Cardiac Injury Biomarkers Research Articles

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.

Residual post-infarct myocardial inflammation detected by 68Ga-DOTATATE PET/MRI predicts long-term adverse cardiac remodelling

Abstract Background Maladaptive inflammatory responses are associated with adverse cardiac remodelling after myocardial infarction (MI), but clinical methods for detecting residual myocardial inflammation post-MI are lacking. Purpose To investigate somatostatin receptor subtype 2 (SST2) positron emission tomography (PET)/magnetic resonance imaging (MRI) using 68Ga-DOTATATE after MI. Methods In a prospective observational cohort study, infarct-related myocardial inflammation detected by 68Ga-DOTATATE PET at 2wk and 3mo post-MI was compared with MRI characteristics including left ventricular (LV) volumetric changes at 1yr, as well circulating immune cell phenotyping and serum proteomic markers. Patients with a prior history of MI or heart failure were excluded. Histological SST2 expression was assessed in myocardial biopsies. Results 38 participants (mean age 60 [SD 9] years; 84% male) with recent MI were enrolled, of whom 58% had an ST-segment elevation MI. Mean peak Troponin I was 16,665 (range 408 to >25,000) ng/L and mean post-infarct LV ejection fraction was 51 (SD 9) %. 68Ga-DOTATATE maximum standardized uptake values (SUVmax) at 10 (SD 4) days accurately localised infarcted myocardial segments defined by late-gadolinium enhancement MRI (LGE; Fig. 1); were 14.2% higher in akinetic/hypokinetic vs. normo-kinetic segments (p<0.0001); and were correlated both with peak segmental strain (r=0.47, p=0.003) and segmental T1 values (r=0.51, p=0.02). Mean infarct SUVmax was 19.7% lower on repeat PET/MRI after a mean 102 (SD 22) days (p<0.0001), and this change was in keeping with parallel reductions in T2-weighted oedema signal on MRI and serum biomarkers of cardiac injury and systemic inflammation. Residual inflammation assessed by mean infarct SUVmax at 3mo was correlated with ΔLV indexed end-diastolic volume at 369 (SD 14) days, after adjustment for baseline infarct size and other clinical variables (p=0.038). The 3mo:2wk ratio of mean infarct SUVmax was an even stronger predictor of adverse myocardial remodelling (p=0.0025). Circulating SST2+ classical monocytes were correlated with infarct 68Ga-DOTATATE signal (r=0.47, p=0.02), and SST2 was co-expressed with CD68+ macrophages in inflamed myocardial specimens of patients with recent MI and ischaemic heart failure. After statistical feature selection and multiple comparisons adjustments, among the blood markers associated with 3mo:2wk infarct SUVmax was CCL25, a chemokine involved in macrophage recruitment which has been implicated in adverse cardiac remodelling. Conclusions Here, in the first prospective clinical study of serial SST2 PET/MRI after MI, we show that 68Ga-DOTATATE can identify and track resolving infarct-related myocardial inflammation. Moreover, residual inflammation detected by 68Ga-DOTATATE is associated with long-term adverse myocardial remodelling and could provide a potential future imaging biomarker to help stratify high-risk patients for emerging immunomodulatory therapies.Figure 1.68Ga-DOTATATE PET-MRI after MI

Dexmedetomidine Ameliorates Myocardial Ischemia-Reperfusion Injury by Inhibiting MDH2 Lactylation via Regulating Metabolic Reprogramming.

Myocardial ischemia-reperfusion injury (MIRI) significantly worsens the outcomes of patients with cardiovascular diseases. Dexmedetomidine (Dex) is recognized for its cardioprotective properties, but the related mechanisms, especially regarding metabolic reprogramming, have not been fully clarified. A total of 60 patients with heart valve disease are randomly assigned to Dex or control group. Blood samples are collected to analyze cardiac injury biomarkers and metabolomics. In vivo and vitro rat models of MIRI are utilized to assess the effects of Dex on cardiac function, lactate production, and mitochondrial function. It is found that postoperative CK-MB and cTNT levels are significantly lower in the Dex group. Metabolomics reveals that Dex regulates metabolic reprogramming and reduces lactate level. In Dex-treated rats, the myocardial infarction area is reduced, and myocardial contractility is improved. Dex inhibits glycolysis, reduces lactate, and improves mitochondrial function following MIRI. Lactylation proteomics identifies that Dex reduces the lactylation of Malate Dehydrogenase 2（MDH2), thus alleviating myocardial injury. Further studies reveal that MDH2 lactylation induces ferroptosis, leading to MIRI by impairing mitochondrial function. Mechanistic analyses reveal that Dex upregulates Nuclear Receptor Subfamily 3 Group C Member 1（NR3C1)phosphorylation, downregulates Pyruvate Dehydrogenase Kinase 4 (PDK4), and reduces lactate production and MDH2 lactylation. These findings provide new therapeutic targets and mechanisms for the treatment for MIRI.

2-[18F]Fluoropropionic Acid PET Imaging of Doxorubicin-induced Cardiotoxicity.

Treatment of pediatric cancers with doxorubicin is a common and predictable cause of cardiomyopathy. Early diagnosis of treatment-induced cardiotoxicity and intervention are major determinants for the prevention of advanced disease. The onset of cardiomyopathies is often accompanied by profound changes in lipid metabolism, including an enhanced uptake of short-chain fatty acids (SCFA). Therefore, we explored the utility of 2-[18F]fluoropropionic acid ([18F]FPA), an SCFA analog, as an imaging biomarker of cardiac injury in mice exposed to doxorubicin. Procedures: Cardiotoxicity and cardiac dysfunction were induced in mice by an 8-dose regimen of doxorubicin (cumulative dose 24 mg/kg) administered over 14 days. The effects of doxorubicin exposure were assessed by measurement of heart weights, left ventricular ejection fractions, and blood cardiac troponin levels. Whole body and cardiac [18F]FPA uptakes were determined by PET and tissue gamma counting in the presence or absence of AZD3965, a pharmacological inhibitor of monocarboxylate transporter 1 (MCT1). Radiation absorbed doses were estimated using tissue time-activity concentrations. Significantly higher cardiac [18F]FPA uptake was observed in doxorubicin-treated animals. This uptake remained constant from 30 min to 120 min post-injection. Pharmacological inhibition of MCT1-mediated transport by AZD3965 selectively decreased the uptake of [18F]FPA in tissues other than the heart. Co-administration of [18F]FPA and AZD3965 enhanced the imaging contrast of the diseased heart while reducing overall exposure to radioactivity. [18F]FPA, especially when co-administered with AZD3965, is a new tool for imaging changes in fatty acid metabolism occurring in response to doxorubicin-induced cardiomyopathy by PET.

Unleashing the cardioprotective potential of Ezetimibe against Doxorubicin-induced cardiotoxicity in Wistar rats: Targeting oxidative stress and NF-κB-mediated inflammation

Background Doxorubicin (DOX) is a potent antineoplastic agent used in treating various adult and pediatric cancers, but it tends to provoke dose-dependent cardiotoxicity. Ezetimibe (EZE), a cholesterol-lowering drug, has been reported to possess defensive actions against oxidative stress and inflammation, which are two of the main proposed mechanisms underlying the development of DOX-induced cardiotoxicity (DIC), hence, we aimed to inspect the possible protective effect of EZE against DIC in rats. Methods 24 adult male Wistar rats were allocated into four groups of six: control, DOX, 10 mg/kg EZE plus DOX and 20 mg/kg EZE plus DOX. At the end of the study, the experimental rats were anesthetized and blood samples were collected for biochemical analysis, after which the hearts were excised and heart tissue samples were obtained for biochemical and gene expression analyses. Results Pretreatment with EZE at a dose of 10 or 20 mg/kg alleviated cardiac damage induced by DOX, as EZE blunted the rise in serum levels of cardiac injury biomarkers, including cardiac troponin I (cTnI) and N-terminal pro-B-type natriuretic peptide (NT-proBNP). Additionally, pretreating rats with EZE at either dose mitigated DOX-induced oxidative stress by elevating the levels of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), with consequent reduction in the lipid peroxidation biomarker malondialdehyde (MDA) in cardiac tissues. Furthermore, pretreatment with either dose of EZE hindered DOX-mediated inflammation, where EZE suppressed cardiac nuclear factor-kappa B (NF-κB) signaling and negatively regulated the gene expression of its downstream proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) with either dose and interleukin-1 beta (IL-1β) with the higher one. Conclusions Our findings indicate that EZE exhibited cardioprotection against DIC in rats, which makes EZE an interesting area for further investigations, animal- and human-wise, that can pave the way for a potential clinical application in preventing DIC in the future.

Predicting troponin biomarker elevation from electrocardiograms using a deep neural network.

Elevated troponin levels are a sensitive biomarker for cardiac injury. The quick and reliable prediction of troponin elevation for patients with chest pain from readily available ECGs may pose a valuable time-saving diagnostic tool during decision-making concerning this patient population. The data used included 15 856 ECGs from patients presenting to the emergency rooms with chest pain or dyspnoea at two centres in Sweden from 2015 to June 2023. All patients had high-sensitivity troponin test results within 6 hours after 12-lead ECG. Both troponin I (TnI) and TnT were used, with biomarker-specific cut-offs and sex-specific cut-offs for TnI. On this dataset, a residual convolutional neural network (ResNet) was trained 10 times, each on a unique split of the data. The final model achieved an average area under the curve for the receiver operating characteristic curve of 0.7717 (95% CI±0.0052), calibration curve analysis revealed a mean slope of 1.243 (95% CI±0.075) and intercept of -0.073 (95% CI±0.034), indicating a good correlation between prediction and ground truth. Post-classification, tuned for F1 score, accuracy was 71.43% (95% CI±1.28), with an F1 score of 0.5642 (95% CI±0.0052) and a negative predictive value of 0.8660 (95% CI±0.0048), respectively. The ResNet displayed comparable or surpassing metrics to prior presented models. The model exhibited clinically meaningful performance, notably its high negative predictive accuracy. Therefore, clinical use of comparable neural networks in first-line, quick-response triage of patients with chest pain or dyspnoea appears as a valuable option in future medical practice.

Association Between High Sensitivity Troponin I and NTproBNP With Rejection and Graft Loss in Pediatric Heart Transplant Recipients.

Troponin I is a blood biomarker of cardiac injury and levels measured using a high-sensitivity assay after pediatric heart transplantation (HT) have not been described. We sought to assess the association between high-sensitivity troponin I (hsTnI) and N-terminal pro-B-type natriuretic peptide (NTproBNP) with treated acute rejection (AR) and graft loss in pediatric heart transplant (HT) recipients. Serum was collected and banked from pediatric HT recipients prior to cardiac catheterization. Patients with samples drawn within 365 days post-HT were included and followed for up to 5 years. Generalized linear mixed-effect models examined the association between hsTnI and treated AR using a random intercept per patient. Cox proportional hazards models tested the association between maximal hsTnI and NT-proBNP and death/graft loss. HsTnI and NTproBNP values decline in the weeks following HT, after which these biomarkers stabilize. HsTnI was higher in AR versus no AR (6.2 vs. 3.5 ng/L, p < 0.001); doubling of hsTnI increased the odds of AR by 33% (p = 0.004). HsTnI showed moderate discrimination for AR with an AUC of 0.811 (95% CI 0.76, 0.87) and a NPV of 96.4% (95% CI 93.0, 98.1). Elevation in NT-proBNP was not associated with AR. In multivariable Cox modeling, a doubling of maximal NT-proBNP was associated with graft loss (HR 8.96, p = 0.014). In this pediatric HT cohort, HsTnI was moderately discriminative for AR and higher maximal NT-proBNP was associated with graft loss. HsTnI may add value in pediatric HT non-invasive AR surveillance, and elevated NTproBNP could suggest an increased risk of graft loss.

Preconditioning with Ginsenoside Rg3 mitigates cardiac injury induced by high-altitude hypobaric hypoxia exposure in mice by suppressing ferroptosis through inhibition of the RhoA/ROCK signaling pathway

Ethnopharmacological relevanceGinseng has historically been utilized as a conventional herbal remedy and dietary supplement to enhance physical stamina and alleviate fatigue. The primary active component of Ginseng, Ginsenoside Rg3 (GS-Rg3), possesses diverse pharmacological properties including immune modulation and anti-inflammatory effects. Furthermore, GS-Rg3 has demonstrated efficacy in mitigating tissue and organ damage associated with metabolic disorders such as hypertension, hyperglycemia, and hyperlipidemia. Nevertheless, its potential impact on high-altitude cardiac injury (HACI) remains insufficiently explored. Aim of the studyThe aim of this study was to examine the potential cardioprotective effects of Ginsenoside Rg3, and to investigate how Ginsenoside Rg3 preconditioning can enhance high-altitude cardiac injury by inhibiting the RhoA/ROCK pathway and ferroptosis in cardiac tissue. The findings of this study may contribute to the development of novel therapeutic strategies using traditional Chinese medicine for high-altitude cardiac injury, based on experimental evidence. Materials and methodsA hypobaric hypoxia chamber was employed to simulate hypobaric hypoxia conditions equivalent to an altitude of 6000 m. Through a randomization process, groups of six male mice were assigned to receive either saline, Ginsenoside Rg3 at doses of 15 mg/kg or 30 mg/kg, or lysophosphatidic acid (LPA) at 1 mg/kg. The impact of Ginsenoside Rg3 on high altitude-induced arrhythmias was evaluated using electrocardiography. Cardiac pathology sections stained with hematoxylin and eosin were evaluated for damage, with the extent of cardiomyocyte damage observed via transmission electron microscopy. The impact of Ginsenoside Rg3 on high-altitude cardiac injury was investigated through analysis of serum biomarkers for cardiac injury (CK-MB, BNP), inflammatory cytokines (TNF, IL-6, IL-1β), reactive oxygen species (ROS) and glutathione (GSH). The expression levels of hypoxia and hypoxia-related proteins in myocardial tissues from each experimental group were assessed using Western blot analysis. Following a review of the existing literature, the traditional regulatory mechanisms of ferroptosis were examined. Immunofluorescence staining of cardiac tissues and Western blotting techniques were utilized to investigate the impact of Ginsenoside Rg3 on cardiomyocyte ferroptosis through the RhoA/ROCK signaling pathway under conditions of hypobaric hypoxia exposure. ResultsPre-treatment with Ginsenoside Rg3 improved high altitude-induced arrhythmias, reduced cardiomyocyte damage, decreased cardiac injury biomarkers and inflammatory cytokines, and lowered the expression of hypoxia-related proteins in myocardial tissues. Both Western blotting and immunofluorescence staining of cardiac tissues demonstrated that exposure to high-altitude hypobaric hypoxia results in elevated expression of ferroptosis and proteins related to the RhoA/ROCK pathway. Experimental validation corroborated that the role of the RhoA/ROCK signaling pathway in mediating ferroptosis. ConclusionsThe findings of our study suggest that preconditioning with Ginsenoside Rg3 may attenuate cardiac injury caused by high-altitude hypobaric hypoxia exposure in mice by inhibiting ferroptosis through the suppression of the RhoA/ROCK signaling pathway. These findings contribute to the current knowledge of Ginsenoside Rg3 and high-altitude cardiac injury, suggesting that Ginsenoside Rg3 shows potential as a therapeutic agent for high-altitude cardiac injury.

Potential mechanisms underlying podophyllotoxin-induced cardiotoxicity in male rats: toxicological evidence chain (TEC) concept.

Podophyllotoxin (PPT) is a high-content and high-activity compound extracted from the traditional Chinese medicinal plant Dysosma versipellis (DV) which exhibits various biological activities. However, its severe toxicity limits its use. In clinical settings, patients with DV poisoning often experience adverse reactions when taking large doses in a short period. The heart is an important toxic target organ, so it is necessary to conduct 24-h acute cardiac toxicity studies on PPT to understand its underlying toxicity mechanism. Based on the concept of the toxicological evidence chain (TEC), we utilized targeted metabolomic and transcriptomic analyses to reveal the mechanism of the acute cardiotoxicity of PPT. The manifestation of toxicity in Sprague-Dawley rats, including changes in weight and behavior, served as Injury Phenotype Evidence (IPE). To determine Adverse Outcomes Evidence (AOE), the hearts of the rats were evaluated through histopathological examination and by measuring myocardial enzyme and cardiac injury markers levels. Additionally, transcriptome analysis, metabolome analysis, myocardial enzymes, and cardiac injury markers were integrated to obtain Toxic Event Evidence (TEE) using correlation analysis. The experiment showed significant epistaxis, hypokinesia, and hunched posture in PPT group rats within 24h after exposure to 120mg/kg PPT. It is found that PPT induced cardiac injury in rats within 24h, as evidenced by increased serum myocardial enzyme levels, elevated concentrations of cardiac injury biomarkers, and altered cardiac cell morphology, all indicating some degree of cardiac toxicity. Transcriptome analysis revealed that primary altered metabolic pathway was arachidonic acid metabolism after PPT exposure. Cyp2e1, Aldob were positively correlated with differential metabolites, while DHA showed positive correlation with differential genes Fmo2 and Timd2, as well as with heart injury markers BNP and Mb. This study comprehensively evaluated cardiac toxicity of PPT and initially revealed the mechanism of PPT-induced acute cardiotoxicity, which involved oxidative stress, apoptosis, inflammatory response, and energy metabolism disorder.

Role of Circulating Biomarkers in Diabetic Cardiomyopathy.

Type 2 diabetes mellitus (T2DM) is a metabolic disorder that has alarmingly increased in incidence in recent decades. One of the most serious complications of T2DM is diabetic cardiomyopathy (DCM), an often underrecognized yet severe condition that is a leading cause of mortality among diabetic patients. In the early stages of DCM, patients typically show no symptoms and maintain normal systolic and diastolic left ventricle function, making early detection challenging. Currently available clinical markers are often not specific enough to detect the early stage of DCM. Conventional biomarkers of cardiac mechanical stress and injury, such as natriuretic peptides (NPs) and cardiac troponin I (cTnI), have shown limited predictive value for patients with T2DM. NPs have proven efficacy in detecting diastolic dysfunction in diabetic patients when used alongside 2D echocardiography, but their utility as biomarkers is limited to symptomatic individuals. While cTnI is a reliable indicator of general cardiac damage, it is not specific to cardiac injury caused by high glucose levels or T2DM. This underscores the need for research into biomarkers that can enable early diagnosis and management of DCM to reduce mortality rates. Promising novel biomarkers that showed good performance in detecting diastolic dysfunction or heart failure in diabetic patients include galectin-3, ST2, FGF-21, IGFBP-7, GDF-15, and TGF-β. This review summarizes the current understanding of DCM biomarkers, aiming to generate new ideas for the early recognition and treatment of DCM by exploring related pathophysiological mechanisms.

Rationale and design of RESILIENCE: A prospective randomized clinical trial evaluating remote ischaemic conditioning for the prevention of anthracycline cardiotoxicity.

There is a lack of therapies able to prevent anthracycline cardiotoxicity (AC). Remote ischaemic conditioning (RIC) has shown beneficial effects in preclinical models of AC. REmote iSchemic condItioning in Lymphoma PatIents REceiving ANthraCyclinEs (RESILIENCE) is a multinational, prospective, phase II, double-blind, sham-controlled, randomized clinical trial that evaluates the efficacy and safety of RIC in lymphoma patients receiving anthracyclines. Patients scheduled to undergo ≥5 chemotherapy cycles including anthracyclines and with ≥1 AC-associated risk factors will be randomized to weekly RIC or sham throughout the chemotherapy period. Patients will undergo three multiparametric cardiac magnetic resonance (CMR) studies, at baseline, after the third cycle (intermediate CMR), and 2 months after the end of chemotherapy. Thereafter, patients will be followed up for clinical events over an anticipated median of ≥24 months. The primary endpoint is the absolute change from baseline in CMR-based left ventricular ejection fraction (LVEF). The main secondary outcome is the incidence of AC events, defined as (1) a drop in CMR-based LVEF of ≥10 absolute points, or (2) a drop in CMR-based LVEF of ≥5 and <10 absolute points to a value <50%. Intermediate CMR will test the ability of T2 mapping to predict AC versus classical markers (left ventricular strain and cardiac injury biomarkers). A novel CMR sequence allowing ultrafast cine acquisition will be validated in this vulnerable population. The RESILIENCE trial will test RIC (a novel non-invasive intervention to prevent AC) in a cohort of high-risk patients. The trial will also test candidate markers for their capacity to predict AC and will validate a novel CMR sequence reducing acquisition time in a vulnerable population.

Aminopeptidasic Enzymes as Early Biomarkers of Cardiac Surgery-Associated Acute Kidney Injury and Long-Term Events.

Diagnosis of acute kidney injury (AKI) relies on serum creatinine (SCr) changes. This study investigated if urinary aminopeptidases are early and predictive biomarkers of cardiac surgery-associated AKI (CSA-AKI). Glutamyl aminopeptidase (GluAp), alanyl aminopeptidase (AlaAp), dipeptidyl peptidase-4 (DPP4), proteinuria, albuminuria, N-acetyl-β-D-glucosaminidase (NAG), and neutrophile gelatinase-associated lipocalin (NGAL) were measured in urine samples from 44 patients at arrival in the intensive care unit (ICU) after cardiac surgery. Sensitivity, specificity, and positive and negative predictive value for diagnosis of stages 1, 2, and 3 of AKI were analyzed for the highest quartile of each marker. We also studied the relationship with SCr after surgery, 6- and 12-month glomerular filtration rates (GFRs), and other long-term events over the next 5 years. GluAp diagnosed the maximal number of patients that developed stage 2 or 3 of AKI, increasing diagnostic sensitivity from 0% to 75%. In addition, GluAp and DPP4 were related to the decrease in GFR at 6 or 12 months after surgery. Urinary aminopeptidases are a potential tool for the early diagnosis of CSA-AKI, with GluAp being the most effective marker for diagnosing stage 2 or 3 of AKI at ICU admission. GluAp and DPP4 serve as predictive biomarkers for a decrease in GFR.

Allicin and L-carnitine as Preventive Agents Against Doxorubicin-induced Cardiac Damage in Rats

Background: Doxorubicin (DOX) is a potent anthracycline chemotherapy agent widely employed to treat various malignancies, such as cancers and this study sought to determine how allicin (ALC) and or L-carnitine (LC) affect DOX-induced cardiotoxicity in rats.Methods: In this study, the possible alleviative role of ALC (20 mg/kg/day orally (PO)) or LC (100 mg/kg/day PO) or the combined treatment of both ALC and LC (with the previously mentioned dosages) was evaluated against the cardiotoxic effect of a widely used chemotherapeutic agent, DOX (20 mg DOX /kg intraperitoneal injection (IP) as a single dose) in rats in 30 days experiment. Results: The results revealed that ALC and LC significantly suppressed the DOX-induced increment in serum levels of cardiac damage biomarkers, such as lactate dehydrogenase (LDH), creatine kinase (CK) and creatine kinase-megabyte (CK-MB). Moreover, DOX-associated oxidative stress, including the elevation in malondialdehyde (MDA) level and reduced activity of antioxidant enzymes, such as catalase (CAT) and superoxide dismutase (SOD) and the level of reduced glutathione (GSH) was corrected in ALC and or LC treated groups. Furthermore, DOX-induced cardiomyopathy showed significant pathological changes, including myocyte degeneration, vacuolization, interstitial edema, and focal necrosis. Nevertheless, the histopathological lesions were corrected in the treated groups mostly in the combined treatment with ALC plus LC. Compared to ALC and LC, ALC plus LC was more effective at restoring the cardiac injury biomarkers, inhibiting cardiac oxidative damage and preserving the cardiac architecture. Conclusions: Conclusively, the study results evidenced the beneficial role of the combined treatment with ALC plus LC in mitigating DOX-induced cardiotoxicity.

Dibenzazepine, a γ-Secretase Enzyme Inhibitor, Protects Against Doxorubicin-Induced Cardiotoxicity by Suppressing NF-κB, iNOS, and Hes1/Hey1 Expression.

Doxorubicin (DOX) is an effective chemotherapeutic drug; however, its cardiotoxicity and resistance compromise its therapeutic index. The Notch pathway was reported to contribute to DOX cancer resistance. The role of Notch pathway in DOX cardiotoxicity has not been identified yet. Notch receptors are characterized by their extracellular (NECD) and intracellular(NICD) domains (NICD). The γ-secretase enzyme helps in the release of NICD. Dibenzazepine (DBZ) is a γ-secretase inhibitor. The present study investigated the effect of Notch pathway inhibition on DOX cardiotoxicity. Twenty-four male Wistar rats were divided into four groups: control group, DOX group, acute cardiotoxicity was induced by a single dose of DOX (20 mg/kg) i.p., DOX (20 mg/kg) plus DBZ group, and DBZ group. The third and fourth groups received i.p. injection of DBZ daily for 14 days at 2 mg/kg dose. DOX cardiotoxicity increased the level of serum creatine kinase-MB and cardiac troponin I, and it was confirmed by the histopathological examination. Moreover, the antioxidants glutathione peroxidase and superoxide dismutase levels were markedly decreased, and the inflammatory markers, inducible nitric oxide synthase, nuclear factor-ķB, and tumor necrosis factor-α were markedly increased. Furthermore, DOX increased BAX protein and downregulated BCL-2. In addition, DOX upregulated Notch pathway-related parameters: Hes1 and Hey1 mRNA levels, and increased Hes1 protein levels. DBZ ameliorated DOX-induced cardiotoxicity, evidenced by reducing the cardiac injury biomarkers, improving cardiac histopathological changes, correcting antioxidant levels, and reducing inflammatory and apoptotic proteins. Our study indicates the protective effect of Notch inhibitor against DOX-induced cardiotoxicity.

SiO2 Induces Iron Overload and Ferroptosis in Cardiomyocytes in a Silicosis Mouse Model

ObjectiveThe aim of this study was to explore the role and mechanism of ferroptosis in SiO2-induced cardiac injury using a mouse model. MethodsMale C57BL/6 mice were intratracheally instilled with SiO2 to create a silicosis model. Ferrostatin-1 (Fer-1) and deferoxamine (DFO) were used to suppress ferroptosis. Serum biomarkers, oxidative stress markers, histopathology, iron content, and the expression of ferroptosis-related proteins were assessed. ResultsSiO2 altered serum cardiac injury biomarkers, oxidative stress, iron accumulation, and ferroptosis markers in myocardial tissue. Fer-1 and DFO reduced lipid peroxidation and iron overload, and alleviated SiO2-induced mitochondrial damage and myocardial injury. SiO2 inhibited Nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant genes, while Fer-1 more potently reactivated Nrf2 compared to DFO. ConclusionIron overload-induced ferroptosis contributes to SiO2-induced cardiac injury. Targeting ferroptosis by reducing iron accumulation or inhibiting lipid peroxidation protects against SiO2 cardiotoxicity, potentially via modulation of the Nrf2 pathway.

NET burden in left atrial blood is associated with biomarkers of thrombosis and cardiac injury in patients with enlarged left atria.

Emerging data suggest an association between left atrial (LA) enlargement, thrombus formation, and ischemic stroke. However, it is unknown what may mediate such clot formation in LA dysfunction. Neutrophils promote large vessel occlusion and microthrombosis via neutrophil extracellular trap (NET) release, thus lying at the interface of inflammation, thrombosis, and fibrosis. We conducted a prospective all-comers cohort study in patients undergoing catheterization procedures with atrial transseptal access (MitraClip, MC; left atrial appendage closure, LAAC; pulmonary vein ablation, PVA; patent foramen ovale closure, PFO). We measured NETs, cytokines, thrombotic factors, and cardiac injury markers in paired blood samples collected from peripheral blood and within the left atrium. We correlated these biomarkers with echocardiographic measures of LA structure and function (including left atrial volume index, LAVI). Data were analyzed by procedure type, and stratified by LAVI or atrial fibrillation (AF) status. We enrolled 70 patients (mean age 64years, 53% women). NETs, but not other markers, were elevated in LA compared to peripheral blood samples. Most thrombotic, inflammatory, and cardiac damage markers were elevated in LAs from MC or LAAC compared to PFO patients. Overall, NET biomarkers positively correlated with VWF, LAVI, and markers of cardiac injury and negatively with ADAMTS13 activity. LA enlargement and the presence of AF similarly stratified patients based on thromboinflammation measurements, but this was not limited to AF at the time of sample collection. Elevated NETs and VWF in patients with enlarged LA or AF suggest enhanced thromboinflammation within the LA.

β stimulator induces upregulation of miR-27a in the rat heart one hour after the injection

MicroRNAs (miRs) are non-coding small RNA containing 18 to 22 nucleotides, that post-transcriptionally regulates mRNA expression. Chronic injection of β stimulator is known to induce cardiac injury and change of miRs expression level in the heart with some pathological changes such as fibrosis, heart failure, myocardial infarction. We investigated the changes in the expression level of miRs in the rat heart one hour after isoproterenol (a β stimulator) injection.Male Sprague-Dawley rats were assigned into three groups and received subcutaneous injection of normal sarin (NS) or 0.1 mg/kg isoproterenol (ISO-0.1) or 10 mg/kg isoproterenol (ISO-10). After one hour, we collected their heart and plasma. Total RNA was extracted from the left ventricle and used for deep miRNA sequencing. Based on the results of miRNA sequencing, we performed real-time polymerase chain reaction (RT-PCR) using 8 miR primers. Cardiac injury was evaluated by hematoxylin and eosin, and phosphotungstic acid–hematoxylin staining and measuring troponin-I levels in plasma.Troponin-I was significantly increased in ISO-0.1 and ISO-10 groups, but histological observation did not show any cardiac necrosis. miRNA sequencing identified 14 upregulated miRs and 12 downregulated miRs. Of the 26 miRs, RT-PCR confirmed miR-144-3p/5p and miR-451-5p were decreased, and that 5 miRs (miR-27a-5p, miR-30b-3p, miR-92a-1-5p, miR-132-5p, miR-582-3p) were upregulated.This study showed that β stimulus causes downregulation of miR-144/451 cluster and increases expression of five 5 miRs in the heart, especially 6.5-fold upregulation of miR-27a-5p as early as one hour after isoproterenol injection. Therefore, these miRs might be good biomarkers for cardiac injury.

Targeting exercise and sedentary behavior for the prevention of allogeneic stem cell transplant-related cardiovascular dysfunction: The ALLO-Active trial.

12018 Targeting Exercise and Sedentary Behavior to Prevent Allogeneic Stem Cell Transplant-Related Cardiovascular Dysfunction: The ALLO-Active Trial Background: Allogeneic stem cell transplantation (allo-SCT) is a potentially life-saving therapy for hematological malignancy, however, quality of life and longevity post allo-SCT are hampered by exercise intolerance, cardiac dysfunction, and cardiovascular mortality. This randomized controlled trial evaluated the efficacy of a novel multi-component activity program on cardiorespiratory fitness (peak oxygen uptake [VO2peak]) and cardiac function in adults undergoing allo-SCT. Methods: Sixty-two hematological malignancy patients scheduled for allo-SCT were randomized to a 4-month multi-component Activity program (n = 30) designed to increase aerobic and resistance exercise (3-day.week-1) and reduce sedentary time (≥30-min.day-1), or to usual care ( UC, n = 32). The Activity program was delivered over two distinct phases: ‘Inpatient’, which commenced upon admission for allo-SCT and continued until discharge (~4 weeks), and ‘Outpatient’,which commenced at discharge and continued for 12-weeks. Physiological assessments were conducted pre-admission, and 12-weeks post-discharge (4-months from baseline) and included: (1) cardiopulmonary exercise testing to quantify VO2peak, (2) exercise cardiac magnetic resonance imaging to determine peak cardiac output and stroke volume index (COIpeak and SVIpeak), (3) standard of care resting echocardiography-derived left ventricular ejection fraction and global longitudinal strain, and (4) cardiac biochemistry (troponin, B-type natriuretic peptide). Results: Fifty-two patients (84%) completed follow-up (25 Activity; 27 UC), and median (IQR) intervention adherence was 73% (50-81). Activity preserved VO2peak (-0.9ml.kg-1.min-1 [95%CI -2.5, 0.8]) which showed a marked decline with UC (-3.4ml.kg-1.min-1 [95%CI -4.9, -1.8]; interaction, p= 0.029). Activity also showed significant benefits on exercise cardiac function, as shown by a preservation of COIpeak (0.30L.min-1.m2, [95%CI -0.34, 0.41]) and SVIpeak (0.6ml.m2 [95%CI -1.3, 2.5]), both of which declined with UC (COIpeak: -0.68L.min-1.m2, [95%CI -1.3, -0.32]; interaction, p= 0.008; SVIpeak: -2.7ml.m2 [95%CI -4.6, -0.9], interaction, p =0.014). There were no treatment effects of Activity on cardiac injury biomarkers or global longitudinal strain and no changes in left ventricular ejection fraction in either group. Conclusions: Intervening early in the allo-SCT process with an exercise and sedentary behavior intervention can have significant benefits for the preservation of patient’s cardiovascular reserve capacity. Our results may have important long-term implications for cardiovascular disease incidence and mortality in allo-SCT recipients. Clinical trial information: ANZCTR12619000741189.

Artesunate attenuates isoprenaline induced cardiac hypertrophy in rats via SIRT1 inhibiting NF-κB activation

Cardiac Hypertrophy is an adaptive response of the body to physiological and pathological stimuli, which increases cardiomyocyte size, thickening of cardiac muscles and progresses to heart failure. Downregulation of SIRT1 in cardiomyocytes has been linked with the pathogenesis of cardiac hypertrophy. The present study aimed to investigate the effect of Artesunate against isoprenaline induced cardiac hypertrophy in rats via SIRT1 inhibiting NF-κB activation. Experimental cardiac hypertrophy was induced in rats by subcutaneous administration of isoprenaline (5 mg/kg) for 14 days. Artesunate was administered simultaneously for 14 days at a dose of 25 mg/kg and 50 mg/kg. Artesunate administration showed significant dose dependent attenuation in mean arterial pressure, electrocardiogram, hypertrophy index and left ventricular wall thickness compared to the disease control group. It also alleviated cardiac injury biomarkers and oxidative stress. Histological observation showed amelioration of tissue injury in the artesunate treated groups compared to the disease control group. Further, artesunate treatment increased SIRT1 expression and decreased NF-kB expression in the heart. The results of the study show the cardioprotective effect of artesunate via SIRT1 inhibiting NF-κB activation in cardiomyocytes.

Mesenchymal stem cells improve cardiac function in diabetic rats by reducing cardiac injury biomarkers and downregulating JAK/STAT/iNOS and iNOS/Apoptosis signaling pathways

Cardiovascular complications are prevalent manifestations of type 2 diabetes mellitus (T2DM) and are usually the main cause of death. This study aims to show the underlying mechanisms of the potential therapeutic effect of mesenchymal stem cells (MSCs) on diabetic cardiac dysfunction. Twenty-four male Wistar rats were randomly assigned to one of three groups The control group received standard laboratory chow, and the groups with T2DM received a single dose of 45 mg/kg body weight of streptozotocin (STZ) after 3 weeks of pretreatment with a high-fat diet (HFD). Eight weeks after the diagnosis of T2DM, rats were divided into two groups: the T2DM model group and the T2DM + MSCs group. BM-MSCs were administered systemically at 2 × 106 cells/rat doses.A Significant amelioration in Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and dyslipidemia was noted 2 weeks post-administration of MSCs. Administration of MSCs improved dyslipidemia, the altered cardiac injury biomarkers (p ≤ 0.0001), downregulated Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3)/inducible Nitric oxide synthase (iNOS) and iNOS/Apoptosis signaling pathways. This was associated with improved cardiac dysfunction (impaired left ventricular performance and decreased contractility index).Our results show that MSCs ameliorate cardiac dysfunction associated with diabetic cardiomyopathy by lowering dyslipidemia and insulin resistance, inhibiting oxidative stress, and inflammation, downregulating JAK2/STAT3/iNOS and iNOS/Apoptosis signaling pathways.