Loss of TRIM21 alleviates cardiotoxicity by suppressing ferroptosis induced by the chemotherapeutic agent doxorubicin

BACKGROUND

Doxorubicin, an anthracycline chemotherapeutic agent, is widely used in the treatment of many cancers. However, doxorubicin posts a great risk of adverse cardiovascular events, which are thought to be caused by oxidative stress. We recently reported that the ubiquitin E3 ligase TRIM21 interacts and ubiquitylates p62 and negatively regulates the p62-Keap1-Nrf2 antioxidant pathway. Therefore, we sought to determine the role TRIM21 in cardiotoxicity induced by oxidative damage.

METHODS

Using TRIM21 knockout mice, we examined the effects of TRIM21 on cardiotoxicity induced by two oxidative damage models: the doxorubicin treatment model and the Left Anterior Descending (LAD) model. We also explored the underlying mechanism by RNA-sequencing of the heart tissues, and by treating the mouse embryonic fibroblasts (MEFs), immortalized rat cardiomyocyte line H9c2, and immortalized human cardiomyocyte line AC16 with doxorubicin.

FINDINGS

TRIM21 knockout mice are protected from heart failure and fatality in both the doxorubicin and LAD models. Hearts of doxorubicin-treated wild-type mice exhibit deformed mitochondria and elevated level of lipid peroxidation reminiscent of ferroptosis, which is alleviated in TRIM21 knockout hearts. Mechanistically, TRIM21-deficient heart tissues and cultured MEFs and H9c2 cells display enhanced p62 sequestration of Keap1 and are protected from doxorubicin-induced ferroptosis. Reconstitution of wild-type but not the E3 ligase-dead and the p62 binding-deficient TRIM21 mutants impedes the protection from doxorubicin-induced cell death.

INTERPRETATION

Our study demonstrates that TRIM21 ablation protects doxorubicin-induced cardiotoxicity and illustrates a new function of TRIM21 in ferroptosis, and suggests TRIM21 as a therapeutic target for reducing chemotherapy-related cardiotoxicity.

FUNDING

NIH (CA129536; DK108989): data collection, analysis. Shanghai Pujiang Program (19PJ1401900): data collection. National Natural Science Foundation (31971161): data collection. Department of Veteran Affairs (BX004083): data collection. Tianjin Science and Technology Plan Project (17ZXMFSY00020): data collection.

Association of genetic polymorphisms NCF4 rs1883112, CBR3 rs1056892, and ABCC1 rs3743527 with the cardiotoxic effects of doxorubicin in children with acute lymphoblastic leukemia

OBJECTIVES

Cardiotoxicity is a frequent complication secondary to the use of anthracyclines for cancer chemotherapy. Evidence suggests that certain polymorphic genetic variants modify the risk for anthracycline-related cardiotoxicity. Reports documenting the impact of genetic polymorphisms on anthracycline-cardiotoxicity risk in pediatric patients with cancers from Latin American countries are scarce. The objective of this study was to evaluate associations between NCF4 rs1883112, CBR3 rs1056892 and ABCC1 rs3743527 genotype status and echocardiographic parameters indicative of anthracycline-cardiotoxicity in a group of Mexican children with acute lymphoblastic leukemia (ALL).

METHODS

Sixty-seven children (2-18 years old) with ALL were treated at the State Cancer Center in Durango, Mexico. NCF4, CBR3, and ABCC1 genotypes were examined by real-time PCR. Left ventricular ejection fraction and diastolic filling ratio were examined as markers of systolic and diastolic anthracycline-toxicity.

RESULTS

NCF4 rs1883112 genotype status was significantly associated with the risk of doxorubicin cardiotoxicity [odds ratio (OR) = 10.80, 95% confidence interval (CI) 1.69-68.98, P = 0.01]. There was a significant association between heterozygous CBR3 rs1056892 genotype status and anthracycline-cardiotoxicity risk (OR = 9.91, 95% CI 1.07-91.47, P = 0.04). Heterozygosis for the ABCC1 rs3743527 allele was associated with protection from anthracycline-cardiotoxicity (OR = 0.30, 95% CI 0.09-0.91, P = 0.03).

CONCLUSION

This pilot study suggests that selected polymorphic variants may impact the risk for anthracycline-cardiotoxicity in pediatric patients with ALL treated with a contemporary chemotherapeutic regimen in Mexico.

MicroRNA-98 ameliorates doxorubicin-induced cardiotoxicity via regulating caspase-8 dependent Fas/RIP3 pathway

Cardiotoxicity is one of the primary limitations in the clinical use of the anticancer drug doxorubicin (DOX). However, the role of microRNAs (miRNAs) in DOX-induced cardiomyocyte death has not yet been covered. To investigate this, we observed a significant increase in miR-98 expression in neonatal rat ventricular myocytes after DOX treatment, and MTT, LIVE/Dead and Viability/Cytotoxicity staining showed that miR-98 mimic inhibited DOX-induced cell death. This was also confirmed by Flow cytometry and Annexin V-FITC/PI staining. Interestingly, the protein expression of caspase-8 was upregulated by miR-98 mimics during this process, whereas Fas and RIP3 were downregulated. In addition, the effect of miR-98 against the expression of Fas and RIP3 were restored by the specific caspase-8 inhibitor Z-IETD-FMK. Thus, we demonstrate that miR-98 protects cardiomyocytes from DOX-induced injury by regulating the caspase-8-dependent Fas/RIP3 pathway. Our findings enhance understanding of the therapeutic role of miRNAs in the treatment of DOX-induced cardiotoxicity.

Role of Oxidative Stress in the Mechanisms of Anthracycline-Induced Cardiotoxicity: Effects of Preventive Strategies

Anthracycline-induced cardiotoxicity (AIC) persists as a significant cause of morbidity and mortality in cancer survivors. Although many protective strategies have been evaluated, cardiotoxicity remains an ongoing threat. The mechanisms of AIC remain unclear; however, several pathways have been proposed, suggesting a multifactorial origin. When the central role of topoisomerase 2β in the pathophysiology of AIC was described some years ago, the classical reactive oxygen species (ROS) hypothesis shifted to a secondary position. However, new insights have reemphasized the importance of the role of oxidative stress-mediated signaling as a common pathway and a critical modulator of the different mechanisms involved in AIC. A better understanding of the mechanisms of cardiotoxicity is crucial for the development of treatment strategies. It has been suggested that the available therapeutic interventions for AIC could act on the modulation of oxidative balance, leading to a reduction in oxidative stress injury. These indirect antioxidant effects make them an option for the primary prevention of AIC. In this review, our objective is to provide an update of the accumulated knowledge on the role of oxidative stress in AIC and the modulation of the redox balance by potential preventive strategies.

Polymorphisms rs4673 and rs28714259 in predicting anthracycline-mediated cardiotoxicity in patients with breast cancer

INTRODUCTION

Against the background of significant progress in anticancer therapy, which makes it possible to improve the quality of life and life expectancy of patients with cancer, anthracycline antibio-tics retain their relevance, both for scientific research and for clinical practice. However, the therapeutic efficacy of anthracyclines is associated with the development of various complications, among which the most common is cardiotoxicity. Our study was dedicated to searching for possible associations between rs4673 and rs28714259 single nucleotide polymorphisms (SNPs) and the risk of cardiotoxicity in breast cancer patients who underwent anthracycline-containing chemotherapy.

MATERIALS AND METHODS

The study included 256 patients with a dia-gnosis of breast cancer without dia-gnosed cardiovascular changes who were treated at the National Medical Research Center of Oncology in Rostov-on-Don in 2019-2020. For SNP genotyping, DNA was extracted from blood and high resolution melting analysis was performed. The presence of SNPs was confirmed by Sanger sequencing.

RESULTS

The presence of the T-allele rs4673 increased the risk of cardiotoxicity in breast cancer patients 6.49x (95% CI 1.48-28.53; P = 0.002), and the presence of the A-allele rs28714259 increased the risk 3.27x (95% CI 1.23-8.75; P = 0.026). For tests based on genotyping rs4673 and rs28714259 SNPs, the areas under the receiver operating characteristic (ROC) curves were equal to 71.9% and 76.3%, respectively. The two-locus SNP-SNP model turned out to be statistically significant: the training balanced accuracy was 0.77; similarly, the testing balanced accuracy, and the cross-validation consistency was 10/10.

CONCLUSION

Our study confirmed the predictive value of genetic tests based on the determination of the rs4673 and rs28714259 SNPs. Genotyping of both SNPs will significantly improve the accuracy of predicting the development of cardiotoxicity against the background of anthracycline-containing therapy and timely identify the risk group of breast cancer patients for whom it is necessary to adjust the therapeutic strategy.

Use of hiPSC to explicate genomic predisposition to anthracycline-induced cardiotoxicity

The anticancer agents of the anthracycline family are commonly associated with the potential to cause severe toxicity to the heart. To solve the question of why particular a patient is predisposed to anthracycline-induced cardiotoxicity (AIC), researchers have conducted numerous pharmacogenomic studies and identified more than 60 loci associated with AIC. To date, none of these identified loci have been developed into US FDA-approved biomarkers for use in routine clinical practice. With advances in the application of human-induced pluripotent stem cell-derived cardiomyocytes, sequencing technologies and genomic editing techniques, variants associated with AIC can now be validated in a human model. Here, we provide a comprehensive overview of known genetic variants associated with AIC from the perspective of how human-induced pluripotent stem cell-derived cardiomyocytes can be used to help better explain the genomic predilection to AIC.

Melphalan induces cardiotoxicity through oxidative stress in cardiomyocytes derived from human induced pluripotent stem cells

BACKGROUND

Treatment-induced cardiotoxicity is a leading noncancer-related cause of acute and late onset morbidity and mortality in cancer patients on antineoplastic drugs such as melphalan-increasing clinical case reports have documented that it could induce cardiotoxicity including severe arrhythmias and heart failure. As the mechanism by which melphalan impairs cardiac cells remains poorly understood, here, we aimed to use cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) to investigate the cellular and molecular mechanisms of melphalan-induced cardiotoxicity.

METHODS

hiPSC-CMs were generated and treated with clinically relevant doses of melphalan. To characterize melphalan-induced cardiotoxicity, cell viability and apoptosis were quantified at various treatment durations. Ca2+ transient and contractility analyses were used to examine the alterations of hiPSC-CM function. Proteomic analysis, reactive oxygen species detection, and RNA-Sequencing were conducted to investigate underlying mechanisms.

RESULTS

Melphalan treatment of hiPSC-CMs induced oxidative stress, caused Ca2+ handling defects and dysfunctional contractility, altered global transcriptomic and proteomic profiles, and resulted in apoptosis and cell death. The antioxidant N-acetyl-L-cysteine attenuated these genomic, cellular, and functional alterations. In addition, several other signaling pathways including the p53 and transforming growth factor-β signaling pathways were also implicated in melphalan-induced cardiotoxicity according to the proteomic and transcriptomic analyses.

CONCLUSIONS

Melphalan induces cardiotoxicity through the oxidative stress pathway. This study provides a unique resource of the global transcriptomic and proteomic datasets for melphalan-induced cardiotoxicity and can potentially open up new clinical mechanism-based targets to prevent and treat melphalan-induced cardiotoxicity.

Protective effects of valsartan administration on doxorubicin‑induced myocardial injury in rats and the role of oxidative stress and NOX2/NOX4 signaling

Clinical application of doxorubicin (DOX) is hampered by its potential cardiotoxicity, however angiotensin receptor blockers could attenuate DOX‑induced cardiomyopathy. The present study tested the hypothesis that simultaneous administration of valsartan (Val) with DOX could prevent DOX‑induced myocardial injury by modulating myocardial NAD(P)H oxidase (NOX) expression in rats. Eight‑week‑old male Sprague‑Dawley rats were randomly divided into control (CON), DOX, and DOX+Val groups. After 10 weeks, surviving rats underwent echocardiography examination, myocardial mRNA and protein expression detection of NOX1, NOX2 and NOX4. H9C2 cells were used to perform in vitro experiments, reactive oxygen species (ROS) production and apoptosis were observed under the conditions of down‑ or upregulation of NOX2 and NOX4 in DOX‑ and DOX+Val‑treated H9C2 cells. Cardiac function was significantly improved, pathological lesion and collagen volume fraction were significantly reduced in the DOX+Val group compared with the DOX group (all P<0.05). Myocardial protein and mRNA expression of NOX2 and NOX4 was significantly downregulated in DOX+Val group compared with in the DOX group (all P<0.05). In vitro, ROS production and apoptosis in DOX‑treated H9C2 cells was significantly reduced by NOX2‑small interfering (si)RNA and NOX4‑siRNA, and significantly increased by overexpressing NOX2 and NOX4. To conclude, Val applied simultaneously with DOX could prevent DOX‑induced myocardial injury and reduce oxidative stress by downregulating the myocardial expression of NOX2 and NOX4 in rats.

GPR91 Receptor Mediates Protection against Doxorubicin-Induced Cardiotoxicity without Altering Its Anticancer Efficacy. An In Vitro Study on H9C2 Cardiomyoblasts and Breast Cancer-Derived MCF-7 Cells

Doxorubicin (DOX) is an anticancer drug widely used in oncology, especially for breast cancer. The main limitation of DOX treatment is its cardiotoxicity due to the cumulative dose. Clinically, DOX-induced cardiomyopathy develops as a progressive heart failure caused by a progressive cardiomyocyte's death. For long, the oxidative stress induced by DOX was considered as the main toxic mechanism responsible for heart damage, but it is now controverted, and other processes are investigated to develop cardioprotective strategies. Previously, we studied DOX-induced cardiotoxicity and dexrazoxane (DEX), the only cardioprotective compound authorized by the FDA, by 1H-NMR metabonomics in H9C2 cells. We observed an increased succinate secretion in the extracellular fluid of DEX-exposed cardiomyocytes, a finding that led us to the hypothesis of a possible protective role of this agonist of the GPR91 receptor. The objective of the present work was to study the effect of succinate (SUC) and cis-epoxysuccinate (cis-ES), two agonists of the GPR91 receptor, on DOX-induced cardiotoxicity to H9C2 cells. To this purpose, several toxicity parameters, including cell viability, oxidative stress and apoptosis, as well as the GPR91 expression, were measured to assess the effects of DEX, SUC and cis-ES either alone or in combination with DOX in H9C2 cells. A 1H-NMR-based metabonomic study was carried out on cellular fluids collected after 24 h to highlight the metabolic changes induced by those protective compounds. Moreover, the effects of each agonist given either alone or in combination with DOX were evaluated on MCF-7 breast cancer cells. GPR91 expression was confirmed in H9C2 cells, while no expression was found in MCF-7 cells. Under such experimental conditions, both SUC and cis-ES decreased partially the cellular mortality, the oxidative stress and the apoptosis induced by DOX. The SUC protective effect was similar to the DEX effect, but the protective effect of cis-ES was higher on oxidative stress and apoptosis. In addition, the metabonomics findings pointed out several metabolic pathways involved in the cardioprotective effects of both GPR91 agonists: the stimulation of aerobic metabolism with glucose as the main fuel, redox balance and phospholipids synthesis. Finally, none of the GPR91 agonists jeopardized the pharmacological effects of DOX on MCF-7 breast cancer cells.

Adiponectin agonist ADP355 ameliorates doxorubicin-induced cardiotoxicity by decreasing cardiomyocyte apoptosis and oxidative stress

Doxorubicin (DOX) is an anthracycline derivative and widely used as an anticancer drug. However, the severe cardiotoxicity of DOX limits its application. ADP355 is an adiponectin-based active peptide with anti-liver fibrosis and atherosclerosis properties. It remains unclear the effects and involved mechanisms of ADP355 in DOX-induced cardiotoxicity. C57BL/6J mice were intraperitoneally injected DOX once a week to induce heart failure while receiving ADP355 treatment daily for 4 weeks. At the end of experiment, blood and heart tissues were collected. We found that ADP355 markedly improved DOX-induced cardiac dysfunction and histopathological damage, and decreased serum creatine kinase, lactate dehydrogenase and hydroxybutyrate dehydrogenase levels. The anti-apoptotic activity of ADP355 was indicated by reduction in TUNEL-positive cells and cleaved caspase-3 expression, along with decreased BCL2-associated X protein/B cell lymphoma 2 (BAX/BCL2) levels in heart tissues. Additionally, ADP355 markedly increased DOX-decreased cell viability by reducing BAX/BCL2, but inhibited reactive oxygen species production in H9c2 cells. Mechanistically, ADP355 attenuated expression of DOX-reduced nuclear factor-erythroid 2-related factor 2 (Nrf2) and superoxide dismutase 2, as well as mRNA levels of Nrf2 downstream targets. Furthermore, ADP355 activated sirtuin 2 and its target genes. In conclusion, we demonstrate that ADP355 alleviates DOX-induced cardiotoxicity by inhibiting myocardial apoptosis and oxidative stress through Nrf2 and sirtuin 2 signaling pathways. These findings suggest that ADP355 can be a promising candidate for the treatment of cardiac dysfunction.

Attenuation of doxorubicin-induced cardiotoxicity by cryptotanshinone detected through association analysis of transcriptomic profiling and KEGG pathway

OBJECTIVE

The cardiotoxicity of doxorubicin (DOX) reduces the quality of life and prognosis of cancer patients, and therefore its clinical application has been largely restricted. This study aimed to assess the effects of cryptotanshione (CPT) on DOX-induced rat cardiac insufficiency.

RESULTS

CPT treatment significantly suppressed apoptosis in vitro. The oral administration of CPT significantly improved cardiac function in the rat model, reduced collagen production and suppressed apoptosis and the production of reactive oxygen species in the heart tissue. Transcriptomic profiling and its relevant bioinformatics analysis showed that CPT suppressed doxorubicin-induced cardiotoxicity by inhibiting p53 signaling pathway.

CONCLUSION

Transcriptomic profiling and bioinformatics analysis can be used to evaluate the cardio-protective effect of CPT through inactivating p53 signaling pathway in the doxorubicin-mediated myocardial damage model.

METHODS

F-actin staining and flow cytometry were used to assess the effects of CPT on cardiomyocytes. In vivo, echocardiography and hemodynamic evaluation were used to assess the effects of CPT on the cardiac dysfunction in rats. Furthermore, transcriptomic profiling and bioinformatics analysis, as well as western blot analysis, were used to determine that CPT induced changes in the signaling pathways in the model.

Long-term cardiac outcomes of patients with HER2-positive breast cancer treated in the adjuvant lapatinib and/or trastuzumab Treatment Optimization Trial

BACKGROUND

Cardiotoxicity is the most significant adverse event associated with trastuzumab (T), the main component of HER2-positive breast cancer (BC) treatment. Less is known about the cardiotoxicity of dual HER2 blockade with T plus lapatinib (L), although this regimen is used in the metastatic setting.

METHODS

This is a sub-analysis of the ALTTO trial comparing adjuvant treatment options for patients with early HER2-positive BC. Patients randomised to either T or concomitant T + L were eligible. Cardiac events (CEs) rates were compared according to treatment arm.

RESULTS

With 6.9 years of median follow-up (FU) and 4190 patients, CE were observed in 363 (8.6%): 166 (7.9%) of patient in T + L arm vs. 197 (9.3%) in T arm (OR = 0.85 [95% CI, 0.68-1.05]). During anti-HER2 treatment 270 CE (6.4%) occurred while 93 (2.2%) were during FU (median time to onset = 6.6 months [IQR = 3.4-11.7]). While 265 CEs were asymptomatic (73%), 94 were symptomatic (26%) and four were cardiac deaths (1%). Recovery was observed in 301 cases (83.8%). Identified cardiac risk factors were: baseline LVEF < 55% (vs > 64%, OR 3.1 [95% CI 1.54-6.25]), diabetes mellitus (OR 1.85 [95% CI 1.25-2.75]), BMI > 30 kg/m2 (vs < 25 mg/kg2, OR 2.21 [95% CI 1.40-3.49]), cumulative dose of doxorubicin ≥240 mg/m2 (OR 1.36 [95% CI 1.01-1.82]) and of epirubicin≥ 480 mg/m2 (OR 2.33 [95% CI 1.55-3.51]).

CONCLUSIONS

Dual HER2 blockade with T + L is a safe regimen from a cardiac perspective, but cardiac-focused history for proper patient selection is crucial.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT00490139 (registration date: 22/06/2007); EudraCT Number: 2006-000562-36 (registration date: 04/05/2007); Sponsor Protocol Number: BIG2-06 /EGF106708/N063D.

Doxorubicin induces cardiomyocyte apoptosis and atrophy through cyclin-dependent kinase 2-mediated activation of forkhead box O1

Recent clinical investigations indicate that anthracycline-based chemotherapies induce early decline in heart mass in cancer patients. Heart mass decline may be caused by a decrease in cardiac cell number because of increased cell death or by a reduction in cell size because of atrophy. We previously reported that an anthracycline, doxorubicin (DOX), induces apoptotic death of cardiomyocytes by activating cyclin-dependent kinase 2 (CDK2). However, the signaling pathway downstream of CDK2 remains to be characterized, and it is also unclear whether the same pathway mediates cardiac atrophy. Here we demonstrate that DOX exposure induces CDK2-dependent phosphorylation of the transcription factor forkhead box O1 (FOXO1) at Ser-249, leading to transcription of its proapoptotic target gene, Bcl-2-interacting mediator of cell death (Bim). In cultured cardiomyocytes, treatment with the FOXO1 inhibitor AS1842856 or transfection with FOXO1-specific siRNAs protected against DOX-induced apoptosis and mitochondrial damage. Oral administration of AS1842856 in mice abrogated apoptosis and prevented DOX-induced cardiac dysfunction. Intriguingly, pharmacological FOXO1 inhibition also attenuated DOX-induced cardiac atrophy, likely because of repression of muscle RING finger 1 (MuRF1), a proatrophic FOXO1 target gene. In conclusion, DOX exposure induces CDK2-dependent FOXO1 activation, resulting in cardiomyocyte apoptosis and atrophy. Our results identify FOXO1 as a promising drug target for managing DOX-induced cardiotoxicity. We propose that FOXO1 inhibitors may have potential as cardioprotective therapeutic agents during cancer chemotherapy.

MicroRNA-143 Increases Oxidative Stress and Myocardial Cell Apoptosis in a Mouse Model of Doxorubicin-Induced Cardiac Toxicity

BACKGROUND Oxidative stress and myocardial apoptosis are features of doxorubicin-induced cardiac toxicity that can result in cardiac dysfunction. Previous studies showed that microRNA-143 (miR-143) was expressed in the myocardium and had a role in cardiac function. This study aimed to investigate the effects and possible molecular mechanisms of miR-143 on oxidative stress and myocardial cell apoptosis in a mouse model of doxorubicin-induced cardiac toxicity. MATERIAL AND METHODS Mice underwent intraperitoneal injection of doxorubicin (15 mg/kg) daily for eight days to develop the mouse model of doxorubicin-induced cardiac toxicity. Four days before doxorubicin administration, a group of mice was pretreated daily with a miR-143 antagonist (25 mg/kg/day) for four consecutive days by tail vein injection. The study included the use of a miR-143 antagomir, or anti-microRNA, an oligonucleotide that silenced endogenous microRNA (miR), and an agomir to miR-143, and also the AKT inhibitor, MK2206. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunoblot analysis were used to measure mRNA and protein expression, respectively. RESULTS Doxorubicin treatment increased the expression of miR-143, which was reduced by the miR-143 antagomir. Overexpression of miR-143 increased doxorubicin-induced myocardial apoptosis and oxidative stress. The use of the miR-143 antagomir significantly activated protein kinase B (PKB) and AKT, which were reduced in the presence of the AKT inhibitor, MK2206. However, the use of the miR-143 antagomir further down-regulated AKT phosphorylation following doxorubicin treatment and increased AKT activation. CONCLUSIONS In a mouse model of doxorubicin-induced cardiac toxicity, miR-143 increased oxidative stress and myocardial cell apoptosis following doxorubicin treatment by inhibiting AKT.

Sinapic Acid Ameliorates Oxidative Stress, Inflammation, and Apoptosis in Acute Doxorubicin-Induced Cardiotoxicity via the NF-κB-Mediated Pathway

In the present study, we explored SA's activity against DOX-induced cardiotoxicity and revealed its underlying mechanisms. Male Wistar rats (weight, 190-210g; n = 6) were randomly divided into four groups: group I, normal control; group II, DOX 15 mg/kg via intraperitoneal (ip) route; group III, administered DOX+SA 20 mg/kg; and group IV, administered DOX+captopril (CAP 30 mg/kg). SA and CAP were administered orally for seven days, and DOX (15 mg/kg) was injected intraperitoneally an hour before SA treatment on the fifth day. Forty-eight hours after DOX administration, animals were anesthetized and sacrificed for molecular and histology experiments. SA significantly mitigated the myocardial effects of DOX, and following daily administration, it reduced serum levels of lactate dehydrogenase (LDH) and creatine kinase isoenzyme-MB to near normal values. Levels of oxidative stress markers, glutathione-peroxidase, superoxide dismutase, and catalase, in the cardiac tissue were significantly increased, whereas malondialdehyde levels decreased after SA treatment in DOX-administered rats. Furthermore, DOX caused an inflammatory reaction by elevating the levels of proinflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and endothelin- (ET-) 1, as well as nuclear factor kappa-B (NF-κB) expression. Daily administration of SA significantly repressed TNF-α, IL-1β, ET-1, and NF-κB levels. caspase-3 and Bax expression, bcl-2-like protein and caspase-3 activities and levels. Overall, we found that SA could inhibit DOX-induced cardiotoxicity by inhibiting oxidative stress, inflammation, and apoptotic damage.

Retinoid X receptor alpha is a spatiotemporally predominant therapeutic target for anthracycline-induced cardiotoxicity

To uncover the genetic basis of anthracycline-induced cardiotoxicity (AIC), we recently established a genetic suppressor screening strategy in zebrafish. Here, we report the molecular and cellular nature of GBT0419, a salutary modifier mutant that affects retinoid x receptor alpha a (rxraa). We showed that endothelial, but not myocardial or epicardial, RXRA activation confers AIC protection. We then identified isotretinoin and bexarotene, two FDA-approved RXRA agonists, which exert cardioprotective effects. The therapeutic effects of these drugs only occur when administered during early, but not late, phase of AIC or as pretreatment. Mechanistically, these spatially- and temporally-predominant benefits of RXRA activation can be ascribed to repair of damaged endothelial cell-barrier via regulating tight-junction protein Zonula occludens-1. Together, our study provides the first in vivo genetic evidence supporting RXRA as the therapeutic target for AIC, and uncovers a previously unrecognized spatiotemporally-predominant mechanism that shall inform future translational efforts.

Use of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes in Preclinical Cancer Drug Cardiotoxicity Testing: A Scientific Statement From the American Heart Association

It is now well recognized that many lifesaving oncology drugs may adversely affect the heart and cardiovascular system, including causing irreversible cardiac injury that can result in reduced quality of life. These effects, which may manifest in the short term or long term, are mechanistically not well understood. Research is hampered by the reliance on whole-animal models of cardiotoxicity that may fail to reflect the fundamental biology or cardiotoxic responses of the human myocardium. The emergence of human induced pluripotent stem cell-derived cardiomyocytes as an in vitro research tool holds great promise for understanding drug-induced cardiotoxicity of oncological drugs that may manifest as contractile and electrophysiological dysfunction, as well as structural abnormalities, making it possible to deliver novel drugs free from cardiac liabilities and guide personalized therapy. This article briefly reviews the challenges of cardio-oncology, the strengths and limitations of using human induced pluripotent stem cell-derived cardiomyocytes to represent clinical findings in the nonclinical research space, and future directions for their further use.

miR-146a attenuates apoptosis and modulates autophagy by targeting TAF9b/P53 pathway in doxorubicin-induced cardiotoxicity

Clinical therapy of doxorubicin (DOX) is limited due to its cardiotoxicity. miR-146a was proved as a protective factor in many cardiovascular diseases, but its role in chronic DOX-induced cardiotoxicity is unclear. The objective of this study was to demonstrate the role of miR-146a in low-dose long-term DOX-induced cardiotoxicity. Experiments have shown that DOX intervention caused a dose-dependent and time-dependent cardiotoxicity involving the increased of apoptosis and dysregulation of autophagy. The cardiotoxicity was inhibited by overexpressed miR-146a and was more severe when miR-146a was downgraded. Further research proved that miR-146a targeted TATA-binding protein (TBP) associated factor 9b (TAF9b), a coactivator and stabilizer of P53, indirectly destroyed the stability of P53, thereby inhibiting apoptosis and improving autophagy in cardiomyocytes. Besides, miR-146a knockout mice were used for in vivo validation. In the DOX-induced model, miR-146a deficiency made it worse whether in cardiac function, cardiomyocyte apoptosis or basal level of autophagy, than wild-type. In conclusion, miR-146a partially reversed the DOX-induced cardiotoxicity by targeting TAF9b/P53 pathway to attenuate apoptosis and adjust autophagy levels.

Mechanisms mediating the cardioprotective effect of carvedilol in cadmium induced cardiotoxicity. Role of eNOS and HO1/Nrf2 pathway

Cadmium (Cd) is a highly toxic heavy metal with several harmful effects including cardiotoxicity. For the first time, we aimed to evaluate the possible cardioprotective effect of carvedilol (CAR) in Cd induced cardiotoxicity and study the mechanisms involved in such protection including endothelial nitric oxide synthase (eNOS) and HO1/Nrf2 pathway. CAR (1,10 mg/kg/d) was administered orally for 4 weeks with Cd induced cardiac injury (3 mg/kg/d) orally for 4 weeks. We measured cardiac enzymes, mean arterial pressure changes, heme oxygenase-1 (HO1) and total antioxidant capacity (TAC). Moreover; cardiac tissue malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), western blotting of caspase3 and eNOS levels and histopathology were evaluated. Immunoexpression of eNOS in cardiac tissue, gene expression changes of HO1, and nuclear factor erythroid 2-related factor 2 (Nrf2) using real time polymerase chain reactions (rtPCR) were detected. Our results showed that CAR could significantly decrease Cd induced cardiotoxicity.

C1qTNF-related protein-6 protects against doxorubicin-induced cardiac injury

The clinical use of doxorubicin (DOX) is limited by its toxic effect. However, there is no specific drug that can prevent DOX-related cardiac injury. C1qTNF-related protein-6 (CTRP6) is a newly identified adiponectin paralog with many protective functions on metabolism and cardiovascular diseases. However, little is known about the effect of CTRP6 on DOX-induced cardiac injury. The present study aimed to investigate whether CTRP6 could protect against DOX-related cardiotoxicity. To induce acute cardiotoxicity, the mice were intraperitoneally injected with a single dose of DOX (15 mg/kg). Cardiomyocyte-specific CTRP6 overexpression was achieved using an adenoassociated virus system at 4 weeks before DOX injection. The data in our study demonstrated that CTRP6 messenger RNA and protein expression were decreased in DOX-treated hearts. CTRP6 attenuated cardiac atrophy induced by DOX injection and inhibited cardiac apoptosis and improved cardiac function in vivo. CTRP6 also promoted the activation of protein kinase B (AKT/PKB) signaling pathway in DOX-treated mice. CTRP6 prevented cardiomyocytes from DOX-induced apoptosis and activated the AKT pathway in vitro. CTRP6 lost its protection against DOX-induced cardiac injury in mice with AKT inhibition. In conclusion, CTRP6 protected the heart from DOX-cardiotoxicity and improves cardiac function via activation of the AKT signaling pathway.

Comparative Transcriptomics Reveals the Role of the Toll-Like Receptor Signaling Pathway in Fluoride-Induced Cardiotoxicity

Many studies have shown that fluorosis due to long-term fluoride intake has damaging effects on the heart. However, the mechanisms underlying cardiac fluorosis have not been illuminated in detail. We performed high-throughput transcriptome sequencing (RNA-Seq) on rat cardiac tissue to explore the molecular effects of NaF exposure. In total, 372 and 254 differentially expressed genes (DEGs) were identified between a group given 30 mg/L NaF and control and between a group given 90 mg/L NaF and control, respectively. The transcript levels of most of these genes were significantly down-regulated and many were distributed in the Toll-like receptor signaling pathway. Transcriptome analysis revealed that herpes simplex infection, ECM-receptor interaction, influenza A, cytokine-cytokine receptor interaction, apoptosis, and Toll-like receptor signaling pathway were significantly affected. IL-6 and IL-10 may play a crucial role in the cardiac damage caused by NaF as external stimuli according to protein-protein interaction (PPI) network analysis. The results of qRT-PCR and Western blotting showed a marked decreased mRNA and protein levels of IL-1, IL-6, and IL-10 in the low concentration fluoride (LF) and high concentration fluoride (HF) groups, which was in agreement with RNA-Seq results. This is the first study to investigate NaF-induced cardiotoxicity at a transcriptome level.

Circulating microRNAs as biomarkers of radiation-induced cardiac toxicity in non-small-cell lung cancer

PURPOSE

Radiation-induced cardiac toxicity (RICT) is an increasingly well-appreciated source of morbidity and mortality in patients receiving thoracic radiotherapy (RT). Currently available methods to predict RICT are suboptimal. We investigated circulating microRNAs (c-miRNAs) as potential biomarkers of RICT in patients undergoing definitive RT for non-small-cell lung cancer (NSCLC).

METHODS

Data from 63 patients treated on institutional trials were analyzed. Prognostic models of grade 3 or greater (G3 +) RICT based on pre-treatment c-miRNA levels ('c-miRNA'), mean heart dose (MHD) and pre-existing cardiac disease (PCD) ('clinical'), and a combination of these ('c-miRNA + clinical') were developed. Elastic net Cox regression and full cross validation were used for variable selection, model building, and model evaluation. Concordance statistic (c-index) and integrated Brier score (IBS) were used to evaluate model performance.

RESULTS

MHD, PCD, and serum levels of 14 c-miRNA species were identified as jointly prognostic for G3 + RICT. The 'c-miRNA and 'clinical' models yielded similar cross-validated c-indices (0.70 and 0.72, respectively) and IBSs (0.26 and 0.28, respectively). However, prognostication was not improved by combining c-miRNA and clinical factors (c-index 0.70, IBS 0.28). The 'c-miRNA' and 'clinical' models were able to significantly stratify patients into high- and low-risk groups of developing G3 + RICT. Chi-square testing demonstrated a marginally significantly higher prevalence of PCD in patients with high- compared to low-risk c-miRNA profile (p = 0.09), suggesting an association between some c-miRNAs and PCD.

CONCLUSIONS

We identified a pre-treatment c-miRNA signature prognostic for G3 + RICT. With further development, pre- and mid-treatment c-miRNA profiling could contribute to patient-specific dose selection and treatment adaptation.

The protective activity of nanomicelle curcumin in bisphenol A-induced cardiotoxicity following subacute exposure in rats

Bisphenol A (BPA), an estrogenic compound, is used in manufacture of polycarbonate plastics and epoxy resins. Curcumin, the active ingredient of turmeric, is a potent protective compound against cardiac diseases. In this study the protective effect of nanomicelle curcumin on BPA-induced subchronic cardiotoxicity in rats was evaluated. Rats were divided into 6 groups including control, nanomicelle curcumin (50 mg/kg, gavage), BPA (50 mg/kg, gavage), nanomicelle curcumin (10, 25, and 50 mg/kg) plus BPA. The treatments were continued for 4 weeks. Results revealed that BPA significantly induced histophatological injuries including focal lymphatic inflammation, nuclear degenerative changes and cytoplasmic vacuolation, increased body weight, systolic and diastolic blood pressures, malondialdehyde and Creatine phosphokinase-MB level and decreased glutathione content in comparison with control group. In addition, in electrocardiographic graph, RR, QT, and PQ intervals were increased by BPA. Western blot analysis showed that BPA up-regulated phosphorylated p38 (p38-mitogen-activated protein kinase) and JNK (c-jun NH2 terminal kinases), while down-regulated phosphorylated AKT (Protein Kinase B) and ERK1/2 (extracellular signal-regulated protein kinases 1 and 2). However, nanomicelle curcumin (50 mg/kg) significantly improved these toxic effects of BPA in rat heart tissue. The results provide evidence that nanomicelle curcumin showed preventive effects on subchronic exposure to BPA induced toxicity in the heart tissue in rats.

Doxorubicin Exposure Causes Subacute Cardiac Atrophy Dependent on the Striated Muscle-Specific Ubiquitin Ligase MuRF1

Background Anthracycline chemotherapeutics, such as doxorubicin, are used widely in the treatment of numerous malignancies. The primary dose-limiting adverse effect of anthracyclines is cardiotoxicity that often presents as heart failure due to dilated cardiomyopathy years after anthracycline exposure. Recent data from animal studies indicate that anthracyclines cause cardiac atrophy. The timing of onset and underlying mechanisms are not well defined, and the relevance of these findings to human disease is unclear. Methods and Results Wild-type mice were sacrificed 1 week after intraperitoneal administration of doxorubicin (1-25 mg/kg), revealing a dose-dependent decrease in cardiac mass ( R2=0.64; P<0.0001) and a significant decrease in cardiomyocyte cross-sectional area (336±29 versus 188±14 µm2; P<0.0001). Myocardial tissue analysis identified a dose-dependent upregulation of the ubiquitin ligase, MuRF1 (muscle ring finger-1; R2=0.91; P=0.003) and a molecular profile of muscle atrophy. To investigate the determinants of doxorubicin-induced cardiac atrophy, we administered doxorubicin 20 mg/kg to mice lacking MuRF1 (MuRF1-/-) and wild-type littermates. MuRF1-/- mice were protected from cardiac atrophy and exhibited no reduction in contractile function. To explore the clinical relevance of these findings, we analyzed cardiac magnetic resonance imaging data from 70 patients in the DETECT-1 cohort and found that anthracycline exposure was associated with decreased cardiac mass evident within 1 month and persisting to 6 months after initiation. Conclusions Doxorubicin causes a subacute decrease in cardiac mass in both mice and humans. In mice, doxorubicin-induced cardiac atrophy is dependent on MuRF1. These findings suggest that therapies directed at preventing or reversing cardiac atrophy might preserve the cardiac function of cancer patients receiving anthracyclines.

Cardiotoxicity and myocardial infarction-associated DNA damage induced by thiamethoxam in vitro and in vivo: Protective role of Trigonella foenum-graecum seed-derived polysaccharide

The risk of pesticides on the human health and environment has drawn increasing attention. Today, new tools are developed to reduce pesticide adverse effects. This study aimed to evaluate the toxicity induced by, thiamethoxam (TMX), and the cytoprotective effect of a novel polysaccharide, named fenugreek seed water polysaccharide (FWEP) in vitro using H9c2 cardiomyoblastes and in vivo using Wistar rat model. Animals were assigned into four groups per eight rats each: group 1 served as a control group, group 2 received TMX, group 3, and group 4 received both FWEP and TMX tested at two doses (100 and 200 mg/kg, respectively). Regarding the in vitro study, our results demonstrated that TMX induced a decrease in H9c2 cell viability up to 70% with the highest concentration. In vivo, TMX injection induced marked heart damage noted by a significant increase in plasma lactate dehydrogenase, creatine phosphokinase, troponin-T, aspartate amino transferase activities, cholesterol, and triglyceride levels. Concomitant alterations in cardiac antioxidant defense system revealed depletion in the levels of glutathione and non-protein thiol and an increase in the activity of superoxide dismutase, catalase, and glutathione peroxidase. Similarly, a significant increase in heart lipid, malondialdehyde, advanced oxidation protein product and in protein carbonyls levels was also noted. In addition, heart tissues histo-architecture displayed major presence of apoptosis and necrosis as confirmed by DNA degradation. However, supplementation with FWEP alleviated heart oxidative damage and genotoxicity. In this manner, ABTS radical-scavenging activity, linoleic acid oxidation tests and heart genomic and DNA nicking assay had proved FWEP strong antioxidant potential. In conclusion, FWEP provided significant protection against TMX-induced heart injury, and could be a useful and efficient agent against cardiotoxicity and atherosclerosis.