Targeted pharmacotherapy for ischemia reperfusion injury in acute myocardial infarction

Targeting high-mobility-group-box-1-mediated inflammation: a promising therapeutic approach for myocardial infarction

Myocardial ischemia, resulting from coronary artery blockage, precipitates cardiac arrhythmias, myocardial structural changes, and heart failure. The pathophysiology of MI is mainly based on inflammation and cell death, which are essential in aggravating myocardial ischemia and reperfusion injury. Emerging research highlights the functionality of high mobility group box-1, a non-histone nucleoprotein functioning as a chromosomal stabilizer and inflammatory mediator. HMGB1's release into the extracellular compartment during ischemia acts as damage-associated molecular pattern, triggering immune reaction by pattern recognition receptors and exacerbating tissue inflammation. Its involvement in signaling pathways like PI3K/Akt, TLR4/NF-κB, and RAGE/HMGB1 underscores its significance in promoting angiogenesis, apoptosis, and reducing inflammation, which is crucial for MI treatment strategies. This review highlights the complex function of HMGB1 in the pathogenesis of myocardial infarction by summarizing novel findings on the protein in ischemic situations. Understanding the mechanisms underlying HMGB1 could widen the way to specific treatments that minimize the severity of MI and enhance patient outcomes.

GP VI-Mediated Platelet Activation and Procoagulant Activity Aggravate Inflammation and Aortic Wall Remodeling in Abdominal Aortic Aneurysm

BACKGROUND

Platelets play an important role in cardiovascular and cerebrovascular diseases. Abdominal aortic aneurysm (AAA) is a highly lethal, atherosclerosis-related disease with characteristic features of progressive dilatation of the abdominal aorta and degradation of the vessel wall, accompanied by chronic inflammation. Platelet activation and procoagulant activity play a decisive role in the AAA pathology as they might trigger AAA development in both mice and humans.

METHODS

The present study investigated the impact of the major platelet collagen receptor GP (platelet glycoprotein) VI in pathophysiological processes underlying AAA initiation and progression. For experimental AAA induction in mice, PPE (porcine pancreatic elastase) and the external PPE model were used.

RESULTS

Genetic deletion of GP VI offered protection of mice against aortic diameter expansion in experimental AAA. Mechanistically, GP VI deficiency resulted in decreased inflammation with reduced infiltration of neutrophils and platelets into the aortic wall. Furthermore, remodeling of the aortic wall was improved in the absence of GP VI, as indicated by reduced MMP (matrix metalloproteinase)-2/9 and OPN (osteopontin) plasma levels and an enhanced α-SMA (α-smooth muscle actin) content within the aortic wall, accompanied by reduced cell apoptosis. Consequently, an elevation in intima/media thickness and elastin content was observed in GP VI-deficient PPE mice, resulting in a significantly reduced aortic diameter expansion and reduced aneurysm incidence. In patients with AAA, enhanced plasma levels of soluble GP VI and fibrin, as well as fibrin accumulation within the intraluminal thrombus might serve as new biomarkers to detect AAA early. Moreover, we hypothesize that GP VI might play a role in procoagulant activity and thrombus stabilization via binding to fibrin.

CONCLUSIONS

In conclusion, our results emphasize the potential need for a GP VI-targeted antiplatelet therapy to reduce AAA initiation and progression, as well as to protect patients with AAA from aortic rupture.

Oxidative Stress and Inflammation in Myocardial Ischemia-Reperfusion Injury: Protective Effects of Plant-Derived Natural Active Compounds

Acute myocardial infarction (AMI) remains a leading cause of death among patients with cardiovascular diseases. Percutaneous coronary intervention (PCI) has been the preferred clinical treatment for AMI due to its safety and efficiency. However, research indicates that the rapid restoration of myocardial oxygen supply following PCI can lead to secondary myocardial injury, termed myocardial ischemia-reperfusion injury (MIRI), posing a grave threat to patient survival. Despite ongoing efforts, the mechanisms underlying MIRI are not yet fully elucidated. Among them, oxidative stress and inflammation stand out as critical pathophysiological mechanisms, playing significant roles in MIRI. Natural compounds have shown strong clinical therapeutic potential due to their high efficacy, availability, and low side effects. Many current studies indicate that natural compounds can mitigate MIRI by reducing oxidative stress and inflammatory responses. Therefore, this paper reviews the mechanisms of oxidative stress and inflammation during MIRI and the role of natural compounds in intervening in these processes, aiming to provide a basis and reference for future research and development of drugs for treating MIRI.

Pharmacological upregulation of macrophage-derived itaconic acid by pubescenoside C attenuated myocardial ischemia-reperfusion injury

INTRODUCTION

Myocardial ischemia-reperfusion injury (MIRI) remains a prevalent clinical challenge globally, lacking an ideal therapeutic strategy. Macrophages play a pivotal role in MIRI pathophysiology, exhibiting dynamic inflammatory and resolutive functions. Macrophage polarization and metabolism are intricately linked to MIRI, presenting potential therapeutic targets. Pubescenoside C (PBC) from Ilex pubescens showed significantly anti-inflammatory effects, however, the effect of PBC on MIRI is unknown.

OBJECTIVES

This study aimed to assess the cardioprotective effects of PBC against MIRI and elucidate the underlying mechanisms.

METHODS

Sprague-Dawley rats, H9c2 and RAW264.7 macrophages were used to establish the in vitro and in vivo models of MIRI. TTC/Evans blue staining, immunohistochemical staining, metabonomics analysis, chemical probe, surface plasmon resonance (SPR), co-immunoprecipitation (CO-IP) assays were used for pharmacodynamic and mechanism study.

RESULTS

PBC administration effectively reduced myocardial infarct size, decreased ST-segment elevation, and lowered CK-MB levels, concurrently promoting macrophage M2 polarization in MIRI. Furthermore, PBC-treated macrophages and their conditioned culture medium attenuated the apoptosis of H9c2 cells induced by oxygen-glucose deprivation/reoxygenation (OGD/R). Metabonomics analysis revealed that PBC increased the production of itaconic acid (ITA) and malic acid (MA) in macrophages, which conferred protection against OGD/R injury in H9c2 cells. Mechanistic investigations indicated that ITA exerted its effects by covalently modifying pyruvate kinase M2 (PKM2) at Cys474, Cys424, and Lys151, thereby facilitating PKM2's mitochondrial translocation and enhancing the PKM2/Bcl2 interaction, subsequently leading to decreased degradation of Bcl2. SPR assays further revealed that PBC bound to HSP90, facilitating the interaction between HSP90 and GSK3β and resulting in the inactivation of GSK3β activity and upregulation of key metabolic enzymes for ITA and MA production (Acod1 and Mdh2).

CONCLUSION

PBC alleviates MIRI-induced cardiomyocyte apoptosis by modulating the HSP90/ITA/PKM2 axis. Furthermore, pharmacological upregulation of ITA emerges as a promising therapeutic approach for MIRI, hinting at PBC's potential as a candidate drug for MIRI therapy.

Amplification of Cardioprotective Response of Remote Ischemic Preconditioning in Rats by Quercetin: Potential Role of Activation of mTOR-dependent Autophagy and Nrf2

OBJECTIVES

Noninvasive remote ischemic preconditioning (RIPC) is a practical, acceptable, and feasible conditioning technique reported to provide cardioprotection in myocardial ischemia-reperfusion injury (MIRI). It has been well-reported that quercetin possesses antioxidant and anti-inflammatory properties. This study investigates the modification of the cardioprotective response of RIPC by quercetin.

METHODS

Adult Wistar rats were randomized into 12 groups of six animals each. MIRI was induced by subjecting the isolated hearts of Wistar rats to global ischemia for 30 min, succeeded by reperfusion of 120 min after mounting on the Langendorff PowerLab apparatus. Hind limb RIPC was applied in four alternate cycles of ischemia and reperfusion of 5 min each by tying the pressure cuff before isolation of hearts.

RESULTS

MIRI was reflected by significantly increased infarct size, LDH-1, and CK-MB, TNF-α, TBARS, and decreased GSH, catalase, and hemodynamic index, and modulated Nrf2. Pretreatment of quercetin (25 and 50 mg/kg; i.p.) significantly attenuated the MIRI-induced cardiac damage and potentiated the cardioprotective response of RIPC at the low dose. Pretreatment of ketamine (10 mg/kg; i.p.), an mTOR-dependent autophagy inhibitor, significantly abolished the cardioprotective effects of quercetin and RIPC.

CONCLUSIONS

The findings highlight the modification of the cardioprotective effect of RIPC by quercetin and that quercetin protects the heart against MIRI through multiple mechanisms, including mTOR-dependent activation of autophagy and Nrf-2 activation.

Identification of potential crucial cuproptosis-related genes in myocardial ischemia-reperfusion injury through the bioinformatic analysis

BACKGROUND

Cuproptosis is known to regulate diverse physiological functions in many diseases, but its role in regulating Myocardial Ischemia-Reperfusion Injury (MI/RI) remains unclear.

METHODS

For this purpose, the MI/RI microarray datasets GSE61592 were downloaded from the Gene Expression Omnibus (GEO) database, and the Differently Expressed Genes (DEGs) in MI/RI were identified using R software. Moreover, the MI/RI mice model was established to confirm further the diagnostic value of Pyruvate Dehydrogenase B (Pdhb), Dihydrolipoamide S-acetyltransferase (Dlat), and Pyruvate dehydrogenase E1 subunit alpha 1 (Pdhα1).

RESULTS

The analysis of microarray datasets GSE61592 revealed that 798 genes were upregulated and 768 were downregulated in the myocardial tissue of the ischemia-reperfusion injury mice. Furthermore, Dlat, Pdhb, Pdhα1, and cuproptosis-related genes belonged to the downregulated genes. The receiver operating characteristics curve analysis results indicated that the Dlat, Pdhb, and Pdhα1 levels were downregulated in MI/RI and were found to be potential biomarkers for MI/RI diagnosis and prognosis. Similarly, analysis of Dlat, Pdhb, and Pdhα1 levels in the MI/RI mice revealed Pdhb being the key diagnostic marker.

CONCLUSIONS

This study demonstrated the prognostic value of cuproptosis-related genes (Dlat, Pdhb, and Pdhα1), especially Pdhb, MI/RI, providing new insight into the MI/RI treatment.

Management of ROS and Regulatory Cell Death in Myocardial Ischemia-Reperfusion Injury

Myocardial ischemia-reperfusion injury (MIRI) is fatal to patients, leading to cardiomyocyte death and myocardial remodeling. Reactive oxygen species (ROS) and oxidative stress play important roles in MIRI. There is a complex crosstalk between ROS and regulatory cell deaths (RCD) in cardiomyocytes, such as apoptosis, pyroptosis, autophagy, and ferroptosis. ROS is a double-edged sword. A reasonable level of ROS maintains the normal physiological activity of myocardial cells. However, during myocardial ischemia-reperfusion, excessive ROS generation accelerates myocardial damage through a variety of biological pathways. ROS regulates cardiomyocyte RCD through various molecular mechanisms. Targeting the removal of excess ROS has been considered an effective way to reverse myocardial damage. Many studies have applied antioxidant drugs or new advanced materials to reduce ROS levels to alleviate MIRI. Although the road from laboratory to clinic has been difficult, many scholars still persevere. This article reviews the molecular mechanisms of ROS inhibition to regulate cardiomyocyte RCD, with a view to providing new insights into prevention and treatment strategies for MIRI.

Dynamic molecular signatures of acute myocardial infarction based on transcriptomics and metabolomics

Acute myocardial infarction (AMI) commonly precedes ventricular remodeling, heart failure. Few dynamic molecular signatures have gained widespread acceptance in mainstream clinical testing despite the discovery of many potential candidates. These unmet needs with respect to biomarker and drug discovery of AMI necessitate a prioritization. We enrolled patients with AMI aged between 30 and 70. RNA-seq analysis was performed on the peripheral blood mononuclear cells collected from the patients at three time points: 1 day, 7 days, and 3 months after AMI. PLC/LC-MS analysis was conducted on the peripheral blood plasma collected from these patients at the same three time points. Differential genes and metabolites between groups were screened by bio-informatics methods to understand the dynamic changes of AMI in different periods. We obtained 15 transcriptional and 95 metabolite expression profiles at three time points after AMI through high-throughput sequencing. AMI-1d: enrichment analysis revealed the biological features of 1 day after AMI primarily included acute inflammatory response, elevated glycerophospholipid metabolism, and decreased protein synthesis capacity. Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) might stand promising biomarkers to differentiate post-AMI stage. Anti-inflammatory therapy during the acute phase is an important direction for preventing related pathology. AMI-7d: the biological features of this stage primarily involved the initiation of cardiac fibrosis response and activation of platelet adhesion pathways. Accompanied by upregulated TGF-beta signaling pathway and ECM receptor interaction, GP5 help assess platelet activation, a potential therapeutic target to improve haemostasis. AMI-3m: the biological features of 3 months after AMI primarily showed a vascular regeneration response with VEGF signaling pathway, NOS3 and SHC2 widely activated, which holds promise for providing new therapeutic approaches for AMI. Our analysis highlights transcriptional and metabolomics signatures at different time points after MI, which deepens our understanding of the dynamic biological responses and associated molecular mechanisms that occur during cardiac repair.

Effect of adjuvant therapy with compound danshen drip pill on inflammatory factors and cardiac function after percutaneous coronary intervention for acute myocardial infarction: a systematic review and meta-analysis

Objectives: The purpose of the study was to comprehensively evaluate efficacy and safety of CDDP in patients with AMI undergoing PCI. Methods: A computerised search was conducted on the CNKI, WF, VIP, CBM, PubMed, Embase, Web of Science, and Cochrane Library databases for RCTs of CDDP adjuvant therapy for AMI up to May 2023. STATA 17.0 was used to perform meta-analyses, sensitivity analyses, subgroup analyses, meta-regression, and publication bias assessments. TSA 0.9.5.10 Beta was used for trial sequential analysis (TSA). Evidence confidence of meta results was evaluated by GRADE (Grading of Recommendations Assessment, Development and Evaluation) according to the instructions. Results: The results of the meta-analysis showed that CDDP combined with conventional western treatment (CWT) was superior to CWT in increasing LVEF and TCER and decreasing LVEDD, hs-CRP, IL-6 and TNF-α. The quality of evidence for TCER was moderate, LVEF, LVEDD, IL-6, and TNF-α were low. The TSA results showed that the total number of samples collected in this study met the requirements for meta-analysis and excluded the possibility of false positives, further confirming the efficacy of CDDP for the treatment of AMI undergoing PCI. Conclusion: Adjuvant treatment of AMI with CDDP has shown exciting and safe benefits in improving cardiac function and reducing inflammatory response in patients with AMI undergoing PCI, but the quality of some of the included studies was poor, and the results should be interpreted with caution until further confirmation by well-designed RCTs. Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/#recordDetails], identifier [CRD42023453293].

Myocardial Ischemia-Reperfusion Injury: Unraveling Pathophysiology, Clinical Manifestations, and Emerging Prevention Strategies

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.

Myocardial Oedema as a Consequence of Viral Infection and Persistence-A Narrative Review with Focus on COVID-19 and Post COVID Sequelae

Microvascular integrity is a critical factor in myocardial fluid homeostasis. The subtle equilibrium between capillary filtration and lymphatic fluid removal is disturbed during pathological processes leading to inflammation, but also in hypoxia or due to alterations in vascular perfusion and coagulability. The degradation of the glycocalyx as the main component of the endothelial filtration barrier as well as pericyte disintegration results in the accumulation of interstitial and intracellular water. Moreover, lymphatic dysfunction evokes an increase in metabolic waste products, cytokines and inflammatory cells in the interstitial space contributing to myocardial oedema formation. This leads to myocardial stiffness and impaired contractility, eventually resulting in cardiomyocyte apoptosis, myocardial remodelling and fibrosis. The following article reviews pathophysiological inflammatory processes leading to myocardial oedema including myocarditis, ischaemia-reperfusion injury and viral infections with a special focus on the pathomechanisms evoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In addition, clinical implications including potential long-term effects due to viral persistence (long COVID), as well as treatment options, are discussed.

Platelets regulate ischemia-induced revascularization and angiogenesis by secretion of growth factor-modulating factors

In ischemic tissue, platelets can modulate angiogenesis. The specific factors influencing this function, however, are poorly understood. Here, we characterized the complement anaphylatoxin C5a-mediated activation of C5a receptor 1 (C5aR1) expressed on platelets as a potent regulator of ischemia-driven revascularization. We assessed the relevance of the anaphylatoxin receptor C5aR1 on platelets in patients with coronary artery disease as well as those with peripheral artery disease and used genetic mouse models to characterize its significance for ischemia and growth factor-driven revascularization. The presence of C5aR1-expressing platelets was increased in the hindlimb ischemia model. Ischemia-driven angiogenesis was significantly improved in C5aR1-/- mice but not in C5-/- mice, suggesting a specific role of C5aR1. Experiments using the supernatant of C5a-stimulated platelets suggested a paracrine mechanism of angiogenesis inhibition by platelets by means of antiangiogenic CXC chemokine ligand 4 (CXCL4, PF4). Lineage-specific C5aR1 deletion verified that the secretion of CXCL4 depends on C5aR1 ligation on platelets. Using C5aR1-/-CXCL4-/- mice, we observed no additional effect in the revascularization response, underscoring a strong dependence of CXCL4 secretion on the C5a-C5aR1-axis. We identified a novel mechanism for inhibition of neovascularization via platelet C5aR1, which was mediated by the release of antiangiogenic CXCL4.

Naringin improves post-ischemic myocardial injury by activation of KATP channels

Naringin (NRG) is a flavonoid with recognized cardioprotective effects. Then, it was investigated the cardioprotective mechanisms of NRG against ischemia-reperfusion (I/R) injury. The rats were pretreated for 7 days (v.o.) with NRG (25 mg/kg) or n-acetylcysteine (NAC, 100 mg/kg) and their isolated hearts were subjected to global ischemia (30 min) and reperfusion (60 min). Furthermore, isolated hearts were perfused with 5 μM NRG in the presence of 10 μM glibenclamide (GLI) and subjected to I/R protocol. In healthy ventricular cardiomyocyte, it was evaluated the acute effect of 5 μM NRG on the GLI sensitive current. The results showed that NRG pretreatment restored the cardiac function and electrocardiogram (ECG) alterations induced by I/R injury, decreasing arrhythmia scores and the occurrence of severe arrhythmias. Lactate dehydrogenase and infarct area were decreased while superoxide dismutase (SOD), catalase and citrate synthase activities increased. Expression of SOD CuZn and SOD Mn not was altered. NRG treatment decreased reactive oxygen species (ROS) generation and lipid peroxidation without alter sulfhydryl groups and protein carbonylation. Also, NRG (5 μM) increased the glibenclamide sensitive current in isolated cardiomyocytes. In isolated heart, the cardioprotection of NRG was significantly reduced by GLI. Furthermore, NRG promoted downregulation of Bax expression and Bax/Bcl-2. Histopathological analysis showed that NRG decreased cell edema, cardiomyocytes and nucleus diameter. Thus, NRG has a cardioprotective effect against cardiac I/R injury which is mediated by its antioxidant and antiapoptotic actions and KATP channels activation.

Micro- and Macrovascular Effects of Inflammation in Peripheral Artery Disease-Pathophysiology and Translational Therapeutic Approaches

Inflammation has a critical role in the development and progression of atherosclerosis. On the molecular level, inflammatory pathways negatively impact endothelial barrier properties and thus, tissue homeostasis. Conformational changes and destruction of the glycocalyx further promote pro-inflammatory pathways also contributing to pro-coagulability and a prothrombotic state. In addition, changes in the extracellular matrix composition lead to (peri-)vascular remodelling and alterations of the vessel wall, e.g., aneurysm formation. Moreover, progressive fibrosis leads to reduced tissue perfusion due to loss of functional capillaries. The present review aims at discussing the molecular and clinical effects of inflammatory processes on the micro- and macrovasculature with a focus on peripheral artery disease.

Effect and mechanisms of dexmedetomidine combined with macrophage migration inhibitory factor inhibition on the expression of inflammatory factors and AMPK in mice

Reperfusion after acute myocardial infarction can cause ischemia/reperfusion (I/R) injury, which not only impedes restoration of the functions of tissues and organs but may also aggravate structural tissue and organ damage and dysfunction, worsening the patient's condition. Thus, the mechanisms that underpin myocardial I/R injury need to be better understood. We aimed to examine the effect of dexmedetomidine on macrophage migration inhibitory factor (MIF) in cardiomyocytes from mice with myocardial I/R injury and to explore the mechanistic role of adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling in this process. Myocardial I/R injury was induced in mice. The expression of serum inflammatory factors, reactive oxygen species (ROS), adenosine triphosphate (ATP), and AMPK pathway-related proteins, as well as myocardial tissue structure and cell apoptosis rate, were compared between mice with I/R injury only; mice with I/R injury treated with dexmedetomidine, ISO-1 (MIF inhibitor), or both; and sham-operated mice. Dexmedetomidine reduced serum interleukin (IL)-6 and tumor necrosis factor-α concentrations and increased IL-10 concentration in mice with I/R injury. Moreover, dexmedetomidine reduced myocardial tissue ROS content and apoptosis rate and increased ATP content and MIF expression. MIF inhibition using ISO-1 reversed the protective effect of dexmedetomidine on myocardial I/R injury and reduced AMPK phosphorylation. Dexmedetomidine reduces the inflammatory response in mice with I/R injury and improves adverse symptoms, and its mechanism of action may be related to the MIF-AMPK pathway.

Material basis and integrative pharmacology of danshen decoction in the treatment of cardiovascular diseases

BACKGROUND

Cardiovascular diseases (CVDs) are among the primary and predominant threats to human health with increasing incidence. Danshen Decoction (DSD) as an adjuvant therapy can benefit CVDs patients by improving clinical efficacy.

PURPOSE

The purpose of this study was to identify the active components and potential pharmacological mechanisms of DSD by combining mass spectrometry with a network pharmacology strategy and to review the use of DSD in the treatment of CVDs.

METHOD

First, the composition of DSD was analyzed by ultrahigh-performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS). Second, the network pharmacology method was used to elucidate the underlying material basis and possible pharmacological mechanism of DSD for the treatment of CVDs. Finally, clinical and experimental studies on DSD in the past ten years were retrieved from the PubMed and CNKI database, and the content of these studies was used to summarize the latest progress in DSD treatment of CVDs.

OUTCOME

A total of 35 compounds were found in DSD by manual identification from the analysis of MS, which may be the material basis for the therapeutic effect of DSD. After taking the intersection of 2086 targets related to CVDs, these 35 compounds are considered to play a role in the treatment of CVDs through 210 targets including signal transducer and activator of transcription 3 (STAT3), sarcoma (SRC) and phosphoinositide-3-kinase regulatory subunit (PIK3R), and a total of 168 signaling pathways were involved in the regulation of CVDs by DSD, including PI3K-AKT signaling pathway, Alzheimer disease, and Rap1 signaling pathway. A total of 29 clinical studies using DSD in the treatment of CVDs were included in the literature review, and these studies showed the positive significance of DSD as adjuvant therapy, while 14 experimental studies included in the literature review also demonstrated the effectiveness of DSD in the treatment of CVDs.

CONCLUSION

DSD plays a role in the treatment of CVDs through a variety of active ingredients. Large-scale clinical research and more in-depth experimental research will help to further reveal the mechanism of DSD in the treatment of CVDs.

Protective Biomolecular Mechanisms of Glutathione Sodium Salt in Ischemia-Reperfusion Injury in Patients with Acute Coronary Syndrome-ST-Elevation Myocardial Infarction

Ischemia-Reperfusion Injury (IRI) is responsible for adverse outcomes in patients with ST-Elevation Myocardial Infarction (STEMI). Oxidative stress, resulting from the production of Reactive Oxygen Species (ROS) and low availability of Glutathione (GSH), are the two main mediators of IRI. The effectiveness of exogenous antioxidant therapy in this scenario is still debated, since the encouraging results obtained in animal models have not been fully reproduced in clinical studies. In this review we focus on the role of GSH, specifically on the biomolecular mechanisms that preserve myocardial cells from damage due to reperfusion. In this regard, we provide an extensive discussion about GSH intrinsic antioxidant properties, its current applications in clinical practice, and the future perspectives.

Natural emodin reduces myocardial ischemia/reperfusion injury by modulating the RUNX1/miR‑142‑3p/DRD2 pathway and attenuating inflammation

Acute myocardial infarction is one of the leading causes of death worldwide. Although timely reperfusion could attenuate myocardial ischemia injury and reduce mortality, it causes severe secondary injury to the myocardium known as myocardial ischemia/reperfusion injury (MIRI) with unmet clinical needs. Emodin has a protective effect on MIRI in rodents. However, the precise mechanism underlying its pharmacological effect remains poorly understood. Accordingly, the present study used mRNA and microRNA (miRNA) sequencing based on MIRI mouse models to determine the mechanism involved. Emodin was found to prevent MIRI and attenuate the inflammation of myocardium in the MIRI model. In addition, by using an interdisciplinary approach, the present study uncovered that emodin suppressed the runt-related transcription factor 1 (RUNX1), which is a transcription factor of miR-142-3p, in either MIRI or the hypoxia/reoxygenation injury model. Furthermore, miR-142-3p can negatively regulate dopamine receptor D2 (DRD2), which acted as an anti-inflammatory factor to suppress NF-κB-dependent inflammation and prevent MIRI. These results were demonstrated by both cellular hypoxia/reoxygenation and mouse MIRI models. Overall, the present study provided an unrevealed molecular mechanism for emodin function. Emodin could inhibit NF-κB-triggered inflammation in MIRI by regulating the RUNX1/miR-142-3p/DRD2 pathway. Therefore, the RUNX1/miR-142-3p/DRD2 pathway presented a novel target for MIRI treatment, and the application of emodin in clinical practice may improve the treatment of MIRI.

MiR-199a-5p promotes ferroptosis-induced cardiomyocyte death responding to oxygen-glucose deprivation/reperfusion injury via inhibiting Akt/eNOS signaling pathway

Myocardial ischemia/reperfusion (I/R) injury is associated with the poor outcome and higher mortality after myocardial infarction. Recent studies have revealed that miR-199a-5p participates in the process of myocardial I/R injury, but the precise roles and molecular mechanisms of miR-199a-5p in myocardial I/R injury remain not well-studied. Ferroptosis has been proposed to promote cardiomyocyte death, closely associated with myocardial I/R injury. Herein, the present study aimed to explore the function and mechanisms by which miR-199a-5p regulates whether miR-199a-5p contributes to ferroptosis-induced cardiomyocyte death responding to oxygen-glucose deprivation/reoxygenation (OGD/R) injury, an in vitro model of myocardial I/R injury focusing on Akt/eNOS signaling pathway. The results found that ferroptosis-induced cardiomyocyte death occurs and is accompanied by an increase in miR-199a-5p level in OGD/R-treated H9c2 cells. MiR-199a-5p inhibitor ameliorated ferroptosis-induced cardiomyocyte death as evidenced by the increased cell viability, the reduced reactive oxygen species (ROS) generation, lactate dehydrogenase (LDH) activity, malondialdehyde (MDA) and Fe²⁺ contents, and the up-regulated glutathione (GSH)/glutathione disulphide (GSSG) ratio as well as glutathione peroxidase 4 (Gpx4) protein expression in H9c2 cells-exposed to OGD/R, while miR-199a-5p mimic had the opposite effects. In addition, OGD/R led to the inhibition of Akt/eNOS signaling pathway, which was also blocked by miR-199a-5p inhibitor and aggravated by miR-199a-5p mimic. Furthermore, LY294002, an inhibitor of Akt/eNOS signaling pathway, abrogated miR-199a-5p inhibitor-induced the reduction of ferroptosis-induced cardiomyocyte death. In summary, our findings demonstrated that miR-199a-5p plays a central role in stimulating ferroptosis-induced cardiomyocyte death during ischemic/hypoxic injury via inhibiting Akt/eNOS signaling pathway.

Research Progress on the Role of Pyroptosis in Myocardial Ischemia-Reperfusion Injury

Myocardial ischemia-reperfusion injury (MIRI) results in the aggravation of myocardial injury caused by rapid recanalization of the ischemic myocardium. In the past few years, there is a growing interest in investigating the complex pathophysiological mechanism of MIRI for the identification of effective targets and drugs to alleviate MIRI. Currently, pyroptosis, a type of inflammatory programmed death, has received greater attention. It is involved in the MIRI development in combination with other mechanisms of MIRI, such as oxidative stress, calcium overload, necroptosis, and apoptosis, thereby forming an intertwined association between different pathways that affect MIRI by regulating common pathway molecules. This review describes the pyroptosis mechanism in MIRI and its relationship with other mechanisms, and also highlights non-coding RNAs and non-cardiomyocytes as regulators of cardiomyocyte pyroptosis by mediating associated pathways or proteins to participate in the initiation and development of MIRI. The research progress on novel small molecule drugs, clinical drugs, traditional Chinese medicine, etc. for regulating pyroptosis can play a crucial role in effective MIRI alleviation. When compared to research on other mature mechanisms, the research studies on pyroptosis in MIRI are inadequate. Although many related protective drugs have been identified, these drugs generally lack clinical applications. It is necessary to further explore and verify these drugs to expand their applications in clinical setting. Early inhibition of MIRI by targeted regulation of pyroptosis is a key concern that needs to be addressed in future studies.

Healing the Broken Hearts: A Glimpse on Next Generation Therapeutics

Cardiovascular diseases are the leading cause of death worldwide, accounting for 32% of deaths globally and thus representing almost 18 million people according to WHO. Myocardial infarction, the most prevalent adult cardiovascular pathology, affects over half a million people in the USA according to the last records of the AHA. However, not only adult cardiovascular diseases are the most frequent diseases in adulthood, but congenital heart diseases also affect 0.8–1.2% of all births, accounting for mild developmental defects such as atrial septal defects to life-threatening pathologies such as tetralogy of Fallot or permanent common trunk that, if not surgically corrected in early postnatal days, they are incompatible with life. Therefore, both congenital and adult cardiovascular diseases represent an enormous social and economic burden that invariably demands continuous efforts to understand the causes of such cardiovascular defects and develop innovative strategies to correct and/or palliate them. In the next paragraphs, we aim to briefly account for our current understanding of the cellular bases of both congenital and adult cardiovascular diseases, providing a perspective of the plausible lines of action that might eventually result in increasing our understanding of cardiovascular diseases. This analysis will come out with the building blocks for designing novel and innovative therapeutic approaches to healing the broken hearts.

Na+/H+ Exchanger 1, a Potential Therapeutic Drug Target for Cardiac Hypertrophy and Heart Failure

Cardiac hypertrophy is defined as increased heart mass in response to increased hemodynamic requirements. Long-term cardiac hypertrophy, if not counteracted, will ultimately lead to heart failure. The incidence of heart failure is related to myocardial infarction, which could be salvaged by reperfusion and ultimately invites unfavorable myocardial ischemia-reperfusion injury. The Na⁺/H⁺ exchangers (NHEs) are membrane transporters that exchange one intracellular proton for one extracellular Na⁺. The first discovered NHE isoform, NHE1, is expressed almost ubiquitously in all tissues, especially in the myocardium. During myocardial ischemia-reperfusion, NHE1 catalyzes increased uptake of intracellular Na⁺, which in turn leads to Ca²⁺ overload and subsequently myocardial injury. Numerous preclinical research has shown that NHE1 is involved in cardiac hypertrophy and heart failure, but the exact molecular mechanisms remain elusive. The objective of this review is to demonstrate the potential role of NHE1 in cardiac hypertrophy and heart failure and investigate the underlying mechanisms.

Recent advances in potential of Fisetin in the management of myocardial ischemia-reperfusion injury-A systematic review

BACKGROUND

The primary therapeutic strategy in managing ischemic heart diseases is to restore the perfusion of the myocardial ischemic area by surgical methods that often result in an unavoidable injury called ischemia-reperfusion injury (IR). Fisetin is an effective flavonoid with antioxidant and anti-inflammatory properties, proven to be cardioprotective against IR injury in both in-vitro and invivo models, apart from its promising health benefits against cancer, diabetes, and neurodegenerative ailments.

PURPOSE

The potential of fisetin in attenuating myocardial IR is inconclusive as the effectiveness of fisetin needs more understanding in terms of its possible target sites and underlying different mechanisms. Considering the surge in recent scientific interests in fisetin as a pharmacological agent, this review not only updates the existing preclinical and clinical studies with fisetin and its underlying mechanisms but also summarizes its possible targets during IR protection.

METHODS

We performed a literature survey using search engines Pubmed, PMC, Science direct, Google, and research gate published across the years 2006-2021. The relevant studies were extracted from the databases with the combinations of the following keywords and summarized: myocardial ischemia-reperfusion injury, natural products, flavonoid, fisetin, PI3K, JAK-STAT, Nrf2, PKC, JNK, autophagy.

RESULTS

Fisetin is reported to be effective in attenuating IR injury by delaying the clotting time, preserving the mitochondrial function, reducing oxidative stress, and inhibiting GSK 3β. But it failed to protect diseased cardiomyocytes challenged to IR. As discussed in the current review, fisetin not only acts as a conventional antioxidant and anti-inflammatory agent to exert its biological effect but may also exert modulatory action on the cellular metabolism and adaptation via direct action on various signalling pathways that comprise PI3K, JAK-STAT, Nrf2, PKC, JNK, and autophagy. Moreover, the dosage of fisetin and co-morbidities like diabetes and obesity are found to be detrimental factors for cardioprotection.

CONCLUSION

For further evaluation and smooth clinical translation of the fisetin molecule in IR treatment, researchers should pay close attention to the potential of fisetin to possibly alter the key cardioprotective pathways and dosage, as the efficacy of fisetin is tissue and cell type-specific and varies with different doses.

Role of Oxidative Stress in Cardiac Dysfunction and Subcellular Defects Due to Ischemia-Reperfusion Injury

Ischemia-reperfusion (I/R) injury is well-known to be associated with impaired cardiac function, massive arrhythmias, marked alterations in cardiac metabolism and irreversible ultrastructural changes in the heart. Two major mechanisms namely oxidative stress and intracellular Ca²⁺-overload are considered to explain I/R-induced injury to the heart. However, it is becoming apparent that oxidative stress is the most critical pathogenic factor because it produces myocardial abnormalities directly or indirectly for the occurrence of cardiac damage. Furthermore, I/R injury has been shown to generate oxidative stress by promoting the formation of different reactive oxygen species due to defects in mitochondrial function and depressions in both endogenous antioxidant levels as well as regulatory antioxidative defense systems. It has also been demonstrated to adversely affect a wide variety of metabolic pathways and targets in cardiomyocytes, various resident structures in myocardial interstitium, as well as circulating neutrophils and leukocytes. These I/R-induced alterations in addition to myocardial inflammation may cause cell death, fibrosis, inflammation, Ca²⁺-handling abnormalities, activation of proteases and phospholipases, as well as subcellular remodeling and depletion of energy stores in the heart. Analysis of results from isolated hearts perfused with or without some antioxidant treatments before subjecting to I/R injury has indicated that cardiac dysfunction is associated with the development of oxidative stress, intracellular Ca²⁺-overload and protease activation. In addition, changes in the sarcolemma and sarcoplasmic reticulum Ca²⁺-handling, mitochondrial oxidative phosphorylation as well as myofibrillar Ca²⁺-ATPase activities in I/R hearts were attenuated by pretreatment with antioxidants. The I/R-induced alterations in cardiac function were simulated upon perfusing the hearts with oxyradical generating system or oxidant. These observations support the view that oxidative stress may be intimately involved in inducing intracellular Ca²⁺-overload, protease activation, subcellular remodeling, and cardiac dysfunction as a consequence of I/R injury to the heart.

Integrated Bioinformatics Analysis and Verification of Gene Targets for Myocardial Ischemia-Reperfusion Injury

Background

Myocardial ischemia-reperfusion injury (MIRI) has become a thorny and unsolved clinical problem. The pathological mechanisms of MIRI are intricate and unclear, so it is of great significance to explore potential hub genes and search for some natural products that exhibit potential therapeutic efficacy on MIRI via targeting the hub genes.

Methods

First, the differential expression genes (DEGs) from GSE58486, GSE108940, and GSE115568 were screened and integrated via a robust rank aggregation algorithm. Then, the hub genes were identified and verified by the functional experiment of the MIRI mice. Finally, natural products with protective effects against MIRI were retrieved, and molecular docking simulations between hub genes and natural products were performed.

Results

230 integrated DEGs and 9 hub genes were identified. After verification, Emr1, Tyrobp, Itgb2, Fcgr2b, Cybb, and Fcer1g might be the most significant genes during MIRI. A total of 75 natural products were discovered. Most of them (especially araloside C, glycyrrhizic acid, ophiopogonin D, polyphyllin I, and punicalagin) showed good ability to bind the hub genes.

Conclusions

Emr1, Tyrobp, Itgb2, Fcgr2b, Cybb, and Fcer1g might be critical in the pathological process of MIRI, and the natural products (araloside C, glycyrrhizic acid, ophiopogonin D, polyphyllin I, and punicalagin) targeting these hub genes exhibited potential therapeutic efficacy on MIRI. Our findings provided new insights to explore the mechanism and treatments for MIRI and revealed new therapeutic targets for natural products with protective properties against MIRI.

Therapeutic Targets for Regulating Oxidative Damage Induced by Ischemia-Reperfusion Injury: A Study from a Pharmacological Perspective

Ischemia-reperfusion (I-R) injury is damage caused by restoring blood flow into ischemic tissues or organs. This complex and characteristic lesion accelerates cell death induced by signaling pathways such as apoptosis, necrosis, and even ferroptosis. In addition to the direct association between I-R and the release of reactive oxygen species and reactive nitrogen species, it is involved in developing mitochondrial oxidative damage. Thus, its mechanism plays a critical role via reactive species scavenging, calcium overload modulation, electron transport chain blocking, mitochondrial permeability transition pore activation, or noncoding RNA transcription. Other receptors and molecules reduce tissue and organ damage caused by this pathology and other related diseases. These molecular targets have been gradually discovered and have essential roles in I-R resolution. Therefore, the current study is aimed at highlighting the importance of these discoveries. In this review, we inquire about the oxidative damage receptors that are relevant to reducing the damage induced by oxidative stress associated with I-R. Several complications on surgical techniques and pathology interventions do not mitigate the damage caused by I-R. Nevertheless, these therapies developed using alternative targets could work as coadjuvants in tissue transplants or I-R-related pathologies

Effects of Ulinastatin on Myocardial Ischemia-Reperfusion Injury, Cardiac Function, and Serum TNF-α and IL-10 Levels in Patients Undergoing Cardiac Valve Replacement under Cardiopulmonary Bypass

Background

Myocardial ischemia-reperfusion injury (MIRI) is a very common adverse reaction after cardiac valve replacement (CVR) under cardiopulmonary bypass, which seriously affects the rehabilitation and prognosis of patients.

Objective

The prevention and treatment of MIRI are a hotspot of modern medical research, and this study is aimed at providing reliable reference and guidance for future clinical prevention and treatment of MIRI by analyzing the effects of ulinastatin (UL) on cardiac function and MIRI of patients after CVR.

Methods

A total of 104 patients undergoing CVR under cardiopulmonary bypass in our hospital were selected as research participants. Among them, 52 patients treated with UL were assigned to the observation group, and the rest 52 patients given the same amount of normal saline were assigned to the control group. The cardiopulmonary bypass status, postoperative status, cardiac function, inflammatory response, oxidative stress response, and hemodynamics were observed and compared between the two groups. In addition, clinical efficacy and safety and patient prognosis were compared.

Results

Through experimental analysis, we found that UL had no significant effect on the clinical efficacy, safety, and prognosis of patients after surgery (P > 0.05) but had obvious protective effects on cardiopulmonary bypass status, cardiac function, inflammation, oxidative stress, and hemodynamics (P < 0.05).

Conclusion

UL can effectively prevent the occurrence of MIRI after CVR under cardiopulmonary bypass, which is worthy of clinical application.

Asiatic Acid Alleviates Myocardial Ischemia-Reperfusion Injury by Inhibiting the ROS-Mediated Mitochondria-Dependent Apoptosis Pathway

Myocardial ischemia-reperfusion injury (MIRI) is a major cause of heart failure in patients with coronary heart disease (CHD). Mitochondrial dysfunction is the crucial factor of MIRI; oxidative stress caused by mitochondrial reactive oxygen species (ROS) aggravates myocardial cell damage through the mitochondria-dependent apoptosis pathway. Asiatic acid (AA) is a type of pentacyclic triterpene compound purified from the traditional Chinese medicine Centella asiatica, and its protective pharmacological activities have been reported in various disease models. This study is aimed at investigating the protective effects of AA and the underlying mechanisms in MIRI. To achieve this goal, an animal model of MIRI in vivo and a cell model of oxygen-glucose deprivation/reperfusion (OGD/R) in vitro were established. The results show that AA exerts a protective effect on MIRI by improving cardiac function and reducing cardiomyocyte damage. Due to its antioxidant properties, AA alleviates mitochondrial oxidative stress, as evidenced by the stable mitochondrial structure, maintained mitochondrial membrane potential (MMP), and reduced ROS generation, otherwise due to its antiapoptotic properties. AA inhibits the mitogen-activated protein kinase (MAPK)/mitochondria-dependent apoptosis pathway, as evidenced by the limited phosphorylation of p38-MAPK and JNK-MAPK, balanced proportion of Bcl-2/Bax, reduced cytochrome c release, inhibition of caspase cascade, and reduced apoptosis. In conclusion, our study confirms that AA exerts cardiac-protective effects by regulating ROS-induced oxidative stress via the MAPK/mitochondria-dependent apoptosis pathway; the results provide new evidence that AA may represent a potential treatment for CHD patients.

APPL1 ameliorates myocardial ischemia‑reperfusion injury by regulating the AMPK signaling pathway

Myocardial ischemia-reperfusion injury results in elevated reactive oxygen species (ROS) production and causes oxidative stress damage. Therefore, the current study aimed to investigate whether adaptor protein phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1) could induce the expression of antioxidant enzymes through AMP-activated protein kinase (AMPK) signaling in order to alleviate the injury caused by ischemia/hypoxia-reperfusion. Following induction of hypoxia-reoxygenation (H/R) injury in H9c2 cells, the liver kinase B1 (LKB1)/AMPK/acetyl-CoA carboxylase α (ACC) signaling pathway was investigated using western blot analysis, along with the detection of superoxide dismutase (SOD)2 and SOD3 expression. Additionally, cell viability was detected using a Cell Counting Kit-8 assay and ROS production was analyzed using ROS staining, whereas the expression levels of inflammatory mediators (TNF-α, monocyte chemoattractant protein 1 and IL-1β), apoptosis mediators [cleaved caspase-3, cleaved poly (ADP-ribose) polymerase and Bcl-2] and nuclear factor erythroid 2-related factor 2 signaling pathway-related proteins were detected via western blot analysis following overexpression of APPL1 alone or in combination with compound C treatment (an AMPK inhibitor). The results indicated that H/R induction upregulated the phosphorylation levels of LKB1, AMPK and ACC, and decreased the expression levels of APPL1 and SOD enzyme activities. APPL1 overexpression increased the phosphorylation levels of LKB1, AMPK and ACC, SOD enzyme activity and cell viability whereas the expression levels of proinflammatory mediators and proapoptotic mediators, and the levels of ROS production were markedly decreased when compared with H/R group with empty plasmid transfection. APPL overexpression-mediated effects were significantly abrogated by compound C. Taken together, the data indicated that APPL1 inhibited ROS production and H/R-induced myocardial injury via the AMPK signaling pathway. Therefore, APPL1 may serve as a potential therapeutic target for myocardial H/R injury.

Sinomenine in Cardio-Cerebrovascular Diseases: Potential Therapeutic Effects and Pharmacological Evidences

Cardio-cerebrovascular diseases, as a major cause of health loss all over the world, contribute to an important part of the global burden of disease. A large number of traditional Chinese medicines have been proved effective both clinically and in pharmacological investigations, with the acceleration of the modernization of Chinese medicine. Sinomenine is the main active constituent of sinomenium acutum and has been generally used in therapies of rheumatoid arthritis and neuralgia. Varieties of pharmacological effects of sinomenine in cardio-cerebrovascular system have been discovered recently, suggesting an inspiring application prospect of sinomenine in cardio-cerebrovascular diseases. Sinomenine may retard the progression of atherosclerosis by attenuating endothelial inflammation, regulating immune cells function, and inhibiting the proliferation of vascular smooth muscle cells. Sinomenine also alleviates chronic cardiac allograft rejection relying on its anti-inflammatory and anti-hyperplastic activities and suppresses autoimmune myocarditis by immunosuppression. Prevention of myocardial or cerebral ischemia-reperfusion injury by sinomenine is associated with its modulation of cardiomyocyte death, inflammation, calcium overload, and oxidative stress. The regulatory effects on vasodilation and electrophysiology make sinomenine a promising drug to treat hypertension and arrhythmia. Here, in this review, we will illustrate the pharmacological activities of sinomenine in cardio-cerebrovascular system and elaborate the underlying mechanisms, as well as give an overview of the potential therapeutic roles of sinomenine in cardio-cerebrovascular diseases, trying to provide clues and bases for its clinical usage.

Cyclophilin D Regulates the Nuclear Translocation of AIF, Cardiac Endothelial Cell Necroptosis and Murine Cardiac Transplant Injury

Ischemia-reperfusion injury (IRI) is an inevitable consequence of organ transplant procedure and associated with acute and chronic organ rejection in transplantation. IRI leads to various forms of programmed cell death, which worsens tissue damage and accelerates transplant rejection. We recently demonstrated that necroptosis participates in murine cardiac microvascular endothelial cell (MVEC) death and murine cardiac transplant rejection. However, MVEC death under a more complex IRI model has not been studied. In this study, we found that simulating IRI conditions in vitro by hypoxia, reoxygenation and treatment with inflammatory cytokines induced necroptosis in MVECs. Interestingly, the apoptosis-inducing factor (AIF) translocated to the nucleus during MVEC necroptosis, which is regulated by the mitochondrial permeability molecule cyclophilin D (CypD). Furthermore, CypD deficiency in donor cardiac grafts inhibited AIF translocation and mitigated graft IRI and rejection (n = 7; p = 0.002). Our studies indicate that CypD and AIF play significant roles in MVEC necroptosis and cardiac transplant rejection following IRI. Targeting CypD and its downstream AIF may be a plausible approach to inhibit IRI-caused cardiac damage and improve transplant survival.

Reactive oxygen species-based nanomaterials for the treatment of myocardial ischemia reperfusion injuries

Interventional coronary reperfusion strategies are widely adopted to treat acute myocardial infarction, but morbidity and mortality of acute myocardial infarction are still high. Reperfusion injuries are inevitable due to the generation of reactive oxygen species (ROS) and apoptosis of cardiac muscle cells. However, many antioxidant and anti-inflammatory drugs are largely limited by pharmacokinetics and route of administration, such as short half-life, low stability, low bioavailability, and side effects for treatment myocardial ischemia reperfusion injury. Therefore, it is necessary to develop effective drugs and technologies to address this issue. Fortunately, nanotherapies have demonstrated great opportunities for treating myocardial ischemia reperfusion injury. Compared with traditional drugs, nanodrugs can effectively increase the therapeutic effect and reduces side effects by improving pharmacokinetic and pharmacodynamic properties due to nanodrugs’ size, shape, and material characteristics. In this review, the biology of ROS and molecular mechanisms of myocardial ischemia reperfusion injury are discussed. Furthermore, we summarized the applications of ROS-based nanoparticles, highlighting the latest achievements of nanotechnology researches for the treatment of myocardial ischemia reperfusion injury.

•

Cardiovascular diseases are the leading cause of death worldwide. Researches of the myocardial infarction pathology and development of new treatments have very important scientific significance in the biomedical field.

•

Many nanomaterials have shown amazing therapeutic effects to reduce myocardial damage by eliminating ROS.

•

Nanomaterials effectively reduced myocardial damage through eliminating ROS from NOXs, M-ETC, M-Ca²⁺, M-mPTP, and RIRR.

New Insight Into the Cardioprotective Effects of Allium ursinum L. Extract Against Myocardial Ischemia-Reperfusion Injury

This study aimed to estimate the effects of increasing doses of Allium ursinum methanol extract on cardiac ischemia/reperfusion injury (I/R) with a special emphasis on the role of oxidative stress. Fifty rats were randomly divided into five groups (10 animals per group) depending on the applied treatment as follows: sham, rats who drank only tap water for 28 days and hearts were retrogradely perfused for 80 min without I/R injury, I/R, rats who drank only tap water for 28 days and hearts were exposed to ex vivo I/R injury and rats who consumed increasing doses of A. ursinum 125, 250, and 500 mg/kg for 28 days before I/R injury. Hearts from all rats were isolated and retrogradely perfused according to the Langendorff technique. Parameters of oxidative stress were spectrophotometrically measured in blood, coronary venous effluent, and heart tissue samples. Intake of wild garlic extract for 28 days significantly contributed to the recovery of cardiac function, which was reflected through preserved cardiac contractility, systolic function, and coronary vasodilatory response after ischemia. Also, wild garlic extract showed the potential to modulate the systemic redox balance and stood out as a powerful antioxidant. The highest dose led to the most efficient decrease in cardiac oxidative stress and improve recovery of myocardial function after I/R injury. We might conclude that wild garlic possesses a significant role in cardioprotection and strong antioxidant activity, which implicates the possibility of its use alone in the prevention or as adjuvant antioxidant therapy in cardiovascular diseases (CVD).

Protective Effect of Optic Atrophy 1 on Cardiomyocyte Oxidative Stress: Roles of Mitophagy, Mitochondrial Fission, and MAPK/ERK Signaling

Myocardial infarction is associated with oxidative stress and mitochondrial damage. However, the regulatory mechanisms underlying cardiomyocyte oxidative stress during myocardial infarction are not fully understood. In the present study, we explored the cardioprotective action of optic atrophy 1- (Opa1-) mediated mitochondrial autophagy (mitophagy) in oxidative stress-challenged cardiomyocytes, with a focus on mitochondrial homeostasis and the MAPK/ERK pathway. Our results demonstrated that overexpression of Opa1 in cultured rat H9C2 cardiomyocytes, a procedure that stimulates mitophagy, attenuates oxidative stress and increases cellular antioxidant capacity. Activation of Opa1-mediated mitophagy suppressed cardiomyocyte apoptosis by downregulating Bax, caspase-9, and caspase-12 and upregulating Bcl-2 and c-IAP. Using mitochondrial tracker staining and a reactive oxygen species indicator, our assays showed that Opa1-mediated mitophagy attenuated mitochondrial fission and reduced ROS production in cardiomyocytes. In addition, we found that inhibition of the MAPK/ERK pathway abolished the antioxidant action of Opa1-mediated mitophagy in these cells. Taken together, our data demonstrate that Opa1-mediated mitophagy protects cardiomyocytes against oxidative stress damage through inhibition of mitochondrial fission and activation of MAPK/ERK signaling. These findings reveal a critical role for Opa1 in the modulation of cardiomyocyte redox balance and suggest a potential target for the treatment of myocardial infarction.