The Role of Oxidative Stress in Myocardial Ischemia and Reperfusion Injury and Remodeling: Revisited

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.

Protein-Like Polymers Targeting Keap1/Nrf2 as Therapeutics for Myocardial Infarction

Myocardial infarction (MI) results in oxidative stress to the myocardium and frequently leads to heart failure (HF). There is an unmet clinical need to develop therapeutics that address the inflammatory stress response and prevent negative left ventricular remodeling. Here, the Keap1/Nrf2 protein-protein interaction is specifically targeted, as Nrf2 activation is known to mitigate the inflammatory response following MI. This is achieved using a Nrf2-mimetic protein-like polymer (PLP) to inhibit the Keap1-Nrf2 interaction. The PLP platform technology provides stability in vivo, potent intracellular bioactivity, and multivalency leading to high avidity Keap1 binding. In vitro and in vivo assays to probe cellular activity and MI therapeutic utility are employed. These Keap1-inhibiting PLPs (Keap1i-PLPs) impart cytoprotection from oxidative stress via Nrf2 activation at sub-nanomolar concentrations in primary cardiomyocytes. Single-digit mg kg-1, single-dose, intravenous PLP administration significantly improves cardiac function in rats post-MI through immunomodulatory, anti-apoptotic, and angiogenic mechanisms. Thus Keap1i-PLPs disrupt key intracellular protein-protein interactions following intravenous, systemic administration in vivo. These results have broad implications not only for MI but also for other oxidative stress-driven diseases and conditions.

Adhesion-Assisted Antioxidant-Engineered Mesenchymal Stromal Cells for Enhanced Cardiac Repair in Myocardial Infarction

Mesenchymal stromal cell (MSC) therapy holds great promise for treating myocardial infarction (MI). However, the inflammatory and reactive oxygen species (ROS)-rich environment in infarcted myocardium challenges MSC survival, limiting its therapeutic impact. In this study, we demonstrate that chemical modification of MSCs with anti-VCAM1 and polydopamine (PD) significantly enhances MSC survival and promotes cardiac repair. Anti-VCAM1 modification facilitates MSC adhesion to inflamed tissue, ensuring MSC retention in the injured myocardium, while PD scavenges ROS surrounding MSCs, creating a conducive environment for cell transplantation. Our data indicate that chemically engineered MSCs effectively disrupt the inflammation-ROS cycle and modulate inflammation-related immune responses, thus improving MI microenvironments. Single-cell RNA sequencing of rat hearts reveals that treatment with engineered MSCs inhibits cardiac fibrosis by suppressing HB-EGF-EGFR signaling between anti-inflammatory macrophages and activated fibrillates. Ultimately, engineered MSCs demonstrate superior therapeutic efficacy in a rat model of MI. This study presents a straightforward, safe, and efficient chemical method for enhancing MSC therapy.

Involvement of Oxidative Stress and Antioxidants in Modification of Cardiac Dysfunction Due to Ischemia-Reperfusion Injury

Delayed reperfusion of the ischemic heart (I/R) is known to impair the recovery of cardiac function and produce a wide variety of myocardial defects, including ultrastructural damage, metabolic alterations, subcellular Ca2+-handling abnormalities, activation of proteases, and changes in cardiac gene expression. Although I/R injury has been reported to induce the formation of reactive oxygen species (ROS), inflammation, and intracellular Ca2+ overload, the generation of oxidative stress is considered to play a critical role in the development of cardiac dysfunction. Increases in the production of superoxide, hydroxyl radicals, and oxidants, such as hydrogen peroxide and hypochlorous acid, occur in hearts subjected to I/R injury. In fact, mitochondria are a major source of the excessive production of ROS in I/R hearts due to impairment in the electron transport system as well as activation of xanthine oxidase and NADPH oxidase. Nitric oxide synthase, mainly present in the endothelium, is also activated due to I/R injury, leading to the production of nitric oxide, which, upon combination with superoxide radicals, generates nitrosative stress. Alterations in cardiac function, sarcolemma, sarcoplasmic reticulum Ca2+-handling activities, mitochondrial oxidative phosphorylation, and protease activation due to I/R injury are simulated upon exposing the heart to the oxyradical-generating system (xanthine plus xanthine oxidase) or H2O2. On the other hand, the activation of endogenous antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, and the concentration of a transcription factor (Nrf2), which modulates the expression of various endogenous antioxidants, is depressed due to I/R injury in hearts. Furthermore, pretreatment of hearts with antioxidants such as catalase plus superoxide dismutase, N-acetylcysteine, and mercaptopropionylglycerine has been observed to attenuate I/R-induced subcellular Ca2+ handling and changes in Ca2+-regulatory activities; additionally, it has been found to depress protease activation and improve the recovery of cardiac function. These observations indicate that oxidative stress is intimately involved in the pathological effects of I/R injury and different antioxidants attenuate I/R-induced subcellular alterations and improve the recovery of cardiac function. Thus, we are faced with the task of developing safe and effective antioxidants as well as agents for upregulating the expression of endogenous antioxidants for the therapy of I/R injury.

Carbidopa and ZnCarbidopa Induce Reductive Stress in MDA-MB-231 Cells

The redox imbalance, caused by depletion or generation of reactive oxygen species (ROS), is a key mechanism by which metal complexes exert anticancer effects. Carbidopa has shown the ability to inhibit the MDA-MB-231 cell line, a highly aggressive triple-negative human breast adenocarcinoma, by inducing reductive stress. The metal complex of carbidopa with zinc (ZnCarbi) was designed to modify carbidopa's structure and exhibited increased cytotoxicity against MDA-MB-231 cells. Interestingly, ZnCarbi selectively targets certain cancer cells, showing no impact on the viability of normal HEK293 (human embryonic kidney) cells or other cancer cell lines like A549 (human lung adenocarcinoma), LM3 (murine breast adenocarcinoma), or HCT116 (human colon cancer). Treatment with carbidopa and ZnCarbi induces reductive stress, decreases ROS levels, increases the GSH/GSSG ratio, and protects cells from H2O2-induced death. Both compounds also cause mitochondrial damage, leading to cell death, and exhibit antimetastatic effects by inhibiting cell migration and invasion of MDA-MB-231 cells. Interaction studies with bovine serum albumin showed moderate binding through hydrophobic association. Overall, ZnCarbi demonstrates enhanced anticancer properties compared to carbidopa alone, highlighting its potential as an anticancer and antimetastatic compound.

Anti-Inflammatory and Antioxidant Effects of White Grape Pomace Polyphenols on Isoproterenol-Induced Myocardial Infarction

Grape pomace (GP), the residue left after grape pressing in winemaking, is rich in polyphenols, including flavonoids, tannins, and phenolic acids, which have antioxidant and anti-inflammatory properties. The present study aimed to evaluate the cardioprotective effects of white grape pomace (WGP) extract in two concentrations rich in polyphenols (795 mg polyphenols from WGP/kg body weight (bw) and 397.5 mg polyphenols from WGP/kg bw)), on isoproterenol (ISO)-induced myocardial infarction (MI), focusing on its anti-inflammatory and antioxidant effects. White grape pomace administration for 14 days offered a cardio-protective effect and prevented prolongation of the QT and QTc intervals on the electrocardiogram. Both concentrations of WGP prevented the elevation of nitric oxide (NO) and malondialdehyde (MDA) in the serum, with the best results being observed for the highest concentration (p < 0.05). White grape pomace administration offered a reduction in pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β) in both serum and tissue in a dose-dependent manner, with the highest WGP concentration having the best effect (p < 0.05). Moreover, WGP reduced histological changes associated with MI. The findings of the present study demonstrate that WGP extract exerts cardio protective effects by reducing MI-associated inflammation and oxidative stress.

Mapping the knowledge of omics in myocardial infarction: A scientometric analysis in R Studio, VOSviewer, Citespace, and SciMAT

Many researchers nowadays choose multi-omics techniques for myocardial infarction studies. However, there's yet to be a review article integrating myocardial infarction multi-omics. Hence, this study adopts the popular bibliometrics. Based on its principles, we use software like R Studio, Vosviewer, Citespace, and SciMAT to analyze literature data of myocardial infarction omics research (1991-2022) from Web of Science. By extracting key information and calculating weights, we conduct analyses from 4 aspects: Collaboration Network Analysis, Co-word Analysis, Citing and Cited Journal Analysis, and Co-citation and Clustering Analysis, aiming to understand the field's cooperation, research topic evolution, and knowledge flow. The results show that myocardial infarction omics research is still in its early stage with limited international cooperation. In terms of knowledge flow, there's no significant difference within the discipline, but non-biomedical disciplines have joined, indicating an interdisciplinary integration trend. In the overall research field, genomics remains the main topic with many breakthroughs identifying susceptibility sites. Meanwhile, other omics fields like lipidomics and proteomics are also progressing, clarifying the pathogenesis. The cooperation details in this article enable researchers to connect with others, facilitating their research. The evolution trend of subject terms helps them set goals and directions, quickly grasp the development context, and read relevant literature. Journal analysis offers submission suggestions, and the analysis of research base and frontier provides references for the research's future development.

Small Molecules Targeting Mitochondria: A Mechanistic Approach to Combating Doxorubicin-Induced Cardiotoxicity

Doxorubicin (Dox) is a commonly used chemotherapy drug effective against a range of cancers, but its clinical application is greatly limited by dose-dependent and cumulative cardiotoxicity. Mitochondrial dysfunction is recognized as a key factor in Dox-induced cardiotoxicity, leading to oxidative stress, disrupted calcium balance, and activation of apoptotic pathways. Recent research has emphasized the potential of small molecules that specifically target mitochondria to alleviate these harmful effects. This review provides a comprehensive analysis of small molecules that offer cardioprotection by preserving mitochondrial function in the context of doxorubicin-induced cardiotoxicity (DIC). The mechanisms of action include the reduction of reactive oxygen species (ROS) production, stabilization of mitochondrial membrane potential, enhancement of mitochondrial biogenesis, and modulation of key signaling pathways involved in cell survival and apoptosis. By targeting mitochondria, these small molecules present a promising therapeutic strategy to prevent or reduce the cardiotoxic effects associated with Dox treatment. This review not only discusses the mechanistic actions of these agents but also emphasizes their potential in improving cardiovascular outcomes for cancer patients. Gaining insight into these mechanisms can help in creating more effective strategies to safeguard the heart during chemotherapy, allowing for the ongoing use of Dox with a lower risk to the patient's cardiovascular health. This review highlights the critical role of mitochondria-targeted therapies as a promising approach in addressing DIC.

Insight into the cardioprotective effects of melatonin: shining a spotlight on intercellular Sirt signaling communication

Cardiovascular diseases (CVDs) are the leading causes of death and illness worldwide. While there have been advancements in the treatment of CVDs using medication and medical procedures, these conventional methods have limited effectiveness in halting the progression of heart diseases to complete heart failure. However, in recent years, the hormone melatonin has shown promise as a protective agent for the heart. Melatonin, which is secreted by the pineal gland and regulates our sleep-wake cycle, plays a role in various biological processes including oxidative stress, mitochondrial function, and cell death. The Sirtuin (Sirt) family of proteins has gained attention for their involvement in many cellular functions related to heart health. It has been well established that melatonin activates the Sirt signaling pathways, leading to several beneficial effects on the heart. These include preserving mitochondrial function, reducing oxidative stress, decreasing inflammation, preventing cell death, and regulating autophagy in cardiac cells. Therefore, melatonin could play crucial roles in ameliorating various cardiovascular pathologies, such as sepsis, drug toxicity-induced myocardial injury, myocardial ischemia-reperfusion injury, hypertension, heart failure, and diabetic cardiomyopathy. These effects may be partly attributed to the modulation of different Sirt family members by melatonin. This review summarizes the existing body of literature highlighting the cardioprotective effects of melatonin, specifically the ones including modulation of Sirt signaling pathways. Also, we discuss the potential use of melatonin-Sirt interactions as a forthcoming therapeutic target for managing and preventing CVDs.

Impaired hemodynamic forces assessed by routine CMR and its determinants in different duration T2DM patients with normal LV function and myocardial strain

Background

Early detection of subclinical myocardial dysfunction in asymptomatic patients with type 2 diabetes mellitus (T2DM) is essential before overt changes in left ventricular ejection fraction (LVEF) and myocardial strain occur. The objective of this study is to quantitatively assess hemodynamic forces (HDFs) using a rigorous mathematical model based on conventional cine cardiac magnetic resonance (CMR) images in patients with T2DM, and investigate their correlation with late gadolinium enhancement (LGE) and duration of diabetes.

Methods

We recruited 63 T2DM patients and 50 healthy volunteers to undergo contrast-enhanced CMR examinations. T2DM patients were divided into three groups according to the course of disease: early, middle and later stage (time <5 years, 5 ≤ time <10 years, time ≥10 years, respectively). LV deformation parameters, global circumferential strain (LVGCS), radial strain (LVGRS), longitudinal strain (LVGLS) and HDFs parameters such as longitudinal (apical-basal/A-B), transversal (lateral-septal/L-S) HDF strength (RMS) were measured and compared among the three groups.

Results

Compared with healthy volunteers, no significant differences in LV function and strains were observed (P > 0.05), while HDF Strength (RMS) L-S (%) were significantly higher in T2DM patients (p < 0.001). LVGLS was significantly decreased in late T2DM patients (p < 0.05), but HDF Strength (RMS) L-S (%) was significantly increased compared with early T2DM patients. Both HDF Strength (RMS) L-S (%) and HDF Strength (RMS) A-B (%) value were independently related to the extent of LGE (β = 0.435, p = 0.001; β = -0.329, p = 0.006, respectively). In addition, HDF Strength (RMS) L-S (%) was also independently correlated with insulin treatment(β = 0.291, p = 0.013).

Conclusions

HDF analysis can provide valuable insights into subclinical myocardial dysfunction prior to changes in ejection fraction and myocardial strain, suggesting that HDF analysis may be a potential early marker of subclinical myocardial dysfunction. LVGLS damage is gradually obvious with the prolongation of diabetes duration in T2DM patients. HDFs parameters are associated with the extent of LGE, and the transversal component of HDF increased with the duration of diabetes.

Somatic Genomic and Transcriptomic Changes in Single Ischemic Human Heart Cardiomyocytes

Heart failure is a multifaceted syndrome contributing significantly to mortality and hospitalization rates among the global population1. One of the prevalent causes of heart failure is ischemic heart disease (IHD), often caused by a blockage in a coronary artery, ultimately leading to the loss of myocardial tissue and contractile force2. The impact of this ischemic ambiance on the cardiomyocyte genome and transcriptome has not been thoroughly studied. During normal aging, cardiomyocytes progressively accumulate somatic mutations faster than many dividing cells, suggesting that internal and external factors specific to cardiomyocytes might influence this accumulation3. In this study, we analyzed single-cell whole-genome and transcriptome data from the left ventricle of 5 individuals with IHD and 10 healthy control individuals. We found that somatic DNA alterations significantly increase in IHD cardiomyocytes, with distinct mutational patterns indicating a disrupted DNA repair system and a cytotoxic environment, potentially associated with increased inflammatory response in the myocardium and a compensatory anti-inflammatory response in IHD. An in vitro iPS-derived hypoxic cardiomyocyte mutational profile indicates similar mutational spectra. Transcriptomic analysis revealed increased expression of EGR1, FOS, and collagen genes in ischemic heart cardiomyocytes, leading to a more fibrotic heart. The aberrant accumulation of DNA alterations and changes in transcriptional patterns in the ischemic heart cardiomyocytes provide insight into the development of IHD.

Why the ROS matters: One-electron oxidants focus DNA damage and repair on G-quadruplexes for gene regulation

Hydrogen peroxide is a precursor to reactive oxygen species (ROS) in cells because of its high reactivity with iron(II) carbonate complexes formed in the labile iron pool due to a high concentration of intracellular bicarbonate (25-100 mM). This chemistry leads to the formation of carbonate radical anion rather than hydroxyl radical, and unlike the latter ROS, CO3•- is a milder one-electron oxidant with high specificity for guanine oxidation in DNA and RNA. In addition to metabolism, another major source of DNA oxidation is inflammation which generates peroxynitrite, another precursor to CO3•- via reaction with dissolved CO2. The identity of the ROS is important because not all radicals react with DNA in the same way. Whereas hydroxyl radical forms adducts at all four bases and reacts with multiple positions on ribose leading to base loss and strand breaks, carbonate radical anion is focused on guanosine oxidation to yield 8-oxo-7,8-dihydroguanosine in nucleic acids and the nucleotide pool, a modification that can function epigenetically in the context of a G-quadruplex. DNA sequences of multiple adjacent guanines, as found in G-quadruplex-forming sequences of gene promoters, are particularly susceptible to oxidative damage, and the focusing of CO3•- chemistry on these sites can lead to a transcriptional response during base excision repair. In this pathway, AP-endonuclease 1 plays a key role in accelerating G-quadruplex folding as well as recruiting activating transcription factors to impact gene expression.

Hydroxytyrosol protects isoproterenol-induced myocardial infarction through activating notch signaling

Objectives

In this investigation, the protective effects of hydroxytyrosol (HT) administered prior to myocardial infarction in rats were examined, with a particular focus on its potential roles within the Notch pathway.

Materials and Methods

The animals were categorized into seven groups (n=7): control, myocardial infarction (MI) 6th hr, MI 24th hr, MI 7th day, MI+HT 6th hr, MI+HT 24th hr, MI+HT 7th day. In order to create infarction, the rats received a subcutaneous injection of isoproterenol at a dose of 200 mg/kg. Rats were given 4 ml/kg/day liquid containing HT orally for six weeks before infarction. Histopathological examination was conducted on heart tissue to assess Notch1, Hes1, and DLL4. Biochemical parameters were analyzed in serum using the ELISA method.

Results

The study revealed an increase in Notch1 and DLL4 levels, particularly at the 24th hr and 7th day after the occurrence of myocardial infarction. DLL4 increased at 24 hr and 7 days of infarction after HT administration compared to control. Hes1 levels increased towards the seventh day after infarction and following HT application before infarction. It was noted that the severity of histopathological damage in heart tissue was reduced at the 24th hr of infarction in rats treated with HT prior to infarction. A significant decrease in fibrosis was observed on the seventh day of infarction in rats given HT before infarction. The levels of biochemical parameters decreased with the administration of HT before the occurrence of infarction.

Conclusion

HT is thought to exert a cardioprotective effect in MI, potentially mediated through the Notch pathway.

Regulation of the microRNA profiles related to Myh7 and Myh6 in myocardial ischemia through proanthocyanidins and different intensity exercise training

Objective

Myocardial ischemia (MI) and circulatory arrest are associated with unfavorable cardiovascular outcomes. This study aims to investigate the effects of proanthocyanidins (PC) and regular exercise with various intensity training protocols (low, moderate, and high) on cardiac protection in a rat model of MI induced by isoproterenol.

Materials and Methods

Based on bioinformatics, a pool of microRNAs and mRNAs was assessed according to significant differential expression in MI condition. Further, the networks of hub genes and mRNA-microRNAs were constructed. After 14 weeks of low, moderate, and high-intensity interval training and oral administration of 300 mg/kg of PC, MI was established in the rats by injecting isoproterenol. The real-time qPCR assessed the relative expressions.

Results

Based on the in-silico analysis, Fn1 (fibronectin-1) and Myh7 (myosin heavy chain 7) are potentially druggable cut points to reduce cardiac tissue damage. High-intensity interval training (HIIT) and consumption of PC modified the relative expression of Myh6 (myosin heavy chain 6), Myh7, and Nf1. Moreover, High-intensity interval training and PC regulated the mir92a-3p, mir181a-5p, mir29a-3p, and mir133a-3p.

Conclusion

Here, the data indicated that the HIIT protocol could have an effective strategy compared to low-intensity interval training (LIIT) and moderate-intensity interval training protocols (MIIT). Furthermore, HIIT and PC might have protective effects on the MI condition.

Cardioprotective Potential of d-limonene against Isoproterenol induced Myocardial Infarction in Rats

d-limonene is a type of colorless liquid hydrocarbon that falls under the category of cyclic monoterpene. It is the component found in the oil extracted from fruit peels. Isoproterenol, a synthetic β-adrenergic agonist, was administered to rats to induce myocardial injury by increasing heart rate and myocardial oxygen demand, leading to ischemia and oxidative stress. This study aims to investigate the properties of d limonene, against myocardial infarction induced by isoprenaline (ISO) in rats. Male Sprague Dawley rats were treated with d-limonene (200 & 400 mg/kg, p.o) daily for 28 days and administered ISO (85 mg/kg, s.c) on the 29th and 30th days at an interval of 24 hr to induce myocardial injury. Morphological and antioxidant parameters, biochemical markers, lipid profile, troponin-I, cardiac ATPase, heart mitochondrial, and lysosomal enzymes were assayed followed by histopathological screening. Rats treated with isoproterenol (85 mg/kg, s.c), administered twice at an interval of 24 h on 29th and 30th day showed a significant change in morphological and antioxidant parameters, biochemical markers, lipid profile, troponin-I, cardiac ATPase, heart mitochondrial, lysosomal enzymes activities and transcription factor (TNF-α/IL-6/NF-kB) expression. Pretreatment with d-limonene (200 and 400 mg/kg, p.o) for 28 days followed by ISO administration on 29th and 30th day significantly reversed the effects of isoproterenol-induced ischemic changes. Moreover, the biochemical results were validated by histopathological findings. The research indicates that d-limonene demonstrates cardioprotective potential against isoproterenol-induced myocardial infarction. This is attributed to its antioxidant properties, stabilization of myocardial membranes, improved scavenging of free radicals, and inhibition of membrane lipid peroxidation.

Astaxanthin Prevents Oxidative Damage and Cell Apoptosis Under Oxidative Stress Involving the Restoration of Mitochondrial Function

Oxidative stress (OS) is one of the factors that result in cell damage and the development of neurological diseases such as Alzheimer's disease (AD). Astaxanthin (ASTA), a natural compound known for its potent antioxidant properties, shows the biological activities in anti-apoptosis and antitumor. However, its specific mechanism on mitochondrial function remains unclear. This study investigated the effects of ASTA on regulation in mitochondrial function and cell apoptosis under OS induced by hydrogen peroxide (H2O2). The results demonstrated that ASTA (0.1, 1, 10 μmol/L) protected cells form H2O2-induced cell damage and apoptosis through mitochondrial pathway. ASTA significantly reduced H2O2-induced mitochondrial dysfunctions and restored the intracellular reactive oxygen species (ROS), mitochondrial membrane potential, and respiratory capacity. These findings suggest that ASTA's antioxidant properties can benefit neurons by maintaining mitochondrial function and alleviating oxidative damage and cell apoptosis induced by H2O2.

Aerobic interval training preconditioning protocols inhibit isoproterenol-induced pathological cardiac remodeling in rats: Implications on oxidative balance, autophagy, and apoptosis

This study aimed to investigate the potential cardioprotective effects of moderate and high-intensity aerobic interval training (MIIT and HIIT) preconditioning. The focus was on histological changes, pro-oxidant-antioxidant balance, autophagy initiation, and apoptosis in myocardial tissue incited by isoproterenol-induced pathological cardiac remodeling (ISO-induced PCR). Male Wistar rats were randomly divided into control (n ​= ​6), ISO (n ​= ​8), MIIT (n ​= ​4), HIIT (n ​= ​4), MIIT ​+ ​ISO (n ​= ​8), and HIIT ​+ ​ISO (n ​= ​8) groups. The MIIT and HIIT protocols were administered for 10 weeks, followed by the induction of cardiac remodeling using subcutaneous injection of ISO (100 ​mg/kg for two consecutive days). Alterations in heart rate (HR), mean arterial pressure (MAP), rate pressure product (RPP), myocardial oxygen consumption (MV ˙ O2), cardiac hypertrophy, histopathological changes, pro-oxidant-antioxidant balance, autophagy biomarkers (Beclin-1, Atg7, p62, LC3 I/II), and apoptotic cell distribution were measured. The findings revealed that the MIIT ​+ ​ISO and HIIT ​+ ​ISO groups demonstrated diminished myocardial damage, hemorrhage, immune cell infiltration, edema, necrosis, and apoptosis compared to ISO-induced rats. MIIT and HIIT preconditioning mitigated HR, enhanced MAP, and preserved MV ˙ O2 and RPP. The pro-oxidant-antioxidant balance was sustained in both MIIT ​+ ​ISO and HIIT ​+ ​ISO groups, with MIIT primarily inhibiting pro-apoptotic autophagy progression through maintaining pro-oxidant-antioxidant balance, and HIIT promoting pro-survival autophagy. The results demonstrated the beneficial effects of both MIIT and HIIT as AITs preconditioning in ameliorating ISO-induced PCR by improving exercise capacity, hemodynamic parameters, and histopathological changes. Some of these protective effects can be attributed to the modulation of cardiac apoptosis, autophagy, and oxidative stress.

Longxuetongluo Capsule alleviate ischemia/reperfusion induced cardiomyocyte apoptosis through modulating oxidative stress and mitochondrial dysfunction

BACKGROUND

Chinese dragon's blood, the red resin of Dracaena cochinchinensis (Lour.) S. C. Chen., is widely used to treat cardiovascular and cerebrovascular diseases in China. Longxuetongluo Capsule (LTC) is a total phenolic compound extracted from Chinese dragon's blood, currently used in treating ischemic stroke. Myocardial injury can be aggravated after reperfusion of ischemic myocardium, which is called myocardial ischemia-reperfusion injury (MIRI), and the mechanism of MIRI is complex. However, the exact effect and mechanism of LTC on MIRI are still unclear. We explore the effect of LTC on alleviating MIRI based on mitochondrial dysfunction and oxidative stress.

AIM OF THE STUDY

To explore the cardioprotective mechanism of LTC against MIRI.

MATERIALS AND METHODS

A rat MIRI model was constructed through ligation of the left anterior descending coronary artery, and LTC was given continuously for 28 days before surgery. The H9c2 cardiomyocyte injury model was induced by oxygen-glucose deprivation/reperfusion (OGD/R), and LTC was given 24 h before OGD. Myocardial ischemia areas were detected with 2,3,5-triphenyltetrazolium chloride (TTC) staining. Cardiac histopathological changes were detected with hematoxylin-eosin (HE) staining. And biochemical indexes were detected with serum biochemical kit. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) staining and flow cytometry were used to detect apoptosis. Fluorescent probes were used to observe reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), Ca2+and other indexes. MitoTracker staining and immunofluorescence were used to observe the morphology of mitochondria and translocation of dynamin-related protein 1 (Drp1). Finally, immunohistochemistry and Western blotting were used to examine the expression of proteins related to apoptosis, mitochondrial fission and fusion and oxidative stress.

RESULTS

LTC could ameliorate cardiac pathological changes, decrease myocardial infarct area and the content or level of relevant serum cardiac enzymes, indicating that LTC could alleviate MIRI. Meanwhile, LTC could inhibit cardiomyocyte apoptosis via regulating apoptosis-related protein expression, and it could restore mitochondrial morphology, maintain ΔΨm, inhibit mitochondrial ROS generation and Ca2+ accumulation, increase the expression of mitochondrial fusion protein 2 (Mfn2), decrease the level of phosphorylation dynamin-related protein 1 (p-Drp1), and regulate ATP synthesis, thereby significantly ameliorating mitochondrial dysfunction. Moreover, LTC significantly reduced the expression of NADPH oxidase 2 (NOX2), NADPH oxidase 4 (NOX4) and neutrophil cytosolic factor 2 (NOXA2/p67phox), and reduced ROS production.

CONCLUSION

The study demonstrated that LTC could inhibit MIRI induced cardiomyocyte apoptosis by inhibiting ROS generation and mitochondrial dysfunction, and these fundings suggested that LTC can be used to alleviate MIRI, which provides a potential therapeutic approach for future treatment of MIRI.

Plasma metabolic profiling reveals that crude and processed Polygonatum cyrtonema hua extract ameliorates myocardial ischemia-induced damage by regulating branched-chain amino acid and energy metabolism

Polygonatum cyrtonema Hua and its processed products have demonstrated cardio-protective effects, though the underlying mechanisms remain unclear. In this study, plasma metabolic profiling and pattern recognition were employed to explore the cardio-protective mechanisms of both crude and processed P. cyrtonema in a myocardial ischemia model induced by ligation, using gas chromatography-mass spectrometry. Post-modeling, plasma levels of creatine kinase-MB, lactate dehydrogenase, troponin T, and malondialdehyde were significantly elevated but were notably reduced after treatment. Conversely, plasma levels of glutathione peroxidase and superoxide dismutase, which were significantly decreased post-modeling, were restored following treatment. Hematoxylin-eosin (HE) and Masson staining revealed that both crude and processed P. cyrtonema effectively reduced inflammatory infiltration and fibrosis in cardiac tissue. Metabolic profiling identified 34 differential endogenous metabolites in the treatment groups, with 19 confirmed using standard compounds. The linear correlation coefficients (R2) for these standards ranged from 0.9960 to 0.9996, indicating high accuracy. The method exhibited excellent precision and repeatability, with relative standard deviation (RSD) values below 8.57%. Recovery rates were between 95.02% and 105.15%, and the stability of the standard compounds was confirmed after three freeze-thaw cycles, with RSD values under 4.42%. Both crude and processed P. cyrtonema were found to alleviate myocardial ischemia symptoms by regulating branched-chain amino acid metabolism and energy metabolism. These findings provide a solid foundation for the potential clinical use of this herb and its processed products in treating heart disease.

Treatment of Acute and Long-COVID, Diabetes, Myocardial Infarction, and Alzheimer's Disease: The Potential Role of a Novel Nano-Compound-The Transdermal Glutathione-Cyclodextrin Complex

Oxidative stress (OS) occurs from excessive reactive oxygen species or a deficiency of antioxidants-primarily endogenous glutathione (GSH). There are many illnesses, from acute and post-COVID-19, diabetes, myocardial infarction to Alzheimer's disease, that are associated with OS. These dissimilar illnesses are, in order, viral infections, metabolic disorders, ischemic events, and neurodegenerative disorders. Evidence is presented that in many illnesses, (1) OS is an early initiator and significant promotor of their progressive pathophysiologic processes, (2) early reduction of OS may prevent later serious and irreversible complications, (3) GSH deficiency is associated with OS, (4) GSH can likely reduce OS and restore adaptive physiology, (5) effective administration of GSH can be accomplished with a novel nano-product, the GSH/cyclodextrin (GC) complex. OS is an overlooked pathological process of many illnesses. Significantly, with the GSH/cyclodextrin (GC) complex, therapeutic administration of GSH is now available to reduce OS. Finally, rigorous prospective studies are needed to confirm the efficacy of this therapeutic approach.

Proteomics Profiling of Bilirubin Nanoparticle Treatment against Myocardial Ischemia-Reperfusion Injury

In myocardial infarction, ischemia-reperfusion injury (IRI) poses a significant challenge due to a lack of effective treatments. Bilirubin, a natural compound known for its anti-inflammatory and antioxidant properties, has been identified as a potential therapeutic agent for IRI. Currently, there are no reports about proteomic studies related to IRI and bilirubin treatment. In this study, we explored the effects of bilirubin nanoparticles in a rat model of myocardial IRI. A total of 3616 protein groups comprising 76,681 distinct peptides were identified using LC-MS/MS, where we distinguished two kinds of protein groups: those showing increased expression in IRI and decreased expression in IRI with bilirubin treatment, and vice versa, accounting for 202 and 35 proteins, respectively. Our proteomic analysis identified significant upregulation in the Wnt and insulin signaling pathways and increased Golgi markers, indicating their role in mediating bilirubin nanoparticle's protective effects. This research contributes to the proteomic understanding of myocardial IRI and suggests bilirubin nanoparticles as a promising strategy for cardiac protection, warranting further investigation in human models.

PKM2 regulates metabolic flux and oxidative stress in the murine heart

Cardiac metabolism ensures a continuous ATP supply, primarily using fatty acids in a healthy state and favoring glucose in pathological conditions. Pyruvate kinase muscle (PKM) controls the final step of glycolysis, with PKM1 being the main isoform in the heart. PKM2, elevated in various heart diseases, has been suggested to play a protective role in cardiac stress, but its function in basal cardiac metabolism remains unclear. We examined hearts from global PKM2 knockout (PKM2-/-) mice and found reduced intracellular glucose. Isotopic tracing of U-13C glucose revealed a shift to biosynthetic pathways in PKM2-/- cardiomyocytes. Total ATP content was two-thirds lower in PKM2-/- hearts, and functional analysis indicated reduced mitochondrial oxygen consumption. Total reactive oxygen species (ROS) and mitochondrial superoxide were also increased in PKM2-/- cardiomyocytes. Intriguingly, PKM2-/- hearts had preserved ejection fraction compared to controls. Mechanistically, increased calcium/calmodulin-dependent kinase II activity and phospholamban phosphorylation may contribute to higher sarcoendoplasmic reticulum calcium ATPase 2 pump activity in PKM2-/- hearts. Loss of PKM2 led to altered glucose metabolism, diminished mitochondrial function, and increased ROS in cardiomyocytes. These data suggest that cardiac PKM2 acts as an important rheostat to maintain ATP levels while limiting oxidative stress. Although loss of PKM2 did not impair baseline contractility, its absence may make hearts more sensitive to environmental stress or injury.

The application of extracorporeal shock wave therapy on stem cells therapy to treat various diseases

In the last ten years, stem cell (SC) therapy has been extensively used to treat a range of conditions such as degenerative illnesses, ischemia-related organ dysfunction, diabetes, and neurological disorders. However, the clinical application of these therapies is limited due to the poor survival and differentiation potential of stem cells (SCs). Extracorporeal shock wave therapy (ESWT), as a non-invasive therapy, has shown great application potential in enhancing the proliferation, differentiation, migration, and recruitment of stem cells, offering new possibilities for utilizing ESWT in conjunction with stem cells for the treatment of different systemic conditions. The review provides a detailed overview of the advances in using ESWT with SCs to treat musculoskeletal, cardiovascular, genitourinary, and nervous system conditions, suggesting that ESWT is a promising strategy for enhancing the efficacy of SC therapy for various diseases.

Safflower Yellow Injection Alleviates Myocardial Ischemia/Reperfusion Injury by Reducing Oxidative and Endoplasmic Reticulum Stress

Safflower yellow is an extract of the famous Chinese medicine Carthamus tinctorious L, and safflower yellow injection (SYI) is widely used clinically to treat angina pectoris. However, there are few studies on the anti-myocardial ischemia/reperfusion (I/R) injury effect of SYI, and its mechanisms are unclear. In the present study, we aimed to investigate the protective effect of SYI on myocardial I/R injury and explore its underlying mechanisms. Male Sprague Dawley rats were randomly divided into a control group, sham group, model group, and SYI group (20 mg/kg, femoral vein injection 1 h before modeling). The left anterior descending coronary artery was ligated to establish a myocardial I/R model. H9c2 cells were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) after incubation with 80 μg/mL SYI for 24 h. In vivo, TsTC, HE, and TUNEL staining were performed to evaluate myocardial injury and apoptosis. A kit was used to detect superoxide dismutase (SOD) and malondialdehyde (MDA) to assess oxidative stress. In vitro, flow cytometry was used to detect the reactive oxygen species (ROS) content and apoptosis rate. Protein levels were determined via Western blotting. Pretreatment with SYI significantly reduced infarct size and pathological damage in rat hearts and suppressed cardiomyocyte apoptosis in vivo and in vitro. In addition, SYI inhibited oxidative stress by increasing SOD activity and decreasing MDA content and ROS production. Myocardial I/R and OGD/R activate endoplasmic reticulum (ER) stress, as evidenced by increased expression of activating transcription factor 6 (ATF6), glucose-regulated protein 78 (GRP78), cysteinyl aspartate-specific proteinase caspase-12, and C/EBP-homologous protein (CHOP), which were all inhibited by SYI. SYI ameliorated myocardial I/R injury by attenuating apoptosis, oxidative damage, and ER stress, which revealed new mechanistic insights into its application.

A Proof of Principle 2D Spatial Proteome Mapping Analysis Reveals Distinct Regional Differences in the Cardiac Proteome

Proteomics studies often explore phenotypic differences between whole organs and systems. Within the heart, more subtle variation exists. To date, differences in the underlying proteome are only described between whole cardiac chambers. This study, using the bovine heart as a model, investigates inter-regional differences and assesses the feasibility of measuring detailed, cross-tissue variance in the cardiac proteome. Using a bovine heart, we created a two-dimensional section through a plane going through two chambers. This plane was further sectioned into 4 × 4 mm cubes and analysed using label-free proteomics. We identified three distinct proteomes. When mapped to the extracted sections, the proteomes corresponded largely to the outer wall of the right ventricle and secondly to the outer wall of the left ventricle, right atrial appendage, tricuspid and mitral valves, modulator band, and parts of the left atrium. The third separate proteome corresponded to the inner walls of the left and right ventricles, septum, and left atrial appendage. Differential protein abundancies indicated differences in energy metabolism between regions. Data analyses of the mitochondrial proteins revealed a variable pattern of abundances of complexes I-V between the proteomes, indicating differences in the bioenergetics of the different cardiac sub-proteomes. Mapping of disease-associated proteins interestingly showed desmoglein-2, for which defects in this protein are known to cause Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy, which was present predominantly in the outer wall of the left ventricle. This study highlights that organs can have variable proteomes that do not necessarily correspond to anatomical features.

A Systematic Review on Advances in Management of Oxidative Stress-Associated Cardiovascular Diseases

Oxidative stress plays a significant role in the pathogenesis of cardiovascular diseases, such as myocardial ischemia/reperfusion injury, atherosclerosis, heart failure, and hypertension. This systematic review aims to integrate most relevant studies on oxidative stress management in cardiovascular diseases. We searched relevant literatures in the PubMed database using specific keywords. We put emphasis on those manuscripts that were published more recently and in higher impact journals. We reviewed a total of 200 articles. We examined current oxidative stress managements in cardiovascular diseases, including supplements like resveratrol, vitamins C and E, omega-3 fatty acids, flavonoids, and coenzyme-10, which have shown antioxidative properties and potential cardiovascular benefits. In addition, we reviewed the pharmacological treatments including newly discovered antioxidants and nanoparticles that show potential effects in targeting the specific oxidative stress pathways. Lastly, we examined biomarkers, such as soluble transferrin receptor, transthyretin, and cystatin C in evaluating antioxidant status and identifying cardiovascular risk. By addressing oxidative stress management and mechanisms, this paper emphasizes the importance of maintaining the balance between oxidants and antioxidants in the progression of cardiovascular diseases. This review paper is registered with the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY), registration # INPLASY202470064.

Cardioprotective effects of the aqueous extract of Echinops cephalotes on myocardial ischemia-reperfusion in rats by modulation of MMP-2, MMP-9, TIMP, and oxidative stress

Echinops plants have received great attention for the treatment of many diseases due to pharmacological properties such as their antidiabetic, antioxidant, and anti-inflammatory characteristics. The major purpose of the present study was to investigate the cardioprotective benefits of Echinops cephalotes (Ech) against myocardial ischemia-reperfusion (MI/R) injury. Male Wistar rats were randomly allocated to three groups: sham, MI, and MI + Ech. The left coronary artery (LAD) was blocked for 30 minutes to induce MI. In the treatment group, rats were given 150 mg/kg/day of Ech extract for 28 days. Aqueous extracts were made from Echinops plants. To study heart function, fibrosis, cardiac damage indicators, and oxidative stress factors, echocardiography, Masson's trichrome staining, and biochemical tests were used. The expression of matrix metalloproteinase 2 and 9 (MMP2 and MMP-9) and tissue inhibitor of metalloproteinase (TIMP) was determined using Western blotting. Tissue damage was assessed using hematoxylin and eosin staining. MI group exhibited significantly reduced ejection fraction (EF) and fractional shortening (FS), enhanced levels of lactate dehydrogenase (LDH), creatine kinase MB (CK-MB), cardiac Troponin I (cTnI), and malondialdehyde (MDA), as well as a decrease in the Glutathione (GSH) tissue content, reduced activity of superoxide dismutase (SOD), increasing fibrosis, upregulations of MMP-2 and MMP-9, and reduction of TIMP compared to the sham group. The findings suggest that Ech in particular, could be a promising therapeutic agent to reduce the damage in MI by targeting oxidative stress and modulating the activities of matrix metalloproteinases and their tissue inhibitors.

Proteomic Analysis and Sex-Specific Changes in Chronically Ischemic Swine Myocardium Treated with Sodium-Glucose Cotransporter-2 Inhibitor Canagliflozin

BACKGROUND

Although sodium-glucose cotransporter-2 inhibitors have been shown to improve cardiovascular outcomes in general, little is presently known about any sex-specific changes that may result from this therapy. We sought to investigate and quantify potential sex-specific changes seen with the sodium-glucose cotransporter-2 inhibitor canagliflozin (CAN) in a swine model of chronic myocardial ischemia.

STUDY DESIGN

Eighteen Yorkshire swine underwent left thoracotomy with placement of an ameroid constrictor. Two weeks postop, swine were assigned to receive either control (F = 5 and M = 5) or CAN 300 mg daily (F = 4 and M = 4). After 5 weeks of therapy, swine underwent myocardial functional measurements, and myocardial tissue was sent for proteomic analysis.

RESULTS

Functional measurements showed increased cardiac output, stroke volume, ejection fraction, and ischemic myocardial flow at rest in male swine treated with CAN compared with control male swine (all p < 0.05). The female swine treated with CAN had no change in cardiac function as compared with control female swine. Proteomic analysis demonstrated 6 upregulated and 97 downregulated proteins in the CAN female group compared with the control female group. Pathway analysis showed decreases in proteins in the tricarboxylic acidic cycle. The CAN male group had 639 upregulated and 172 downregulated proteins compared with control male group. Pathway analysis showed increases in pathways related to cellular metabolism and decreases in pathways relevant to the development of cardiomyopathy and to oxidative phosphorylation.

CONCLUSIONS

Male swine treated with CAN had significant improvements in cardiac function that were not observed in female swine treated with CAN. Moreover, CAN treatment in male swine was associated with significantly more changes in protein expression than in female swine treated with CAN. The increased proteomic changes seen in the CAN male group likely contributed to the more robust changes in cardiac function seen in male swine treated with CAN.

Small extracellular vesicle-mediated CRISPR-Cas9 RNP delivery for cardiac-specific genome editing

Myocardial infarction (MI) is a major cause of morbidity and mortality worldwide. Although clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) gene editing holds immense potential for genetic manipulation, its clinical application is hindered by the absence of an efficient heart-targeted drug delivery system. Herein, we developed CRISPR-Cas9 ribonucleoprotein (RNP)-loaded extracellular vesicles (EVs) conjugated with cardiac-targeting peptide (T) for precise cardiac-specific genome editing. RNP complexes containing Cas9 and single guide RNA targeting miR-34a, an MI-associated molecular target, were loaded into EVs (EV@RNP). Gene editing by EV@RNP attenuated hydrogen peroxide-induced apoptosis in cardiomyocytes via miR-34a inhibition, evidenced by increased B-cell lymphoma 2 levels, decreased Bcl-2-associated X protein levels, and the cleavage of caspase-3. Additionally, to improve cardiac targeting in vivo, we used click chemistry to form functional T-EV@RNP by conjugating T peptides to EV@RNP. Consequently, T-EV@RNP-mediated miR-34a genome editing might exert a protective effect against MI, reducing apoptosis, ameliorating MI injury, and facilitating the recovery of cardiac function. In conclusion, the genome editing delivery system established by loading CRISPR/Cas9 RNP with cardiac-targeting EVs is a powerful approach for precise and tissue-specific gene therapy for cardiovascular disease.

Protectin D1 Alleviates Myocardial Ischemia/Reperfusion Injury by Regulating PI3K/AKT Signaling Pathway

Myocardial ischemia/reperfusion (I/R) injury after the onset of acute myocardial infarction (AMI) can be life-threatening, and there is no effective strategy for therapeutic intervention. Here, we studied the potential of protectin D1 in protecting from I/R-induced cardiac damages and investigated the underlying mechanisms. An in vivo rat model of I/R after AMI induction was established through the ligation of the left anterior descending (LAD) artery to assess the cardiac functions and evaluate the protective effect of protectin D1. Protectin D1 protected against I/R-induced oxidative stress and inflammation in the rat model, improved the cardiac function, and reduced the infarct size in myocardial tissues. The beneficial effect of protectin D1 was associated with the up-regulation of miRNA-210 and the effects on PI3K/AKT signaling and HIF-1α expression. Together, our data suggest that protectin D1 could serve as a potential cardioprotective agent against I/R-associated cardiac defects.

Clerodendrum Glandulosum Lindl.: A Review of Ethnopharmacology, Pharmacological Potentials, and their Mechanism of Action

Clerodendrum glandulosum Lindl. is popularly known for its traditional herbal remedies and therapeutic properties among the people of Northeast Indian communities, as well as Chinese traditional medicine. For the myriad pharmacological properties, viz., anti-hypertensive, hypolipidemic, hepatoprotective, anti-inflammatory, and neuroprotective, planting this species in kitchen gardens is a common practice to treat various ailments, especially hypertension, diabetes, and other metabolic complications. Different phytochemicals, representing the diverse classes of secondary metabolites comprising physiological and phytopharmaceutical significance, have been reported from C. glandulosum. Compounds with terpenoids, steroids, and phenolics are in demand in the pharmaceutical industry. An overview of the mechanism of action of the prominent compounds has also been collated for future research on C. glandulosum-based therapeutics. Current information focuses on this important medicinal plant's ethnomedicinal use, phytochemistry, pharmacology, associated mechanisms, and toxicology. This review will help explore this potential medicinal plant, which can pave the path for its application in the pharmaceutical industry.

Myrtenal exhibits cardioprotective effects by attenuating the pathological progression associated with myocardial infarction

BACKGROUND

Myocardial infarction poses major risks to human health because of their incredibly high rates of morbidity and mortality. Infarctions are more likely to develop as a result of dysregulation of cell death. Myrtenal can be considered for their bioactive beneficial activity in the context of cardiovascular pathologies and, particularly, in the protection toward oxidative stress followed by ischemic injury.

OBJECTIVE

This study aimed to put limelight on the antioxidant, anti-apoptotic, and antibacterial properties of Myrtenal.

METHODS

An in vitro model of oxidative stress-induced injury was entrenched in H9c2 cells using hydrogen peroxide, and the effects of Myrtenal were investigated. The MTT, cellular enzyme level, staining, and flow cytometry analysis were used to examine protective, antioxidant, and anti-apoptotic effects. The gene expressions were detected by qPCR. Antibacterial effect and biofilm formation were also done.

RESULT

The findings revealed that Myrtenal alone had negligible cytotoxic effects and that Myrtenal protects H9c2 against H2 O2 -induced cell death at micromolar concentrations. Myrtenal pre-treatment inhibited the generation of reactive oxygen species (ROS) as well as remarkably decreased the fluorescence intensity of ROS. Additionally, Myrtenal considerably increased the synthesis of antioxidant enzymes while dramatically decreasing the production of MDA and LDH. qPCR demonstrated the downregulation of Cas-9, TNF-α, NF-κB, P53, BAX, iNOS, and IL-6 expression while an upregulation of Bcl-2 expression in Myrtenal pre-treated groups. Myrtenal also holds the magnificent property of inhibiting bacterial growth.

CONCLUSION

Myrtenal ameliorates H2 O2 -induced cardiomyocyte injury and protects cardiomyocyte by inhibiting oxidative stress, inflammation, and apoptosis and may be a promise drug for the treatment of heart diseases.

Underlying mechanisms and cardioprotective effects of SGLT2i and GLP-1Ra: insights from cardiovascular magnetic resonance

Originally designed as anti-hyperglycemic drugs, Glucagon-Like Peptide-1 receptor agonists (GLP-1Ra) and Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have demonstrated protective cardiovascular effects, with significant impact on cardiovascular morbidity and mortality. Despite several mechanisms have been proposed, the exact pathophysiology behind these effects is not yet fully understood. Cardiovascular imaging is key for the evaluation of diabetic patients, with an established role from the identification of early subclinical changes to long-term follow up and prognostic assessment. Among the different imaging modalities, CMR may have a key-role being the gold standard for volumes and function assessment and having the unique ability to provide tissue characterization. Novel techniques are also implementing the possibility to evaluate cardiac metabolism through CMR and thereby further increasing the potential role of the modality in this context. Aim of this paper is to provide a comprehensive review of changes in CMR parameters and novel CMR techniques applied in both pre-clinical and clinical studies evaluating the effects of SGLT2i and GLP-1Ra, and their potential role in better understanding the underlying CV mechanisms of these drugs.

Oxidative stress and ion channels in neurodegenerative diseases

Numerous neurodegenerative diseases result from altered ion channel function and mutations. The intracellular redox status can significantly alter the gating characteristics of ion channels. Abundant neurodegenerative diseases associated with oxidative stress have been documented, including Parkinson's, Alzheimer's, spinocerebellar ataxia, amyotrophic lateral sclerosis, and Huntington's disease. Reactive oxygen and nitrogen species compounds trigger posttranslational alterations that target specific sites within the subunits responsible for channel assembly. These alterations include the adjustment of cysteine residues through redox reactions induced by reactive oxygen species (ROS), nitration, and S-nitrosylation assisted by nitric oxide of tyrosine residues through peroxynitrite. Several ion channels have been directly investigated for their functional responses to oxidizing agents and oxidative stress. This review primarily explores the relationship and potential links between oxidative stress and ion channels in neurodegenerative conditions, such as cerebellar ataxias and Parkinson's disease. The potential correlation between oxidative stress and ion channels could hold promise for developing innovative therapies for common neurodegenerative diseases.

Intramyocardial Injection of Hypoxia-Conditioned Extracellular Vesicles Modulates Response to Oxidative Stress in the Chronically Ischemic Myocardium

INTRODUCTION

Patients with advanced coronary artery disease (CAD) who are not eligible for stenting or surgical bypass procedures have limited treatment options. Extracellular vesicles (EVs) have emerged as a potential therapeutic target for the treatment of advanced CAD. These EVs can be conditioned to modify their contents. In our previous research, we demonstrated increased perfusion, decreased inflammation, and reduced apoptosis with intramyocardial injection of hypoxia-conditioned EVs (HEVs). The goal of this study is to further understand the function of HEVs by examining their impact on oxidative stress using our clinically relevant and extensively validated swine model of chronic myocardial ischemia.

METHODS

Fourteen Yorkshire swine underwent a left thoracotomy for the placement of an ameroid constrictor on the left circumflex coronary artery to model chronic myocardial ischemia. After two weeks of recovery, the swine underwent a redo thoracotomy with injection of either HEVs (n = 7) or a saline control (CON, n = 7) into the ischemic myocardium. Five weeks after injection, the swine were subjected to terminal harvest. Protein expression was measured using immunoblotting. OxyBlot analysis and 3-nitrotyrosine staining were used to quantify total oxidative stress.

RESULTS

There was a significant increase in myocardial expression of the antioxidants SOD 2, GPX-1, HSF-1, UCP-2, catalase, and HO-1 (all p ≤ 0.05) in the HEV group when compared to control animals. The HEVs also exhibited a significant increase in pro-oxidant NADPH oxidase (NOX) 1, NOX 3, p47phox, and p67phox (all p ≤ 0.05). However, no change was observed in the expression of NFkB, KEAP 1, and PRDX1 (all p > 0.05) between the HEV and CON groups. There were no significant differences in total oxidative stress as determined by OxyBlot and 3-nitrotyrosine staining (p = 0.64, p = 0.32) between the groups.

CONCLUSIONS

Administration of HEVs in ischemic myocardium induces a significant increase in pro- and antioxidant proteins without a net change in total oxidative stress. These findings suggest that HEV-induced changes in redox signaling pathways may play a role in increased perfusion, decreased inflammation, and reduced apoptosis in ischemic myocardium. Further studies are required to determine if HEVs alter the net oxidative stress in ischemic myocardium at an earlier time point of HEV administration.

Mitochondria-derived methylmalonic acid aggravates ischemia-reperfusion injury by activating reactive oxygen species-dependent ferroptosis

Ferroptosis is a regulatory cell death process pivotal in myocardial ischemia-reperfusion (I/R) injury. However, the precise mechanism underlying myocardial ferroptosis remains less known. In this study, we investigated the pathophysiological mechanisms of methylmalonic acid (MMA) associated with ferroptosis activation in cardiomyocytes after I/R. We found an increase level of MMA in patients with acute myocardial injury after reperfusion and AC16 cells under hypoxia/reoxygenation (H/R) condition. MMA treatment was found to be associated with excessive oxidative stress in cardiomyocytes, leading to ferroptosis-related myocardial injury. In mice with I/R injury, MMA treatment aggravated myocardial oxidative stress and ferroptosis, which amplified the myocardial infarct size and cardiac dysfunction. Mechanistically, MMA promoted NOX2/4 expression to increase reactive oxygen species (ROS) production in cardiomyocytes, aggravating myocardial injury. Notably, the increased ROS further activated ferroptosis by inhibiting solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) expression. In addition, MMA decreased the ectopic nuclear distribution of nuclear factor E2-related factor 2 (NRF2) by increasing the interaction between NRF2 and kelch-like ECH-associated protein 1 (KEAP1). This impeded the activation of GPX4/SLC7A11, downstream of NRF2, activating ferroptosis and aggravating myocardial cell injury. Collectively, our study indicates that MMA activates oxidative stress and ROS generation, which induces ferroptosis to exacerbate cardiomyocyte injury in an I/R model. These findings may provide a new perspective for the clinical treatment of I/R injury and warrant further investigation.

Exploring the molecular mechanism of Yinao Fujian formula on ischemic stroke based on network pharmacology and experimental verification

Background

Ischemic stroke (IS) is a leading cause of long-term disability and even mortality, threatening people's lives. Yinao Fujian (YNFJ) formula is a Traditional Chinese Medicine formula that has been widely used to treat patients with IS. However, the molecular mechanism of YNFJ for the treatment of IS is still elusive. Our study aimed to explore the potential protective effect and the underlying mechanisms of YNFJ on IS using a network pharmacology approach coupled with experimental validation.

Materials and methods

Effective compounds of YNFJ were collected from BATMAN-TCM and TCMSP databases, while IS targets were obtained from GeneCards, OMIM, TTD and DrugBank databases. The protein-protein interaction (PPI) network was constructed to further screen the hub targets of YNFJ in IS treatment. GO and KEGG enrichment analyses were used to identify the critical biological processes and signaling pathways of YNFJ for IS. Moreover, Nissl staining, HE, TTC staining and Tunel staining were used in the MCAO model to prove the neuroprotective effect of YNFJ. Oxidative damage, inflammatory factor release and related pathways were tested in MCAO rat model and hypoxia-induced BV2 cell model, respectively.

Results

We found that YNFJ treatment significantly alleviated MCAO-induced nerve damage and apoptosis. Then, network pharmacology screening combined with literature research revealed IL6, TNF, PTGS2, NFKBIA and NFE2L2 as the critical targets in a PPI network. Moreover, the top 20 signaling pathways and biological processes associated with the protective effects of YNFJ on IS were enriched through GO and KEGG analyses. Further analysis indicated that NF-κB and Nrf2/HO-1 signaling pathways might be highly involved in the protective effects of YNFJ on IS. Finally, in vitro and in vivo experiments confirmed that YNFJ inhibited the release of inflammatory factors (IL-6 and TNF-α) and MDA content, and increased the activity of SOD. In terms of the mechanism, YNFJ inhibited the release of inflammatory factors by suppressing the NF-κB pathway and decreased the expression of iNOS and COX-2 to protect microglia from inflammation damage. In addition, YNFJ initiated the dissociation of Keap-1 and Nrf2, and activated the downstream protein HO-1, NQO1, thus decreasing oxidative stress.

Conclusion

Taken together, the findings in our research showed that the protective effects of YNFJ on IS were mainly achieved by regulating the NF-κB and Nrf2/HO-1 signaling pathways to inhibit oxidative stress damage and inflammatory damage of microglia.

Cardioprotective effects of asiaticoside against diabetic cardiomyopathy: Activation of the AMPK/Nrf2 pathway

Diabetic cardiomyopathy (DCM) is a chronic microvascular complication of diabetes that is generally defined as ventricular dysfunction occurring in patients with diabetes and unrelated to known causes. Several mechanisms have been proposed to contribute to the occurrence and persistence of DCM, in which oxidative stress and autophagy play a non-negligible role. Diabetic cardiomyopathy is involved in a variety of physiological and pathological processes. The 5' adenosine monophosphate-activated protein kinase/nuclear factor-erythroid 2-related factor 2 (AMPK/Nrf2) are expressed in the heart, and studies have shown that asiaticoside (ASI) and activated AMPK/Nrf2 have a protective effect on the myocardium. However, the roles of ASI and AMPK/Nrf2 in DCM are unknown. The intraperitoneal injection of streptozotocin (STZ) and high-fat feed were used to establish the DCM models in 100 C57/BL mice. Asiaticoside and inhibitors of AMPK/Nrf2 were used for intervention. Cardiac function, oxidative stress, and autophagy were measured in mice. DCM mice displayed increased levels of oxidative stress while autophagy levels declined. In addition, AMPK/Nrf2 was activated in DCM mice with ASI intervention. Further, we discovered that AMPK/Nrf2 inhibition blocked the protective effect of ASI by compound C and treatment with ML-385. The present study demonstrates that ASI exerts a protective effect against DCM via the potential activation of the AMPK/Nrf2 pathway. Asiaticoside is a potential therapeutic target for DCM.

Circadian regulated control of myocardial ischemia-reperfusion injury

Circadian mechanisms have been associated with the pathogenesis of a variety of cardiovascular diseases, including myocardial ischemia-reperfusion injury (I-R). Myocardial ischemia resulting from impaired oxygen delivery to cardiac muscle sets into motion a cascade of cellular events that paradoxically triggers greater cardiac dysfunction upon reinstitution of coronary blood supply, a phenomenon known as I-R. I-R injury has been attributed to a number of cellular defects including increased reactive oxygen species (ROS), increased intracellular calcium and impaired mitochondrial bioenergetics that ultimately lead to cardiac cell death, ventricular remodeling and heart failure. Emerging evidence has identified a strong correlation between cellular defects that underlie I-R and the disrupted circadian. In fact, recent studies have shown that circadian dysfunction exacerbates cardiac injury following MI from impaired cellular quality control mechanisms such as autophagy, which are vital in the clearance of damaged cellular proteins and organelles such as mitochondria from the cell. The accumulation of cellular debris is posited as the central underlying cause of excessive cardiac cell death and ventricular dysfunction following MI. The complexities that govern the interplay between circadian biology and I-R injury following MI is at its infancy and understanding how circadian misalignment, such as in shift workers impacts I-R injury is of great scientific and clinical importance toward development of new therapeutic strategies using chronotherapy and circadian regulation to mitigate cardiac injury and improve cardiac outcomes after injury. In this review, we highlight recent advances in circadian biology and adaptive cellular quality control mechanisms that influence cardiac injury in response to MI injury with a specific focus on how circadian biology can be utilized to further cardiovascular medicine and patient care.

Aldehyde Dehydrogenase 2 Preserves Mitochondrial Function in the Ischemic Heart: A Redox-dependent Mechanism for AMPK Activation by Thioredoxin-1

ABSTRACT

Aldehyde dehydrogenase 2 (ALDH2) protects the ischemic heart by activating adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling. However, the molecular mechanisms linking ALDH2 and AMPK signaling are not fully understood. This study aimed to explore the potential mechanisms linking ALDH2 and AMPK in myocardial ischemic injury. An ischemic model was established by ligating the left anterior descending coronary artery in rats. The overexpression or knockdown of ALDH2 in H9c2 cells treated with oxygen-glucose deprivation was obtained through lentivirus infection. Transferase-mediated dUTP nick-end labeling was used to evaluate apoptosis in an ischemic rat model and oxygen-glucose deprivation cells. ALDH2 activity, mitochondrial oxidative stress markers, adenosine triphosphate, respiratory control ratio, and cell viability in H9c2 cells were evaluated using a biological kit and 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide. Protein expression of ALDH2 , 4-hydroxynonenal, thioredoxin-1 (Trx-1), and AMPK-proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) signaling pathway was detected through Western blotting. ALDH2 activation reduced ischemic-induced myocardial infarct size and apoptosis. ALDH2 protected mitochondrial function by enhancing mitochondrial respiratory control ratio and adenosine triphosphate production, alleviated mitochondrial oxidative stress, and suppressed myocardial apoptosis. Moreover, ALDH2 attenuated ischemia-induced oxidative stress and maintained Trx-1 levels by reducing 4-hydroxynonenal, thereby promoting AMPK-PGC-1α signaling activation. Inhibiting Trx-1 or AMPK abolished the cardioprotective effect of ALDH2 on ischemia. ALDH2 alleviates myocardial injury through increased mitochondrial biogenesis and reduced oxidative stress, and these effects were achieved through Trx1-mediating AMPK-PGC1-α signaling activation.

Effects of coenzyme Q10 supplementation on oxidative stress biomarkers following reperfusion in STEMI patients undergoing primary percutaneous coronary intervention

Introduction

It is well-established that oxidative stress is deeply involved in myocardial ischemia-reperfusion injury. Considering the potent antioxidant properties of coenzyme Q10 (CoQ10), we aimed to assess whether CoQ10 supplementation could exert beneficial effects on plasma levels of oxidative stress biomarkers in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPIC).

Methods

Seventy patients with the first attack of STEMI, eligible for PPCI were randomly assigned to receive either standard treatments plus CoQ10 (400 mg before PPCI and 200 mg twice daily for three days after PPCI) or standard treatments plus placebo. Plasma levels of oxidative stress biomarkers, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), total antioxidant capacity (TAC), and malondialdehyde (MDA) were measured at 6, 24, and 72 hours after completion of PPCI.

Results

The changes in plasma levels of the studied biomarkers at 6 and 24 hours after PPCI were similar in the both groups (P values>0.05). This is while at 72 hours, the CoQ10- treated group exhibited significantly higher plasma levels of SOD (P value<0.001), CAT (P value=0.001), and TAC (P value<0.001), along with a lower plasma level of MDA (P value=0.002) compared to the placebo-treated group. The plasma activity of GPX showed no significant difference between the groups at all the study time points (P values>0.05).

Conclusion

This study showed that CoQ10 has the potential to modulate the balance between antioxidant and oxidant biomarkers after reperfusion therapy. Our results suggest that CoQ10, through its antioxidant capacity, may help reduce the reperfusion injury in ischemic myocardium.

Mitochondrial transplantation reduces lower limb ischemia-reperfusion injury by increasing skeletal muscle energy and adipocyte browning

Recent studies have shown that mitochondrial transplantation can repair lower limb IRI, but the underlying mechanism of the repair effect remains unclear. In this study, we found that in addition to being taken up by skeletal muscle cells, human umbilical cord mesenchymal stem cells (hMSCs)-derived mitochondria were also taken up by adipocytes, which was accompanied by an increase in optic atrophy 1 (OPA1) and uncoupling protein 1. Transplantation of hMSCs-derived mitochondria could not only supplement the original damaged mitochondrial function of skeletal muscle, but also promote adipocyte browning by increasing the expression of OPA1. In this process, mitochondrial transplantation can reduce cell apoptosis and repair muscle tissue, which promotes the recovery of motor function in vivo. To the best of our knowledge, there is no study on the therapeutic mechanism of mitochondrial transplantation from this perspective, which could provide a theoretical basis.

Comparison of the preconditioning effect of different exercise training modalities on myocardial ischemia-reperfusion injury

The study of exercise preconditioning can develop strategies to prevent cardiovascular diseases and outline the efficient exercise model. However, the exercise type with the most protective effect against ischemia-reperfusion injury is unknown. In this study, we examined the effects of three kinds of exercise preconditioning on myocardial ischemia-reperfusion in adult rats and explored the possible underlying mechanisms. Male Wistar rats subjected to ten weeks of endurance, resistance, and concurrent training underwent ischemia (30 min) and reperfusion (120 min) induction. Then, infarction size, serum levels of the CK-MB, the redox status, and angiogenesis proteins (VEGF, ANGP-1, and ANGP-2) were measured in the cardiac tissue. Results showed that different exercise training modes have the same reduction effects on infarction size, but ischemia-reperfusion-induced CK-MB was lower in response to endurance training and concurrent training. Furthermore, cardiac VEGF levels increased in all three kinds of exercise preconditioning but ischemia-reperfusion-induced ANGP-1 elevated more in endurance training. The cardiac GPX activity was improved significantly through the resistance and concurrent exercise compared to the endurance exercise. In addition, all three exercise preconditioning models decreased MPO levels, and ischemia reperfusion-induced MDA was lower in endurance and resistance training. Overall, these results indicated that cardioprotection of exercise training against ischemia-reperfusion injury depends on the exercise modality. Cardioprotective effects of aerobic, resistance, and concurrent exercises are due to different mechanisms. The preconditioning effects of endurance training are mediated mainly by pervasive angiogenic responses and resistance training through oxidative stress amelioration. The preconditioning effects of concurrent training rely on both angiogenesis and oxidative stress amelioration.

Design and synthesis of 3,4-seco-lupane triterpene derivatives to resist myocardial ischemia-reperfusion injury by inhibiting oxidative stress-mediated mitochondrial dysfunction via the PI3K/AKT/HIF-1α axis

In this study, 86 new seco-lupane triterpenoid derivatives were designed, synthesized, and characterized, and their protective activities against ischemia-reperfusion injury were investigated in vitro and in vivo. Structure-activity relationship studies revealed that most target compounds could protect cardiomyocytes against hypoxia/reoxygenation-induced injury in vitro, with compound 85 being the most active and exhibiting more potent protective activity than clinical first-line drugs. Furthermore, all thiophene derivatives exhibited stronger protective activity than furan, pyridine, and pyrazine derivatives, and the protective activity gradually increased with the extension of the alkyl chain and changed in the substituent. The data from the in-vitro and in-vivo experiments revealed that compound 85 protected mitochondria from damage by inhibiting excessive production of oxidative stressors, such as intracellular ROS, which in turn inhibited the apoptosis and necrotize of cardiomyocytes and reduced infarct size, thereby protecting normal cardiac function. It was associated with enhanced activation of the PI3K/AKT-mediated HIF-1α signaling pathway. Therefore, compound 85 acts as an oxidative stress inhibitor, blocks ROS production, protects mitochondria and cells from myocardial ischemia/reperfusion (MI/R) injury, and represents an effective new drug for treating MI/R injury.

Dexmedetomidine attenuates myocardial ischemia-reperfusion injury in hyperlipidemic rats by inhibiting inflammation, oxidative stress and NF-κB

The present study was conducted to determine the protective effect of Dexmedetomidine (DEX) in myocardial ischemia-reperfusion injury in hyperlipidemic rats. Towards this, the effect of DEX was first evaluated on the infarct size and the histopathology of cardiac tissues using TTC and H and E staining, and it was found that DEX significantly improved the infarct size and architecture of the myocardial tissues following the I/R injury. DEX also showed significant improvement in various examined hemodynamic parameters (e.g., LVSP, and ± dp/dtmax ) in a dose-dependent manner. The lipid profile (LDL, VLDL, TC, TG, and HDL level) of the rats were also found significantly improved in DEX-treated rats. The level of various pro-inflammatory cytokines (IL-1β, IL-6, IL-10, IL-17, and TNF-α), cardiac injury (CK, CK-MB, Troponin I AST, ALT, and LDH), and oxidative stress (MDA, SOD, and GSH) biomarkers were also found to be restored near to the normal in DEX-treated group. It has been found that DEX also significantly reduces apoptosis of rat cardiomyocytes. In western blot analysis, DEX showed a significant reduction in the activation of NF-κB. In conclusion, our study demonstrated the protective effect of Dexmedetomidine in myocardial ischemia-reperfusion injury in hyperlipidemic rats possibly via amelioration of oxidative stress, and inflammation apoptosis.

Mannose binding lectin-associated serine protease-1 is a novel contributor to myocardial ischemia/reperfusion injury

BACKGROUND

The lectin pathway has been demonstrated to play a critical role in the pathological process of myocardial ischemia/reperfusion injury (IRI). Mannose-binding lectin (MBL)-associated serine protease-1 (MASP-1), especially different from other components of the lectin pathway, mediates proinflammatory and procoagulant reactions independent of complement cascades. However, the role of MASP-1 in myocardial IRI remains unknown so far.

METHODS

Myocardial IRI was established with 45 min ischemia and 24 h reperfusion in mice. C1 inhibitor, as the natural inhibitor of MASP-1, was administrated at 20 IU/Kg via tail vein 5 min before surgical operation. Cardiac function and myocardial infarct size were assessed. Myocardial histology and fibrosis were evaluated by H&E and Masson staining, respectively. Deposition of MASP-1, expression of PAR-1/4 and neutrophil extracellular traps (NET) were investigated on myocardium tissue by IHC staining. Cell apoptosis was detected by TUNEL assay. Levels of myocardial enzymes and proinflammatory cytokines were determined by ELISA.

RESULTS

Inhibition of MASP-1 with C1 INH improved cardiac function and alleviated myocardium tissue injury (infarct size, enzymes, histology and fibrosis) after myocardial IRI. Deposition of MASP-1 and expression PAR-1, as well as NET formation in myocardial tissue were suppressed by MASP-1 inhibitor, while PAR-4 was elevated. Levels of apoptosis, HMGB-1 and IL-6 were lower after blocking MASP-1. Yet, IL-8 and TNF-α remained unchanged.

CONCLUSIONS

MASP-1, as a new contributor, played a critical role in myocardial IRI. Inhibition of MASP-1 protected myocardial tissue from IRI probably via regulation of PARs/NET pathway. This may provide a novel target strategy against myocardial IRI.

Effects of electrospun fibers containing ascorbic acid on oxidative stress reduction for cardiac tissue engineering

Tissue engineering provides promise for regeneration of cardiac tissue following myocardial infarction. However, the harsh microenvironment of the infarct hampers the efficacy of regenerative therapies. Ischemia-reperfusion injury dramatically increases the levels of reactive oxygen species (ROS) within the infarcted area, causing a cascade of further cellular injury. Implantable tissue engineered grafts can target this oxidative stress by delivering pharmaceutical compounds directly into the diseased tissue. Herein, we successfully fabricated electrospun polycaprolactone (PCL) fibers containing varying concentrations of ascorbic acid, a potent antioxidant well known for its ROS-scavenging capabilities. The antioxidant scaffolds displayed significantly improved scavenging of DPPH radicals, superoxide anions and hydroxyl radicals, in a dose dependent manner. Mechanical properties testing indicated that incorporation of ascorbic acid enhanced the strength and Young's modulus of the material, correlating with a moderate but non-significant increase in the crystallinity. Moreover, the scaffolds supported adhesion and maintained survival of human umbilical vein endothelial cells in vitro, indicating good cytocompatibility. These results provide motivation for the use of ascorbic acid-containing fibrous scaffolds to regulate the highly oxidative microenvironment following myocardial infarction.

Association of prognostic nutritional index with long-term mortality in patients receiving percutaneous coronary intervention for acute coronary syndrome: a meta-analysis

The predictive value of the prognostic nutritional index (PNI) for the long-term prognosis of patients with acute coronary syndrome (ACS) remains uncertain. Medline, Embase, Cochrane Library, and Google Scholar were searched from inception until January 2023 to study the relationship between all-cause mortality risk and PNI in patients receiving percutaneous coronary intervention for ACS (i.e., primary outcome). Thirteen observational studies were included in this meta-analysis. Analysis of seven studies using PNI as a categorical variable showed a pooled hazard ratio (HR) of all-cause mortality of 2.97 (95% CI 1.65 to 5.34, p = 0.0003, I2 = 89%, n = 11,245) for patients with a low PNI. The meta-analysis also showed a higher risk of major adverse cardiovascular events (MACEs) in patients with a low PNI (HR 2.04; 95% CI 1.59 to 2.61; p < 0.00001; I2 = 21%; n = 8534). Moreover, advanced age, diabetes mellitus, and high Global Registry of Acute Coronary Events risk scores were associated with a high risk of all-cause mortality, whereas a high body mass index was associated with a low risk of all-cause mortality. The results showed an association between a low PNI and an increased risk of long-term mortality in patients undergoing coronary interventions for ACS. Further randomized controlled trials are necessary to confirm these findings.

Potential of graphene-based nanomaterials for cardiac tissue engineering

Cardiovascular diseases are the primary cause of death worldwide. Despite significant advances in pharmacological treatments and surgical interventions to restore heart function after myocardial infarction, it can progress to heart failure due to the restricted inherent potential of adult cardiomyocytes to self-regenerate. Hence, the evolution of new therapeutic methods is critical. Nowadays, novel approaches in tissue engineering have assisted in restoring biological and physical specifications of the injured myocardium and, hence, cardiac function. The incorporation of a supporting matrix that could mechanically and electronically support the heart tissue and stimulate the cells to proliferate and regenerate will be advantageous. Electroconductive nanomaterials can facilitate intracellular communication and aid synchronous contraction via electroactive substrate creation, preventing the issue of arrhythmia in the heart. Among a wide range of electroconductive materials, graphene-based nanomaterials (GBNs) are promising for cardiac tissue engineering (CTE) due to their outstanding features including high mechanical strength, angiogenesis, antibacterial and antioxidant properties, low cost, and scalable fabrication. In the present review, we discuss the effect of applying GBNs on angiogenesis, proliferation, and differentiation of implanted stem cells, their antibacterial and antioxidant properties, and their role in improving the electrical and mechanical properties of the scaffolds for CTE. Also, we summarize the recent research that has applied GBNs in CTE. Finally, we present a concise discussion on the challenges and prospects.

Regulatory effects of trimetazidine in cardiac ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury is a tissue damage during reperfusion after an ischemic condition. I/R injury is induced by pathological cases including stroke, myocardial infarction, circulatory arrest, sickle cell disease, acute kidney injury, trauma, and sleep apnea. It can lead to increased morbidity and mortality in the context of these processes. Mitochondrial dysfunction is one of the hallmarks of I/R insult, which is induced via reactive oxygen species (ROS) production, apoptosis, and autophagy. MicroRNAs (miRNAs, miRs) are non-coding RNAs that play a main regulatory role in gene expression. Recently, there are evidence, which miRNAs are the major modulators of cardiovascular diseases, especially myocardial I/R injury. Cardiovascular miRNAs, specifically miR-21, and probably miR-24 and miR-126 have protective effects on myocardial I/R injury. Trimetazidine (TMZ) is a new class of metabolic agents with an anti-ischemic activity. It has beneficial effects on chronic stable angina by suppressing mitochondrial permeability transition pore (mPTP) opening. The present review study addressed the different mechanistic effects of TMZ on cardiac I/R injury. Online databases including Scopus, PubMed, Web of Science, and Cochrane library were assessed for published studies between 1986 and 2021. TMZ, an antioxidant and metabolic agent, prevents the cardiac reperfusion injury by regulating AMP-activated protein kinase (AMPK), cystathionine-γ-lyase enzyme (CSE)/hydrogen sulfide (H2S), and miR-21. Therefore, TMZ protects the heart against I/R injury by inducing key regulators such as AMPK, CSE/H2S, and miR-21.