Molecular mechanisms of flavonoids in myocardial ischemia reperfusion injury: Evidence from in-vitro and in-vivo studies.

OBJECTIVES: Flavonoids are polyphenolic compounds found in a wide range of foods, including fruits, vegetables, tea plants, and other natural products. They have been mainly classified as flavanols, flavonols, flavones, isoflavones, flavanones, and flavanonols. In this comprehensive review, we will discuss preclinical pieces of evidence on the potential of flavonoids for the prevention/treatment of myocardial ischemia-reperfusion (IR) injury. KEY FINDINGS: In-vitro and in-vivo studies have shown that flavonoids play an important role in preventing ischemic heart disease (IHD). They possess strong anti-oxidant, anti-inflammatory, anti-bacterial, anti-thrombotic, anti-apoptotic, and anti-carcinogenic activities. In addition, at a molecular level, flavonoids also modulate various pathways like MAPK, NFκB etc. to confer beneficial effects. SUMMARY: The current review of flavonoids in myocardial ischemia-reperfusion injury furnishes updated information that could drive future research. The in-vitro and in-vivo experiments have demonstrated various favourable pharmacological properties of flavonoids. This review provides valuable information to conduct clinical studies, validating the safety aspects of flavonoids in the clinical domain.

[Retracted] LncRNA TUG1 serves an important role in hypoxia­induced myocardial cell injury by regulating the miR­145­5p­Binp3 axis.

Following the publication of this article, a concerned reader drew to the Editor's attention that, for several of the figures showing the results of Transwell migration and invasion assay experiments, unexpected areas of similarity were identified in terms of cellular patterns comparing among data panels where the results from differently performed experiments were intended to have been shown, although the areas immediately surrounding these areas often featured comparatively different distributions of cells. Moreover, several of the figures contained invasion/migration assay data that were strikingly similar to data that had appeared in articles published previously by different authors at different research institutes. In addition, the western blots in this article were presented with atypical, unusually shaped and possibly anomalous protein bands in many cases. After having conducted an internal investigation, the Editor of Molecular Medicine Reports has reached the conclusion that the potentially anomalous data in this paper were unlikely to have arisen by coincidence. Therefore, on the grounds of a lack of confidence in the integrity of these data, and given the fact that some of the data were strikingly similar to that which had been published previously in other articles and journals, the Editor has decided that the article should be retracted from the publication. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused, and thanks the concerned reader for drawing this matter to our attention. [Molecular Medicine Reports 42: 2422­2430, 2018; DOI: 10.3892/mmr.2017.8116].

lncRNA Oip5-as1 inhibits excessive mitochondrial fission in myocardial ischemia/reperfusion injury by modulating DRP1 phosphorylation.

BACKGROUND: Aberrant mitochondrial fission, a critical pathological event underlying myocardial ischemia/reperfusion (MI/R) injury, has emerged as a potential therapeutic target. The long non-coding RNA (lncRNA) Oip5-as1 is increasingly recognized for its regulatory roles, particularly in MI/R injury. However, its precise mechanistic role in modulating mitochondrial dynamics remains elusive. This study aims to elucidate the mechanistic role of Oip5-as1 in regulating mitochondrial fission and evaluate its therapeutic potential against MI/R injury. METHODS: To simulate in vitro MI/R injury, HL-1 cardiomyocytes were subjected to hypoxia/reoxygenation (H/R). Lentiviral vectors were employed to achieve overexpression or knockdown of Oip5-as1 in HL-1 cells by expressing Oip5-as1 or shRNA targeting Oip5-as1, respectively. The impact of Oip5-as1 on mitochondrial dynamics in HL-1 cells was assessed using CCK-8 assay, flow cytometry, immunofluorescence staining, and biochemical assays. MI/R injury was induced in mice by ligating the left anterior descending coronary artery. Conditional knockout mice for Oip5-as1 were generated using the CRISPR/Cas9 genome editing technology, while overexpression of Oip5-as1 in mice was achieved via intramyocardial administration of AAV9 vectors. In mice, the role of Oip5-as1 was evaluated through echocardiographic assessment, histopathological staining, and transmission electron microscopy. Furthermore, Western blotting, RNA pull-down, RNA immunoprecipitation, and co-immunoprecipitation assays were conducted to investigate Oip5-as1's underlying mechanisms. RESULTS: The expression levels of Oip5-as1 are significantly decreased in MI/R-injured HL-1 cells and myocardium. In HL-1 cells undergoing H/R injury, overexpression of Oip5-as1 attenuated excessive mitochondrial fission, preserved mitochondrial functionality, and reduced cellular apoptosis, while knockdown of Oip5-as1 exhibited the opposite effects. Furthermore, in a mouse model of MI/R injury, overexpression of Oip5-as1 diminished mitochondrial fission, myocardial infarct size and improved cardiac function. However, knockout of Oip5-as1 exacerbated myocardial injury and cardiac dysfunction, which were significantly reversed by treatment with a mitochondrial division inhibitor-1 (Mdivi-1). Mechanistically, Oip5-as1 selectively interacts with AKAP1 and CaN proteins, inhibiting CaN activation and subsequent DRP1 dephosphorylation at Ser637, thereby constraining DRP1's translocation to the mitochondria and its involvement in mitochondrial fission. CONCLUSIONS: Our study underscores the pivotal role of Oip5-as1 in mitigating excessive mitochondrial fission during MI/R injury. The findings not only enhance our comprehension of the molecular mechanisms underlying MI/R injury but also identify Oip5-as1 as a potential therapeutic target for ameliorating MI/R injury.

Myocardial infarction detection method based on the continuous T-wave area feature and multi-lead-fusion deep features.

OBJECTIVE: Myocardial infarction (MI) is one of the most threatening cardiovascular diseases. This paper aims to explore a method for using an algorithm to autonomously classify myocardial infarction based on the electrocardiogram (ECG). APPROACH: A detection method of MI that fuses continuous T-wave area (C_TWA) feature and ECG deep features is proposed. This method consists of three main parts: (1) The onset of MI is often accompanied by changes in the shape of the T-wave in the ECG, thus the area of the T-wave displayed on different heartbeats will be quite different. The adaptive sliding window method is used to detect the start and end of the T-wave, and calculate the C_TWA on the same ECG record. Additionally, the coefficient of variation (CV) of C_TWA is defined as the C_TWA feature of the ECG. (2) The multi lead fusion convolutional neural network (Multi-lead-fusion CNN) was implemented to extract the deep features of the ECG. (3) The C_TWA feature and deep features of the ECG were fused by soft attention, and then inputted into the multi-layer perceptron to obtain the detection result. RESULTS: According to the interpatient paradigm, the proposed method reached a 97.67% accuracy, 96.59% precision, and 98.96% recall on the PTB dataset, whereas the proposed method reached 93.15% accuracy, 93.20% precision, and 95.14% recall on the clinical dataset. SIGNIFICANCE: The proposed method accurately extracts the feature of the C_TWA, and combines the deep features of the signal, thereby improving the detection accuracy and achieving ideal results on clinical datasets.

DJ-1 preserves ischemic postconditioning-induced cardioprotection in STZ-induced type 1 diabetic rats: role of PTEN and DJ-1 subcellular translocation.

BACKGROUND: Ischemic postconditioning (IPostC) has been reported as a promising method for protecting against myocardial ischemia-reperfusion (MI/R) injury. Our previous study found that the infarct-limiting effect of IPostC is abolished in the heart of diabetes whose cardiac expression of DJ-1 (also called PARK7, Parkinsonism associated deglycase) is reduced. However, the role and in particular the underlying mechanism of DJ-1 in the loss of sensitivity to IPostC-induced cardioprotection in diabetic hearts remains unclear. METHODS: Streptozotocin-induced type 1 diabetic rats were subjected to MI/R injury by occluding the left anterior descending artery (LAD) and followed by reperfusion. IPostC was induced by three cycles of 10s of reperfusion and ischemia at the onset of reperfusion. AAV9-CMV-DJ-1, AAV9-CMV-C106S-DJ-1 or AAV9-DJ-1 siRNA were injected via tail vein to either over-express or knock-down DJ-1 three weeks before inducing MI/R. RESULTS: Diabetic rats subjected to MI/R exhibited larger infarct area, more severe oxidative injury concomitant with significantly reduced cardiac DJ-1 expression and increased PTEN expression as compared to non-diabetic rats. AAV9-mediated cardiac DJ-1 overexpression, but not the cardiac overexpression of DJ-1 mutant C106S, restored IPostC-induced cardioprotection and this effect was accompanied by increased cytoplasmic DJ-1 translocation toward nuclear and mitochondrial, reduced PTEN expression, and increased Nrf-2/HO-1 transcription. Our further study showed that AAV9-mediated targeted DJ-1 gene knockdown aggravated MI/R injury in diabetic hearts, and this exacerbation of MI/R injury was partially reversed by IPostC in the presence of PTEN inhibition or Nrf-2 activation. CONCLUSIONS: These findings suggest that DJ-1 preserves the cardioprotective effect of IPostC against MI/R injury in diabetic rats through nuclear and mitochondrial DJ-1 translocation and that inhibition of cardiac PTEN and activation of Nrf-2/HO-1 may represent the major downstream mechanisms whereby DJ-1 preserves the cardioprotective effect of IPostC in diabetes.

Panax quinquefolius saponins and panax notoginseng saponins attenuate myocardial hypoxia-reoxygenation injury by reducing excessive mitophagy.

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

Nicotinamide riboside attenuates myocardial ischemia-reperfusion injury via regulating SIRT3/SOD2 signaling pathway.

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.

Myocardial ischemia-reperfusion injury released cellular fibronectin containing domain A (CFN-EDA): A destructive positive loop amplifying arterial thrombosis formation and exacerbating myocardial reperfusion injury.

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

The activation of P38MAPK Signaling Pathway Impedes the Delivery of the Cx43 to the Intercalated Discs During Cardiac Ischemia-Reperfusion Injury.

Ischemic heart disease is caused by coronary artery occlusion. Despite the increasing number and success of interventions for restoring coronary artery perfusion, myocardial ischemia-reperfusion (I/R) injury remains a significant cause of morbidity and mortality worldwide. Inspired by the impact of I/R on the Cx43 trafficking to the intercalated discs (ICDs), we aim to explore the potential mechanisms underlying the downregulation of Cx43 in ICDs after myocardial I/R. Gene set enrichment analysis (GSEA), Western blotting, and immunofluorescence experiments showed that Myocardial I/R activated the P38MAPK signaling pathway and promoted microtubule depolymerization. Inhibition of P38MAPK signaling pathway activation attenuated I/R-induced microtubule depolymerization. The ability of SB203580 to recover the distribution of Cx43 and electrophysiological parameters in I/R myocardium depended on microtubule stability. Our study suggests that microtubule depolymerization caused by the activation of the P38MAPK signaling pathway is an important mechanism underlying the downregulation of Cx43 in ICDs after myocardial I/R.

Mitochondria-associated endoplasmic reticulum membranes as a therapeutic target for cardiovascular diseases.

Cardiovascular diseases (CVDs) are currently the leading cause of death worldwide. In 2022, the CVDs contributed to 19.8 million deaths globally, accounting for one-third of all global deaths. With an aging population and changing lifestyles, CVDs pose a major threat to human health. Mitochondria-associated endoplasmic reticulum membranes (MAMs) are communication platforms between cellular organelles and regulate cellular physiological functions, including apoptosis, autophagy, and programmed necrosis. Further research has shown that MAMs play a critical role in the pathogenesis of CVDs, including myocardial ischemia and reperfusion injury, heart failure, pulmonary hypertension, and coronary atherosclerosis. This suggests that MAMs could be an important therapeutic target for managing CVDs. The goal of this study is to summarize the protein complex of MAMs, discuss its role in the pathological mechanisms of CVDs in terms of its functions such as Ca2+ transport, apoptotic signaling, and lipid metabolism, and suggest the possibility of MAMs as a potential therapeutic approach.

A Membrane-Targeting Aggregation-Induced Emission Probe for Monitoring Lipid Droplet Dynamics in Ischemia/Reperfusion-Induced Cardiomyocyte Ferroptosis.

Myocardial ischemia/reperfusion injury (MIRI) is the leading cause of irreversible myocardial damage. A pivotal pathogenic factor is ischemia/reperfusion (I/R)-induced cardiomyocyte ferroptosis, marked by iron overload and lipid peroxidation. However, the impact of lipid droplet (LD) changes on I/R-induced cardiomyocyte ferroptosis is unclear. In this study, an aggregation-induced emission probe, TPABTBP is developed that is used for imaging dynamic changes in LD during myocardial I/R-induced ferroptosis. TPABTBP exhibits excellent LD-specificity, superior capability for monitoring lipophagy, and remarkable photostability. Molecular dynamics (MD) simulation and super-resolution fluorescence imaging demonstrate that the TPABTBP is specifically localized to the phospholipid monolayer membrane of LDs. Imaging LDs in cardiomyocytes and myocardial tissue in model mice with MIRI reveals that the LD accumulation level increase in the early reperfusion stage (0-9 h) but decrease in the late reperfusion stage (>24 h) via lipophagy. The inhibition of LD breakdown significantly reduces the lipid peroxidation level in cardiomyocytes. Furthermore, it is demonstrated that chloroquine (CQ), an FDA-approved autophagy modulator, can inhibit ferroptosis, thereby attenuating MIRI in mice. This study describes the dynamic changes in LD during myocardial ischemia injury and suggests a potential therapeutic target for early MIRI intervention.

Challenging situation of coronary artery anomaly associated with ischemia and/or risk of sudden death.

Coronary artery anomaly is known as one of the causes of angina pectoris and sudden death and is an important clinical entity that cannot be overlooked. The incidence of coronary artery anomalies is as low as 1%-2% of the general population, even when the various types are combined. Coronary anomalies are practically challenging when the left and right coronary ostium are not found around their normal positions during coronary angiography with a catheter. If there is atherosclerotic stenosis of the coronary artery with an anomaly and percutaneous coronary intervention (PCI) is required, the suitability of the guiding catheter at the entrance and the adequate back up force of the guiding catheter are issues. The level of PCI risk itself should also be considered on a case-by-case basis. In this case, emission computed tomography in the R-1 subtype single coronary artery proved that ischemia occurred in an area where the coronary artery was not visible to the naked eye. Meticulous follow-up would be crucial, because sudden death may occur in single coronary arteries. To prevent atherosclerosis with full efforts is also important, as the authors indicated admirably.

Metabolomics analysis reveals the effects of Salvia Miltiorrhiza Bunge extract on ameliorating acute myocardial ischemia in rats induced by isoproterenol.

Salvia miltiorrhiza Bunge (SM) is a widespread herbal therapy for myocardial ischemia (MI). Nevertheless, the therapeutic signaling networks of SM extract on MI is yet unknown. Emerging evidences suggested that alterations in cardiac metabolite influences host metabolism and accelerates MI progression. Herein, we employed an isoproterenol (ISO)-induced acute myocardial ischemia (AMI) rat model to confirm the pharmacological effects of SM extract (0.8, 0.9, 1.8 g/kg/day) via assessment of the histopathological alterations that occur within the heart tissue and associated cytokines; we also examined the underlying SM extract-mediated signaling networks using untargeted metabolomics. The results indicated that 25 compounds with a relative content higher than 1 % in SM aqueous extract were identified using LC-MS/MS analysis, which included salvianolic acid B, lithospermic acid, salvianolic acid A, and caffeic acid as main components. An in vivo experiment showed that pretreatment with SM extract attenuated ISO-induced myocardial injury, shown as decreased myocardial ischemic size, transformed electrocardiographic, histopathological, and serum biochemical aberrations, reduced levels of proinflammatory cytokines, inhibited oxidative stress (OS), and reversed the trepidations of the cardiac tissue metabolic profiles. Metabolomics analysis shows that the levels of 24 differential metabolites (DMs) approached the same value as controls after SM extract therapy, which were primarily involved in histidine; alanine, aspartate, and glutamate; glycerophospholipid; and glycine, serine, and threonine metabolisms through metabolic pathway analysis. Correlation analysis demonstrated that the levels of modulatory effects of SM extract on the inflammation and OS were related to alterations in endogenous metabolites. Overall, SM extract demonstrated significant cardioprotective effects in an ISO-induced AMI rat model, alleviating myocardial injury, inflammation and oxidative stress, with metabolomics analysis indicating potential therapeutic pathways for myocardial ischemia.

PM2.5 toxicity in blood impairs cardiac redox balance and promotes mitochondrial dysfunction in rat heart that further aggravates ischemia reperfusion injury by modulating PI3K/AKT/mTOR/NF-kB signaling axis.

According to the pathophysiological mechanisms linking particulate matter (PM2.5) exposure and cardiovascular diseases, PM2.5 may directly translocate into the blood stream and remote target organs and thereby induce cardiovascular effects. The toxicity of PM2.5 is known to induce oxidative stress in pulmonary tissue, but its impact on the redox state in heart (distant organ) is unknown and how it modulates the cardiac response to ischemia reperfusion (IR) remains unclear. In the present study, we evaluated the toxic effect of PM2.5 on cardiac physiology in the presence and absence of IR after introducing PM2.5 into the blood. Female Wistar rats were injected with diesel particulate matter (DPM) via i.p & i.v routes at a concentration of 10 µg/ml. The toxic impact of PM2.5 not only adversely affects the cardiac ultra-structure (leading to nuclear infiltration, edema, irregularities in heart muscle and nuclear infiltration), but also altered the cellular redox balance, elevated inflammation and promoted the upregulation of proapoptotic mediator genes at the basal level of myocardium. The results showed alterations in cardiac ultrastructure, elevated oxidative stress and significant redox imbalance, increased inflammation and proapoptotic mediators at the basal level of myocardium. Moreover, the cardioprotective pro survival signaling axis was declined along with an increased NF-kB activation at the basal level. IR inflicted further injury with deterioration of cardiac hemodynamic indices (Heart rate [HR], Left ventricular developed pressure [LVDP], Left ventricular end-diastolic pressure [LVEDP] and rate pressure product [RPP]) along with prominent inactivation of signaling pathways. Furthermore, the levels of GSH/GSSG, NADH/NAD, NADPH/NADP were significantly low along with increased lipid peroxidation in mitochondria of PM2.5 treated IR rat hearts. This observation was supported by downregulation of glutaredoxin and peroxiredoxin genes in the myocardium. Similarly the presence of oxidative stress inducing metals was found at a higher concentration in cardiac mitochondria. Thus, the toxic impact of PM2.5 in heart augment the IR associated pathological changes by altering the physiological response, initiating cellular metabolic alterations in mitochondria and modifying the signaling molecules.

Potential Targets of Natural Products for Improving Cardiac Ischemic Injury: The Role of Nrf2 Signaling Transduction.

Myocardial ischemia is the leading cause of health loss from cardiovascular disease worldwide. Myocardial ischemia and hypoxia during exercise trigger the risk of sudden exercise death which, in severe cases, will further lead to myocardial infarction. The Nrf2 transcription factor is an important antioxidant regulator that is extensively engaged in biological processes such as oxidative stress, inflammatory response, apoptosis, and mitochondrial malfunction. It has a significant role in the prevention and treatment of several cardiovascular illnesses, since it can control not only the expression of several antioxidant genes, but also the target genes of associated pathological processes. Therefore, targeting Nrf2 will have great potential in the treatment of myocardial ischemic injury. Natural products are widely used to treat myocardial ischemic diseases because of their few side effects. A large number of studies have shown that the Nrf2 transcription factor can be used as an important way for natural products to alleviate myocardial ischemia. However, the specific role and related mechanism of Nrf2 in mediating natural products in the treatment of myocardial ischemia is still unclear. Therefore, this review combs the key role and possible mechanism of Nrf2 in myocardial ischemic injury, and emphatically summarizes the significant role of natural products in treating myocardial ischemic symptoms, thus providing a broad foundation for clinical transformation.

Evaluation of fractional flow reserve and atherosclerotic plaque characteristics on coronary non-contrast T1-weighted magnetic resonance imaging.

BACKGROUND AND AIMS: The relationship between high-risk coronary plaque characteristics regardless of the severity of lesion stenosis and myocardial ischemia remains unsettled. High-intensity plaques (HIPs) on non-contrast T1-weighted magnetic resonance imaging (T1WI) have been characterized as high-risk coronary plaques. We sought to elucidate whether the presence of coronary HIPs on T1WI influences fractional flow reserve (FFR) in the distal segment of the vessel. METHODS: We retrospectively analyzed 281 vessels in 231 patients with chronic coronary syndrome who underwent invasive FFR measurement and coronary T1WI using a multicenter registry. The plaque-to-myocardial signal intensity ratio (PMR) of the most stenotic lesion was evaluated; a coronary plaque with PMR ≥1.4 was defined as a HIP. RESULTS: The median PMR of coronary plaques on T1WI in vessels with FFR ≤0.80 was significantly higher than that of plaques with FFR >0.80 (1.17 [interquartile range (IQR): 0.99-1.44] vs. 0.97 [IQR: 0.85-1.09]; p < 0.001). Multivariable analysis showed that an increase in PMR of the most stenotic segment was associated with lower FFR (beta-coefficient, -0.050; p < 0.001). The presence of coronary HIPs was an independent predictor of FFR ≤0.80 (odds ratio (OR), 6.18; 95% confidence interval (CI), 1.93-19.77; p = 0.002). Even after adjusting for plaque composition characteristics based on computed tomography angiography, the presence of coronary HIPs was an independent predictor of FFR ≤0.80 (OR, 4.48; 95% CI, 1.19-16.80; p = 0.026). CONCLUSIONS: Coronary plaques with high PMR are associated with low FFR in the corresponding vessel, indicating that plaque morphology might influence myocardial ischemia severity.

Mitigation of myocardial ischemia/reperfusion-induced chronic heart failure via Shexiang Baoxin Pill-mediated regulation of the S1PR1 signaling pathway.

BACKGROUND: Well-defined and effective pharmacological interventions for clinical management of myocardial ischemia/reperfusion (MI/R) injury are currently unavailable. Shexiang Baoxin Pill (SBP), a traditional Chinese medicine Previous research on SBP has been confined to single-target treatments for MI/R injury, lacking a comprehensive examination of various aspects of MI/R injury and a thorough exploration of its underlying mechanisms. PURPOSE: This study aimed to investigate the therapeutic potential of SBP for MI/R injury and its preventive effects on consequent chronic heart failure (CHF). Furthermore, we elucidated the specific mechanisms involved, contributing valuable insights into the potential pharmacological interventions for the clinical treatment of MI/R injury. METHODS: We conducted a comprehensive identification of SBP components using high-performance liquid chromatography. Subsequently, we performed a network pharmacology analysis based on the identification results, elucidating the key genes influenced by SBP. Thereafter, through bioinformatics analysis of the key genes and validation through mRNA and protein assays, we ultimately determined the centralized upstream targets. Lastly, we conducted in vitro experiments using myocardial and endothelial cells to elucidate and validate potential underlying mechanisms. RESULTS: SBP can effectively mitigate cell apoptosis, oxidative stress, and inflammation, as well as promote vascular regeneration following MI/R, resulting in improved cardiac function and reduced CHF risk. Mechanistically, SBP treatment upregulates sphingosine-1-phosphate receptor 1 (S1PR1) expression and activates the S1PR1 signaling pathway, thereby regulating the expression of key molecules, including phosphorylated Protein Kinase B (AKT), phosphorylated signal transducer and activator of transcription 3, epidermal growth factor receptor, vascular endothelial growth factor A, tumor necrosis factor-α, and p53. CONCLUSION: This study elucidated the protective role of SBP in MI/R injury and its potential to reduce the risk of CHF. Furthermore, by integrating downstream effector proteins affected by SBP, this research identified the upstream effector protein S1PR1, enhancing our understanding of the pharmacological characteristics and mechanisms of action of SBP. The significance of this study lies in providing compelling evidence for the use of SBP as a traditional Chinese medicine for MI/R injury and consequent CHF prevention.

In Vivo Mapping of Myocardial Injury Outside the Infarct Zone: Tissue at an Intermediate Pathological State.

BACKGROUND: The goal was to determine the feasibility of mapping the injured-but-not-infarcted myocardium using 99mTc-duramycin in the postischemic heart, with spatial information for its characterization as a pathophysiologically intermediate tissue, which is neither normal nor infarcted. METHODS AND RESULTS: Coronary occlusion was conducted in Sprague Dawley rats with preconditioning and 30-minute ligation. In vivo single-photon emission computed tomography was acquired after 3 hours (n=6) using 99mTc-duramycin, a phosphatidylethanolamine-specific radiopharmaceutical. The 99mTc-duramycin+ areas were compared with infarct and area-at-risk (n=8). Cardiomyocytes and endothelial cells were isolated for gene expression profiling. Cardiac function was measured with echocardiography (n=6) at 4 weeks. In vivo imaging with 99mTc-duramycin identified the infarct (3.9±2.4% of the left ventricle and an extensive area 23.7±2.2% of the left ventricle) with diffuse signal outside the infarct, which is pathologically between normal and infarcted (apoptosis 1.8±1.6, 8.9±4.2, 13.6±3.8%; VCAM-1 [vascular cell adhesion molecule 1] 3.2±0.8, 9.8±4.1, 15.9±4.2/mm2; tyrosine hydroxylase 14.9±2.8, 8.6±4.4, 5.6±2.2/mm2), with heterogeneous changes including scattered micronecrosis, wavy myofibrils, hydropic change, and glycogen accumulation. The 99mTc-duramycin+ tissue is quantitatively smaller than the area-at-risk (26.7% versus 34.4% of the left ventricle, P=0.008). Compared with infarct, gene expression in the 99mTc-duramycin+-noninfarct tissue indicated a greater prosurvival ratio (BCL2/BAX [B-cell lymphoma 2/BCL2-associated X] 7.8 versus 5.7 [cardiomyocytes], 3.7 versus 3.2 [endothelial]), and an upregulation of ion channels in electrophysiology. There was decreased contractility at 4 weeks (regional fractional shortening -8.6%, P<0.05; circumferential strain -52.9%, P<0.05). CONCLUSIONS: The injured-but-not-infarcted tissue, being an intermediate zone between normal and infarct, is mapped in vivo using phosphatidylethanolamine-based imaging. The intermediate zone contributes significantly to cardiac dysfunction.

The pathological mechanisms and potential therapeutic drugs for myocardial ischemia reperfusion injury.

BACKGROUND: Cardiovascular disease is the main cause of death and disability, with myocardial ischemia being the predominant type that poses a significant threat to humans. Reperfusion, an essential therapeutic approach, promptly reinstates blood circulation to the ischemic myocardium and stands as the most efficacious clinical method for myocardial preservation. Nevertheless, the restoration of blood flow associated with this process can potentially induce myocardial ischemia-reperfusion injury (MIRI), thereby diminishing the effectiveness of reperfusion and impacting patient prognosis. Therefore, it is of great significance to prevent and treat MIRI. PURPOSE: MIRI is an important factor affecting the prognosis of patients, and there is no specific in-clinic treatment plan. In this review, we have endeavored to summarize its pathological mechanisms and therapeutic drugs to provide more powerful evidence for clinical application. METHODS: A comprehensive literature review was conducted using PubMed, Web of Science, Embase, Medline and Google Scholar with a core focus on the pathological mechanisms and potential therapeutic drugs of MIRI. RESULTS: Accumulated evidence revealed that oxidative stress, calcium overload, mitochondrial dysfunction, energy metabolism disorder, ferroptosis, inflammatory reaction, endoplasmic reticulum stress, pyroptosis and autophagy regulation have been shown to participate in the process, and that the occurrence and development of MIRI are related to plenty of signaling pathways. Currently, a range of chemical drugs, natural products, and traditional Chinese medicine (TCM) preparations have demonstrated the ability to mitigate MIRI by targeting various mechanisms. CONCLUSIONS: At present, most of the research focuses on animal and cell experiments, and the regulatory mechanisms of each signaling pathway are still unclear. The translation of experimental findings into clinical practice remains incomplete, necessitating further exploration through large-scale, multi-center randomized controlled trials. Given the absence of a specific drug for MIRI, the identification of therapeutic agents to reduce myocardial ischemia is of utmost significance. For the future, it is imperative to enhance our understanding of the pathological mechanism underlying MIRI, continuously investigate and develop novel pharmaceutical agents, expedite the clinical translation of these drugs, and foster innovative approaches that integrate TCM with Western medicine. These efforts will facilitate the emergence of fresh perspectives for the clinical management of MIRI.

[Mechanism of Guizhi Gancao Decoction against myocardial ischemia-reperfusion injury based on network pharmacology and experimental verification].

This study employed network pharmacology to investigate the effect of Guizhi Gancao Decoction(GGD) on myocardial ischemia-reperfusion injury(MI/RI) in rats and decipher the underlying mechanism. Firstly, the chemical components and targets of GGD against MI/RI were searched against the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), SwissTargetPrediction, and available articles. STRING and Cytoscape 3.7.2 were used to establish the protein-protein interaction(PPI) network for the common targets, and then Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses were carried out for the core targets. The "drug-active component-target-pathway" network was built. Furthermore, molecular docking between key active components and targets was conducted in AutoDock Vina. Finally, the rat model of MI/RI was established, and the myocardial infarction area was measured. Hematoxylin-eosin(HE) staining and transmission electron microscopy(TEM) were employed to detect cardiomyocyte pathology and ultrastructural changes. Western blot was employed to determine the expression of related proteins in the myocardial tissue. A total of 75 chemical components of GGD were screened out, corresponding to 318 targets. The PPI network revealed 46 core targets such as tumor protein p53(TP53), serine/threonine kinase 1(AKT1), signal transducer and activator of transcription 3(STAT3), non-receptor tyrosine kinase(SRC), mitogen-activated protein kinase 1(MAPK1), MAPK3, and tumor necrosis factor(TNF). According to GO and KEGG enrichment analyses, the core targets mainly affected the cell proliferation and migration, signal transduction, apoptosis, and transcription, involving advanced glycation end products-receptor(AGE-RAGE), MAPK and other signaling pathways in cancers and diabetes complications. The molecular docking results showed that the core components of GGD, such as licochalcone A,(+)-catechin, and cinnamaldehyde, had strong binding activities with the core target proteins, such as MAPK1 and MAPK3. The results of animal experiments showed that compared with the model group, GGD significantly increase superoxide dismutase, decreased malondialdehyde, lactate dehydrogenase, and creatine kinase-MB, and reduced the area of myocardial infarction. HE staining and TEM results showed that GGD pretreatment restored the structure of cardiomyocytes and alleviated the pathological changes and ultrastructural damage of mitochondria in the model group. In addition, GGD significantly down-regulated the phosphorylation of c-Jun N-terminal kinase and p38 and up-regulate that of extracellular regulated kinases 1/2 in the myocardial tissue. The results suggested that GGD may exert the anti-MI/RI effect by regulating the MAPK signaling pathway via the synergistic effects of Cinnamomi Ramulus and Glycyrrhizae Radix et Rhizoma.