Triterpene saponin from Ilex pubescens attenuates ferroptosis in myocardial ischemia/reperfusion injury by inhibiting the lncRNA Hmga2-as1/Sox10/GPX4 axis.

To demonstrate that a recently reported bright ferritin magnetic resonance imaging (MRI) platform can track transplanted human pluripotent stem cell (hPSC)-derived cardiomyocytes (hPSC-CMs) longitudinally and on-demand in the rat heart. Ferritin-overexpressing hPSCs were differentiated into cardiomyocytes and assessed for cell viability, contractile functional proteins, and electrophysiological properties in vitro. In an immunodeficient rat model, hPSC-CMs injected into the left ventricular myocardium were tracked on cardiac MRI at 3 Tesla over 8 weeks in both healthy and infarcted hearts. Longitudinal MRI was accompanied by MnCl2 supplementation for on-demand recall of bright signal from ferritin-overexpressing hPSC-CMs. MRI findings were corroborated against histological validation. Ferritin-overexpressing hPSC-CMs displayed normal morphological and functional phenotypes and created viable grafts in vivo. On-demand recall of bright contrast on MRI was achieved, regardless of interval post-cell transplantation, via MnCl2 administration to precisely map surviving hPSC-CMs in both healthy and infarcted hearts. The spatial distribution of hPSC-CMs on MRI was confirmed throughout the heart by histology. Echocardiography confirmed MnCl2 had no impact on cardiac function, although in vitro tests revealed transiently dampened calcium handling and contractility, an effect from which cells fully recovered after removing MnCl2. Bright ferritin MRI allows longitudinal, non-invasive, and on-demand imaging of the distribution of viable transplanted hPSC-CMs in the healthy and infarcted rat heart.

The protective role of Astaxanthin against the central and peripheral detrimental effects for chronic administration of sweeteners in a rat model: Involvement of multiple signaling axes.

Oxidative stress occurs when the production of reactive species exceeds the antioxidant capacity. In the heart muscle, this imbalance is associated with heart failure. The objective of this study was to evaluate the markers of cardiac damage and the antioxidant system in the hearts of rats fed a low-protein, high-carbohydrate diet for 15 days. Male Wistar rats (Rattus norvegicus), weighing 90-100 g and approximately 21 days old were used (CEUA: n° 23108.006061/2021-11). The animals were randomly divided into two groups: low-protein, high-carbohydrate (LPHC), animals fed 77% carbohydrates and 6% protein, and control (C), animals fed a normoprotein diet (64% carbohydrates and 17% proteins). At the end of day 15, the animals were anesthetized and euthanized, and blood and heart muscle were collected. An increase in the content of carbonylated proteins, substances reactive to thiobarbituric acid, and catalase, glutathione peroxidase, glutathione-S-transferase, and myeloperoxidase (serum + plasma) activity was observed. A reduction in absolute heart weight, total antioxidant capacity, reduced glutathione, intracellular oxidation, superoxide dismutase gene expression, glutathione reductase, and myeloperoxidase (heart muscle) activity was observed in LPHC animals compared with those in group C. These data suggest that consuming the LPHC diet for 15 days may lead to an oxidative imbalance in the heart muscle, altering the antioxidant capacity induced by stress.

Integrating network toxicology and transcriptomics reveals the potential targets of chlorfenapyr-induced myocardial injury.

Cardiac fibrosis with excessive extracellular matrix (ECM) accumulation is a hallmark of hypertensive heart failure. Characterizing glycan alterations within fibrotic ECM requires analytical strategies that integrate molecular detection with spatial and structural information. However, spatial glycomics approaches applicable to ECM-rich tissue regions remain limited. Here, we established an integrated lectin-based spatial glycomics workflow combining lectin microarray-based tissue glycome mapping, lectin histochemical staining, and low-vacuum scanning electron microscopy (LVSEM). This hierarchical analytical design enables lectin signal detection, spatial localization, and structural visualization within the same tissue section. Using this workflow, we mapped N- and O-glycan distribution in fibrotic regions of hypertensive heart failure rat hearts. Among 45 lectins, Maackia amurensis hemagglutinin (MAH)-reactive sialo-O-glycans were markedly increased in WFA-positive fibrotic regions compared with controls. Glycosidase pretreatment selectively reduced WFA and MAH signals, confirming their specificities for N- and O-glycans, respectively. High-resolution single-slide imaging combining lectin fluorescence histochemistry with LVSEM revealed distinct spatial partitioning of WFA and MAH signals within fibrotic ECM regions. Co-staining with ECM glycoproteins, including periostin, collagen VI α6 chain, cartilage intermediate layer protein 1, and thrombospondin 4, showed partial spatial overlap with lectin signals, suggesting that multiple ECM glycoproteins may contribute to the observed glycan signals. These results demonstrate a lectin-based spatial glycomics workflow integrating glycomic signal detection, spatial localization, and ultrastructural validation, establishing a lectin-based multimodal analytical framework for spatially resolved glycan partitioning in fibrotic tissues.

Cardiac glycolytic rates are altered under many pathological conditions, although the mechanism(s) responsible for these changes in glycolysis is not completely clear. Since cardiac hyperacetylation also occurs under many pathological conditions, we determined whether glycolytic enzyme lysine acetylation can regulate cardiac glycolysis rates. The effects of modifying cardiac acetylation on glycolysis were examined in isolated working rat hearts and H9c2 cardiomyocytes using sirtuin 2 (SIRT2) inhibition (AGK2 or siRNA knockdown), SIRT1 inhibition (EX-527), pan-sirtuin inhibition (NAM), or acetyltransferase inhibition (C646). Glycolysis rates were directly measured in hearts or cardiomyocytes perfused with 5 mM glucose and 0.8 mM palmitate, using radiolabeled [5-3H] glucose. SIRT2 inhibition significantly decreased glycolysis rates in isolated working rat hearts compared with controls (1,844 ± 153 vs. 2,753 ± 236 nmol·g dry wt-1·min-1, P < 0.05) with no significant effect on glucose oxidation rates. In H9c2 cardiomyocytes, both SIRT2 inhibition and knockdown reduced glycolysis rates compared with controls (524 ± 108 vs. 2,631 ± 372 and 745 ± 31 vs. 1,659 ± 168 nmol·mg protein-1·h-1, P < 0.05, respectively). This decrease in glycolysis was accompanied by increased acetylation of glycolytic enzymes, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoglycerate mutase (PGAM), without changes in global acetylation patterns. SIRT2 inhibition or knockdown did not affect the phosphorylation status of insulin signaling proteins. However, SIRT2 inhibition did attenuate the phenylephrine-mediated hypertrophic response in H9c2 cells. We conclude that SIRT2 inhibition increases the acetylation of cardiac glycolytic enzymes and decreases glycolysis rates, suggesting that posttranslational acetylation is an important pathway regulating cardiac glycolysis.NEW & NOTEWORTHY Protein lysine acetylation differentially regulates cardiac fatty acid and glucose oxidation. However, its role in controlling glycolysis remains poorly defined. Using pharmacological inhibition and siRNA-mediated knockdown of sirtuin 2 (SIRT2), we demonstrate that loss of SIRT2 increases acetylation of glycolytic enzymes and reduces cardiac glycolytic flux in isolated working hearts and cardiomyocytes, independent of insulin signaling. Our findings reveal an important role of SIRT2-dependent deacetylation in regulating cardiac glycolytic flux.

Metabolomics is a powerful tool for assessing drug safety and understanding the biochemical effects of pharmaceutical compounds. Favipiravir, a drug widely used during the COVID-19 pandemic, has been associated with damage to various organs, including the heart. However, a comprehensive analysis of its metabolic impact on cardiac tissue has not yet been performed. This study utilized high-resolution 1H NMR-based metabolomics to investigate metabolic alterations in rat heart tissue following favipiravir treatment. For this purpose, 60 male Wistar Albino rats were randomly assigned to three groups: control, low-dose favipiravir (200 mg/kg), and high-dose favipiravir (300 mg/kg), with 20 rats in each group. Treatments were administered via oral gavage, and heart tissue samples were collected for 1H NMR analysis after the treatment period. Bioinformatics analysis results showed significant dose-dependent changes in key metabolites in the favipiravir-treated groups. Decreased levels of ATP, citrate, and valine accompanied by increased levels of lactate and AMP suggest a disruption in mitochondrial energy production and a shift towards anaerobic glycolysis. At the higher dose, more pronounced disruptions were noted, including decreases in glutamate, glutamine, aspartate, tyrosine, 3-methylhistidine, and asparagine, suggesting a broader metabolic dysfunction. These findings offer valuable insights into the cardiotoxic effects of favipiravir and highlight the utility of NMR metabolomics in identifying drug-induced metabolic disturbances.

Adenosine, acting through A1 adenosine receptors (A1ARs), exerts anti-adrenergic effects by inhibiting β1-adrenergic receptor (β1AR)-mediated cAMP production and contractility in the heart. While the functional interaction between A1ARs and β1ARs is well established in both atrial and ventricular myocytes, the subcellular compartmentalisation of this crosstalk and how it is disrupted in heart failure (HF) remains incompletely understood. This study investigates the spatial confinement of A1AR-β1AR signalling within atrial microdomains and assesses how structural remodelling in HF alters this regulatory axis. qPCR analysis revealed that A1AR is the predominant adenosine receptor subtype in both rat and human atrial tissues. In healthy rat and mouse atrial myocytes, A1AR activation reduced β1AR-induced cAMP production and sarcomere shortening, with suppression of cAMP signals at sarcolemmal microdomains enriched in PKA type II. This was further supported by Scanning Ion Conductance Microscopy (SICM)-guided scanning patch-clamp showed that A1AR suppressed β1AR-driven L-type Ca2+ channel (LTCC) activity at both T-tubule and crest membrane domains. In atrial myocytes isolated from failing rat and human hearts, A1AR-mediated inhibition of β1AR-induced cAMP production and contractility was impaired. Caveolar disruption by methyl-β-cyclodextrin in rat atrial myocytes or via cardiac-specific caveolin-3 knockout in mice abolished this A1AR-mediated inhibition. Notably, cholesterol repletion alone did not restore membrane cAMP regulation, whereas Cav3 over-expression rescued A1AR-dependent suppression, supporting a requirement for Cav3-dependent organisation. In mouse atrial preparations isolated from failing hearts, high-resolution optical mapping showed that A1AR-mediated anti-adrenergic regulation of Ca2+ cycling was selectively lost in the intercaval region, correlating with the regional absence of T-tubule and downregulation of caveolae structures. A1ARs provide anti-adrenergic restraint of β1AR signalling through Cav3-dependent membrane organisation. In HF, regional caveolar disorganisation uncouples this protective pathway, contributing to spatially heterogeneous Ca2+ dysregulation in the atrium. Adenosine acting via A1 receptors provides an endogenous constraint on β-adrenergic signalling in the atria. We show that this protection relies on Cav3-dependent caveolar organisation and is lost in heart failure, particularly in the inter-caval region of the right atrium where caveolae density is downregulated. Diminished A1 anti-adrenergic control permits enhanced β1AR-cAMP-Ca2+ signalling and regional Ca2+ dysregulation, a substrate linked to atrial ectopy and atrial fibrillation in structural heart disease. These findings identify membrane microdomain integrity as a determinant of atrial autonomic balance and suggest that stabilising caveolar organisation may help restore adenosine-mediated restraint in heart failure.

Type 2 diabetes (T2D) greatly alters cardiac fuel handling, yet how mitochondrial function adapts to the diabetic substrate environment remains unclear. This study investigated substrate-specific cardiac mitochondrial bioenergetics from a T2D rat model induced by a high-fat diet and low-dose streptozotocin. High-resolution respirometry and fluorimetry were used to measure mitochondrial O2 flux, ATP flux, reactive oxygen species production rate and mitochondrial membrane potential in cardiac tissue homogenates in two key substrate conditions: carbohydrate and fatty acid. Liquid chromatography-mass spectrometry was used to analyse the abundance of metabolites involved in the Krebs cycle and in various fatty acid metabolic pathways. Carbohydrate-supported mitochondrial respiration, ATP flux, reactive oxygen species production and mitochondrial membrane potential were preserved in T2D myocardium. In contrast, fatty acid-supported mitochondrial respiration and ATP flux in oxidative phosphorylation were significantly decreased despite increased myocardial abundance of several fatty acid species, including palmitoleic acid, cis-8-heptadecenoic acid and linoleic acid. Metabolite intermediates of the Krebs cycle were largely unchanged. These findings reveal a substrate-specific energetic defect in the diabetic heart, in which excess fatty acid supply is not matched by mitochondrial oxidative capacity, leading to metabolic inflexibility and impaired ATP generation. This work provides mechanistic insight into how nutrient overload contributes to mitochondrial inefficiency in T2D and establishes a foundation for future studies targeting lipid-mitochondria interactions.

Short-term heat therapy enhances heart thermotolerance: Cyclic thermal stress reveals adaptive resilience in cardiac function.

Purpose Left ventricular hypertrophy (LVH) is a major complication of chronic hypertension and an independent cardiovascular risk factor. No clinically validated markers exist to identify hypertensive individuals at risk for developing LVH. We previously described metabolic changes preceding LVH in hypertensive rat hearts, including alterations in branched-chain amino acid (BCAA) metabolism. This study investigated whether impaired cardiac leucine uptake, measured with dynamic 5-[ 18 F]fluoroleucine ([ 18 F]FLE) PET imaging, could serve as in vivo marker for hypertension-induced LVH development. Procedures: [ 18 F]FLE was synthesized following established radiochemistry protocols and dynamic [ 18 F]FLE-PET/CT imaging was performed in 3-month-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) control rats (n = 4/group). Cardiac MR (CMR) imaging enabled structural co-registration. A dual-output reversible two-tissue compartment model with spill-over and partial volume corrections quantified the first-pass rate constant (K 1 ) and total distribution volume (V t ). L-type amino acid transporter 1 (LAT1/SLC7A5) protein expression and branched-chain keto acid dehydrogenase (BCKDH) phosphorylation status were assessed by immunoblotting of heart tissue. Results SHR demonstrated markedly lower K 1 and V t compared with WKY rats, consistent with reduced cardiac leucine uptake. Simultaneously, LAT1 expression was significantly reduced in SHR hearts. Elevated BCKDH phosphorylation at Ser293 suggested impaired BCAA catabolism. Conclusions Dynamic cardiac [ 18 F]FLE-PET detects decreased leucine uptake in hypertensive rat hearts at 3 months of age, before LVH is established at 5 months. Impaired cardiac leucine uptake may thus serve as an early cardiometabolic biomarker to identify hypertensive patients at risk for LVH progression.

Effect of Levofloxacin and moxifloxacin on arsenic metabolism and cardiotoxicity in APL patients treated with arsenic trioxide.

Offline two-dimensional liquid chromatography-mass spectrometry for comprehensive characterization of chemical constituents and in vivo metabolism of Shiqi Waigan Granules.

Unveiling the comprehensive alterations in the in vivo components, tissue distribution profiles, and pharmacokinetic characteristics between Jiawei Erzhi formula and Erzhi formula.

Etoxazole (ETX) is a widely used acaricide, yet its systemic toxicity and effects on oxidative balance in non-hepatic tissues remain poorly understood. This study investigated the dose-dependent impact of ETX on oxidative stress markers in rat heart, lung, and spleen tissues. Forty-two female Wistar albino rats were divided into six groups: one control and five treatment groups receiving 25-750 mg/kg ETX via oral gavage for 28 days. Total sulfhydryl (t-SH), adenosine deaminase (ADA), ischemia-modified albumin (IMA), and asymmetric dimethylarginine (ADMA) levels were measured spectrophotometrically. ETX exposure was associated with significant, dose-dependent alterations in oxidative stress biomarkers across all examined tissues. t-SH levels decreased, whereas ADA, IMA, and ADMA levels increased with increasing ETX doses. Cardiac IMA rose 2.7-fold increase at higher doses, indicating enhanced oxidative stress-related biochemical alterations. Elevated ADMA levels suggested alterations in nitric oxide-related pathways. These findings indicate that subchronic ETX exposure disrupts redox homeostasis in extrahepatic tissues in a dose-dependent manner. ETX induces systemic oxidative imbalance in rat tissues, highlighting the need for further mechanistic investigations. This study was conducted in female rats and focused on biochemical biomarkers without histopathological evaluation or inclusion of a positive control, which should be considered when interpreting the findings.

This study employed a multiplatform approach to compare in vivo exposure of saponins across six ginseng species, namely Panax ginseng (PG), red ginseng (RG), P. quinquefolius (PQ), P. notoginseng (PN), P. japonicus (PJ), and P. japonicus var. major (PJm). A strategy combining in-source fragmentation tracing with liquid chromatography/mass spectrometry was developed, facilitating characterization of 242 ginsenoside prototypes and metabolites. Tissue distribution patterns were visualized through desorption electrospray ionization mass spectrometry imaging (DESI-MSI), revealing significant accumulation of specific ginsenosides in the heart and kidney of rats. Pharmacokinetics of eight ginsenosides were analyzed by scheduled multiple reaction monitoring. PN had the highest exposure to ginsenosides Rb1 and Rd, while PQ showed high ginsenoside Rb1 but low ginsenoside Re levels. PJ and PJm had low exposure to oleanolic acid-type ginsenosides. This study elucidated the in vivo behavior of ginsenosides simultaneously across six ginseng species, providing insights for their quality control and functional application.

Cardiovascular disease and cancer are the two leading causes of morbidity and mortality worldwide. Metabolic dysregulation of cancer cells extends beyond the tumor microenvironment and increases the risk for cardiovascular diseases. One common somatic mutation in cancer cells affects isocitrate dehydrogenase (IDH) 1 and 2, which catalyzes the oxidative decarboxylation of isocitrate to alpha-ketoglutarate in the cytosol and mitochondria, respectively. IDH1 and 2 mutations cause the production of the oncometabolite D-2-hydroxyglutarate (D2-HG), which allosterically inhibits α-ketoglutarate dehydrogenase (α-KGDH) and is associated with reduced cardiac contractile function. We combined stable isotope tracer studies with computational modeling to investigate the fundamental role of IDH isoforms in cardiac adaptation under oncometabolic stress. We uncovered an unexpected cardiac phenotype that expands the role of IDH1 in the heart beyond oxidative metabolism. We quantified the stable isotopomer distributions from glucose and glutamine in perfused working rat hearts and isolated adult ventricular cardiomyocytes using mass spectrometry-based metabolomics. Our analysis revealed that defective mitochondrial metabolism causes the redirection of carbon flux from oxidative towards reductive pathways. Reductive carboxylation of α-KGDH increases glutamine uptake and glutamine-derived citrate formation in working rat heart perfusions and cultured adult mouse ventricular cardiomyocytes. To identify which IDH isoform is responsible for redirecting carbon flux, we developed knockout models of IDH1, IDH2, and IDH3 in adult mouse ventricular cardiomyocytes. Loss of IDH1 expression impaired the reductive formation of citrate and caused functional defects in cardiomyocytes. Lastly, epigenetic analyses of histone marks revealed that IDH1 induces widespread alterations in histone acetylation and tri-methylation. Our results highlight a novel role for IDH1 in cardiac metabolism and transcriptional control of metabolic adaptation to tumor-mediated stress and provide evidence that reductive-citrate formation may induce epigenetic modifications in the heart.

Green-synthesized Punica granatum-mediated silver nanoparticles mitigate environmental endotoxin-induced cardiovascular oxidative inflammation in rats.

BackgroundCurrent therapeutic strategies for acute myocardial infarction rely on reperfusion and pharmacological management, which are typically administered hours after an event. Activation of the cardiac cholinergic efferents superior to the heart soon after a coronary occlusion has shown promise as a potential therapy to reduce arrhythmias and improve ventricular function. We tested whether selective activation of cholinergic neurons within the intrinsic cardiac ganglia (ICG) would also reduce arrhythmias and improve oxygenation of ischemic border zone tissue after an acute coronary occlusion.MethodsDesigner Receptors Exclusively Activated by Designer Drugs (DREADDs) were selectively expressed in cholinergic neurons of the ICG via pericardial sac injections of an HM3Dq DREADDs virus in transgenic rats that expressed Cre recombinase in cholinergic neurons. Cholinergic ICG neurons were activated using the synthetic DREADDs ligand clozapine-N-oxide (CNO). Heart rate reductions after intraperitoneal injection of CNO confirmed downstream effect of DREADDs-mediated cholinergic ICG activation in ECG telemetry studies. The effect of cholinergic ICG activation on PR interval, arrhythmia burden, ischemic border zone tissue oxygenation and epicardial NADH fluorescence 20 min after ligation of the left anterior descending coronary artery (LAD) was then studied in excised perfused hearts of DREADDS-expressing rats and rats that did not receive the HM3Dq DREADDs virus.ResultsLAD ligation resulted in a well defined ischemic zone that encompassed a large portion of the left ventricle, where pO2 in the center of the ischemic zone typically dropped to 0 mmHg within 10 s. Subsequent DREADDs-mediated cholinergic ICG activation prolonged the PR interval from 39.13 6.17 ms to 42.46 6.87 ms and lowered the incidence of arrhythmia from 0.9398 0.5063 to .5727 0.3103 . DREADDs-mediated cholinergic ICG activation also increased ischemic border zone pO2 from 42.13 49.82 mmHg to 82.25 66.87 mmHg and NADH fluorescence trended lower in the ischemic zone, indicating increased mitochondrial oxidation. These effects were blocked when the muscarinic antagonist atropine was administered before CNO.ConclusionResults indicate that selective stimulation of cholinergic ICG neurons could improve local delivery of oxygen to the ischemic border zone soon after a coronary occlusion and reduce arrhythmia burden through a muscarinic-dependent mechanism, supporting further studies of the intrinsic cardiac cholinergic network as a therapeutic target for early intervention before reperfusion therapy to activate cardioprotective pathways.