Myocardial Ischemia-reperfusion Injury Research Articles

Ilexgenin A Alleviates Myocardial Ferroptosis in Response to Ischemia Reperfusion Injury via the SIRT1 Pathway.

Myocardial ischemia-reperfusion (I/R) injury has emerged as an increasingly serious cardiovascular health concern worldwide, with ferroptosis playing a pivotal role as the underlying pathogenic process. This study aimed to investigate the pharmacological effect and mechanism of Ilexgenin A on cardiomyocyte ferroptosis induced by myocardial I/R injury. Invivo, we established a murine anterior descending artery ligation/recanalization model to evaluate the cardioprotective effect of Ilexgenin A. Bioinformatics analysis, molecular docking, and Surface Plasmon Resonance imaging were conducted to predict the pharmacological targets of Ilexgenin A. Invitro experiments, the neonatal rat cardiomyocytes (NRCMs) were utilized to further explore the mechanism of Ilexgenin A in inhibiting ferroptosis using chemiluminescence and immunofluorescence staining, electron microscopy, biochemical assay, RT-qPCR, western blotting, and so on. The results showed that Ilexgenin A protected against cardiac dysfunction, ameliorated myocardial ferroptosis and mitochondrial damage induced by murine myocardial I/R injury via the silence information regulator 1 (SIRT1) pathway, the trend was consistently observed in NRCMs. Additionally, the SIRT1 knockdown by siRNA delivery partially abrogated the beneficial effects of Ilexgenin A on ameliorating mitochondrial damage, and then aggravated erastin-induced ferroptosis in NRCMs. Overall, Our research demonstrated that the inhibition of ferroptosis via the SIRT1 pathway was one of the mechanisms by which Ilexgenin A exerted cardioprotective effect.

SHEP1 alleviates cardiac ischemia reperfusion injury via targeting G3BP1 to regulate macrophage infiltration and inflammation

The macrophage-associated inflammation response plays an important role in myocardial ischemia-reperfusion injury (MIRI). SHEP1(SH2 domain-containing Eph receptor-binding protein 1) has been implicated in adhesion and migration of inflammatory cells. However, the role and molecular mechanism of SHEP1 regulating macrophage remains unclear during MIRI. Here, the expression of SHEP1 was increased in macrophages co-cultured with hypoxia-reoxygenated cardiomyocytes and within ischemia-reperfusion injured myocardium at the early stage of injury. Cell migration and inflammation were also enhanced in SHEP1 knock-out macrophages and macrophage-specific deficiency of SHEP1 mice under MIRI, which further led to deteriorated cardiac injury and cardiac function in vivo. Mechanistically, macrophage-derived SHEP1 competitively bound to G3BP1 to suppress inflammation via the MAPK pathway. In addition, administrating inhibitor of G3BP1 could improve cardiac function in macrophage-specific deficiency of SHEP1 mice under MIRI. Our results demonstrate that SHEP1 deficiency in macrophages exacerbates MIRI through G3BP1-dependent signaling pathway. SHEP1-G3BP1 interaction are therefore indispensable for SHEP1 regulated- infiltration and proinflammatory responses of macrophages, which provided a potential and clinically significant therapeutic target for MIRI.

Mechanisms and Therapeutic Potential of Multiple Forms of Cell Death in Myocardial Ischemia–Reperfusion Injury

Programmed cell death, especially programmed necrosis such as necroptosis, ferroptosis, and pyroptosis, has attracted significant attention recently. Traditionally, necrosis was thought to occur accidentally without signaling pathways, but recent discoveries have revealed that molecular pathways regulate certain forms of necrosis, similar to apoptosis. Accumulating evidence indicates that programmed necrosis is involved in the development of various diseases, including myocardial ischemia–reperfusion injury (MIRI). MIRI occurs when blood flow and oxygen return to an ischemic area, causing excessive production of reactive oxygen species. While this reperfusion is critical for treating myocardial infarction, it inevitably causes cellular damage via oxidative stress. Furthermore, this cellular damage triggers multiple forms of cardiomyocyte death, which is the primary cause of inflammation, cardiac tissue remodeling, and ensuing heart failure. Therefore, understanding the molecular mechanisms of various forms of cell death in MIRI is crucial for therapeutic target discovery. Developing therapeutic strategies to inhibit multiple cell death pathways simultaneously could provide effective protection against MIRI. In this paper, we review the fundamental molecular pathways and MIRI-specific mechanisms of apoptosis, necroptosis, ferroptosis, and pyroptosis. Additionally, we suggest that the simultaneous suppression of multiple cell death pathways could be an effective therapy and identify potential therapeutic targets for implementing this strategy.

Mechanisms and Therapeutic Strategies for Myocardial Ischemia-Reperfusion Injury in Diabetic States.

In patients with myocardial infarction, one of the complications that may occur after revascularization is myocardial ischemia-reperfusion injury (IRI), characterized by a depleted myocardial oxygen supply and absence of blood flow recovery after reperfusion, leading to expansion of myocardial infarction, poor healing of myocardial infarction and reversal of left ventricular remodeling, and an increase in the risk for major adverse cardiovascular events such as heart failure, arrhythmia, and cardiac cell death. As a risk factor for cardiovascular disease, diabetes mellitus increases myocardial susceptibility to myocardial IRI through various mechanisms, increases acute myocardial infarction and myocardial IRI incidence, decreases myocardial responsiveness to protective strategies and efficacy of myocardial IRI protective methods, and increases diabetes mellitus mortality through myocardial infarction. This Review summarizes the mechanisms, existing therapeutic strategies, and potential therapeutic targets of myocardial IRI in diabetic states, which has very compelling clinical significance.

Aerobic exercise training attenuates ischemia-reperfusion injury in mice by decreasing the methylation level of METTL3-associated m6A RNA in cardiomyocytes.

Ischemic heart disease (IHD) presents a significant global health challenge, with myocardial ischemia-reperfusion injury (MIRI) being a major pathophysiological contributor and lacking effective interventions. While aerobic exercise training (AET) enhances cardiovascular health, its protective mechanism in MIRI remains elusive. This study aims to elucidate the protective effect of AET in MIRI and its underlying mechanism. A mouse model of AET and MIRI was established to evaluate basic indices, cardiac ultrasound, and myocardial injury markers. Dot Blot, qRT-PCR, and Western blot were employed to assess m6A RNA methylation levels and related protein expression in myocardial tissue. In vitro, primary cardiomyocyte culture was utilized to mimic MIRI, evaluating cell viability, mitochondrial membrane potential, etc. Finally, myocardial tissues of MIRI mice were immunoprecipitated for m6A RNA methylation and sequenced to analyze related signaling pathways. AET significantly improved cardiac function and mitigated myocardial injury and fibrosis. Moreover, AET protected myocardium from MIRI by reducing m6A RNA methylation levels and modulating METTL3 expression. In vitro experiments demonstrated that the decrease in m6A RNA methylation levels and METTL3 expression conferred resistance to hypoxia/reoxygenation-induced injury. Furthermore, sequencing results indicated elevated myocardial tissue m6A RNA methylation levels during MIRI, activation of the Nrf2-related signaling pathway, and AET-mediated regulation of the Nrf2/HO-1 signaling pathway, thereby attenuating MIRI through modulation of METTL3-related m6A methylation. AET attenuates MIRI by reducing the level of METTL3-related m6A RNA methylation in cardiomyocytes and activating the Nrf2/HO-1 antioxidant signaling pathway. This finding provides a novel insight and strategy for the prevention and treatment of IHD, holding significant clinical implications.

The Role of Exosomes in Myocardial Ischemia-Reperfusion Injury.

Acute myocardial infarction (AMI) is one of the critical and serious diseases in the cardiovascular system, and reperfusion therapy is the preferred treatment for AMI, but it often worsens cardiac injury and leads to myocardial ischemia reperfusion injury (MIRI), which can further result in arrhythmia, heart failure, and death. More and more studies have found that mesenchymal stem cells (MSCs)-derived exosomes play an important role in improving the cardiac injury after MIRI, and can exert anti-apoptosis, anti-inflammation, anti-fibrosis, and promotion of endothelial cells and angiogenesis functions. This review summarizes the mechanisms of action of exosomes in the treatment of MIRI and discusses exosomes as a new approach for the treatment of MIRI. 1) Exosomes play a variety of protective roles in MIRI by carrying miRNAs and other bioactive substances. 2) Exosomes can be used as carriers of drugs or active substances for the treatment of cardiovascular diseases.

A Novel Method for Mitochondrial Membrane Potential Detection in Heart Tissue Following Ischemia-reperfusion in Mice.

Myocardial ischemia-reperfusion (I/R) injury is associated with a significant reduction in the mitochondrial membrane potential (MMP, ΔΨm). Fluorescence-based assays are effective for labelling active mitochondria in living cells; their application in heart tissue, however, represents a challenge because of a low yield of viable cardiomyocytes after cardiac perfusion. This study aimed to examine a novel method for detecting the changes in the MMP of mouse heart tissue following I/R injury. The I/R model was established, which was characterized by distinct ischemic area and apoptosis in heart tissue. The MMP was detected via a confocal microscope after the ascending aorta was clamped and the mitochondrial probe solution (containing Mito-Tracker Deep Red FM) was perfused from the apex via a peristaltic pump. This method enabled the distribution of the probe solution throughout the cardiac tissue via the coronary circulation. Fluorescence detection revealed that the MMP was profoundly reduced in both ischemic area and border area following I/R when compared with that in the sham group. There was no obvious difference in the MMP of the remote area between the I/R group and the sham group. This study presents a novel method for detecting the MMP in heart tissue, and this method will facilitate the evaluation of changes in the MMP in different regions following I/R.

DanShen Decoction targets miR-93-5p to provide protection against MI/RI by regulating the TXNIP/NLRP3/Caspase-1 signaling pathway

BackgroundBone marrow mesenchymal stem cells (BMSCs) derived exosomes have demonstrated potential therapeutic efficacy on myocardial ischemia/reperfusion injury (MI/RI). This study has explored the underlying mechanisms of Danshen decoction (DSD) pretreated BMSCs-exosomes to treat MI/RI in vivo and in vitro. MethodsExtracellular vesicles extracted from BMSCs were identified, miRNA sequencing was performed to screen the effects of DSD, and verified to target TXNIP in vivo. After MI/RI modeling, rats were treated with BMSCs-exosomes pretreated with DSD or miRNA inhibitor. BMSCs-exosomes, DSD-pretreated BMSCs-exosomes, and miRNA inhibitor/anti-miRNA-pretreated BMSCs-exosomes were used to treat H9c2 cells or MI/RI rats. CCK-8, Tunnel staining, and flow cytometry were performed to measure cell viability. LDH, CK, CK-MB were detected to evaluate cell injury. MDA, SOD, and ROS were used to confirm oxidative stress. Furthermore, IL-1β, IL-18, cleaved-caspase-1, pro-caspase-1, NLRP3, TXNIP, and GSDMD were quantified for the TXNIP/NLRP3/Caspase-1 signaling activation. In addition, echocardiography was used to observe the heart function, and H&E stain was performed to detect pathological injury. ResultsFollowing DSD pretreatment, there was a marked elevation in the expression levels of miR-93-5p, miR-16-5p, and miR-15b-5p, with miR-93-5p exhibiting the highest baseMean value. The administration of a miR-93-5p inhibitor yielded effects counteractive to those observed with DSD treatment, leading to reduced cell proliferation, heightened oxidative stress (as indicated by increased levels of SOD and ROS, alongside a decrease in MDA), and enhanced cell apoptosis. Furthermore, DSD effectively mitigated the miR-93-5p-induced upregulation of key inflammatory and apoptotic markers, including IL-1β, IL-18, caspase-1, NLRP3, TXNIP, and GSDMD. Notably, exosomes derived from DSD-pretreated BMSCs demonstrated a capacity to alleviate cardiac damage. ConclusionDSD may target miR-93-5p within BMSC-derived exosomes to confer protection against cardiac damage by inhibiting the activation of the TXNIP/NLRP3/Caspase-1 signaling pathway, thereby mitigating cardiomyocyte pyroptosis. This study provides a theoretical foundation for the application of DSD in the treatment of MI/RI.

Interleukin-38 ameliorates myocardial Ischemia-Reperfusion injury via inhibition of NLRP3 inflammasome activation in fibroblasts through the IL-1R8/SYK axis

ObjectiveAlthough IL-38 is recognized for its regulatory role in a spectrum of chronic inflammatory diseases, investigations into its cardiac physiological and pathophysiological functions are nascent. Our aim was to delineate the biological impact of IL-38 in the context of myocardial ischemia–reperfusion injury (MIRI) and to uncover the mechanisms through which it exerts its effects. Methods and ResultsIn this study, we used an MIRI mouse model, LPS/ATP stimulation, and a hypoxia/reoxygenation cell model to determine the regulatory influence of IL-38 on MIRI. We observed that the administration of recombinant IL-38 to mice led to a reduction in infarct size, an enhancement in cardiac function, and a suppression of NLRP3 inflammasome activation. In contrast, genetic deletion of IL-38 was associated with an increase in infarct size, worsening of cardiac function, and upregulation of NLRP3 inflammasome activity. The detrimental effects associated with the absence of IL-38 were mitigated by the administration of a specific NLRP3 inhibitor, suggesting that the inhibition of NLRP3 is a critical component of the protective effect mediated by IL-38 in MIRI. In vitro assays revealed that IL-38 inhibited NLRP3 inflammasome activation in cardiac fibroblasts through the engagement of IL-1R8 and the modulation of SYK phosphorylation. Silencing of IL-1R8 negated the suppressive effect of IL-38 on the NLRP3 inflammasome. ConclusionIL-38 acts as a potent negative regulator of inflammasome activation after MIRI. It achieves this regulatory effect within cardiac fibroblasts by inhibiting SYK phosphorylation, a process mediated by IL-1R8.

Blockage of polycystin-2 alleviates myocardial ischemia/reperfusion injury by inhibiting autophagy through the Ca2+/Akt/Beclin 1 pathway.

Autophagy is a well-conserved self-protection process that plays an important role in cardiovascular diseases. Excessive autophagy during myocardial ischemia/reperfusion injury (MIRI) induces calcium overload and the overactivation of an autophagic response, thereby aggravating cardiomyocyte damage. Polycystin-2 (PC2) is a Ca2+-permeable nonselective cation channel implicated in the regulation of autophagy. In the present study, autophagy was upregulated in myocardial ischemia/reperfusion in vivo and in vitro. PC2 knockdown using adeno-associated virus9 particles containing Pkd2 short hairpin RNA infection markedly ameliorated MIRI, evidenced by reduced infarct size, diminished morphological changes, decreased cTnI levels, and improved cardiac function. Silencing PC2 reduced the autophagic flux in H9c2 cells. PC2 overexpression-mediated autophagic flux was inhibited by intracellular Ca2+ chelation with BAPTA-AM. Furthermore, PC2 ablation upregulated p-Akt (Ser473) and downregulated Beclin 1 in H/R. BAPTA-AM downregulated p-Akt(Ser473) and upregulated Beclin 1in PC2-overexpressing H9c2 cells. Moreover, the Akt inhibitor MK2206 abolished the BAPTA-AM-blunted PC2-dependent control of autophagy. Collectively, these results indicated that blockade of PC2 may be associated with the Ca2+/Akt/Beclin 1 signaling, thereby inhibiting excessive autophagy and serving as a potential strategy for mitigating MIRI.

Platelet-mimicking Nanoparticles Loaded with Diallyl Trisulfide for Mitigating Myocardial Ischemia-Reperfusion Injury in Rats

Platelet-mimicking Nanoparticles Loaded with Diallyl Trisulfide for Mitigating Myocardial Ischemia-Reperfusion Injury in Rats

Cardioprotective effects of S-equol, a soybean metabolite with estrogen activity, and role of the PI3K/Akt pathway in a male rat model of ischemic reperfusion

PurposeS-equol, an isoflavone metabolite with high estrogenic activity, exhibits organ-protective effects via the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. While estrogen has cardioprotective effects against ischemia–reperfusion injury, whether S-equol shares this capability remains uncertain. This study aimed to assess the cardioprotective effects of S-equol on stunned myocardium using an isolated rat heart model and investigate the involvement of PI3K/Akt signaling pathway. MethodsMale rat hearts were perfused using the Langendorff system and divided into four groups: 1) modified Krebs–Henseleit (KH) buffer containing 1 μmol/L S-equol (EQ); 2) KH buffer (Cont); 3) KH buffer supplemented with 1 μmol/L S-equol and 100 nmol/L wortmannin (a specific PI3K inhibitor) (EQW); or 4) KH buffer containing wortmannin (ContW). After stabilization, each group was perfused for 20 min before undergoing 7.5 min of no-flow ischemia, followed by 20 min reperfusion. The primary outcome was the maximum left ventricular derivative of pressure development (left ventricle [LV] dP/dt max)after 20 min of reperfusion. Myocardial Akt and glycogen synthase kinase-3 beta (GSK-3β) were assayed using western blotting. ResultsLV dP/dt max was greater in the EQ group than that in the Cont group after 15 and 20 min of reperfusion; however, this effect was attenuated in the presence of PI3K inhibitors. S-equol treatment increased Akt and suppressed GSK-3β expression in the EQ group compared to that in the Cont group. However, these effects were not observed in the presence of wortmannin. ConclusionS-equol exerts a protective effect against myocardial ischemia–reperfusion injury, possibly by activating PI3K/Akt signaling.

Innovative engineering of superoxide dismutase for enhanced cardioprotective biocatalysis in myocardial ischemia-reperfusion injury

The present research compares the stability, catalytic activity, and cardioprotective benefits of the designed superoxide dismutase (SOD) variation SOD-M3 to those of the naturally occurring enzyme, along with additional alternatives. SOD-M3 exhibited a 51.5 % increase in expression yield, reaching 50 mg/L, compared to the wild-type's 33 mg/L. In structural biology, the average distance between atoms of stacked proteins or molecules is measured by RMSD. Testing the precision of protein-ligand docking models is a typical application. The projected structure closely resembles the reference or native structure when the RMSD is low. The enzyme's durability improved significantly, resulting in negligible aggregation in the Size Exclusion Chromatography (SEC) and root mean square deviation (RMSD) of 2.1 Å. SOD-M3 catalytically increased superoxide radical scavenging capability by 40 % and inhibited nitroblue tetrazolium (NBT) reduction by 90 % at 1 μg/mL concentration. The material exhibited increased stability, as seen by its decomposition temperature (Tm) of about 80 °C, as opposed to 65 °C in the wild-type strains. In cardiomyocyte protection experiments, SOD-M3 reduced lactate dehydrogenase (LDH) production by 55 % while decreasing reactive oxygen species (ROS) concentrations by 60 %. Since a 51.5 % increase in expression yield for SOD-M3 indicates improved production efficiency, which makes large-scale manufacturing more viable for clinical applications, it is therapeutically essential. Higher expression yields mean more cost-effective manufacture for enzyme-based therapy research and commercialization. In vivo, SOD-M3 decreased myocardial infarction diameter by 44 % while improving cardiac function, including increased ejection percentage and fractional contraction. The histopathological investigation revealed undamaged heart tissue and less necrotic areas. The results reported here demonstrate SOD-M3's superior activity of enzymes, cardioprotective perspective, and stability, making it a promising therapeutic alternative for illnesses related to cellular oxidation & ischemic cardiac diseases. An increase in enzyme concentrations can enhance the obtaining of reactive oxygen species (ROS), which build up during ischaemia episodes; therefore, this increase is essential. Improving the enzyme's solubility and stability by site-directed modifications makes SOD-M3 more stable and effective in physiological circumstances where its activity is crucial for therapeutic efficacy maximization. A further benefit of increased expression yield is that it can lower manufacturing costs, which will help get SOD-M3 into clinical settings. These modifications raise SOD-M3's cardioprotective potential, making it a strong contender for novel therapies against cardiac ischemia-reperfusion impacts.

Andrographolide Attenuates Myocardial Ischemia-Reperfusion Injury in Mice by Up-Regulating PPAR-α.

Andrographolide (AGP), a bioactive diterpene lactone, is an active constituent extracted from Andrographis paniculata. It has many biological activities, such as antioxidant, antitumor, antivirus, anti-inflammation, hepatoprotection, and cardioprotection. The aim of the present study is to investigate the cardioprotective effects of AGP in a mouse model of myocardial ischemia-reperfusion injury (MIRI). Adult male C57BL/6J mice were pre-treated orally with AGP (25mg/kg) for six days. After 30min of the left anterior descending coronary artery occlusion followed by 24h of reperfusion, mice received an additional dose of AGP. The results showed that: (i) AGP pretreatment significantly reduced myocardial infarct size and cardiac injury biomarkers in MIRI mice and improved left ventricular ejection fraction (EF) and fractional shortening (FS); (ii) AGP pretreatment attenuated MIRI-induced oxidative stress imbalance in MIRI mice by increasing total antioxidant capacity (T-AOC) and reducing the levels of hydrogen peroxide (H2O2), nitric oxide (NO), malondialdehyde (MDA), and dihydroethidium (DHE); (iii) AGP pretreatment increased Bcl-2 expression and decreased caspase-3 and Bax expression in ischemic myocardial tissue, along with a reduction in TUNEL-positive cells. Further analysis showed that stimulation by I/R decreased peroxisome proliferator-activated receptor-α (PPAR-α) expression in ischemic cardiac tissue, which was prevented by AGP administration. Moreover, administration of the PPAR-α antagonist GW6471 (1mg/kg) abolished the protective effect of AGP on oxidative stress and apoptosis in the ischemic heart tissue of mice stimulated by ischemia-reperfusion. Taken together, these results suggest that AGP attenuates MIRI-induced cardiac injury by up-regulating PPAR-α expression, thereby preventing oxidative stress and cellular apoptosis.

Moderate-intensity aerobic exercise inhibits cell pyroptosis to improve myocardial ischemia-reperfusion injury.

Myocardial ischemia-reperfusion injury (MI/RI) significantly impacts the patients with acute myocardial infarction (AMI), with the NLRP3-mediated necrosis exacerbates the pathological progression of myocardial infarction. Exercise, recognized as a crucial approach for both disease prevention and treatment, is widely utilized in clinical practice worldwide and has demonstrated broad effectiveness in cardiovascular disease (CVD) prevention. To explore the cardio protective effect of exercise preconditioning and the mechanism by which exercise modulation of NLRP3 improves myocardial ischemia and reperfusion injury. In this study, C57BL/6N mice were employed to establish an exercise preconditioning model and a MI/RI model. The exercise intervention involved moderate-intensity aerobic exercise on a treadmill (50-70% VO2max) for small animals. Our research findings indicate that moderate-intensity aerobic exercise intervention improved cardiac function, reduced myocardial injury and inflammatory response, decreased myocardial infarction area and degree of cell apoptosis in mice compared to those raised under conventional conditions. Additionally, the expression of NLRP3 in the myocardial tissue of mice with MI/RI was reduced after exercise intervention. Moreover, exercise inhibited the activation of apoptosis related proteins such as Caspase-1 and GSDMD, while reducing the levels of inflammatory factors such as IL-1β and IL-18. This study found that moderate-intensity aerobic exercise can reduce the inflammatory response, reduce the degree of cell pyroptosis, reduce myocardial ischemia and reperfusion injury, and achieve endogenous protective effects on the myocardium.

Protective Role of Vitamin D Receptor in Cerebral Ischemia/Reperfusion Injury In Vitro and In Vivo Model.

Vitamin D receptor (VDR) can prevent myocardial ischemia reperfusion injury (MIRI). Hence, we aimed to illuminate the effect of VDR on cerebral ischemia/reperfusion injury (CIRI). C57BL/6 mice and SK-N-SH cells were utilized to establish CIRI and cellular oxygen deprivation/reoxygenation (OGD/R) models. Mice were injected with 1 μg/kg Calcitriol or 1 μg/kg Paricalcitol (PC) and adenovirus-mediated VDR overexpression or knockdown plasmids. 2,3,5-triphenyl-tetrazolium chloride (TTC) and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays were performed to measure the brain infarct volume and the apoptosis of cerebral cells. SK-N-SH cells were treated with 5 mM N-acetyl-L-cysteine (NAC) and transfected with VDR knockdown plasmid. Flow cytometry and Cell Counting Kit-8 (CCK-8) assays were employed to assess the apoptosis and cell viability. Enzyme-Linked Immunosorbent Assay (ELISA), quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) and Western blot were exploited to quantify the levels of reactive species oxygen (ROS), other oxidative stress-related factors, VDR and apoptosis-related factors. The level of VDR in mouse cerebral tissue was elevated by CIRI (p < 0.001). CIRI-induced cerebral infarction (p < 0.001) and the apoptosis of cerebral cells (p < 0.001) in mice were mitigated by the activation of VDR. VDR overexpression abrogated while VDR silencing enhanced CIRI-induced infarction, oxidative stress and apoptosis of cerebral cells (p < 0.05). Furthermore, VDR silencing aggravated the oxidative stress and apoptosis in OGD/R-treated SK-N-SH cells (p < 0.05). NAC, a scavenger of oxidative stress, could reverse the effects of VDR silencing on apoptosis and oxidative stress in OGD/R-treated SK-N-SH cells (p < 0.01). VDR alleviates the oxidative stress to protect against CIRI.

LDHA exacerbates myocardial ischemia-reperfusion injury through inducing NLRP3 lactylation

Myocardial ischemia-reperfusion (I/R) injury caused by revascularization treatment is the leading cause of cardiac damage aggravation in ischemic heart disease. Increasing evidence has unraveled the crucial role of pyroptosis in myocardial I/R injury. Of note, lactylation has been validated to be participated in modulating pyroptosis. Hence, this study was aimed to elaborate the potential and mechanism of lactylation in myocardial I/R damage. We established the cell model of I/R through inducing hypoxia/reoxygenation (H/R) of H9c2 cells. It was uncovered that H/R stimulation drove cardiomyocyte pyroptosis and upregulated total lactylation level. Further, we demonstrated that promoting lactylation contributed to H/R-evoked pyroptosis, whereas silencing LDHA led to the opposite results. More than that, LDHA was confirmed to facilitate lactylation of NLRP3 at K245 site and increase its protein stability. Our findings indicated that activation of NLRP3 abolished the function of LDHA deficiency in H/R-treated H9c2 cells. In concert with the aforementioned outcomes, knockout of LDHA attenuated the infarct size and myocardial damage in I/R mice and upregulation of NLRP3 counteracted the effects of LDHA knockout on I/R-evoked injury in vivo. To summarize, the current research provided persuasive evidence that LDHA promoted myocardial I/R damage via enhancing NLRP3 lactylation to induce cardiomyocyte pyroptosis.

Early growth response-1, a dynamic conduit in cardiovascular disease.

The transcription factor, early growth response-1 (Egr-1) is the product of a prototypic immediate-early gene that plays an integral role in the pathogenesis of multiple cardiovascular diseases. Egr-1 has been linked with atherogenesis, myocardial ischemia-reperfusion injury, cardiac fibrosis and heart failure. Egr-1 expression is triggered by a host of factors including cytokines, hormones, growth factors, hyperglycaemia, biomechanical forces and oxygen deprivation. Egr-1 is a molecular conduit that links changes in the cellular environment with the inducible expression of genes whose products play a causative role in this inflammatory disease. It is rapidly synthesised, undergoes post-translational modification, interacts with a range of cofactors and drives gene expression. Studies in Egr-1 deficient mice, animal models using DNAzymes, RNA interference, oligodeoxynucleotide decoys, antisense oligonucleotides, and new insights provided by technologies such as single cell RNA sequencing, have shaped our understanding of the importance of Egr-1 in the initiation and progression of cardiovascular disease. This article describes Egr-1's role in various cardiovascular settings and discusses potential mechanisms of action. Given the range of conditions linked to Egr-1, this zinc finger protein may serve as a therapeutic target for intervention.

Multicellular 3D models to study myocardial ischemia-reperfusion injury.

Coronary heart disease is a major global health threat, with acute myocardial ischemia-reperfusion injury (IRI) being a major contributor to myocardial damage following an ischemic event. IRI occurs when blood flow to ischemic tissues is restored and exacerbates the cellular damage caused by ischemia/hypoxia. Although animal studies investigating IRI have provided valuable insights, their translation into clinical outcomes has been limited, and translation into medical practice remains cumbersome. Recent advancements in engineered three-dimensional human in vitro models could offer a promising avenue to bridge the "therapeutic valley of death" from bench to bedside, enhancing the understanding of IRI pathology. This review summarizes the current state-of-the-art cardiovascular 3D models, including spheroids, organoids, engineered cardiac microtissues, and organ-on-a-chip systems. We provide an overview of their advantages and limitations in the context of IRI, with a particular emphasis on the crucial roles of cell-cell communication and the multi-omics approaches to enhance our understanding of the pathophysiological processes involved in IRI and its treatment. Finally, we discuss currently available multicellular human 3D models of IRI.

Salvianolic acid B alleviated myocardial ischemia-reperfusion injury via modulating SIRT3-mediated crosstalk between mitochondrial ROS and NLRP3

BackgroundMitochondrial ROS (mtROS) accumulation and NLRP3 inflammasome activation are critical in the pathogenesis of myocardial ischemia-reperfusion injury (MIRI). However, their upstream regulatory mechanisms and interaction remain inadequately understood. PurposeThe study aims to investigate the therapeutic effect of Salvianolic acid B (Sal B) on MIRI and elucidate its potential molecular mechanism, mainly focusing on the role of SIRT3. MethodsSIRT3 was knocked down (SIRT3KD) and overexpressed (SIRT3OE) using small interfering RNA and plasmid, respectively. The role of SIRT3 in the cardioprotective effect of Sal B was explored using MIRI rat models and H9c2 cell hypoxia/reoxygenation (H/R) models. SIRT3, NLRP3 inflammasome proteins, and MnSOD expression were analyzed by Western blot and immunofluorescence staining. MtROS levels were assessed with mitochondrial superoxide indicators (MitoSOX™ Red). ELISA was utilized to measure the levels of LDH, CK-MB, cTnT, and markers of inflammation and oxidative stress. The interaction between SIRT3 and Sal B was studied through biolayer interferometry, cellular thermal shift assay and molecular docking. ResultsOur findings revealed significantly decreased SIRT3 level, enhanced MnSOD acetylation, and activated NLRP3 inflammasome in myocardium after MIRI and H9c2 cardiomyocytes exposed to H/R conditions. SIRT3KD promoted MnSOD acetylation and NLRP3 expression, aggravating mtROS accumulation and inflammation. Conversely, SIRT3OE significantly inhibited MnSOD acetylation and NLRP3 inflammasome activation. In vitro studies confirmed the crosstalk between mtROS and NLRP3, demonstrating that mtROS scavenger inhibited NLRP3 inflammasome activation induced by H/R and SIRT3KD, and the NLRP3 inhibitor suppressed MnSOD acetylation in H/R and SIRT3KD cardiomyocytes. Interestingly, Sal B was found to bind and upregulate SIRT3, reduce the expression of Acy-MnSOD, NLRP3, ASC, Caspase-1, and GSDMD, inhibit oxidative stress and inflammatory response, decrease myocardial infarct size and ST-segment elevation, and restore myocardial morphology. However, the protective effect of Sal B against MIRI was nullified by a specific SIRT3 inhibitor. ConclusionThis study unveils that the SIRT3-mediated interplay between mtROS and the NLRP3 inflammasome is pivotal in the pathogenesis of MIRI. Furthermore, it highlights Sal B as a novel therapeutic agent that alleviates MIRI by targeting SIRT3, offering new insights into MIRI treatment.