI/R injury in rats, establishing a connection with the presence of prothrombotic cellular fibronectin containing extra domain A (CFN-EDA) protein. Additionally, the study examines samples from patients with coronary artery disease (CAD) both before and after coronary artery bypass grafting (CABG). Levels of CFN-EDA significantly increase following MI with further elevation observed following reperfusion of the ischemic myocardium. Thrombotic events, such as thrombus formation and growth, show a significant increase, while the time to complete cessation of blood flow in the carotid artery significantly decreases following MI/R injury induced by ferric chloride. The acute infusion of purified CFN-EDA protein accelerates in-vivo thrombotic events in healthy rats and significantly enhances in-vitro adenosine diphosphate and collagen-induced platelet aggregation. Treatment with anti-CFN-EDA antibodies protected the rat against MI/R injury and significantly improved cardiac function as evidenced by increased end-systolic pressure-volume relationship slope and preload recruitable stroke work compared to control. Similarly, in a human study, plasma CFN-EDA levels were notably elevated in CAD patients undergoing CABG. Post-surgery, these levels continued to rise over time, alongside cardiac injury biomarkers such as cardiac troponin and B-type natriuretic peptide. The study highlights that increased CFN-EDA due to CAD or MI initiates a destructive positive feedback loop by amplifying arterial thrombus formation, potentially exacerbating MI/R injury. [Display omitted] • The study emphasizes a direct and robust connection between arterial thrombosis and MI/R injury, previously unidentified. • Increased CFN-EDA levels post-CAD or MI injury potentially accelerate arterial thrombosis events in reperfusion injury. • The significant increase in CFN-EDA following CABG, along with elevated cardiac-injury biomarkers, underscores its clinical significance. • Targeting CFN-EDA before treatment may offer promising strategy to alleviate the hastened thrombotic events linked to MI/R injury. [ABSTRACT FROM AUTHOR]

Objective: Panax quinquefolius saponins (PQS) and Panax notoginseng saponins (PNS) are key bioactive compounds in Panax quinquefolius L. and Panax notoginseng, commonly used in the treatment of clinical ischemic heart disease. However, their potential in mitigating myocardial ischemia-reperfusion injury remains uncertain. This study aims to evaluate the protective effects of combined PQS and PNS administration in myocardial hypoxia/reoxygenation (H/R) injury and explore the underlying mechanisms. Methods: To investigate the involvement of HIF-1α/BNIP3 mitophagy pathway in the myocardial protection conferred by PNS and PQS, we employed small interfering BNIP3 (siBNIP3) to silence key proteins of the pathway. H9C2 cells were categorized into four groups: control, H/R, H/R + PQS + PNS, and H/R + PQS + PNS+siBNIP3. Cell viability was assessed by Cell Counting Kit-8, apoptosis rates determined via flow cytometry, mitochondrial membrane potential assessed with the JC-1 fluorescent probes, intracellular reactive oxygen species detected with 2′,7′-dichlorodihydrofluorescein diacetate, mitochondrial superoxide production quantified with MitoSOX Red, and autophagic flux monitored with mRFP-GFP-LC3 adenoviral vectors. Autophagosomes and their ultrastructure were visualized through transmission electron microscopy. Moreover, mRNA and protein levels were analyzed via real-time PCR and Western blotting. Results: PQS + PNS administration significantly increased cell viability, reduced apoptosis, lowered reactive oxygen species levels and mitochondrial superoxide production, mitigated mitochondrial dysfunction, and induced autophagic flux. Notably, siBNIP3 intervention did not counteract the cardioprotective effect of PQS + PNS. The PQS + PNS group showed downregulated mRNA expression of HIF-1α and BNIP3, along with reduced HIF-1α protein expression compared to the H/R group. Conclusions: PQS + PNS protects against myocardial H/R injury, potentially by downregulating mitophagy through the HIF-1α/BNIP3 pathway. [ABSTRACT FROM AUTHOR]

Acute heart attack is the primary cause of cardiovascular-related death worldwide. A common treatment is reperfusion of ischemic tissue, which can cause irreversible damage to the myocardium. The number of mitochondria in cardiomyocytes is large, which generate adenosine triphosphate (ATP) to sustain proper cardiac contractile function, and mitochondrial dysfunction plays a crucial role in cell death during myocardial ischemia-reperfusion, leading to an increasing number of studies investigating the impact of mitochondria on ischemia-reperfusion injury. The disarray of mitochondrial dynamics, excessive Ca2+ accumulation, activation of mitochondrial permeable transition pores, swelling of mitochondria, ultimately the death of cardiomyocyte are the consequences of ischemia-reperfusion injury. κ-opioid receptors can alleviate mitochondrial dysfunction, regulate mitochondrial dynamics, mitigate myocardial ischemia-reperfusion injury, exert protective effects on myocardium. The mechanism of κ-OR activation during myocardial ischemia-reperfusion to regulate mitochondrial dynamics and reduce myocardial ischemia-reperfusion injury will be discussed, so as to provide theoretical basis for the protection of ischemic myocardium. [ABSTRACT FROM AUTHOR]

Oxidative stress and apoptosis play crucial roles in myocardial ischemia‒reperfusion injury (MIRI). In this study, we investigated the role of circ_0073932 in MIRI as well as its molecular mechanism. A hypoxia/reoxygenation (H/R) cardiomyocyte model was established with H9C2 cardiomyocytes, and RT–qPCR was used to measure gene expression. We observed that circ_0073932 expression was abnormally increased in the H/R cardiomyocyte model and in blood samples from MIRI patients. Inhibition of circ_0073932 suppressed H/R-induced cell apoptosis, oxidative stress (ROS, LDH and MDA), and p-JNK expression. Dual luciferase reporter assays showed that circ_0073932 targeted the downregulation of miR-493-3p, and miR-493-3p targeted the downregulation of FAF1. Furthermore, si-circ_0073932, an miR-493-3p inhibitor, oe-FAF1, or si-FAF1 were transfected into H9C2 cardiomyocytes to investigate the roles of these factors in MIRI. Our results showed that compared with the H/R group, si-circ_0073932 inhibited H/R-induced cell apoptosis, oxidative stress (ROS, LDH and MDA), and p-JNK expression. These results were reversed by the miR-493-3p inhibitor or oe-FAF1. Finally, a rat model of MIRI was established, and si-circ_0073932 was administered. Inhibition of circ_0073932 reduced the area of myocardial infarction and decreased the levels of apoptosis and oxidative stress by inhibiting the JNK signaling pathway. Our study indicated that circ_0073932 mediates MIRI via miR-493-3p/FAF1/JNK in vivo and in vitro, revealing novel insights into the pathogenesis of MIRI and providing a new target for the clinical treatment of MIRI. Suppression of circ_0073932 can inhibit myocardial apoptosis and regulate oxidative stress in MIRI through the miR-493-3p/FAF1/JNK [ABSTRACT FROM AUTHOR]

Research on ferroptosis in myocardial ischemia/reperfusion injury (MIRI) using mitochondrial viscosity as a nexus holds great promise for MIRI therapy. However, high‐precision visualisation of mitochondrial viscosity remains a formidable task owing to the debilitating electrostatic interactions caused by damaged mitochondrial membrane potential. Herein, we propose a dual‐locking mitochondria‐targeting strategy that incorporates electrostatic forces and probe‐protein molecular docking. Even in damaged mitochondria, stable and precise visualisation of mitochondrial viscosity in triggered and medicated MIRI was achieved owing to the sustained driving forces (e.g. pi‐cation, pi‐alkyl interactions, etc.) between the developed probe, CBS, and the mitochondrial membrane protein. Moreover, complemented by a western blot, we confirmed that ferrostatin‐1 exerts its therapeutic effect on MIRI by improving the system xc−/GSH/GPX4 antioxidant system, confirming the therapeutic value of ferroptosis in MIRI. This study presents a novel strategy for developing robust mitochondrial probes, thereby advancing MIRI treatment. [ABSTRACT FROM AUTHOR]

Myocardial ischemia-reperfusion injury (MIRI) is a complex process that occurs when blood flow is restored after myocardium infarction (MI) with exacerbated tissue damage. Macrophages, essential cell type of the immune response, play an important role in MIRI. Macrophage subpopulations, namely M1 and M2, are distinguished by distinct phenotypes and functions. In MIRI, macrophages infiltrate in infarcted area, shaping the inflammatory response and influencing tissue healing. Resident cardiac macrophages interact with monocyte-derived macrophages in MIRI, and influence injury progression. Key factors including chemokines, cytokines, and toll-like receptors modulate macrophage behavior in MIRI. This review aims to address recent findings on the classification and the roles of macrophages in the myocardium, spanning from MI to subsequent MIRI, and highlights various signaling pathways implicated in macrophage polarization underlining the complexity of MIRI. This article will shed light on developing advanced therapeutic strategies for MIRI management. • Modulation of macrophage polarization as a potential target for treating Myocardial Ischemia Reperfusion Injury (MIRI). • Summary for cell types of macrophages and their function. • Localization & phenotypes of macrophages in myocardial tissue. • Conclusion for recent researches of the potential mechanism of macrophages during myocardial infarction (MI) & MIRI. [ABSTRACT FROM AUTHOR]

[Display omitted] Myocardial ischemia–reperfusion injury (MIRI) is a major hindrance to the success of cardiac reperfusion therapy. Although increased neutrophil infiltration is a hallmark of MIRI, the subtypes and alterations of neutrophils in this process remain unclear. Here, we performed single-cell sequencing of cardiac CD45+ cells isolated from the murine myocardium subjected to MIRI at six-time points. We identified diverse types of infiltrating immune cells and their dynamic changes during MIRI. Cardiac neutrophils showed the most immediate response and largest changes and featured with functionally heterogeneous subpopulations, including Ccl3hi Neu and Ym-1hi Neu, which were increased at 6 h and 1 d after reperfusion, respectively. Ym-1hi Neu selectively expressed genes with protective effects and was, therefore, identified as a novel specific type of cardiac cell in the injured heart. Further analysis indicated that neutrophils and their subtypes orchestrated subsequent immune responses in the cardiac tissues, especially instructing the response of macrophages. The abundance of Ym-1hi Neu was closely correlated with the therapeutic efficacy of MIRI when neutrophils were specifically targeted by anti-Lymphocyte antigen 6 complex locus G6D (Ly6G) or anti-Intercellular cell adhesion molecule-1 (ICAM-1) neutralizing antibodies. In addition, a neutrophil subtype with the same phenotype as Ym-1hi Neu was detected in clinical samples and correlated with prognosis. Ym-1 inhibition exacerbated myocardial injury, whereas Ym-1 supplementation significantly ameliorated injury in MIRI mice, which was attributed to the tilt of Ym-1 on the polarization of macrophages toward the repair phenotype in myocardial tissue. Overall, our findings reveal the anti-inflammatory phenotype of Ym-1hi Neu and highlight its critical role in myocardial protection during the early stages of MIRI. [ABSTRACT FROM AUTHOR]

Background: Our previous research shows that Curcumin (CUR) attenuates myocardial ischemia-reperfusion injury (MIRI) by reducing intracellular total RNA m6A levels. However, the mechanism remains unknown. Methods: For ischemia-reperfusion (IR), H9c2 cells were cultured for 6 h in serum-free low-glycemic (1 g/L) medium and a gas environment without oxygen, and then cultured for 6 h in high-glycemic (4.5 g/L) medium supplemented with 10% FBS and a 21% oxygen environment. The effects of different concentrations of CUR (5, 10, and 20 µM) treatments on signaling molecules in conventionally cultured and IR-treated H9c2 cells were examined. Results: CUR treatment significantly up-regulated the H2S levels, and the mRNA and protein expression of cystathionine γ-lyase (CSE), and down-regulated the mRNAs and proteins levels of thiosulfate sulfurtransferase (TST) and ethylmalonic encephalopathy 1 (ETHE1) in H9c2 cells conventionally cultured and subjected to IR. Exogenous H2S supply (NaHS and GYY4137) significantly reduced intracellular total RNA m6A levels, and the expression of RNA m6A "writers" METTL3 and METTL14, and increased the expression of RNA m6A "eraser" FTO in H9c2 cells conventionally cultured and subjected to IR. CSE knockdown counteracted the inhibitory effect of CUR treatment on ROS production, promotion on cell viability, and inhibition on apoptosis of H9c2 cells subjected to IR. Conclusion: CUR attenuates MIRI by regulating the expression of H2S level-regulating enzymes and increasing the endogenous H2S levels. Increased H2S levels could regulate the m6A-related proteins expression and intracellular total RNA m6A levels. [ABSTRACT FROM AUTHOR]

Exosomes are multifunctional, cell-derived nanoscale membrane vesicles. Exosomes derived from certain mammalian cells have been developed as angiogenesis promoters for the treatment of myocardial ischemia–reperfusion injury, as they possess the capability to enhance endothelial cell proliferation, migration, and angiogenesis. However, the low yield of exosomes derived from mammalian cells limits their clinical applications. Therefore, we chose to extract exosome-like nanoparticles from the traditional Chinese medicine Salvia miltiorrhiza, which has been shown to promote angiogenesis. Salvia miltiorrhiza-derived exosome-like nanoparticles offer advantages, such as being economical, easily obtainable, and high-yielding, and have an ideal particle size, Zeta potential, exosome-like morphology, and stability. Salvia miltiorrhiza-derived exosome-like nanoparticles can enhance the cell viability of Human Umbilical Vein Endothelial Cells and can promote cell migration and improve the neovascularization of the cardiac tissues of myocardial ischemia–reperfusion injury, indicating their potential as angiogenesis promoters for the treatment of myocardial ischemia–reperfusion injury. [ABSTRACT FROM AUTHOR]

Myocardial ischemia–reperfusion injury (MIRI) remains a challenge in the context of reperfusion procedures for myocardial infarction (MI). While early revascularization stands as the gold standard for mitigating myocardial injury, recent insights have illuminated the paradoxical role of reperfusion, giving rise to the phenomenon known as ischemia–reperfusion injury. This comprehensive review delves into the intricate pathophysiological pathways involved in MIRI, placing a particular focus on the pivotal role of endothelium. Beyond elucidating the molecular intricacies, we explore the diverse clinical manifestations associated with MIRI, underscoring its potential to contribute substantially to the final infarct size, up to 50%. We further navigate through current preventive approaches and highlight promising emerging strategies designed to counteract the devastating effects of the phenomenon. By synthesizing current knowledge and offering a perspective on evolving preventive interventions, this review serves as a valuable resource for clinicians and researchers engaged in the dynamic field of MIRI. [ABSTRACT FROM AUTHOR]

Myocardial ischemia-reperfusion injury (MIRI) is a critical issue that arises when restoring blood flow after an ischemic event in the heart. Excessive reactive oxygen species (ROS) production during this process exacerbates cellular damage and impairs cardiac function. Recent therapeutic strategies have focused on leveraging the ROS microenvironment to design targeted drug delivery systems. ROS-responsive biomaterials have emerged as promising candidates, offering enhanced therapeutic efficacy with reduced systemic adverse effects. This review examines the mechanisms of ROS overproduction during myocardial ischemia-reperfusion and summarizes significant advancements in ROS-responsive biomaterials for MIRI treatment. We discuss various chemical strategies to impart ROS sensitivity to these materials, emphasizing ROS-induced solubility switches and degradation mechanisms. Additionally, we highlight various ROS-responsive therapeutic platforms, such as nanoparticles and hydrogels, and their unique advantages in drug delivery for MIRI. Preclinical studies demonstrating the efficacy of these materials in mitigating MIRI in animal models are reviewed, alongside their mechanisms of action and potential clinical implications. We also address the challenges and future prospects of translating these state of the art biomaterial-based therapeutics into clinical practice to improve MIRI management and cardiac outcomes. This review will provide valuable insights for researchers and clinicians working on novel therapeutic strategies for MIRI intervention.

Gastric precancerous lesion (GPL) is a crucial stage in the development of gastric cancer, characterized by incomplete intestinal epithelial chemotaxis and heterogeneous hyperplasia with high malignant potential. Early intervention in GPL is vital for preventing gastric cancer. Additionally, there are shared risk factors and pathogenesis between tumors and coronary heart disease (CHD), with an increasing number of tumor patients GPL complicated with CHD due to improved survival rates. Reperfusion therapy in CHD can result in myocardial ischemia-reperfusion injury (MIRI). Traditional Chinese medicine (TCM) has demonstrated unique advantages in treating GPL and MIRI by promoting blood circulation and removing blood stasis. Panax ginseng total saponin (PNS), a component of TCM known for its blood circulation benefits, has shown positive effects in inhibiting tumor growth and improving myocardial ischemia. This study utilized a GPL-MIRI mouse model to investigate the effects of PNS in treatment. Results indicated that PNS significantly improved typical GPL lesions in mice, such as incomplete intestinal epithelialization and heteroplasia, and also reduced myocardial infarction. At the molecular level, PNS exhibited a bidirectional regulatory role in the GPL-MIRI model. It enhanced the autophagic process in gastric mucosal cells by inhibiting the PI3K/Akt/mTOR signaling pathway, while suppressed excessive autophagy in cardiomyocytes. These findings offer new insights and treatment strategies for managing GPL and MIRI using the TCM compound PNS.

Background Myocardial ischemia–reperfusion injury (MIRI) refers to severe damage to the ischemic myocardium following the restoration of blood flow, and it is a major complication of reperfusion therapy for myocardial infarction. Notably, drugs such as metoprolol have been utilized to reduce ischemia–reperfusion injury. Tanshinone IIA is a major constituent extracted from Salvia miltiorrhiza Bunge. Recently, tanshinone IIA has been studied extensively in animal models for controlling MIRI. Therefore, we conducted a meta-analysis on the application of tanshinone IIA in rat models with MIRI to evaluate the therapeutic effects of tanshinone IIA. Methods A comprehensive search was conducted across PubMed, Web of Science, Embase, the Cochrane Library, the China National Knowledge Infrastructure database, the Wanfang database, and the Chinese Scientific Journal Database to gather studies on tanshinone IIA intervention in rat models with MIRI.We employed SYRCLE’s risk of bias tool to assess study quality. The primary outcome indicators were superoxide dismutase (SOD) and malondialdehyde (MDA). Myocardial infarction area was a secondary outcome indicator. This study was registered at PROSPERO (registration number CRD 42022344447). Results According to the inclusion and exclusion criteria, 15 eligible studies were selected from 295 initially identified studies. In rat models with MIRI, tanshinone IIA significantly increased SOD levels while reducing MDA levels and myocardial infarction area. Moreover, the duration of myocardial ischemia influenced the effectiveness of tanshinone IIA. However, additional high-quality research studies are needed to establish the efficacy and definitive guidelines for the use of tanshinone IIA. Animal studies demonstrated that tanshinone IIA exerted a significant therapeutic effect when the ischemia duration was less than 40 minutes. Tanshinone IIA was found to be more effective when administered via intravenous, intraperitoneal, and intragastric routes at doses above 5 mg/kg. Additionally, treatment with tanshinone IIA at all stages—prior to myocardial ischemia, after ischemia but before reperfusion, prior to ischemia and after reperfusion, and after reperfusion—showed satisfactory results. Conclusions Tanshinone IIA enhanced SOD activity and reduced MDA levels, thereby ameliorating oxidative stress damage during MIRI. Additionally, it reduced the myocardial infarction area, indicating its effectiveness in mitigating MIRI-induced damage in rats and demonstrating a myocardial protective effect. These findings contribute valuable insights for developing MIRI treatment strategies.

Exploring and discovering novel circRNAs is one of the ways to develop innovative drugs for the diagnosis and treatment of myocardial ischemia-reperfusion injury (MI/RI). In the work, some dysregulated circRNAs were found by microarray screening analysis in AC16 cells, and hsa_circRNA_104852 named circMIRIAF was screened, which was up-regulated in AC16 cells damaged by hypoxia-reoxygenation injury (H/RI). The comprehensive analysis of ceRNA network revealed the potential relationship of circMIRIAF/miR-544/WDR12. Then, the results of interaction research confirmed that circMIRIAF acted as sponge of miR-544 to positively regulate WDR12 protein expression. Further, the validation results indicate that miR-544 silencing increased the expression of WDR12, and WDR12 activated Notch1 signal to aggravate H/RI of AC16 cells and MI/RI of mice via regulating oxidative stress and inflammation. Furthermore, silencing circMIRIAF caused the decreased circMIRIAF levels and the increased miR-544 levels in cardiomyocytes, while excessive miR-544 inhibited WDR12 expression to alleviate the disorder. On the contrary, excessive circMIRIAF increased WDR12 expression by adsorbing miR-544 to exacerbate H/RI in AC16 cells. In addition, circMIRIAF siRNA reversed the aggravation of H/RI in cells caused by WDR12 overexpression. Overall, circMIRIAF can serve as a drug target or treating MI/RI, and circMIRIAF could sponge miR-544 and enhance WDR12 expression to aggravate MI/RI, which may provide a novel therapeutic strategy for MI/RI treatment.

Abstract Background Myocardial ischemia–reperfusion injury (MIRI) is widespread in the treatment of ischemic heart disease, and its treatment options are currently limited. Adiponectin (APN) is an adipocytokine with cardioprotective properties; however, the mechanisms of APN in MIRI are unclear. Therefore, based on preclinical (animal model) evidence, the cardioprotective effects of APN and the underlying mechanisms were explored. Methods The literature was searched for the protective effect of APN on MIRI in six databases until 16 November 2023, and data were extracted according to selection criteria. The outcomes were the size of the myocardial necrosis area and hemodynamics. Markers of oxidation, apoptosis, and inflammation were secondary outcome indicators. The quality evaluation was performed using the animal study evaluation scale recommended by the Systematic Review Center for Laboratory animal Experimentation statement. Stata/MP 14.0 software was used for the summary analysis. Results In total, 20 papers with 426 animals were included in this study. The pooled analysis revealed that APN significantly reduced myocardial infarct size [weighted mean difference (WMD) = 16.67 (95% confidence interval (CI) = 13.18 to 20.16, P

Abstract Background The key complication of myocardial infarction therapy is myocardial ischemia/reperfusion injury (MI/RI), and there is no effective treatment. The present study elucidates the mechanism of action of lncRNA KCNQ1OT1 in alleviating MI/RI and provides new perspectives and therapeutic targets for cardiac injury-related diseases. Methods An ischemia/reperfusion (I/R) injury model of human adult cardiac myocytes (HACMs) was constructed, and the expression of KCNQ1OT1 and miR-377-3p was determined by RT‒qPCR. The levels of related proteins were detected by western blot analysis. Cell proliferation was detected by a CCK-8 assay, and cell apoptosis and ROS content were determined by flow cytometry. SOD and MDA expression as well as Fe2+ changes were detected by related analysis kits. The target binding relationships between lncRNA KCNQ1OT1 and miR-377-3p as well as between miR-377-3p and heme oxygenase 1 (HMOX1) were verified by a dual-luciferase reporter gene assay. Results Myocardial ischemia‒reperfusion caused oxidative stress in HACMs, resulting in elevated ROS levels, increased Fe2+ levels, decreased cell viability, and increased LDH release (a marker of myocardial injury), and apoptosis. KCNQ1OT1 and HMOX1 were upregulated in I/R-induced myocardial injury, but the level of miR-377-3p was decreased. A dual-luciferase reporter gene assay indicated that lncRNA KCNQ1OT1 targets miR-377-3p and that miR-377-3p targets HMOX1. Inhibition of HMOX1 alleviated miR-377-3p downregulation-induced myocardial injury. Furthermore, lncRNA KCNQ1OT1 promoted the level of HMOX1 by binding to miR-377-3p and aggravated myocardial injury. Conclusion LncRNA KCNQ1OT1 aggravates ischemia‒reperfusion-induced cardiac injury via miR-377-3P/HMOX1.

Abstract Background The management of myocardial ischemia–reperfusion injury (MIRI) presents continuous therapeutic challenges. NAD-dependent deacetylase Sirtuin 6 (Sirt6) plays distinct roles in various disease contexts and is hence investigated for potential therapeutic applications for MIRI. This study aimed to examine the impact of Sirt6-overexpressing exosomes derived from adipose stem cells (S-ASC-Exo) on MIRI, focusing on their influence on AIM2-pyroptosis and mitophagy processes. The sirtuin family of proteins, particularly Sirtuin 6 (Sirt6), play a pivotal role in these processes. This study aimed to explore the potential therapeutic effects of Sirt6-enriched exosomes derived from adipose stem cells (S-ASC-Exo) on regulating MIRI. Results Bioinformatic analysis revealed a significant downregulation of Sirt6 in MIRI subjected to control group, causing a consequential increase in mitophagy and pyroptosis regulator expressions. Therefore, our study revealed that Sirt6-enriched exosomes influenced the progression of MIRI through the regulation of target proteins AIM2 and GSDMD, associated with pyroptosis, and p62 and Beclin-1, related to mitophagy. The introduction of S-ASC-Exo inhibited AIM2-pyroptosis while enhancing mitophagy. Consequently, this led to a significant reduction of GSDMD cleavage and pyroptosis in endothelial cells, catalyzing a deceleration in the progression of atherosclerosis. Extensive in vivo and in vitro assays were performed to validate the expressions of these specific genes and proteins, which affirmed the dynamic modulation by Sirt6-enriched exosomes. Furthermore, treatment with S-ASC-Exo drastically ameliorated cardiac functions and limited infarct size, underlining their cardioprotective attributes. Conclusions Our study underscores the potential therapeutic role of Sirt6-enriched exosomes in managing MIRI. We demonstrated their profound cardioprotective effect, evident in the enhanced cardiac function and attenuated tissue damage, through the strategic modulation of AIM2-pyroptosis and mitophagy. Given the intricate interplay between Sirt6 and the aforementioned processes, a comprehensive understanding of these pathways is essential to fully exploit the therapeutic potential of Sirt6. Altogether, our findings indicate the promise of Sirt6-enriched exosomes as a novel therapeutic strategy in treating ischemia–reperfusion injuries and cardiovascular diseases at large. Future research needs to underscore optimizing the balance of mitophagy during myocardial ischemia to avoid potential loss of normal myocytes.

AbstractAcute myocardial infarction, characterized by high morbidity and mortality, has now become a serious health hazard for human beings. Conventional surgical interventions to restore blood flow can rapidly relieve acute myocardial ischemia, but the ensuing myocardial ischemia-reperfusion injury (MI/RI) and subsequent heart failure have become medical challenges that researchers have been trying to overcome. The pathogenesis of MI/RI involves several mechanisms, including overproduction of reactive oxygen species, abnormal mitochondrial function, calcium overload, and other factors that induce cell death and inflammatory responses. These mechanisms have led to the exploration of antioxidant and inflammation-modulating therapies, as well as the development of myocardial protective factors and stem cell therapies. However, the short half-life, low bioavailability, and lack of targeting of these drugs that modulate these pathological mechanisms, combined with liver and spleen sequestration and continuous washout of blood flow from myocardial sites, severely compromise the expected efficacy of clinical drugs. To address these issues, employing conventional nanocarriers and integrating them with contemporary biomimetic nanocarriers, which rely on passive targeting and active targeting through precise modifications, can effectively prolong the duration of therapeutic agents within the body, enhance their bioavailability, and augment their retention at the injured myocardium. Consequently, these approaches significantly enhance therapeutic effectiveness while minimizing toxic side effects. This article reviews current drug delivery systems used for MI/RI, aiming to offer a fresh perspective on treating this disease.

Background and objective: Macrophages play a crucial and dichotomous role cardiac repair following myocardial ischemia-reperfusion, as they can both facilitate tissue healing and contribute to injury. This duality is intricately linked to environmental factors, and the identification of macrophage subtypes within the context of myocardial ischemia-reperfusion injury (MIRI) may offer insights for the development of more precise intervention strategies. Methods: Specific marker genes were used to identify macrophage subtypes in GSE227088 (mouse single-cell RNA sequencing dataset). Genome Set Enrichment Analysis (GSEA) was further employed to validate the identified LAM subtypes. Trajectory analysis and single-cell regulatory network inference were executed using the R packages Monocle2 and SCENIC, respectively. The conservation of LAM was verified using human ischemic cardiomyopathy heart failure samples from the GSE145154 (human single-cell RNA sequencing dataset). Fluorescent homologous double-labeling experiments were performed to determine the spatial localization of LAM-tagged gene expression in the MIRI mouse model. Results: In this study, single-cell RNA sequencing (scRNA-seq) was employed to investigate the cellular landscape in ischemia-reperfusion injury (IRI). Macrophage subtypes, including a novel Lipid-Associated Macrophage (LAM) subtype characterized by high expression of Spp1, Trem2, and other genes, were identified. Enrichment and Progeny pathway analyses highlighted the distinctive functional role of the SPP1+ LAM subtype, particularly in lipidmetabolismand the regulation of the MAPK pathway. Pseudotime analysis revealed the dynamic differentiation of macrophage subtypes during IRI, with the activation of pro- inflammatory pathways in specific clusters. Transcription factor analysis using SCENIC identified key regulators associated with macrophage differentiation. Furthermore, validation in human samples confirmed the presence of SPP1+ LAM. Co-staining experiments provided definitive evidence of LAM marker expression in the infarct zone. These findings shed light on the role of LAM in IRI and its potential as a therapeutic target. Conclusion: In conclusion, the study identifies SPP1+ LAM macrophages in ischemia-reperfusion injury and highlights their potential in cardiac remodeling. [ABSTRACT FROM AUTHOR]

Patients with acute myocardial infarction complicated with diabetes are more likely to develop myocardial ischemia/reperfusion (I/R) injury (MI/RI) during reperfusion therapy. Both HMGB1 and RAGE play important roles in MI/RI. However, the specific mechanisms of HMGB1 associated with RAGE are not fully clarified in diabetic MI/RI. This study aimed to investigate whether the HMGB1-RAGE axis induces diabetic MI/RI via regulating autophagy and apoptosis. A db/db mouse model of MI/RI was established, where anti-HMGB1 antibody and RAGE inhibitor (FPS-ZM1) were respectively injected after 10 min of reperfusion. The results showed that treatment with anti-HMGB1 significantly reduced the infarct size, serum LDH, and CK-MB level. Similar situations also occurred in mice administrated with FPS-ZM1, though the HMGB1 level was unchanged. Then, we found that treatment with anti-HMGB1 or FPS-ZM1 performed the same effects in suppressing the autophagy and apoptosis, as reflected by the results of lower LAMP2 and LC3B levels, increased Bcl-2 level, reduced BAX and caspase-3 levels. Moreover, the Pink1/Parkin levels were also inhibited at the same time. Collectively, this study indicates that the HMGB1-RAGE axis aggravated diabetic MI/RI via apoptosis and Pink1/Parkin mediated autophagy pathways, and inhibition of HMGB1 or RAGE contributes to alleviating those adverse situations. [ABSTRACT FROM AUTHOR]

The death of cardiomyocytes is the basic pathological factor inducing irreversible injury during myocardial ischemia/reperfusion, including increasing infarct size, cardiac remodeling, and heart failure. Despite debates about their precise mechanisms inducing myocardial ischemia/reperfusion (I/R) injury, ferroptosis, necroptosis, and pyroptosis all contribute to the pathological process of myocardial I/R injury. Ferroptosis and necroptosis both occur in the late reperfusion phase and persist for a long time, even though ferroptotic signals appear during ischemia. Pyroptosis, by contrast, takes place in the early reperfusion phase and is tightly related to chronic inflammation via the NLRP3 inflammasome. There is extensive crosstalk between ferroptosis, necroptosis, and pyroptosis, and accumulating evidence indicates an advantage of their combined inhibition to attenuate myocardial I/R injury. Myocardial ischemia–reperfusion (I/R) injury most commonly occurs in coronary artery disease when prompt reperfusion is used to salvage the ischemic myocardium. Cardiomyocyte death is a significant component of myocardial I/R injury and its mechanism was previously thought to be limited to apoptosis and necrosis. With the discovery of novel types of cell death, ferroptosis, necroptosis, and pyroptosis have been shown to be involved in myocardial I/R. These new forms of regulated cell death cause cardiomyocyte loss and exacerbate I/R injury by affecting reactive oxygen species (ROS) generation, calcium stress, and inflammatory cascades, subsequently mediating adverse remodeling, cardiac dysfunction, and heart failure. Herein, we review the roles of ferroptosis, necroptosis, and pyroptosis in myocardial I/R and discuss their contribution to pathology. [ABSTRACT FROM AUTHOR]

Remote Ischemic Preconditioning (RIPC) can reduce myocardial ischemia-reperfusion injury, but its mechanism is not clear. In order to explore the mechanism of RIPC in myocardial protection, we collected myocardial specimens during cardiac surgery in children with tetralogy of Fallot for sequencing. Our study found RIPC reduces the expression of the calcium channel subunit cacna2d3, thereby impacting the function of calcium channels. As a result, calcium overload during ischemia-reperfusion is reduced, and the activation of calpain 1 is inhibited. This ultimately leads to a decrease in calpain 1 cleavage of Bax, consequently inhibiting increased mitochondrial permeability-mediated apoptosis. Notably, in both murine and human models of myocardial ischemia-reperfusion injury, RIPC inhibiting the expression of the calcium channel subunit cacna2d3 and the activation of calpain 1, improving cardiac function and histological outcomes. Overall, our findings put forth a proposed mechanism that elucidates how RIPC reduces myocardial ischemia-reperfusion injury, ultimately providing a solid theoretical foundation for the widespread clinic application of RIPC. [Display omitted] • Remote ischemic preconditioning reduces myocardial ischemia-reperfusion injury. • RIPC can reduce calcium overload during myocardial ischemia-reperfusion by decreasing the expression of the calcium channel subunit cacna2d3. • Remote ischemic preconditioning decreased the expression of calpain 1 in myocardial ischemia-reperfusion injury. • Calpain 1 cleavage activates Bax in myocardial ischemia-reperfusion injury, ultimately resulting in mitochondrial damage. [ABSTRACT FROM AUTHOR]

Background: Myocardial ischemia–reperfusion injury (MIRI) is widespread in the treatment of ischemic heart disease, and its treatment options are currently limited. Adiponectin (APN) is an adipocytokine with cardioprotective properties; however, the mechanisms of APN in MIRI are unclear. Therefore, based on preclinical (animal model) evidence, the cardioprotective effects of APN and the underlying mechanisms were explored. Methods: The literature was searched for the protective effect of APN on MIRI in six databases until 16 November 2023, and data were extracted according to selection criteria. The outcomes were the size of the myocardial necrosis area and hemodynamics. Markers of oxidation, apoptosis, and inflammation were secondary outcome indicators. The quality evaluation was performed using the animal study evaluation scale recommended by the Systematic Review Center for Laboratory animal Experimentation statement. Stata/MP 14.0 software was used for the summary analysis. Results: In total, 20 papers with 426 animals were included in this study. The pooled analysis revealed that APN significantly reduced myocardial infarct size [weighted mean difference (WMD) = 16.67 (95% confidence interval (CI) = 13.18 to 20.16, P < 0.001)] and improved hemodynamics compared to the MIRI group [Left ventricular end-diastolic pressure: WMD = 5.96 (95% CI = 4.23 to 7.70, P < 0.001); + dP/dtmax: WMD = 1393.59 (95% CI = 972.57 to 1814.60, P < 0.001); -dP/dtmax: WMD = 850.06 (95% CI = 541.22 to 1158.90, P < 0.001); Left ventricular ejection fraction: WMD = 9.96 (95% CI = 7.29 to 12.63, P < 0.001)]. Apoptosis indicators [caspase-3: standardized mean difference (SMD) = 3.86 (95% CI = 2.97 to 4.76, P < 0.001); TUNEL-positive cells: WMD = 13.10 (95% CI = 8.15 to 18.05, P < 0.001)], inflammatory factor levels [TNF-α: SMD = 4.23 (95% CI = 2.48 to 5.98, P < 0.001)], oxidative stress indicators [Superoxide production: SMD = 4.53 (95% CI = 2.39 to 6.67, P < 0.001)], and lactate dehydrogenase levels [SMD = 2.82 (95% CI = 1.60 to 4.04, P < 0.001)] were significantly reduced. However, the superoxide dismutase content was significantly increased [SMD = 1.91 (95% CI = 1.17 to 2.65, P < 0.001)]. Conclusion: APN protects against MIRI via anti-inflammatory, antiapoptotic, and antioxidant effects, and this effect is achieved by activating different signaling pathways. [ABSTRACT FROM AUTHOR]

Objective To investigate the inhibitory effect of eugenol on myocardial ischemia-reperfusion injury(MIRI) in rats and to analyze its mechanism. Methods Wistar rats were randomly divided into sham operation group, MIRI model group, low-dose eugenol group, medium-dose eugenol group, high-dose eugenol group, and positive control group, with 10 rats in each group. Rats in the low-dose eugenol group, medium-dose eugenol group, and high-dose eugenol group were given 50, 100, and 200 mg/(kg·d) eugenol and 30 mg/(kg·d) diltiazepine hydrochloride by gavage for 14 d, respectively, while rats in the sham operation group and MIRI model group were given sodium carboxymethyl cellulose(CMC-Na) solution by gavage. MIRI models were established 1 h after the last administration by ligation of the left anterior descending branch of coronary artery in all groups, except the sham operation group. The left anterior descending branch of coronary artery was only lapped without ligation in sham operation group after chest opening. Serum markers of myocardial injury, such as creatine kinase(CK), creatine kinase isoenzyme(CK-MB), and lactate dehydrogenase(LDH), were detected by automatic biochemical analyzer. The myocardial infarction area ratio was calculated by 2, 3, 5-triphenyltetrazolium chloride (TTC)staining after heart extraction. The differentially expressed genes of MIRI induced by eugenol were screened by transcriptome sequencing. The screened differentially expressed genes underwent Gene ontology (GO)function and Kyoto Encyclopedia of Genes and Genomes (KEGG)signaling pathway enrichment analysis. Results Serum myocardial injury markers CK, CK-MB, and LDH levels were as follows: MIRI group > low-dose eugenol group, medium-dose eugenol group, high-dose eugenol group, and positive control group > sham operation group, and the myocardial infarction area ratio was in the following order: sham-operation group > low-dose eugenol group, medium-dose eugenol group, high-dose eugenol group, and positive control group > MIRI group (all P<0. 05). Compared with the MIRI group, there were a total of 1 035 differentially expressed genes in the low-dose eugenol group, of which 594 genes were up-regulated and 441 genes were down-regulated; there were a total of 513 differentially expressed genes in the medium-dose eugenol group, of which 197 genes were up-regulated and 316 genes were up-regulated; and there were a total of 1 962 differentially expressed genes in the high-dose eugenol group, of which 1 151 genes were up-regulated and 811 genes were down-regulation. GO analysis of the differentially expressed genes in the eugenol dose groups and the MIRI group showed that the biological processes of eugenol in MIRI were mainly related to immune response, oxygen transport, acute phase response pairs, etc. ; the cellular components were mainly related to the extracellular space, chromosomes, and extracellular matrix, etc. ; and the molecular functions were mainly related to the activities of chemokines, oxygen-carrying activity, and calcium-ion binding, etc. KEGG analysis of the differentially expressed genes in the eugenol dose groups and the MIRI group showed that the differentially expressed genes under the action of eugenol were mainly involved in signaling pathways such as the forkhead box O (FOXO)signaling pathway, hypoxia inducible factor-1(HIF-1)signaling pathway, PI3K-AKT signaling pathway, and JAK-STAT signaling pathway and other signaling pathways; among them, the HIF-1 signaling pathway had the highest enrichment score and the most significant difference. Conclusion Eugenol can inhibit the MIRI of rats, and its molecular mechanism may be related to regulating the HIF-1 signaling pathway. [ABSTRACT FROM AUTHOR]

Objective To investigate the preventive effect of Toll-like receptor 4 (TLR4) agonist Lipopolysaccharides (LPS) on myocardial ischemia-reperfusion injury (MIRI) in rats and its mechanism. Methods Sixty rats were divided into the LPS intervention group (0.1 mg/kg, 0.5 mg/kg, 1 mg/kg, all were small doses), verapamil intervention group, model group and sham operation group, with 15 rats in each group. At 7 days before the establishment of MIRI models, rats in the LPS intervention group were given intraperitoneal injection of 0.1 mg/kg, 0.5 mg/kg and 1 mg/kg LPS, rats in the verapamil intervention group were given intraperitoneal injection of 2.5% verapamil (2 mg/kg), rats in the sham operation group and model group were given intraperitoneal injection of equal volume normal saline. All were performed once a day. Then, except for the sham operation group, rats in the other groups underwent ischemia-reperfusion treatment. At 72 h after treatment, the cardiac function of rats in each group was detected by ultrasound, the myocardial histopathological changes were observed by hematoxylin-eosin (HE) staining, and the myocardial infarction size was observed by 2,3, 5-triphenyltetrazolium chloride (TTC) staining. The proteins of forkhead box proteinO3a (FoxO3a), phospho-forkhead box protein O3a (pFoxO3aS253), Beclin-1 and LC in rat myocardial tissues were detected by Western blotting. Results Compared with the sham operation group, left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) decreased (both P＜0.05), myocardial injury was more serious and the percentage of myocardial infarction area increased (both P＜0.05), the relative expression of pFoxO3aS253 protein in the myocardial tissues decreased (P＜0.05), and the relative expression levels of FoxO3a, Beclin-1, and LC proteins increased in the model group (all P＜0.05). Compared with the model group, LVEF and LVFS increased in the verapamil intervention group and LPS intervention group (both P＜0.05); there was no obvious improvement in cardiomyopathy in the 0.1 mg/kg and 0.5 mg/kg LPS intervention groups, and the degree of myocardial fibrosis edema, fracture, necrosis and inflammatory cell infiltration were reduced in the verapamil intervention group and 1 mg/kg LPS intervention group; the percentage of myocardial infarction area decreased (all P＜0.05), the relative expression level of pFoxO3aS253 protein increased (P＜0.05), and the relative expression levels of FoxO3a, Beclin-1 and LC proteins decreased in the verapamil intervention group and LPS intervention group (all P＜0.05). Conclusion Low-dose TLR4 agonist LPS can prevent MIRI in rats, and its mechanism may be related to promoting phosphorylation of FoxO3a and inhibiting activation of Beclin-1 and LC. [ABSTRACT FROM AUTHOR]

Myocardial ischemia-reperfusion injury (MIRI) is closely related to the final infarct size in acute myocardial infarction (AMI). Therefore, reducing MIRI can effectively improve the prognosis of AMI patients. At the same time, the healing process after AMI is closely related to the local inflammatory microenvironment. Regulatory T cells (Tregs) can regulate various physiological and pathological immune inflammatory responses and play an important role in regulating the immune inflammatory response after AMI. However, different subtypes of Tregs have different effects on MIRI, and the same subtype of Tregs may also have different effects at different stages of MIRI. This article systematically reviews the classification and function of Tregs, as well as the role of various subtypes of Tregs in MIRI. A comprehensive understanding of the role of each subtype of Tregs can help design effective methods to control immune reactions, reduce MIRI, and provide new potential therapeutic options for AMI. • A detailed description of Tregs classification and the regulatory functions of different Treg subtypes. • Provides a systematic review of the role of Tregs in ischemia-reperfusion injury. • This research holds great promise for reducing tissue damage, alleviating inflammation, and ultimately improving treatment outcomes for individuals affected by MIRI. [ABSTRACT FROM AUTHOR]

Background: The management of myocardial ischemia–reperfusion injury (MIRI) presents continuous therapeutic challenges. NAD-dependent deacetylase Sirtuin 6 (Sirt6) plays distinct roles in various disease contexts and is hence investigated for potential therapeutic applications for MIRI. This study aimed to examine the impact of Sirt6-overexpressing exosomes derived from adipose stem cells (S-ASC-Exo) on MIRI, focusing on their influence on AIM2-pyroptosis and mitophagy processes. The sirtuin family of proteins, particularly Sirtuin 6 (Sirt6), play a pivotal role in these processes. This study aimed to explore the potential therapeutic effects of Sirt6-enriched exosomes derived from adipose stem cells (S-ASC-Exo) on regulating MIRI. Results: Bioinformatic analysis revealed a significant downregulation of Sirt6 in MIRI subjected to control group, causing a consequential increase in mitophagy and pyroptosis regulator expressions. Therefore, our study revealed that Sirt6-enriched exosomes influenced the progression of MIRI through the regulation of target proteins AIM2 and GSDMD, associated with pyroptosis, and p62 and Beclin-1, related to mitophagy. The introduction of S-ASC-Exo inhibited AIM2-pyroptosis while enhancing mitophagy. Consequently, this led to a significant reduction of GSDMD cleavage and pyroptosis in endothelial cells, catalyzing a deceleration in the progression of atherosclerosis. Extensive in vivo and in vitro assays were performed to validate the expressions of these specific genes and proteins, which affirmed the dynamic modulation by Sirt6-enriched exosomes. Furthermore, treatment with S-ASC-Exo drastically ameliorated cardiac functions and limited infarct size, underlining their cardioprotective attributes. Conclusions: Our study underscores the potential therapeutic role of Sirt6-enriched exosomes in managing MIRI. We demonstrated their profound cardioprotective effect, evident in the enhanced cardiac function and attenuated tissue damage, through the strategic modulation of AIM2-pyroptosis and mitophagy. Given the intricate interplay between Sirt6 and the aforementioned processes, a comprehensive understanding of these pathways is essential to fully exploit the therapeutic potential of Sirt6. Altogether, our findings indicate the promise of Sirt6-enriched exosomes as a novel therapeutic strategy in treating ischemia–reperfusion injuries and cardiovascular diseases at large. Future research needs to underscore optimizing the balance of mitophagy during myocardial ischemia to avoid potential loss of normal myocytes. [ABSTRACT FROM AUTHOR]

Alleviating myocardial ischemia‐reperfusion injury (MIRI) plays a critical role in the prognosis and improvement of cardiac function following acute myocardial infarction. Pyroptosis is a newly identified form of cell death that has been implicated in the regulation of MIRI. In our study, H9c2 cells and SD rats were transfected using a recombinant adenovirus vector carrying cFLIPL, and the transfection was conducted for 3 days. Subsequently, H9c2 cells were subjected to 4 h of hypoxia followed by 12 h of reoxygenation to simulate an in vitro ischemia‐reperfusion model. SD rats underwent 30 min of ischemia followed by 2 h of reperfusion to establish an MIRI model. Our findings revealed a notable decrease in cFLIPL expression in response to ischemia/reperfusion (I/R) and hypoxia/reoxygenation (H/R) injuries. Overexpression of cFLIPL can inhibit pyroptosis, reducing myocardial infarction area in vivo, and enhancing H9c2 cell viability in vitro. I/R and H/R injuries induced the upregulation of ASC, cleaved Caspase 1, NLRP3, GSDMD‐N, IL‐1β, and IL‐18 proteins, promoting cell apoptosis. Our research indicates that cFLIPL may suppress pyroptosis by strategically binding with Caspase 1, inhibiting the release of inflammatory cytokines and preventing cell membrane rupture. Therefore, cFLIPL could potentially serve as a promising target for alleviating MIRI by suppressing the pyroptotic pathway. [ABSTRACT FROM AUTHOR]

Background: The key complication of myocardial infarction therapy is myocardial ischemia/reperfusion injury (MI/RI), and there is no effective treatment. The present study elucidates the mechanism of action of lncRNA KCNQ1OT1 in alleviating MI/RI and provides new perspectives and therapeutic targets for cardiac injury-related diseases. Methods: An ischemia/reperfusion (I/R) injury model of human adult cardiac myocytes (HACMs) was constructed, and the expression of KCNQ1OT1 and miR-377-3p was determined by RT‒qPCR. The levels of related proteins were detected by western blot analysis. Cell proliferation was detected by a CCK-8 assay, and cell apoptosis and ROS content were determined by flow cytometry. SOD and MDA expression as well as Fe2+ changes were detected by related analysis kits. The target binding relationships between lncRNA KCNQ1OT1 and miR-377-3p as well as between miR-377-3p and heme oxygenase 1 (HMOX1) were verified by a dual-luciferase reporter gene assay. Results: Myocardial ischemia‒reperfusion caused oxidative stress in HACMs, resulting in elevated ROS levels, increased Fe2+ levels, decreased cell viability, and increased LDH release (a marker of myocardial injury), and apoptosis. KCNQ1OT1 and HMOX1 were upregulated in I/R-induced myocardial injury, but the level of miR-377-3p was decreased. A dual-luciferase reporter gene assay indicated that lncRNA KCNQ1OT1 targets miR-377-3p and that miR-377-3p targets HMOX1. Inhibition of HMOX1 alleviated miR-377-3p downregulation-induced myocardial injury. Furthermore, lncRNA KCNQ1OT1 promoted the level of HMOX1 by binding to miR-377-3p and aggravated myocardial injury. Conclusion: LncRNA KCNQ1OT1 aggravates ischemia‒reperfusion-induced cardiac injury via miR-377-3P/HMOX1. [ABSTRACT FROM AUTHOR]

Acute heart attack is the primary cause of cardiovascular-related death worldwide. A common treatment is reperfusion of ischemic tissue, which can cause irreversible damage to the myocardium. The number of mitochondria in cardiomyocytes is large, which generate adenosine triphosphate (ATP) to sustain proper cardiac contractile function, and mitochondrial dysfunction plays a crucial role in cell death during myocardial ischemia-reperfusion, leading to an increasing number of studies investigating the impact of mitochondria on ischemia-reperfusion injury. The disarray of mitochondrial dynamics, excessive Ca2+ accumulation, activation of mitochondrial permeable transition pores, swelling of mitochondria, ultimately the death of cardiomyocyte are the consequences of ischemia-reperfusion injury. κ-opioid receptors can alleviate mitochondrial dysfunction, regulate mitochondrial dynamics, mitigate myocardial ischemia-reperfusion injury, exert protective effects on myocardium. The mechanism of κ-OR activation during myocardial ischemia-reperfusion to regulate mitochondrial dynamics and reduce myocardial ischemia-reperfusion injury will be discussed, so as to provide theoretical basis for the protection of ischemic myocardium.

Ischemic heart disease invariably leads to devastating damage to human health. Nicotinamide ribose (NR), as one of the precursors of NAD+ synthesis, has been discovered to exert a protective role in various neurological and cardiovascular disorders. Our findings demonstrated that pretreatment with 200 mg/kg NR for 3 h significantly reduced myocardial infarct area, decreased levels of CK-MB and LDH in serum, and improved cardiac function in the rats during myocardial ischemia-reperfusion (I/R) injury. Meanwhile, 0.5 mM NR also effectively increased the viability and decreased the LDH release of H9c2 cells during OGD/R. We had provided evidence that NR pretreatment could decrease mitochondrial reactive oxygen species (mtROS) production and MDA content, and enhance SOD activity, thereby mitigating mitochondrial damage and inhibiting apoptosis during myocardial I/R injury. Further investigations revealed that NR increased NAD+ content and upregulated SIRT3 protein expression in myocardium. Through using of SIRT3 small interfering RNA and the SIRT3 deacetylase activity inhibitor 3-TYP, we had confirmed that the cardioprotective effect of NR on cardiomyocytes was largely dependent on the inhibition of mitochondrial oxidative stress via SIRT3-SOD2 axis. Overall, our study suggested that exogenous supplementation with NR mitigated mitochondrial damage and inhibited apoptosis during myocardial I/R injury by reducing mitochondrial oxidative stress via SIRT3-SOD2-mtROS pathway.

Ischemic heart disease, associated with high morbidity and mortality, represents a major challenge for the development of drug-based strategies to improve its prognosis. Results of pre-clinical studies suggest that agonists of cannabinoid CB2 receptors and multitarget cannabidiol might be potential cardioprotective strategies against ischemia-reperfusion injury. The aim of our study was to re-evaluate the cardioprotective effects of cannabinoids against ischemia-reperfusion injury according to the IMproving Preclinical Assessment of Cardioprotective Therapies (IMPACT) criteria published recently by the European Union (EU) CARDIOPROTECTION COST ACTION. To meet the minimum criteria of those guidelines, experiments should be performed (i) on healthy small animals subjected to ischemia with reperfusion lasting for at least 2 hours and (ii) confirmed in small animals with comorbidities and co-medications and (iii) in large animals. Our analysis revealed that the publications regarding cardioprotective effects of CB2 receptor agonists and cannabidiol did not meet all three strict steps of IMPACT. Thus, additional experiments are needed to confirm the cardioprotective activities of (endo)cannabinoids mainly on small animals with comorbidities and on large animals. Moreover, our publication underlines the significance of the IMPACT criteria for a proper planning of preclinical experiments regarding cardiac ischemia-reperfusion injury.

Zhou Zhou,1,2,&ast; Xuan Zhang,1,&ast; Shuai Wang,1 Xianliang Wang,1 Jingyuan Mao1 1Cardiovascular Department, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine/National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300381, People’s Republic of China; 2Graduate School, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Xianliang Wang; Jingyuan Mao, Email xlwang1981@126.com; jymao@126.comAbstract: Myocardial ischemia-reperfusion injury (MI/RI) constitutes a pivotal determinant impacting the long-term prognosis of individuals afflicted by ischemic cardiomyopathy subsequent to reperfusion therapy. Stem cells have garnered extensive application within the realm of MI/RI investigation, yielding tangible outcomes. Stem cell therapy encounters certain challenges in its application owing to the complexities associated with stem cell acquisition, a diminished homing rate, and a brief in vivo lifespan. Small extracellular vesicles (sEV) originating from mesenchymal stem cells (MSCs) have been demonstrated to possess the benefits of abundant availability, reduced immunogenicity, and a diminished tumorigenic incidence. They can exert their effects on damaged organs, improving injuries by transporting a lot of constituents, including proteins, RNA, lipid droplets, and more. This phenomenon has garnered substantial attention in the context of MI/RI treatment. Simultaneously, MSC-derived sEV (MSC-sEV) can exhibit enhanced therapeutic advantages through bioengineering modifications, biomaterial incorporation, and natural drug interventions. Within this discourse, we shall appraise the utilization of MSC-sEV and their derivatives in the context of MI/RI treatment, aiming to offer valuable insights for future research endeavors related to MI/RI.Keywords: myocardial ischemia-reperfusion injury, mesenchymal stem cells, small extracellular vesicles, nanoscale modification, natural drug