Infarct Size Research Articles

2′-Hydroxycinnamaldehyde, a Natural Product from Cinnamon, Alleviates Ischemia/Reperfusion-Induced Microvascular Dysfunction and Oxidative Damage in Rats by Upregulating Cytosolic BAG3 and Nrf2/HO-1

2′-Hydroxycinnamaldehyde (HCA), a natural product isolated from the bark of Cinnamomum cassia, has anti-inflammatory and anti-tumor activities. In this study, we explored whether HCA preconditioning could protect the heart against ischemia/reperfusion (I/R)-induced oxidative injury through cytosolic Bcl-2-associated athanogene 3 (BAG3) upregulation. In vivo HCA preconditioning was performed intraperitoneally in adult male Wistar rats (50 mg/kg body weight) three times/week for 2 weeks before cardiac I/R injury. The animals were divided into sham control (sham), I/R, and HCA preconditioning plus I/R (HCA+I/R) groups. We examined left ventricular pressure cardiac hemodynamics, the microcirculation, electrocardiograms, infarct size, and oxidative stress and performed Western blots, immunohistochemistry, and cytokine array assays. HCA pretreatment, via BAG3 overexpression, inhibited H2O2-induced H9c2 cell death. Cardiac I/R injury increased ST-segment elevation, left ventricular end-diastolic pressure, infarct size, myocardial disruption, tissue edema, erythrocyte accumulation, leukocyte infiltration, reactive oxygen species, malondialdehyde, 8-isoprostane, caspase 3-mediated apoptosis, 4HNE/GPX4-mediated ferroptosis, and fibrosis but decreased the microcirculation, cytosolic BAG3, and Beclin-1/LC3 II-mediated autophagy in the I/R hearts. HCA preconditioning significantly decreased these oxidative injuries by increasing cardiac cytosolic BAG3 and Nrf2/HO-1 signaling. HCA preconditioning significantly decreased cardiac I/R-enhanced mitochondrial fission DRP1 expression. Our data suggest that HCA preconditioning can efficiently improve myocardial I/R injury-induced cardiac dysfunction, apoptosis, ferroptosis, mitochondrial fission, and autophagy inhibition through cardiac BAG3 and Nrf2/HO-1 upregulation.

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.

Study on the protective mechanism of Xuemaitong Capsule against acute myocardial ischemia rat based on network pharmacology and metabolomics

BackgroundXuemaitong Capsule (XMT) is a widely recognized traditional Miao medicine extensively utilized in Chinese clinical settings. Previous studies have demonstrated XMT protective effects against acute myocardial ischemia (AMI). However, the mechanism by which XMT provides protection to AMI rats is yet to be fully understood. Aim of the studyThe purpose of this study was to investigate the protective mechanism of XMT on AMI rats through network pharmacology, traditional pharmacodynamics and metabolomics. Material and methodsThe components and potential targets of XMT were identified through the application of traditional Chinese medicine system pharmacology and traditional Chinese medicine molecular mechanism bioinformatics analysis tools. We constructed herb-composition-target networks and analyzed protein–protein interaction (PPI) networks. The potential mechanism was explored by pathway enrichment analysis. Subsequently, the AMI model was constructed by ligation of the anterior descending branch of the left coronary artery, and XMT protective effects on AMI rats were evaluated by analyzing the myocardial enzyme profiles, electrocardiograms(ECG), Triphenyltetrazolium chloride(TTC) staining, and Hematoxylin-Eosin (HE) staining in AMI rats. Metabolomics based on UHPLC-Q-Exactive Orbitrap MS was used to observe the protective effect of XMT on the serum metabolic profile of AMI, and multivariate statistical analysis further revealed the differential patterns of metabolites after XMT treatment. Finally, integrated pathway analysis was carried out to reveal the biological metabolic mechanism. ResultsA total of 392 active components of XMT acted with 624 targets for treating AMI. Pathway enrichment analysis revealed that XMT could treat AMI through TNF, MAPK and PI3K-Akt signaling pathways. Further, XMT could effectively prevent ST-segment elevation in the ECG, reduce the size of myocardial infarction, decrease cardiac weight index and cardiac enzyme levels, and mitigate histological damage in the hearts of AMI rats. In addition, XMT callback 117 metabolites and four metabolic pathways, including taurine and hypotaurine metabolism, phenylalanine metabolism, pyrimidine metabolism and retinol metabolism. Through integrating network pharmacology and metabolomics, we explored the biological mechanism by which XMT treats AMI. It was speculated that the mechanism of XMT is to regulate TNF signaling, PI3K-Akt pathway and MAPK signaling pathway, and participate in cell apoptosis, oxidative stress, immune and inflammatory reaction and other biological processes. ConclusionXMT plays a protective role in AMI rats by regulating multiple metabolic biomarkers, multiple targets and pathways. Therefore, XMT may provide a potential strategy for the treatment of AMI.

Molecular mechanism of METTL14-mediated m6A modification regulating microglial function post ischemic stroke

This study explores the molecular mechanism of METTL14 regulating microglial function post ischemic stroke. A murine model was established by tMCAO. The neurological function was evaluated by mNSS. The cerebral infarct size and pathological changes were observed by TTC and H&E staining. M1 and M2 microglia in brain tissues were detected by flow cytometry. BV2 cells were subjected to OGD/R to establish an in vitro model. qRT-PCR and Western blot were used for detecting METTL14, PAX6, YTHDF2, TREM2, iNOS, and Arg1 expressions. The m6A level was quantitatively analyzed, and the binding of YTHDF2 or m6A to PAX6 was analyzed by RIP. PAX6 mRNA stability was assessed after actinomycin D treatment. ChIP was utilized for determining the enrichment of PAX6 on TREM2 promoter. The binding relationship between TREM2 and PAX6 was verified by dual-luciferase reporter assay. METTL14 was highly expressed after tMCAO, and silence of METTL14 alleviated symptoms of tmcao mice and promoted microglial M2 polarization. METTL14 enhanced PAX6 mRNA m6A modification to promote YTHDF2 binding to PAX6 mRNA and its degradation. PAX6 bound to TREM2 promoter and facilitated its transcription and expression. In conclusion, METTL14-mediated m6A modification aggravates ischemic stroke by promoting microglial M1 polarization via YTHDF2/PAX6/TREM2 axis.

Hepatic Tissue Alterations in ST-Elevation Myocardial Infarction: Determinants and Prognostic Implications.

The presence and clinical significance of hepatic tissue alterations as assessed by cardiac magnetic resonance imaging in patients with ST-segment-elevation myocardial infarction (STEMI), are unclear. This study aimed to investigate associations of hepatic T1 patterns with myocardial tissue damage and clinical outcomes in patients suffering from STEMI. We analyzed 485 patients with STEMI treated with percutaneous coronary intervention who were enrolled in the prospective magnetic resonance imaging in acute ST-elevation myocardial infarction study (MARINA STEMI). Myocardial function and left and right ventricular (RV) infarct characteristics were assessed by cardiac magnetic resonance within the first week after STEMI. Native hepatic T1 times and extracellular volume were evaluated from standard cardiac T1 maps at baseline and 4 months thereafter. Median hepatic T1 times were 559 ms (interquartile range, 514-605) at baseline and decreased to 542 ms (interquartile range, 507-577) at 4 months (P<0.001). Hepatic T1 times at baseline were independently associated with female sex (β 0.116; P=0.008), hyperlipidemia (β -0.116; P=0.008), and myocardial tissue damage (infarct size: β 0.178; P<0.001; microvascular obstruction: β 0.193; P<0.001; RV infarction: β 0.161; P<0.001). Determinants of hepatic T1 times at 4 months were female sex (β 0.123; P=0.002), multivessel disease (β 0.121; P=0.002), N-terminal pro-B-type natriuretic peptide (β 0.101; P=0.010), RV infarction (β 0.501; P<0.001), and RV end-systolic volume index (β 0.087; P=0.031). Patients without a decrease exhibited a higher frequency of major adverse cardiovascular events (13% versus 5%; P=0.003). Hepatic T1 times at baseline (hazard ratio, 1.87 [95% CI, 1.40-2.50]; P<0.001), 4 months (hazard ratio, 2.69 [95% CI, 2.15-3.36]; P<0.001), and hepatic extracellular volume at 4 months (hazard ratio, 1.59 [95% CI, 1.33-1.90]; P<0.001) were associated with major adverse cardiovascular events. After adjustment for univariable associates, only hepatic T1 times at 4 months were independently associated with adverse outcomes (hazard ratio, 2.86 [95% CI, 1.99-4.12]; P<0.001). Hepatic tissue alterations determined by T1 mapping were associated with female sex, hyperlipidemia, multivessel disease, N-terminal pro-B-type natriuretic peptide, and left and RV myocardial tissue damage. These alterations can persist into the chronic phase after STEMI and indicate a worse clinical outcome. URL: https://www.clinicaltrials.gov; Unique identifier: NCT04113356.

Non-thermal atmospheric pressure plasma-irradiated cysteine protects cardiac ischemia/reperfusion injury by preserving supersulfides

Ischemic heart disease is the main global cause of death in the world. Abnormal sulfide catabolism, especially hydrogen sulfide accumulation, impedes mitochondrial respiration and worsens the prognosis after ischemic insults, but the substantial therapeutic strategy has not been established. Non-thermal atmospheric pressure plasma irradiation therapy is attracted attention as it exerts beneficial effects by producing various reactive molecular species. Growing evidence has suggested that supersulfides, formed by catenation of sulfur atoms, contribute to various biological processes involving electron transfer in cells. Here, we report that non-thermal plasma-irradiated cysteine (Cys∗) protects mouse hearts against ischemia/reperfusion (I/R) injury by preventing supersulfide catabolism. Cys∗ has a weak but long-lasting supersulfide activity, and the treatment of rat cardiomyocytes with Cys∗ prevents mitochondrial dysfunction after hypoxic stress. Cys∗ increases sulfide-quinone oxidoreductase (SQOR), and silencing SQOR abolishes Cys∗-induced supersulfide formation and cytoprotection. Local administration of mouse hearts with Cys∗ significantly reduces infarct size with preserving supersulfide levels after I/R. These results suggest that maintaining supersulfide formation through SQOR underlies cardioprotection by Cys∗ against I/R injury.

VDAC1-NF-κB/p65-mediated S100A16 contributes to myocardial ischemia/reperfusion injury by regulating oxidative stress and inflammatory response via Calmodulin/CaMKK2/AMPK pathway

Myocardial injury triggers intense inflammatory reactions and oxidative stress responses. S100 calcium-binding protein A16 (S100A16), a multi-functional calcium (Ca2+)-binding protein, participates in inflammatory responses and contributes to ischemia/reperfusion (I/R) injury. Nevertheless, the precise mechanism by which S100A16 operates in myocardial I/R injury remains uncertain. Cardiac I/R injury was produced by ligation/release of the left anterior descending artery, and mouse cardiac cells were subjected to hypoxia/reoxygenation (H/R) to determine the biological effects in vitro. We demonstrated that S100A16 was upregulated in the ischemic hearts and cardiac cells after I/R and H/R injury. Adenovirus-mediated S100A16 inhibition led to a considerable improvement in cardiac function with a reduced infarct size, accompanied by a reduction in cardiomyocyte apoptosis. Similar effects of S100A16 inhibition on inflammation and reactive oxygen species (ROS) production were observed in cultured cardiomyocytes. Importantly, we showed that I/R and H/R treatment upregulated the expression of voltage-dependent anion channel 1 (VDAC1), which subsequently activated NF-κB/p65 to facilitate the binding of NF-κB/p65 to the S100A16 promoter, thereby activating the transcription and expression of S100A16. Mechanically, S100A16 responded to increasing Ca2+ and interacted with calmodulin (CaM) to regulate the activation of calcium/calmodulin-dependent protein kinase 2 (CAMKK2)/AMPK pathway. In conclusion, VDAC1 sustained the NF-κB p65 pathway activation to elicit increased S100A16 expression, contributing to myocardial damage and heart failure post-I/R via the CaM/CaMKK2/AMPK pathway. This study revealed a crucial role of the VDAC1-S100A16 axis in the process of myocardial I/R injury, providing novel molecular targets for the treatment of cardiac conditions associated with I/R injury.

Exacerbated ischemic brain damage in type 2 diabetes via methylglyoxal-mediated miR-148a-3p decline.

Although microvascular dysfunction is a widespread phenomenon in type 2 diabetes (T2D) and is recognized as a main cause of T2D-aggravated ischemic stroke injury, the underlying mechanisms by which T2D-mediated exacerbation of cerebral damage after ischemic stroke is still largely uncharacterized. Here, we found that methylglyoxal-mediated miR-148a-3p decline can trigger blood-brain barrier dysfunction, thereby exacerbating cerebrovascular injury in diabetic stroke. Using T2D models generated with streptozotocin plus a high-fat diet or db/db mice, and then inducing focal ischemic stroke through middle cerebral artery occlusion and reperfusion (MCAO/R), we established a diabetic stroke mouse model. RNA-sequencing was applied to identify the differentially expressed miRNAs in peri-cerebral infarction of diabetic stroke mice. RT-qPCR confirmed the potential miRNA in the plasma of ischemic stroke patients with or without T2D. Fluorescence in situ hybridization was used to image the localization of the miRNA. Brain pathology was analyzed using magnetic resonance imaging, laser-Doppler flowmetry, and transmission electron microscope in diabetic stroke mice. Immunofluorescence and immunoblotting were performed to elucidate the molecular mechanisms. miR-148a-3p level was downregulated in the peri-infarct cortex of stroke mice and this downregulation was even more enhanced in diabetic stroke mice. A similar decrease in miR-148a-3p expression was also confirmed in the plasma of ischemic stroke patients with T2D compared to patients with ischemic stroke only. This miR-148a-3p downregulation intensified the severity of BBB damage, infarct size, and neurological function impairment caused by stroke. Notably, the reduction in miR-148a-3p levels was primarily triggered by methylglyoxal, a toxic byproduct of glucose metabolism commonly associated with T2D. Furthermore, methylglyoxal somewhat replicated the influence of T2D in exacerbating BBB damage and increasing infarct size caused by ischemia. Mechanistically, we found that downregulation of miR-148a-3p de-repressed SMAD2 and activated matrix metalloproteinase 9 signaling pathway, promoting blood-brain barrier impairment, and exacerbating thecerebral ischemic injury. Blood-brain barrier damage caused by methylglyoxal-mediated miR-148a-3p downregulation may provide a novel target for the therapeutic intervention for the treatment of stroke patients with diabetes.

Endothelial FOSL1 drives angiotensin II-induced myocardial injury via AT1R-upregulated MYH9.

Vascular remodeling represents a pathological basis for myocardial pathologies, including myocardial hypertrophy and myocardial infarction, which can ultimately lead to heart failure. The molecular mechanism of angiotensin II (Ang II)-induced vascular remodeling following myocardial infarction reperfusion is complex and not yet fully understood. In this study, we examined the effect of Ang II infusion on cardiac vascular remodeling in mice. Single-cell sequencing showed Ang IIinduced cytoskeletal pathway enrichment and that FOS like-1 (FOSL1) affected mouse cardiac endothelial dysfunction by pseudotime analysis. Myosin heavy chain 9 (MYH9) was predominantly expressed in primary cardiac endothelial cells. The Ang II type I receptor blocker telmisartan and the protein kinase C inhibitor staurosporine suppressed Ang II-induced upregulation of MYH9 and FOSL1 phosphorylation in human umbilical vein endothelial cells. Silencing MYH9 abolished Ang II-mediated inhibition of angiogenesis in human umbilical vein endothelial cells, and attenuated AngII-induced vascular hyperpermeability. We found that FOSL1 directly bound to the MYH9 promoter and thus activated transcription of MYH9 by the dual luciferase reporter and chromatin immunoprecipitation assays, leading to vascular dysfunction. In vivo, 6 weeks after injecting adeno-associated virus-ENT carrying the TEK tyrosine kinase (tie) promoter-driven short hairpin RNA for silencing FOSL1 (AAV-tie-shFOSL1), cardiac function represented by the ejection fraction and fractional shortening was improved, myocardial fibrosis was decreased, protein levels of phosphorylated FOSL1, MYH9, and collagen type I alpha were reduced, and cardiac vascular density was recovered in mice with endothelial Fosl1-specific knockdown in Ang II-infused mice. In ischemia-reperfusion mice, AAV-shFosl1 mice had a reduced infarct size and preserved cardiac function compared with control AAV mice. Our findings suggest a critical role of the FOSL1/MYH9 axis in hindering Ang II-induced vascular remodeling, and we identified FOSL1 as a potential therapeutic target in endothelial cell injuries induced by myocardial ischemia-reperfusion.

Study on the Mechanism of miR-124-3p Regulating Cerebral Ischemia-Reperfusion Injury

Objective: To investigate the role of miR-124-3p in ischemia-reperfusion injury following ischemic stroke and to evaluate the neuroprotective effects of miR-124-3p inhibition on neurological outcomes, infarct size, and apoptosis. Methods: A middle cerebral artery occlusion (MCAO) model was used to induce ischemia-reperfusion injury in rats. Experimental groups included a sham surgery group, an MCAO group, an MCAO + miR-124-3p NC group, and an MCAO + miR-124-3p antagomir group. Neurological deficits were assessed at 2, 8, and 24 hours post-ischemia. Infarct size and apoptosis levels were measured using brain tissue weight analysis and TUNEL assay, respectively, to evaluate the extent of ischemic damage and cell death. Results: The MCAO group showed progressively worsening neurological deficits, increased infarct size, and extensive apoptosis. In contrast, miR-124-3p inhibition significantly reduced neurological deficits, with lower scores at all time points. The MCAO + miR-124-3p inhibitor group demonstrated a significant reduction in infarct size compared to the MCAO group and the NC group, suggesting tissue preservation. Additionally, the miR-124-3p inhibitor group showed markedly reduced apoptosis, as evidenced by decreased TUNEL-positive signals, indicating a reduction in cell death following ischemia-reperfusion injury. Conclusion: Inhibition of miR-124-3p plays a neuroprotective role in ischemia-reperfusion injury by mitigating neurological deficits, reducing infarct size, and lowering apoptosis levels. These findings suggest that miR-124-3p inhibition could be a promising therapeutic target for minimizing brain damage and improving recovery in ischemic stroke patients.

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.

Effect of ventricular fibrillation on infarct size after myocardial infarction: a translational study.

Ventricular fibrillation (VF)-induced cardiac arrest frequently complicates ST-segment elevation myocardial infarction (STEMI). Although larger infarct sizes (IS) correlate with a higher risk of VF, the influence of VF itself on IS has remained poorly investigated. To address this knowledge gap, we analyzed the effect of VF on IS in patients and two experimental models. From a prospective cohort, 30 STEMI patients with VF were matched 1:2 with STEMI patients without VF on the common determinants of IS. The primary endpoint was IS, assessed using the 48-h area under the curve (AUC) for troponin. We also compared IS in pigs with/without spontaneous VF during STEMI (n = 15/group), and in an isolated rat heart model of myocardial infarction with/without electrically induced VF (n = 7/group). After matching, the patient characteristics, including the area at risk (AR), were similar. IS was 33% lower in the VF group compared to the control group (troponin AUC 1.6 [0.5-3.3] 106 arbitrary units vs. 2.4 [0.9-4.1] 106 arbitrary units; p < 0.05), but infarct scar size (assessed using MRI and ECG) did not differ between the groups at 1 and 6months. In both experimental models, IS, expressed as a percentage of AR, was lower (p < 0.05) in the VF group than in the control group. When common determinants of IS are comparable, VF occurring prior to myocardial infarction reperfusion appears to be associated with smaller IS. Nevertheless, this finding, observed under specific experimental conditions and in a highly selected group of patients, was not associated with reduced infarct scar size.Registration (HIBISCUS-STEMI cohort): ClinicalTrials.gov NCT05794022.

Cardioprotective Effect of Selective μ2-Opioid Receptor Agonist Endomorphin-1 in Cardiac Reperfusion In Vivo and In Vitro.

The effect of the selective μ2-opioid receptor agonist endomorphin-1 in reperfusion injury in male Wistar rats was studied in vivo and in vitro. The in vivo experiment included coronary artery occlusion (45 min) and reperfusion (120 min); in in vitro experiments, 45-min global ischemia of the isolated rat heart was followed by 30-min reperfusion. Endomorphin-1 was administered intravenously 5 min before in vivo reperfusion (at a dose 50 μg/kg) or added to the perfusion solution at the onset of reperfusion of the isolated heart (in a concentration of 152 nmol/liter). In vivo endomorphin-1 reduced the infarct size by 33% compared to the control group. In experiments on isolated heart, endomorphin-1 improved the contractile function during reperfusion and reduced the creatine kinase level in the coronary effluent. Hence, stimulation of cardiac μ2-opioid receptors increases heart tolerance to the pathogenic effects of reperfusion.

A Bifunctional Sulfide Donor Approach for Ischemic Stroke: Leveraging Butylphthalide as a Carrier for Sulfide Prodrug.

The physiological and pharmacological benefits of hydrogen sulfide (H2S) are well established, and various H2S and persulfide donors have been developed. However, few studies have examined the in vivo pharmacokinetics of sulfur donors, as most activity and metabolism tests are conducted in vitro, limiting insights into their clinical applications. This study utilized butylphthalide (NBP), an approved drug for ischemic stroke, by integrating H2S and persulfide moieties directly into NBP's carbonyl groups. We systematically compared drug metabolism in vitro and in vivo and evaluated donor efficacy in ischemia-reperfusion models. Results revealed notable in vitro/in vivo metabolic differences, with thioacid-containing donors showing promising therapeutic effects in cerebral ischemia, reducing infarct size, oxidative stress, and neuronal apoptosis.

Immune response in cerebral ischemic injury: interaction and therapeutic potential

Cerebral ischemia primarily results from vascular stenosis or blockage, which activates inflammatory cells and triggers an immune response. An excessive immune response can exacerbate the damage caused by cerebral ischemia. In this review, the keywords “immune response” and “cerebral ischemia” were entered into the PubMed database, yielding 241 articles, of which 141 were included in the analysis. Relevant literature from 2021 to 2024 was summarized, classified, and synthesized to delineate advancements in this field. Consequently, in exploring the basic physiology of immune responses and brain injury, we found that microglia can phagocytose dead neurons, thereby ameliorating ischemic brain injury. However, inflammatory cells accumulate and attack blood vessels and nerve cells following cerebral ischemia, resulting in additional damage. As a result, targeting CD8 T cells, astrocytes, superoxide dismutase (SOD), interleukin-10 (IL-10), tumor necrosis factor (TNF), NLRP3, and the NF-κB signaling pathway can help mitigate this damage. Furthermore, the specific mechanisms and efficacy of therapeutic drugs in recent years were analyzed, revealing their potential to repair the blood-brain barrier, endothelial cells, and neurons, while also reducing infarct size and inflammatory responses. Together, we highlight that immune cells, particularly microglia, present new therapeutic breakthroughs in neuron phagocytosis, improvement of inflammatory responses, and reduction of vascular endothelial damage. These findings provide clinicians and researchers with cutting-edge references for treatment strategies.

Novel Rat Model of Embolic Cerebral Ischemia Using a Radiopaque Blood Clot and a Microcatheter Under Fluoroscopy.

Conventional rat models of thromboembolic stroke do not allow control of infarct size or spontaneous recanalization. We aimed to develop a novel rat thromboembolic stroke model that ensures highly reproducible infarct sizes and locations within the MCA territory and does not require arterial ligation. Twenty male Sprague-Dawley rats and two sham-operated rats were included. A microcatheter was navigated from the caudal ventral artery to the internal carotid artery using digital subtraction angiography. A blood clot (diameter, 0.86 mm; length, 3 mm) containing zirconium dioxide was advanced in the catheter. Fluoroscopy was performed at 1, 3, 6, and 24 h after stroke model creation, and TTC staining was conducted at 24 h. Neurological deficit scores were measured. In all embolized rats, the ACA and MCA bifurcation were selective. Median operating time was 6 min. The position of the radiopaque blood clot remained unchanged for 24 h after model creation in 19/20 rats. Median infarct volume was 242 mm3 (IQR, 239-262 mm3). We present a novel rat model of highly reproducible focal infarct in only the MCA territory. Fluoroscopy effectively identified any blood clot migration. This model could contribute to the development of new thrombolytic agents.

Qingre Huoxue decoction attenuates myocardial ischemia‒reperfusion injury by regulating the autophagy‒endoplasmic reticulum stress axis via FAM134B-mediated ER-phagy

BackgroundAutophagy‒endoplasmic reticulum (ER) stress axis dysregulation is linked to myocardial ischemia‒reperfusion injury (MIRI), which counteracts the benefits of acute myocardial infarction (AMI) reperfusion therapy. Qingre Huoxue decoction (QRHX) improves the short- and long-term prognosis of AMI after percutaneous coronary intervention and alleviates myocardial injury in AMI rats by stimulating autophagy via the PI3K/Akt pathway. We aimed to further explore the efficacy of QRHX in treating MIRI and its regulatory relationship with FAM134B-mediated ER-phagy.Materials and methodsRats were administered different concentrations of QRHX for 2 weeks, and then MIRI was induced. Ultra-performance liquid chromatography‒tandem mass spectrometry (UPLC‒MS) was used to examine the levels of the main pharmacological metabolites of the serum of rats treated with QRHX. H9c2 cells were pretreated with QRHX-mediating serum (QRHX-MS) for 24 h before being exposed to hypoxia/reoxygenation (H/R). The mechanisms underlying the effects of QRHX-MS were further studied via rescue experiments involving FAM134B knockdown. The myocardial infarct size, cardiac function, morphology and the expression of apoptosis-, autophagy-, and ER stress-related proteins and genes were assessed. The colocalization of autophagosomes with lysosomes and the localization of proteins involved in ER-phagy or autophagic flux was examined.ResultsQRHX decreased the myocardial infarct size and oxidative stress, improved cardiac function and alleviated morphological changes in a dose-dependent manner in MIRI rats by promoting autophagic flux to inhibit ER stress and ER stress-related apoptosis, which was related to FAM134B-mediated ER-phagy, as revealed by autophagy analysis. UPLC‒MS analysis of QRHX-MS revealed 20 major active metabolites of QRHX-MS, including baicalin, cryptotanshinone, 3,4-dihydroxybenzaldehyde and caffeic acid. QRHX-MS attenuated H/R-induced cardiomyocyte injury and apoptosis by increasing autophagic flux to suppress ER stress and ER stress-related apoptotic protein and gene expression. When autophagic flux was inhibited or FAM134B was knocked down in H9c2 cells followed by QRHX-MS pretreatment, the protective effect of QRHX was partially reversed.ConclusionQRHX alleviates myocardial injury, apoptosis and infarct size expansion in MIRI by regulating the autophagy‒ER stress axis via FAM134B-mediated ER-phagy.

Predicting final infarct size and clinical outcomes in patients with acute ischemic stroke after endovascular thrombectomy using the Alberta Stroke Program early CT score on venous-phase CT

Background The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is a semi-quantitative tool for evaluating the extent and distribution of early ischemic changes. Purpose To assess the value of ASPECTS on non-contrast CT (NCCT), arterial-phase CT (APCT), or venous-phase CT (VPCT) in predicting the final infarct core (IC) on follow-up diffusion-weighted imaging (DWI) and the clinical outcomes of patients with acute ischemic stroke (AIS) after endovascular thrombectomy (EVT). Material and Methods In total, 120 patients with AIS who underwent EVT in our center were retrospectively enrolled. Correlations between CT-ASPECTS and follow-up DWI-ASPECTS were analyzed using Spearman's rank correlation coefficient. Mean differences and limit of agreement (LoA) between CT-ASPECTS and follow-up DWI-ASPECTS were assessed using the Bland–Altman plots. Multivariate logistic regression and receiver operating characteristic curve analyses were used to identify independent factors and evaluate their performances in predicting the clinical outcomes. Results VPCT-ASPECTS exhibited the highest correlation with follow-up DWI-ASPECTS (r = 0.846, P &lt; 0.001), followed by APCT-ASPECTS (r = 0.613, P &lt; 0.001) and NCCT-ASPECTS (r = 0.557, P &lt; 0.001). The mean difference between VPCT-ASPECTS and follow-up DWI-ASPECTS was 0.0 (limit of agreement = −2.1 to 2.1). National Institute of Health Stroke Scale (NIHSS) scores at admission (NIHSSpre) (odds ratio [OR]=1.162, 95% confidence interval [CI]=1.063–1.270; P = 0.001) and VPCT-ASPECTS (OR=0.728, 95% CI=0.535–0.991; P = 0.044) were the independent factors associated with clinical outcomes. The combined model integrating NIHSSpre and VPCT-ASPECTS exhibited an excellent performance in predicting good clinical outcomes (area under curve [AUC]=0.807; sensitivity=75.0%; specificity=72.3%). Conclusion VPCT-ASPECTS may be a promising imaging biomarker to predict the final IC and the clinical outcome of the patients with AIS after EVT.

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.

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.