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Myocardial ischemia-reperfusion injury (MIRI) is a significant factor in the development of cardiac dysfunction following a myocardial infarction. Ferroptosis, a type of regulated cell death driven by iron and marked by lipid peroxidation, has garnered growing interest for its crucial involvement in the pathogenesis of MIRI.This review comprehensively examines the mechanisms of ferroptosis, focusing on its regulation through iron metabolism, lipid peroxidation, VDAC signaling, and antioxidant system dysregulation. We also compare ferroptosis with other forms of cell death to highlight its distinct characteristics. Furthermore, the involvement of ferroptosis in MIRI is examined with a focus on recent discoveries concerning ROS generation, mitochondrial impairment, autophagic processes, ER stress, and non-coding RNA regulation. Lastly, emerging therapeutic strategies that inhibit ferroptosis to mitigate MIRI are reviewed, providing new insights into potential clinical applications. [ABSTRACT FROM AUTHOR]

Migratory cells exist in the heart, such as immune cells, fibroblasts, endothelial cells, etc. During myocardium injury, such as ischemia–reperfusion (MIRI), cells migrate to the site of injury to perform repair functions. However, excessive aggregation of these cells may exacerbate damage to the structure and function of the heart, such as acute myocarditis and myocardial fibrosis. Myocardial injury releases exosomes, which are a type of vesicle with signal transduction function and the miRNA carried by exosomes can control cell migration function. Therefore, regulating this migratory cell population through cardiac-derived exosomal miRNA is crucial for protecting and maintaining cardiac function. Through whole transcriptome RNA sequencing, exosomal miRNA sequencing and single-cell dataset analysis, we (1) determined the potential molecular regulatory role of the lncRNA‒miRNA‒mRNA axis in MIRI, (2) screened four important exosomal miRNAs that could be released by cardiac tissue, and (3) screened seven genes related to cell locomotion that are regulated by four miRNAs, among which Tradd and Ephb6 may be specific for promoting migration of different cells of myocardial tissue in myocardial infarct. We generated a core miRNA‒mRNA network based on the functions of the target genes, which may be not only a target for cardiac repair but also a potential diagnostic marker for interactions between the heart and other tissues or organs. In conclusion, we elucidated the potential mechanism of MIRI in cardiac remodeling from the perspective of cell migration, and inhibition of cellular overmigration based on this network may provide new therapeutic targets for MIRI and to prevent MIRI from developing into other diseases. [ABSTRACT FROM AUTHOR]

Myocardial ischemia-reperfusion injury (MIRI) is a significant factor in the development of cardiac dysfunction following a myocardial infarction. Ferroptosis, a type of regulated cell death driven by iron and marked by lipid peroxidation, has garnered growing interest for its crucial involvement in the pathogenesis of MIRI. This review comprehensively examines the mechanisms of ferroptosis, focusing on its regulation through iron metabolism, lipid peroxidation, VDAC signaling, and antioxidant system dysregulation. We also compare ferroptosis with other forms of cell death to highlight its distinct characteristics. Furthermore, the involvement of ferroptosis in MIRI is examined with a focus on recent discoveries concerning ROS generation, mitochondrial impairment, autophagic processes, ER stress, and non-coding RNA regulation. Lastly, emerging therapeutic strategies that inhibit ferroptosis to mitigate MIRI are reviewed, providing new insights into potential clinical applications. [ABSTRACT FROM AUTHOR]

Myocardial ischemia-reperfusion (MI/RI) injury is a type of cardiac damage that occurs during the reperfusion of myocardial tissue following a period of ischemia. While perillaldehyde (PAE) has been suggested to have anti-inflammatory properties, its effects on MI/RI remain unclear. This study aimed to evaluate the impact of PAE on MI/RI injury. To simulate MI/RI in vivo, an ischemia-reperfusion (I/R) rat model was established. The levels of lactate dehydrogenase (LDH), creatine kinase (CK) and oxidative stress-related factors were measured using commercial assay kits. The myocardial infarct size was assessed through triphenyl tetrazolium chloride (TTC) staining. The expression levels of miR-133a-3p and inflammatory factors were determined using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). Myocardial cell apoptosis was evaluated by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) staining, and the protein levels of BCL2 associated X (Bax), BCL2 apoptosis regulator (Bcl-2) and mitogen-activated protein kinase 1 (MAPK1) were analyzed by Western blot. PAE could effectively alleviate MI/RI-induced myocardial injury by reducing the levels of LDH and CK, as well as decreasing infarct size. It also mitigated the myocardial inflammatory response by lowering the levels of proinflammatory factors. Additionally, PAE reduced oxidative stress and apoptosis in myocardial cells. Further experiments showed that these protective effects of PAE were associated with the up-regulation of miR-133a-3p, which in turn decreased MAPK1 levels. In conclusion, PAE attenuated MI/RI-induced myocardial injury, inflammatory response, oxidative stress and apoptosis in rats by inhibiting MAPK1, indicating that PAE may effectively reduce myocardial damage caused by I/R injury. [ABSTRACT FROM AUTHOR]

Objective: We aim to investigate the association between prognosis and outcomes following myocardial ischemia-reperfusion injury, as well as peripheral blood levels of NLRP3 and the triglyceride-glucose index (TyG). Methods: A total of 100 patients who underwent emergency coronary intervention following myocardial infarction confirmed by coronary angiography at our hospital between October 2021 and May 2023 were included in this study. Patients were stratified into two groups based on their prognoses: the control group (n = 73), which did not experience new myocardial infarctions or require hospitalization for heart failure or suffer sudden cardiac death post-interventional treatment; and the observation group (n = 27), which experienced one or more cardiovascular events post-treatment. Patient demographics were obtained from clinical records while biochemical analyses assessed peripheral blood triglycerides, blood glucose levels, and TyG index. Additionally, ELISA measurements determined levels of NLRP3 as well as inflammatory factors IL-6, TNF-α, and CRP in peripheral blood samples. Cardiac function was evaluated according to NYHA standards. Univariable Cox regression analysis identified factors influencing patient prognosis while Pearson correlation analysis examined relationships among prognosis, outcomes following myocardial ischemia-reperfusion injury, TyG index, and peripheral blood NLRP3. Results: No significant differences were observed in the general characteristics between the two patient groups (P > 0.05). However, the observation group exhibited higher levels of peripheral blood triglycerides, blood glucose, and TyG index compared to the control group (P < 0.05). Additionally, levels of NLRP3 and inflammatory factors IL-6, TNF-α, and CRP were elevated in the observation group compared to the control group (P < 0.05). Cardiac function impairment was more pronounced in the observation group (P < 0.05). Notably, TyG index and peripheral blood NLRP3 demonstrated higher risk ratios compared to other biomarkers (P < 0.05), indicating their significance in prognosis and outcomes. Elevated levels of NLRP3 and TyG index were associated with poorer recovery of cardiac function, increased rehospitalization rates, and higher mortality (P < 0.05). Conclusion: Elevated NLRP3 levels and an increased TyG index are strongly associated with impaired cardiac function and heightened risk of cardiovascular events. These findings suggest that these biomarkers may serve as crucial prognostic indicators following myocardial ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

Ferroptosis is a new way of cell death which is reported to participate in the pathology of myocardial ischemia–reperfusion (MI/R) injury, but it's mechanism remains unclear. The present investigation is to study the emerging role of long non-coding RNA (lncRNA) regulator of reprogramming (ROR) in cardiomyocyte ferroptosis after hypoxia/reoxygenation (H/R) administration. RT-qPCR and/or Western blot methods were performed to examine the gene/or protein levels, and CCK-8, ELISA, and DCFH-DA staining determined the cellular viability and ferroptosis. Dual-luciferase and RNA immunoprecipitation were applied to verify molecular interaction. LncRNA ROR and miR-769-5p were overexpressed and reduced in blood samples from MI patients and H/R-treated AC16 cells, respectively. Mechanistically, lncROR sponged to miR-769-5p, thus upregulating CBX7 expression. Functional experiments presented that lncRNA ROR silence mitigated H/R-stimulated inflammatory damage, oxidative stress, and ferroptosis in AC16 cells, whereas these roles could be reversed by co-downregulation of miR-769-5p or co-overexpression of CBX7. These data uncovered that lncRNA ROR prevented against H/R-induced cardiomyocyte ferroptosis by modulating miR-769-5p/CBX7 signaling, emphasizing the therapeutic value of lncRNA ROR in MI/R injury. [ABSTRACT FROM AUTHOR]

Background: Myocardial ischemia-reperfusion injury (MI/RI) is an unavoidable risk event for acute myocardial infarction, with ferroptosis showing close involvement. We investigated the mechanism of MI/RI inducing myocardial injury by inhibiting the ferroptosis-related SLC7A11/glutathione (GSH)/glutathione peroxidase 4 (GPX4) pathway and activating mitophagy. Methods: A rat MI/RI model was established, with myocardial infarction area and injury assessed by TTC and H&E staining. Rat cardiomyocytes H9C2 were cultured in vitro, followed by hypoxia/reoxygenation (H/R) modeling and the ferroptosis inhibitor lipoxstatin-1 (Lip-1) treatment, or 3-Methyladenine or rapamycin treatment and overexpression plasmid (oe-SLC7A11) transfection during modeling. Cell viability and death were evaluated by CCK-8 and LDH assays. Mitochondrial morphology was observed by transmission electron microscopy. Mitochondrial membrane potential was detected by fluorescence dye JC-1. Levels of inflammatory factors, reactive oxygen species (ROS), Fe2+, malondialdehyde, lipid peroxidation, GPX4 enzyme activity, glutathione reductase, GSH and glutathione disulfide, and SLC7A11, GPX4, LC3II/I and p62 proteins were determined by ELISA kit, related indicator detection kits and Western blot. Results: The ferroptosis-related SLC7A11/GSH/GPX4 pathway was repressed in MI/RI rat myocardial tissues, inducing myocardial injury. H/R affected GSH synthesis and inhibited GPX4 enzyme activity by down-regulating SLC7A11, thus promoting ferroptosis in cardiomyocytes, which was averted by Lip-1. SLC7A11 overexpression improved H/R-induced cardiomyocyte ferroptosis via the GSH/GPX4 pathway. H/R activated mitophagy in cardiomyocytes. Mitophagy inhibition reversed H/R-induced cellular ferroptosis. Mitophagy activation partially averted SLC7A11 overexpression-improved H/R-induced cardiomyocyte ferroptosis. H/R suppressed the ferroptosis-related SLC7A11/GSH/GPX4 pathway by inducing mitophagy, leading to cardiomyocyte injury. Conclusions: Increased ROS under H/R conditions triggered cardiomyocyte injury by inducing mitophagy to suppress the ferroptosis-related SLC7A11/GSH/GPX4 signaling pathway activation. [ABSTRACT FROM AUTHOR]

Purpose: 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. [ABSTRACT FROM AUTHOR]

Abstract Migratory cells exist in the heart, such as immune cells, fibroblasts, endothelial cells, etc. During myocardium injury, such as ischemia–reperfusion (MIRI), cells migrate to the site of injury to perform repair functions. However, excessive aggregation of these cells may exacerbate damage to the structure and function of the heart, such as acute myocarditis and myocardial fibrosis. Myocardial injury releases exosomes, which are a type of vesicle with signal transduction function and the miRNA carried by exosomes can control cell migration function. Therefore, regulating this migratory cell population through cardiac-derived exosomal miRNA is crucial for protecting and maintaining cardiac function. Through whole transcriptome RNA sequencing, exosomal miRNA sequencing and single-cell dataset analysis, we (1) determined the potential molecular regulatory role of the lncRNA‒miRNA‒mRNA axis in MIRI, (2) screened four important exosomal miRNAs that could be released by cardiac tissue, and (3) screened seven genes related to cell locomotion that are regulated by four miRNAs, among which Tradd and Ephb6 may be specific for promoting migration of different cells of myocardial tissue in myocardial infarct. We generated a core miRNA‒mRNA network based on the functions of the target genes, which may be not only a target for cardiac repair but also a potential diagnostic marker for interactions between the heart and other tissues or organs. In conclusion, we elucidated the potential mechanism of MIRI in cardiac remodeling from the perspective of cell migration, and inhibition of cellular overmigration based on this network may provide new therapeutic targets for MIRI and to prevent MIRI from developing into other diseases.

Abstract Background Myocardial ischemia-reperfusion injury (MI/RI) is an unavoidable risk event for acute myocardial infarction, with ferroptosis showing close involvement. We investigated the mechanism of MI/RI inducing myocardial injury by inhibiting the ferroptosis-related SLC7A11/glutathione (GSH)/glutathione peroxidase 4 (GPX4) pathway and activating mitophagy. Methods A rat MI/RI model was established, with myocardial infarction area and injury assessed by TTC and H&E staining. Rat cardiomyocytes H9C2 were cultured in vitro, followed by hypoxia/reoxygenation (H/R) modeling and the ferroptosis inhibitor lipoxstatin-1 (Lip-1) treatment, or 3-Methyladenine or rapamycin treatment and overexpression plasmid (oe-SLC7A11) transfection during modeling. Cell viability and death were evaluated by CCK-8 and LDH assays. Mitochondrial morphology was observed by transmission electron microscopy. Mitochondrial membrane potential was detected by fluorescence dye JC-1. Levels of inflammatory factors, reactive oxygen species (ROS), Fe2+, malondialdehyde, lipid peroxidation, GPX4 enzyme activity, glutathione reductase, GSH and glutathione disulfide, and SLC7A11, GPX4, LC3II/I and p62 proteins were determined by ELISA kit, related indicator detection kits and Western blot. Results The ferroptosis-related SLC7A11/GSH/GPX4 pathway was repressed in MI/RI rat myocardial tissues, inducing myocardial injury. H/R affected GSH synthesis and inhibited GPX4 enzyme activity by down-regulating SLC7A11, thus promoting ferroptosis in cardiomyocytes, which was averted by Lip-1. SLC7A11 overexpression improved H/R-induced cardiomyocyte ferroptosis via the GSH/GPX4 pathway. H/R activated mitophagy in cardiomyocytes. Mitophagy inhibition reversed H/R-induced cellular ferroptosis. Mitophagy activation partially averted SLC7A11 overexpression-improved H/R-induced cardiomyocyte ferroptosis. H/R suppressed the ferroptosis-related SLC7A11/GSH/GPX4 pathway by inducing mitophagy, leading to cardiomyocyte injury. Conclusions Increased ROS under H/R conditions triggered cardiomyocyte injury by inducing mitophagy to suppress the ferroptosis-related SLC7A11/GSH/GPX4 signaling pathway activation.

Abstract Objective We aim to investigate the association between prognosis and outcomes following myocardial ischemia-reperfusion injury, as well as peripheral blood levels of NLRP3 and the triglyceride-glucose index (TyG). Methods A total of 100 patients who underwent emergency coronary intervention following myocardial infarction confirmed by coronary angiography at our hospital between October 2021 and May 2023 were included in this study. Patients were stratified into two groups based on their prognoses: the control group (n = 73), which did not experience new myocardial infarctions or require hospitalization for heart failure or suffer sudden cardiac death post-interventional treatment; and the observation group (n = 27), which experienced one or more cardiovascular events post-treatment. Patient demographics were obtained from clinical records while biochemical analyses assessed peripheral blood triglycerides, blood glucose levels, and TyG index. Additionally, ELISA measurements determined levels of NLRP3 as well as inflammatory factors IL-6, TNF-α, and CRP in peripheral blood samples. Cardiac function was evaluated according to NYHA standards. Univariable Cox regression analysis identified factors influencing patient prognosis while Pearson correlation analysis examined relationships among prognosis, outcomes following myocardial ischemia-reperfusion injury, TyG index, and peripheral blood NLRP3. Results No significant differences were observed in the general characteristics between the two patient groups (P > 0.05). However, the observation group exhibited higher levels of peripheral blood triglycerides, blood glucose, and TyG index compared to the control group (P

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.

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]

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]

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]

Abstract Despite the widespread adoption of emergency coronary reperfusion therapy, reperfusion‐induced myocardial injury remains a challenging issue in clinical practice. Following myocardial reperfusion, S100A8/A9 molecules are considered pivotal in initiating and regulating tissue inflammatory damage. Effectively reducing the S100A8/A9 level in ischemic myocardial tissue holds significant therapeutic value in salvaging damaged myocardium. In this study, HA (hemagglutinin)‐ and RAGE (receptor for advanced glycation end products)‐ comodified macrophage membrane‐coated siRNA nanoparticles (MMM/RNA NPs) with siRNA targeting S100A9 (S100A9‐siRNA) are successfully prepared. This nanocarrier system is able to target effectively the injured myocardium in an inflammatory environment while evading digestive damage by lysosomes. In vivo, migration of MMM/RNA NPs to myocardial injury lesions is confirmed in a myocardial ischemia‐reperfusion injury (MIRI) mouse model. Intravenous injection of MMM/RNA NPs significantly reduced S100A9 levels in serum and myocardial tissues, further decreasing myocardial infarction area and improving cardiac function. Targeted reduction of S100A8/A9 by genetically modified macrophage membrane‐coated nanoparticles may represent a new therapeutic intervention for MIRI.

Objective: Dexmedetomidine (Dex) is a potent agonist of the α2 adrenergic receptor that has been shown to possess sedative and hypnotic properties. Dex can protect against myocardial ischemia-reperfusion injury (MIRI) by inhibiting ferroptosis. However, these studies were based on Dex post-conditioning, and the role of α2 adrenergic receptors in this process is unclear. In this study, we investigated whether Dex preconditioning can prevent MIRI by attenuating ferroptosis and whether this effect depends on α2 adrenergic receptors in rats. Methods: Male Sprague–Dawley rats were randomly assigned to five groups: sham (saline-treated), I/R (ischemia-exposed), Dex + I/R (Dex pre-treatment), Dex + Yoh + I/R (Dex and yohimbine pre-treatment), and Yoh + I/R (yohimbine pre-treatment). Cardiac function, myocardial infarction, and morphological changes were assessed. Transmission electron microscopy was used to analyze mitochondrial morphology. Ferroptosis-related indicators and lipid peroxidation were measured using western blotting and qRT-PCR. Results: Our findings indicated that Dex preconditioning improved cardiac function, reduced infarct size and apoptosis, and inhibited ferroptosis in the rat myocardium after MIRI. These effects were associated with the upregulation of Nrf2, SLC7A11, and GPX4 expression, as well as the downregulation of Ferritin, TFR1, ACSL4, COX2, IL-1β, IL-6, and TNF-α expression. Importantly, yohimbine, an α2 adrenergic receptor antagonist, abolished these protective effects. Conclusion: These results suggest that Dex preconditioning can prevent MIRI by attenuating ferroptosis via α2 adrenergic receptor activation and by modulating the Nrf2/SLC7A11/GPX4 pathway.

Myocardial ischemia-reperfusion injury (MIRI) is a secondary injury caused by restoring blood flow after acute myocardial infarction, which may lead to serious arrhythmia and heart damage. In recent years, the role of potassium channels in MIRI has attracted much attention, especially the members of the two-pore domain potassium (K2P) channel family. K2P channel has unique structure and function, and the formation of its heterodimer increases its functional diversity. This paper reviews the structural characteristics, types, expression and physiological functions of K2P channel in the heart. In particular, we pay attention to whether members of the subfamily such as TWIK, TREK, TASK, TALK, THIK and TRESK participate in MIRI and their related mechanisms. Future research will help to reveal the molecular mechanism of K2P channel in MIRI and provide new strategies for the treatment of cardiovascular diseases.

Tilianin, a flavonoid compound derived from Dracocephalum moldavica L., is recognized for its diverse biological functionalities, in particular alleviating myocardial ischemia-reperfusion injury (MIRI). There is ample evidence suggesting that the NLRP3 inflammasome has a significant impact on the development of MIRI. In this study, rats undergoing the ligation and subsequent release of the left anterior descending (LAD) coronary artery and H9c2 cardiomyocytes subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) were used to investigate the effects of tilianin on NLRP3 inflammasome and its anti-MIRI mechanisms. Upon reperfusion, the rats were intraperitoneally injected with tilianin at doses of 3, 10, 30 mg/kg. H9c2 cells were treated with tilianin at concentrations of 10, 30, and 50 μg/mL. Echocardiography, TTC staining and TUNEL staining demonstrated that tilianin remarkably improved cardiac function and mitigated myocardial damage in MIRI rats. Additionally, notable inflammatory response reduction by tilianin was evidenced by subsequent hematatoxylin-eosin (HE) staining, inflammatory cytokines assay, and quantitative proteomics. Further western blotting analysis and immunofluorescence staining showed tilianin decreased the levels of TLR4, p-NF-κB, NLRP3, and ASC in MIRI rats and H9c2 cells exposed to OGD/R, alongside a significant reduction in cleaved gasdermin D, mature IL-1β and IL-18. Molecular docking, cellular thermal shift assay (CETSA) and co-immunoprecipitation (co-IP) assay revealed that tilianin impeded the interaction between NLRP3 and NEK7. Taken together, tilianin protects cardiomyocytes from MIRI by suppressing NLRP3 inflammasome through the inhibition of the TLR4/NF-κB signaling pathway and the disruption of the NEK7/NLRP3 interface. These findings underscore the potential of tilianin as a promising therapeutic candidate for MIRI.

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.

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

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.

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]

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]

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.

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.

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.

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

Abstract This study aimed to explore the role and mechanism of DYRK1a regulating ferroptosis of cardiomyocytes during myocardial ischemia–reperfusion injury (MIRI). H9c2 cells treated with oxygen–glucose deprivation/reoxygenation (OGD/R) were used as MIRI cell models and transfected with sh‐DYRK1a or/and erastin. Cell viability, apoptosis, and DYRK1a mRNA/protein expression were measured accordingly. The levels of reactive oxygen species (ROS), iron, malondialdehyde (MDA), and glutathione (GSH) were determined. The expression of ferroptosis‐related proteins (GPX4, SLC7A11, ACSL4, and TFR1) was detected using western blotting. The MIRI rat model was established to explore the possible role of DYRK1a suppression in cell injury and ferroptosis. OGD/R cells showed elevated mRNA and protein expression for DYRK1a. OGD/R cells transfected with sh‐DYRK1a showed elevated cell viability, GSH content, increased GPX4 and SLC7A11 expression, suppressed iron content, MDA, ROS, ACSL4, and TFR1 expression, and reduced apoptosis rate, whereas co‐transfection of sh‐DYRK1a with erastin reversed the attenuation of sh‐DYRK1a on MIRI. The suppressive effect of sh‐DYRK1a on MI/R injury was confirmed in an MIRI rat model. DYRK1a mediates ferroptosis of cardiomyocytes to deteriorate MIRI progression.

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]

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]

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 myocardial infarction (AMI) is the leading cause of death worldwide. Ischemia-reperfusion (I/R) injury is considered the most common contributor to AMI. Hirsutine has been shown to protect cardiomyocytes against hypoxic injury. The present study investigated whether hirsutine improved AMI induced by I/R injury and the underlying mechanisms. In our study, we used a rat model of myocardial I/R injury. The rats were given hirsutine daily (5, 10, 20 mg/kg) by gavage for 15 days before the myocardial I/R injury. Detectable changes were observed in myocardial infarct size, mitochondrial function, histological damage, and cardiac cell apoptosis. According to our findings, hirsutine pretreatment reduced the myocardial infarct size, enhanced cardiac function, inhibited cell apoptosis, reduced the tissue lactate dehydrogenase (LDH) and reactive oxygen species (ROS) content, as well as enhanced myocardial ATP content and mitochondrial complex activity. In addition, hirsutine balanced mitochondrial dynamics by increasing Mitofusin2 (Mfn2) expression while decreasing dynamin-related protein 1 phosphorylation (p-Drp1), which was partially regulated by ROS and calmodulin-dependent protein kinase II phosphorylation (p-CaMKII). Mechanistically, hirsutine inhibited mitochondrial-mediated apoptosis during I/R injury by blocking the AKT/ASK-1/p38 MAPK pathway. This present study provides a promising therapeutic intervention for myocardial I/R injury. [ABSTRACT FROM AUTHOR]

This study aimed to explore the role and mechanism of DYRK1a regulating ferroptosis of cardiomyocytes during myocardial ischemia–reperfusion injury (MIRI). H9c2 cells treated with oxygen–glucose deprivation/reoxygenation (OGD/R) were used as MIRI cell models and transfected with sh‐DYRK1a or/and erastin. Cell viability, apoptosis, and DYRK1a mRNA/protein expression were measured accordingly. The levels of reactive oxygen species (ROS), iron, malondialdehyde (MDA), and glutathione (GSH) were determined. The expression of ferroptosis‐related proteins (GPX4, SLC7A11, ACSL4, and TFR1) was detected using western blotting. The MIRI rat model was established to explore the possible role of DYRK1a suppression in cell injury and ferroptosis. OGD/R cells showed elevated mRNA and protein expression for DYRK1a. OGD/R cells transfected with sh‐DYRK1a showed elevated cell viability, GSH content, increased GPX4 and SLC7A11 expression, suppressed iron content, MDA, ROS, ACSL4, and TFR1 expression, and reduced apoptosis rate, whereas co‐transfection of sh‐DYRK1a with erastin reversed the attenuation of sh‐DYRK1a on MIRI. The suppressive effect of sh‐DYRK1a on MI/R injury was confirmed in an MIRI rat model. DYRK1a mediates ferroptosis of cardiomyocytes to deteriorate MIRI progression. [ABSTRACT FROM AUTHOR]

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.

Abstract Background Myocardial ischemia-reperfusion injury (MIRI) is one of the main reasons for poor prognosis in patients with ischemic cardiomyopathy (ICM). To date, the mechanism remains unknown. As members of the silent information regulator 2 (SIR2) family, both SIRT1 and SIRT3 have been shown to play critical roles in protecting cardiomyocytes against MIRI, but their specific protective mechanism, their interact between the two and their relationship with ferroptosis are still unclear. Hence, in this study, we investigated the interact and specific mechanism of SIRT1 and SIRT3 in protecting cardiomyocytes against MIRI, as well as their association with ferroptosis. Methods Bioinformatics analysis methods were used to explore the expression of SIRT1 and SIRT3 during MIRI, and then a cell hypoxia/reoxygenation injury model was constructed to verify the results. Then, Pearson correlation analysis was further used to explore the relationship between SIRT1 and SIRT3, whose roles in the regulation of ferroptosis were also analysed by gene knock down, Western Blotting and flow cytometry. Several biomarkers, such as Fe2+ concentration, lipid peroxidation marker MDA and mitochondrial membrane potential (MMP), were used to evaluate changes in ferroptosis. Results The expression of SIRT1 and SIRT3 was abnormal during MIRI, and SIRT1 was significantly negatively correlated with SIRT3 in the SIRT1-SIRT3 axis. Further analysis revealed that the SIRT1-SIRT3 axis was closely correlated with ferroptosis, and its silencing effectively increase the incidence of ferroptosis. Furthermore, SIRT1-SIRT3 axis silencing was accompanied by changes in PINK1, Parkin, P62/SQSTM1 and LC3 expression. PINK1 silencing significantly increased the incidence of ferroptosis, while resveratrol (Res) and/or honokiol (HKL) effectively reversed the outcome. Conclusion Abnormalities in the SIRT1-SIRT3 axis promote MIRI through ferroptosis caused by silencing the PINK1/Parkin signaling pathway.

Junzhuo Wang,1,&ast; Ying Tan,1,&ast; Yang Dai,2,3,&ast; Ke Hu,2 Xi Tan,1 Shaoli Jiang,4 Guannan Li,1 Xinlin Zhang,1 Lina Kang,1 Xiaojian Wang,4 Biao Xu1,2 1Department of Cardiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Nanjing, People’s Republic of China; 2Department of Cardiology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, People’s Republic of China; 3Department of Geriatrics, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Nanjing, People’s Republic of China; 4Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Biao Xu, Department of Cardiology, the Affiliated Hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing, Jiangsu, People’s Republic of China, Email xubiao62@nju.edu.cn Xiaojian Wang, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, People’s Republic of China, Email ias_xjwang@njtech.edu.cnPurpose: Myocardial ischemia-reperfusion injury after myocardial infarction has always been a difficult problem in clinical practice. Endothelial cells and their secreted extracellular vesicles are closely related to inflammation, thrombosis formation, and other processes after injury. Meanwhile, low-molecular-weight gelators have shown great potential for nasal administration. This study aims to explore the therapeutic effects and significance of endothelial cell-derived extracellular vesicles combined with a hydrogel for nasal administration on myocardial ischemia-reperfusion injury.Methods: We chose a gel system composed of a derivative of glutamine amide and benzaldehyde as the extracellular vesicle delivery vehicle. This hydrogel was combined with extracellular vesicles extracted from mouse aortic endothelial cells and administered multiple times intranasally in a mouse model of ischemia-reperfusion injury to the heart. The delivery efficiency of the extracellular vesicle-hydrogel combination was evaluated by flow cytometry and immunofluorescence. Echocardiography, TTC Evan’s Blue and Masson’s staining were used to assess mouse cardiac function, infarct area, and cardiac fibrosis level. Flow cytometry, ELISA, and immunofluorescence staining were used to investigate changes in mouse inflammatory cells, cytokines, and vascular neogenesis.Results: The vesicles combined with the hydrogel have good absorption in the nasal cavity. The hydrogel combined with vesicles reduces the levels of pro-inflammatory Ly6C (high) monocytes/macrophages and neutrophils. It can also reduce the formation of microcirculation thrombi in the infarcted area, improve endothelial barrier function, and increase microvascular density in the injured area. As a result, the heart function of mice is improved and the infarct area is reduced.Conclusion: We first demonstrated that the combination of extracellular vesicles and hydrogel has a better absorption efficiency in the nasal cavity, which can improve myocardial ischemia-reperfusion injury by inhibiting inflammatory reactions and protecting endothelial function. Nasal administration of vesicles combined with hydrogel is a potential therapeutic direction.Graphical Abstract: Keywords: myocardial ischemia-reperfusion injury, extracellular vesicles, hydrogel, intranasal delivery, inflammation

Abstract Background Myocardial ischemia/reperfusion injury (MI/RI) is involved in a variety of pathological states for which there is no effective treatment exists. Shuangshen Ningxin (SSNX) capsule which is developed by Xiyuan Hospital, Chinese Academy of Traditional Chinese Medicine has been demonstrated to alleviate MI/RI, but its mechanism remains to be further elucidated. Methods The MI/RI miniature pigs model was constructed to assess the pharmacodynamics of SSNX by blocking the proximal blood flow of the left anterior descending branch of the cardiac coronary artery through an interventional balloon. The principal chemical compounds and potential targets of SSNX were screened by HPLC–MS and SwissTargetPrediction. The targets of MI/RI were identified based on Online Mendelian Inheritance in Man (OMIM) and GeneCards. Cytoscape 3.9.0 was applied to construct a protein–protein interaction (PPI) network, and Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed using metascape. To further validate the mechanism of SSNX, Molecular docking, Transmission electron microscopy, and Western blot analysis were used to test the effectiveness of targets in related pathways. Results Our results indicated that SSNX significantly improved cardiac function, attenuated myocardial I/R injury. Through network analysis, a total of 15 active components and 201 targets were obtained from SSNX, 75 of which are potential targets for the treatment of MI/RI. KEGG and MCODE analysis showed that SSNX is involved in the mitophagy signaling pathway, and ginsenoside Rg1, ginsenoside Rb1 and ginsenoside Rb2 are key components associated with the mitophagy. Further experimental results proved that SSNX protected mitochondrial structure and function, and significantly reduced the expression of mitophagy-related proteins PTEN-induced putative kinase 1 (PINK1), Parkin, FUN14 domain containing 1 (FUNDC1) and Bcl-2/E1B-19 kDa interacting protein 3 (BNIP3) in MI/RI miniature pigs. Conclusion In our study, the integration of network pharmacology and experiments in vivo demonstrated that SSNX interfered with MI/RI by inhibiting mitophagy.

Abstract Background The favorable effects of nitrate against myocardial ischemia-reperfusion injury (MIRI) have primarily focused on male rats and in short term. Here we determine the impact of long-term nitrate intervention on baseline cardiac function and the resistance to MIRI in female rats. Methods Female Wistar rats were randomly divided into untreated and nitrate-treated (100 mg/L sodium nitrate in drinking water for 9 months) groups (n = 14/group). At intervention end, levels of serum progesterone, nitric oxide metabolites (NOx), heart NOx concentration, and mRNA expressions of NO synthase isoforms (NOS), i.e., endothelial (eNOS), neuronal (nNOS), and inducible (iNOS), were measured. Isolated hearts were exposed to ischemia, and cardiac function indices (CFI) recorded. When the ischemia-reperfusion (IR) period ended, infarct size, NO metabolites, eNOS, nNOS, and iNOS expression were measured. Results Nitrate-treated rats had higher serum progesterone (29.8%, P = 0.013), NOx (31.6%, P = 0.035), and higher heart NOx (60.2%, P = 0.067), nitrite (131%, P = 0.018), and eNOS expression (200%, P = 0.005). Nitrate had no significant effects on baseline CFI but it increased recovery of left ventricular developed pressure (LVDP, 19%, P = 0.020), peak rate of positive (+ dp/dt, 16%, P = 0.006) and negative (–dp/dt, 14%, P = 0.014) changes in left ventricular pressure and decreased left ventricular end-diastolic pressure (LVEDP, 17%, P