Molecular insights into the pathophysiology of doxorubicin-induced cardiotoxicity: a graphical representation

Possible pathogenic mechanisms for doxorubicin-induced splenic atrophy in a human breast cancer xenograft mouse model

Doxorubicin-based chemotherapy is a widely used first-line treatment for breast cancer, yet it is associated with various side effects, including splenic atrophy. However, the pathogenic mechanisms underlying doxorubicin-induced atrophy of the spleen remain unclear. This study investigates that doxorubicin treatment leads to splenic atrophy through several interconnected pathways involving histological changes, an inflammatory response, and apoptosis. Immunohistochemical and western blot analyses revealed reduced size of white and red pulp, decreased cellularity, amyloidosis, and fibrotic remodeling in the spleen following doxorubicin treatment. Additionally, increased secretion of pro-inflammatory cytokines was detected using an antibody array and enzyme-linked immunosorbent assay (ELISA), which triggers inflammation through the regulation of signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappa B (NF-κB) signaling pathways. Further analysis revealed that the loss of regulators and effectors of the oxidative defense system, including sirtuin (Sirt)3, Sirt5, superoxide dismutase (SOD)1, and SOD2, was implicated in the upstream regulation of caspase-dependent cellular apoptosis. These findings provide insights on the pathogenic mechanisms underlying doxorubicin-induced splenic atrophy and suggest that further investigation may be warranted to explore strategies for managing potential side effects in breast cancer patients treated with doxorubicin.

SNX3 Promotes Doxorubicin-Induced Cardiomyopathy by Regulating GPX4-Mediated Ferroptosis

The complete molecular mechanism underlying doxorubicin-induced cardiomyopathy remains incompletely elucidated. In this investigation, we engineered mice with cardiomyocyte-specific sorting nexin 3 knockout (SNX3Cko ) to probe the potential protective effects of SNX3 ablation on doxorubicin-triggered myocardial injury, focusing on GPX4-dependent ferroptosis. Our findings indicate that SNX3 deletion normalized heart contractile/relaxation function and thwarted the escalation of cardiac injury biomarkers following doxorubicin exposure. Additionally, SNX3 deletion in the heart mitigated the inflammatory response and oxidative stress in the presence of doxorubicin. At the molecular level, the detrimental effects of doxorubicin-induced cell death, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction were alleviated by SNX3 deficiency. Molecular analysis revealed the activation of GPX4-mediated ferroptosis by doxorubicin, whereas loss of SNX3 prevented the initiation of GPX4-dependent ferroptosis. Furthermore, treatment with erastin, a ferroptosis inducer, markedly reduced cell viability, exacerbated ER stress, and induced mitochondrial dysfunction in SNX3-depleted cardiomyocytes upon doxorubicin exposure. In summary, our results demonstrate that SNX3 deficiency shielded the heart from doxorubicin-induced myocardial dysfunction by modulating GPX4-associated ferroptosis.

Cardioprotective potentials of myricetin on doxorubicin-induced cardiotoxicity based on biochemical and transcriptomic analysis

Doxorubicin (DOX) is a commonly used anthracycline in cancer chemotherapy. The clinical application of DOX is constrained by its cardiotoxicity. Myricetin (MYR) is a natural flavonoid widely present in many plants with antioxidant and anti-inflammatory properties. However, MYR's beneficial effects and mechanisms in alleviating DOX-induced cardiotoxicity (DIC) remain unknown. C57BL/6 mice were injected with 15 mg/kg of DOX to establish the DIC, and MYR solutions were administrated by gavage to investigate its cardioprotective potentials. Histopathological analysis, physiological indicators assessment, transcriptomics analysis, and RT-qPCR were used to elucidate the potential mechanism of MYR in DIC treatment. MYR reduced cardiac injury produced by DOX, decreased levels of cTnI, AST, LDH, and BNP, and improved myocardial injury and fibrosis. MYR effectively prevented DOX-induced oxidative stress, such as lowered MDA levels and elevated SOD, CAT, and GSH activities. MYR effectively suppressed NLRP3 and ASC gene expression levels to inhibit pyroptosis while regulating Caspase1 and Bax levels to reduce cardiac cell apoptosis. According to the transcriptomic analysis, glucose and fatty acid metabolism were associated with differential gene expression. KEGG pathway analysis revealed differential gene enrichment in PPAR and AMPK pathways, among others. Following validation, MYR was found to alleviate DIC by regulating glycolipid metabolism and AMPK pathway-related genes. Our findings demonstrated that MYR could mitigate DIC by regulating the processes of oxidative stress, apoptosis, and pyroptosis. MYR is critical in improving DOX-induced myocardial energy metabolism abnormalities mediated by the AMPK signaling pathway. In conclusion, MYR holds promise as a therapeutic strategy for DIC.

Ginsenoside Rb1 attenuates doxorubicin induced cardiotoxicity by suppressing autophagy and ferroptosis

Ginsenoside Rb1 (Rb1), an active component isolated from traditional Chinese medicine Ginseng, is beneficial to many cardiovascular diseases. However, whether it can protect against doxorubicin induced cardiotoxicity (DIC) is not clear yet. In this study, we aimed to investigate the role of Rb1 in DIC. Mice were injected with a single dose of doxorubicin (20 mg/kg) to induce acute cardiotoxicity. Rb1 was given daily gavage to mice for 7 days. Changes in cardiac function, myocardium histopathology, oxidative stress, cardiomyocyte mitochondrion morphology were studied to evaluate Rb1's function on DIC. Meanwhile, RNA-seq analysis was performed to explore the potential underline molecular mechanism involved in Rb1's function on DIC. We found that Rb1 treatment can improve survival rate and body weight in Dox treated mice group. Rb1 can attenuate Dox induced cardiac dysfunction and myocardium hypertrophy and interstitial fibrosis. The oxidative stress increase and cardiomyocyte mitochondrion injury were improved by Rb1 treatment. Mechanism study found that Rb1's beneficial role in DIC is through suppressing of autophagy and ferroptosis. This study shown that Ginsenoside Rb1 can protect against DIC by regulating autophagy and ferroptosis.

miRNA Expression Profiles in Isolated Ventricular Cardiomyocytes: Insights into Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX), widely used as a chemotherapeutic agent for various cancers, is limited in its clinical utility by its cardiotoxic effects. Despite its widespread use, the precise mechanisms underlying DOX-induced cardiotoxicity at the cellular and molecular levels remain unclear, hindering the development of preventive and early detection strategies. To characterize the cytotoxic effects of DOX on isolated ventricular cardiomyocytes, focusing on the expression of specific microRNAs (miRNAs) and their molecular targets associated with endogenous cardioprotective mechanisms such as the ATP-sensitive potassium channel (KATP), Sirtuin 1 (SIRT1), FOXO1, and GSK3β. We isolated Guinea pig ventricular cardiomyocytes by retrograde perfusion and enzymatic dissociation. We assessed cell morphology, Reactive Oxygen Species (ROS) levels, intracellular calcium, and mitochondrial membrane potential using light microscopy and specific probes. We determined the miRNA expression profile using small RNAseq and validated it using stem-loop qRT-PCR. We quantified mRNA levels of some predicted and validated molecular targets using qRT-PCR and analyzed protein expression using Western blot. Exposure to 10 µM DOX resulted in cardiomyocyte shortening, increased ROS and intracellular calcium levels, mitochondrial membrane potential depolarization, and changes in specific miRNA expression. Additionally, we observed the differential expression of KATP subunits (ABCC9, KCNJ8, and KCNJ11), FOXO1, SIRT1, and GSK3β molecules associated with endogenous cardioprotective mechanisms. Supported by miRNA gene regulatory networks and functional enrichment analysis, these findings suggest that DOX-induced cardiotoxicity disrupts biological processes associated with cardioprotective mechanisms. Further research must clarify their specific molecular changes in DOX-induced cardiac dysfunction and investigate their diagnostic biomarkers and therapeutic potential.

Role of gut microbiota in doxorubicin-induced cardiotoxicity: from pathogenesis to related interventions

Doxorubicin (DOX) is a broad-spectrum and highly efficient anticancer agent, but its clinical implication is limited by lethal cardiotoxicity. Growing evidences have shown that alterations in intestinal microbial composition and function, namely dysbiosis, are closely linked to the progression of DOX-induced cardiotoxicity (DIC) through regulating the gut-microbiota-heart (GMH) axis. The role of gut microbiota and its metabolites in DIC, however, is largely unelucidated. Our review will focus on the potential mechanism between gut microbiota dysbiosis and DIC, so as to provide novel insights into the pathophysiology of DIC. Furthermore, we summarize the underlying interventions of microbial-targeted therapeutics in DIC, encompassing dietary interventions, fecal microbiota transplantation (FMT), probiotics, antibiotics, and natural phytochemicals. Given the emergence of microbial investigation in DIC, finally we aim to point out a novel direction for future research and clinical intervention of DIC, which may be helpful for the DIC patients.

Potential of Natural Phenolic Compounds against Doxorubicin-Induced Chemobrain: Biological and Molecular Mechanisms Involved

Chemotherapy-induced cognitive impairment or "chemobrain" is a prevalent long-term complication of chemotherapy and one of the more devastating. Most of the studies performed so far to identify the cognitive dysfunctions induced by antineoplastic chemotherapies have been focused on treatment with anthracyclines, frequently administered to breast cancer patients, a population that, after treatment, shows a high possibility of long survival and, consequently, of chemobrain development. In the last few years, different possible strategies have been explored to prevent or reduce chemobrain induced by the anthracycline doxorubicin (DOX), known to promote oxidative stress and inflammation, which have been strongly implicated in the development of this brain dysfunction. Here, we have critically analyzed the results of the preclinical studies from the last few years that have evaluated the potential of phenolic compounds (PheCs), a large class of natural products able to exert powerful antioxidant and anti-inflammatory activities, in inhibiting DOX-induced chemobrain. Several PheCs belonging to different classes have been shown to be able to revert DOX-induced brain morphological damages and deficits associated with learning, memory, and exploratory behavior. We have analyzed the biological and molecular mechanisms implicated and suggested possible future perspectives in this research area.

Galangin attenuates doxorubicin-induced cardiotoxicity via activating nuclear factor erythroid 2-related factor 2/heme oxygenase 1 signaling pathway to suppress oxidative stress and inflammation

Doxorubicin (DOX) has aroused contradiction between its potent anti-tumor capacity and severe cardiotoxicity. Galangin (Gal) possesses antioxidant, anti-inflammatory, and antiapoptotic activities. We aimed to explore the role and underlying mechanisms of Gal on DOX-induced cardiotoxicity. Mice were intraperitoneally injected with DOX (3 mg/kg, every 2 days for 2 weeks) to generate cardiotoxicity model and Gal (15 mg/kg, 2 weeks) was co-administered via gavage daily. Nuclear factor erythroid 2-related factor 2 (Nrf2) specific inhibitor, ML385, was employed to explore the underlying mechanisms. Compared to DOX-insulted mice, Gal effectively improved cardiac dysfunction and ameliorated myocardial damage. DOX-induced increase of reactive oxygen species, malondialdehyde, and NADPH oxidase activity and downregulation of superoxide dismutase (SOD) activity were blunted by Gal. Gal also markedly blocked increase of IL-1β, IL-6, and TNF-α in DOX-insulted heart. Mechanistically, Gal reversed DOX-induced downregulation of Nrf2, HO-1, and promoted nuclear translocation of Nrf2. ML385 markedly blunted the cardioprotective effects of Gal, as well as inhibitive effects on oxidative stress and inflammation. Gal ameliorates DOX-induced cardiotoxicity by suppressing oxidative stress and inflammation via activating Nrf2/HO-1 signaling pathway. Gal may serve as a promising cardioprotective agent for DOX-induced cardiotoxicity.

Potential Biomarker of Acute Anthracycline-induced Cardiotoxicity Among Children With Acute Lymphoblastic Leukemia: Cardiac Adriamycin-responsive Protein

ABSTRACT

This study aimed to investigate whether serum cardiac adriamycin-responsive protein (CARP) can serve as a sensitive and specific biomarker of anthracyclines (ANT)-induced cardiotoxicity. Fifty-five children with acute lymphoblastic leukemia were recruited. Before and after the administration of ANT, serum levels of CARP, high-sensitivity troponin T, creatine kinase-MB, and electrocardiogram were measured. Postchemotherapeutic clinical manifestations of cardiotoxicity were also investigated. Adverse cardiac events (ACEs) were graded according to the Common Terminology Criteria for Adverse Events 4.0. Then, the CARP expression was statistically analyzed among different groups. The receiver operating characteristic curve was used to evaluate the efficacy of CARP in predicting acute ANT-induced cardiotoxicity. After ANT chemotherapy, the serum CARP concentration increased in the non-ACEs group but decreased in the ACEs group ( P < 0.05). In addition, not only the serum CARP levels (△CARP) was negatively correlated with the grade of ACEs (R=-0.754, P < 0.0001) but also the extent of QT interval corrected (QTc) prolongation (△QTc; R=-0.5592, P < 0.01). The area under the receiver operating characteristic curve of CARP was 90.94% ( P < 0.0001), and the sensitivity and specificity were 88.64% and 91.67%, respectively, all of which are superior to △high-sensitivity troponin T, △creatine kinase-MB, and △QTc. In conclusion, serum CARP could serve as a novel sensitive and specific biomarker of acute ANT-induced cardiotoxicity, which is negatively associated with ACE grade.

Effects of miR-143 regulation on cardiomyocytes apoptosis in doxorubicin cardiotoxicity based on integrated bioinformatics analysis

This study aimed to investigate the effect of miRNAs involving oxidative stress response in doxorubicin (DOX)-induced cardiotoxicity based on the data from Gene Expression Omnibus (GEO) database and experimental results via integrated bioinformatics analysis. MiRNA expression profiles of DOX-induced cardiotoxicity in rat myocardial tissues and adult rat cardiomyocytes (ARC) were extracted from GEO datasets (GSE36239). Differential expression miRNA (DEMs) were separately captured in rat myocardial tissues and in ARC, and intersected between rat myocardial tissues and ARC via Venny 2.1. Subsequently, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) analyzed 46 target genes of miR-143, one of 6 DEMs, and HIF-1 and PI3K-Akt signaling pathway were significantly enriched. Further experimental results showed DOX-induced oxidative stress downregulated the expression of miR-143, and then promoted target gene Bbc3 expression and H9c2 apoptosis, the intervention of phosphocreatine (PCr) or N-acetyl-L-cystine (NAC) alleviated oxidative stress, apoptosis and Bbc3 expression, upregulated miR-143 in DOX-induced cardiotoxicity in vivo and in vitro. Our findings elucidated the regulatory network between miR-143 and oxidative stress in DOX-induced cardiotoxicity, and might unveiled a potential biomarker and molecular mechanisms, which could be helpful to the diagnosis and treatment of DOX-induced cardiotoxicity.

Bibliometric and visual analysis of doxorubicin-induced cardiotoxicity

Background: Doxorubicin-induced cardiotoxicity represents a prevalent adverse effect encountered in patients undergoing treatment with doxorubicin. To date, there has been no bibliometric study to summarize the field of doxorubicin-induced cardiotoxicity. In our study, we aim to determine the current status and frontiers of doxorubicin-induced cardiotoxicity by bibliometric analysis. Methods: The documents concerning doxorubicin-induced cardiotoxicity are obtained from the Web of Science Core Collection database (WOSCC), and VOSviewer 1.6.16, CiteSpace 5.1.3 and the WOSCC's literature analysis wire were used to conduct the bibliometric analysis. Results: In total, 7,021 publications were encompassed, which are produced by 37,152 authors and 6,659 organizations, 1,323 journals, and 101 countries/regions. The most productive author, institution, country and journal were Bonnie Ky with 35 publications, University of Texas with 190 documents, the United States with 1,912 publications, and PLOS ONE with 120 documents. The first high-cited article was published in the NEJM with 8,134 citations authored by DJ Slamon et al., in 2001. For keyword analysis, there are four clusters depicted in distinct directions. The keywords in the red cluster are oxidative stress, apoptosis, and cardiomyopathy. The keywords in the green cluster are cardiotoxicity, heart failure, and anthracycline. The keywords in the blue cluster are chemotherapy, trastuzumab, and paclitaxel. The keywords in the purple cluster are doxorubicin, adriamycin, and cancer. Most of the documents were derived from the United States, China and Italy (4,080/7,021, 58.1%). The number of studies from other countries should be increased. Conclusion: In conclusion, the main research hotspots and frontiers in the field of doxorubicin-induced cardiotoxicity include the role of doxorubicin in cardiotoxicity, the mechanisms underlying doxorubicin-induced cardiotoxicity, and the development of treatment strategies for doxorubicin-induced cardiotoxicity. More studies are needed to explore the mechanisms and treatment of doxorubicin-induced cardiotoxicity.

Potential roles of 4HNE-adducted protein in serum extracellular vesicles as an early indicator of oxidative response against doxorubicin-induced cardiomyopathy in rats

Late-onset cardiomyopathy is becoming more common among cancer survivors, particularly those who received doxorubicin (DOXO) treatment. However, few clinically available cardiac biomarkers can predict an unfavorable cardiac outcome before cell death. Extracellular vesicles (EVs) are emerging as biomarkers for cardiovascular diseases and others. This study aimed to measure dynamic 4-hydroxynonenal (4HNE)-adducted protein levels in rats treated chronically with DOXO and examine their link with oxidative stress, antioxidant gene expression in cardiac tissues, and cardiac function. Twenty-two male Wistar rats were randomly assigned to receive intraperitoneal injection of normal saline (n = 8) or DOXO (3 mg/kg, 6 doses, n = 14). Before and after therapy, serum EVs and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were determined. Tunable resistive pulse sensing was used to measure EV size and concentration. ELISA was used to assess 4HNE-adducted protein in EVs and cardiac tissues. Differential-display reverse transcription-PCR was used to quantitate cardiac Cat and Gpx1 gene expression. Potential correlations between 4HNE-adducted protein levels in EVs, cardiac oxidative stress, antioxidant gene expression, and cardiac function were determined. DOXO-treated rats showed more serum EV 4HNE-adducted protein than NSS-treated rats at day 9 and later endpoints, whereas NT-proBNP levels were not different between groups. Moreover, on day 9, surviving rats' EVs had higher levels of 4HNE-adducted protein, and these correlated positively with concentrations of heart tissue 4HNE adduction and copy numbers of Cat and Gpx1, while at endpoint correlated negatively with cardiac functions. Therefore, 4HNE-adducted protein in serum EVs could be an early, minimally invasive biomarker of the oxidative response and cardiac function in DOXO-induced cardiomyopathy.

Low-intensity pulsed ultrasound alleviates doxorubicin-induced cardiotoxicity via inhibition of S100a8/a9-mediated cardiac recruitment of neutrophils

Doxorubicin (DOX)-induced cardiotoxicity limits its broad use as a chemotherapy agent. The development of effective and non-invasive strategies to prevent DOX-associated adverse cardiac events is urgently needed. We aimed to examine whether and how low-intensity pulsed ultrasound (LIPUS) plays a protective role in DOX-induced cardiotoxicity. Male C57BL/6J mice were used to establish models of both acute and chronic DOX-induced cardiomyopathy. Non-invasive LIPUS therapy was conducted for four consecutive days after DOX administration. Cardiac contractile function was evaluated by echocardiography. Myocardial apoptosis, oxidative stress, and fibrosis were analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining, dihydroethidium (DHE) staining, and picrosirius red staining assays. RNA-seq analysis was performed to unbiasedly explore the possible downstream regulatory mechanisms. Neutrophil recruitment and infiltration in the heart were analyzed by flow cytometry. The S100a8/a9 inhibitor ABR-238901 was utilized to identify the effect of S100a8/a9 signaling. We found that LIPUS therapy elicited a great benefit on DOX-induced heart contractile dysfunction in both acute and chronic DOX models. Chronic DOX administration increased serum creatine kinase and lactate dehydrogenase levels, as well as myocardial apoptosis, all of which were significantly mitigated by LIPUS. In addition, LIPUS treatment prevented chronic DOX-induced cardiac oxidative stress and fibrosis. RNA-seq analysis revealed that LIPUS treatment partially reversed alterations of gene expression induced by DOX. Gene ontology (GO) analysis of the downregulated genes between DOX-LIPUS and DOX-Sham groups indicated that inhibition of neutrophil chemotaxis might be involved in the protective effects of LIPUS therapy. Flow cytometry analysis illustrated the inhibitory effects of LIPUS on DOX-induced neutrophil recruitment and infiltration in the heart. Moreover, S100 calcium binding protein A8/A9 (S100a8/a9) was identified as a potential key target of LIPUS therapy. S100a8/a9 inhibition by ABR-238901 showed a similar heart protective effect against DOX-induced cardiomyopathy to LIPUS treatment. LIPUS therapy prevents DOX-induced cardiotoxicity through inhibition of S100a8/a9-mediated neutrophil recruitment to the heart, suggesting its potential application in cancer patients undergoing chemotherapy with DOX.

Cinnamaldehyde alleviates doxorubicin-induced cardiotoxicity by decreasing oxidative stress and ferroptosis in cardiomyocytes

Although doxorubicin (DOX) is an efficient chemotherapeutic drug for human tumors, severe cardiotoxicity restricts its clinical use. Cinnamaldehyde (CA), a bioactive component isolated from Cinnamonum cassia, possesses potent anti-oxidative and anti-apoptotic potentials. The major aim of this study was to evaluate the protective role of CA against DOX-induced cardiotoxicity. To this end, cardiomyocyte injury models were developed using DOX-treated H9c2 cells and DOX-treated rats, respectively. Herein, we found that CA treatment increased cardiomyocyte viability and attenuated DOX-induced cardiomyocyte death in vitro. CA further protected rats against DOX-induced cardiotoxicity, as indicated by elevated creatine kinase (CK) and lactate dehydrogenase (LDH) levels, myocardium injury, and myocardial fibrosis. CA alleviated DOX-induced myocardial oxidative stress by regulating reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels. Mechanistically, CA markedly accelerated nuclear translocation of nuclear erythroid factor 2-related factor 2 (Nrf2) and increased heme oxygenase-1 (HO-1) expression. Consequently, CA decreased DOX-induced cardiomyocyte ferroptosis, while Erastin (a ferroptosis agonist) treatment destroyed the effect of CA on increasing cardiomyocyte viability. Taken together, the current results demonstrate that CA alleviates DOX-induced cardiotoxicity, providing a promising opportunity to increase the clinical application of DOX.

Irisin protects against doxorubicin-induced cardiotoxicity by improving AMPK-Nrf2 dependent mitochondrial fusion and strengthening endogenous anti-oxidant defense mechanisms

Irisin, a new exercise-mediated myokine, plays an important role in cardiovascular diseases by regulating cell energy metabolism. The induction of mitochondrial dysfunction and oxidative stress are the crucial mechanisms involved in doxorubicin-induced cardiomyocyte damage and cardiac dysfunction, but the mitochondria-dependent protective mechanisms of irisin in DOX-impaired cardiomyocytes are poorly understood. In this study, we exposed mouse-FNDC5 (irisin-precursor)-knockout, FNDC5 transgenic mice and their WT littermates, as well as cultured neonatal rat cardiomyocytes to DOX at a dosage of 4 mg/kg (once a week for 4 weeks) in vivo and 2 μM in vitro, respectively, then investigated how irisin alleviated DOX-induced oxidative stress and myocardial injury. Irisin knockout worsened, while irisin overexpression attenuated DOX-induced mortality, body weight loss, myocardial atrophy, damage and oxidative stress, cardiac remodeling and dysfunction in mice. Exogenous irisin supplementation (20 nM) also relieved these DOX-induced damage in cardiomyocytes. Intriguingly, irisin activated AMPK-Nrf2 signaling axis, and then up-regulated the transcription and protein expression of the downstream target genes of Nrf2, including mitochondrial fusion-related genes (mitofusin 1/2 and Optic Atrophy Type 1) and endogenous anti-oxidant genes, to promote mitochondrial fusion, improve mitochondrial dynamics and mitochondrial function, and reduced oxidative stress damage in DOX-induced cardiomyocytes. These results suggest that irisin protects the hearts from DOX-induced cardiotoxicity by improving mitochondrial dynamics and strengthening the endogenous anti-oxidant system through an AMPK-Nrf2 axis dependent manner, thus reducing DOX-induced oxidative stress injury in cardiomyocytes.

Nrf2: a dark horse in doxorubicin-induced cardiotoxicity

Being a broad-spectrum anticancer drug, doxorubicin is indispensable for clinical treatment. Unexpectedly, its cardiotoxic side effects have proven to be a formidable obstacle. Numerous studies are currently devoted to elucidating the pathological mechanisms underlying doxorubicin-induced cardiotoxicity. Nrf2 has always played a crucial role in oxidative stress, but numerous studies have demonstrated that it also plays a vital part in pathological mechanisms like cell death and inflammation. Numerous studies on the pathological mechanisms associated with doxorubicin-induced cardiotoxicity demonstrate this. Several clinical drugs, natural and synthetic compounds, as well as small molecule RNAs have been demonstrated to prevent doxorubicin-induced cardiotoxicity by activating Nrf2. Consequently, this study emphasizes the introduction of Nrf2, discusses the role of Nrf2 in doxorubicin-induced cardiotoxicity, and concludes with a summary of the therapeutic modalities targeting Nrf2 to ameliorate doxorubicin-induced cardiotoxicity, highlighting the potential value of Nrf2 in doxorubicin-induced cardiotoxicity.

The effects and mechanism of LncRNA NORAD on doxorubicin-induced cardiotoxicity

In recent years, the role and mechanism of long non-coding RNA (LncRNA) in cardiovascular diseases have received increasing attention. The chemotherapy agent, doxorubicin (DOX), is one of the most effective drugs for various cancers, but its efficacy is limited by its cardiotoxicity. Therefore, further exploration is required for the molecular mechanism of DOX-induced cardiotoxicity. This study intended to investigate the role of LncRNA Non-coding RNA activated by DNA damage (NORAD) in DOX-induced cardiotoxicity, for which we adopted the AC16 human cardiomyocyte cell line for the exploration. The results showed that LncRNA NORAD knockdown could increase DOX-induced cardiomyocyte apoptosis and mitochondrial ROS level. LncRNA NORAD overexpression obtained reverse results, which further validated its role in DOX-induced cardiomyocyte apoptosis and mitochondrial ROS level. Moreover, cardiotoxicity was induced in both LncRNA NORAD-knockout and wild-type mice with DOX, showing that gene knockout aggravated pathologic lesions in the myocardial tissues of mice. Taken together, LncRNA NORAD affected DOX-induced cardiotoxicity via mitochondrial apoptosis, fission (PUM-MFF), and autophagy (p53-Parkin) pathways both in vivo and in vitro. AVAILABILITY OF DATA AND MATERIALS: The datasets of this study are available on request to the corresponding author.

Curing childhood cancer the "Natural" Way: Nature as the source of chemotherapy agents

For many centuries, products of natural origin from plants, marine, microbes and soil micro-organisms have been studied by numerous researchers across the world to yield many of the chemotherapeutic agents we use in this modern era. There has been a tremendous gain in knowledge from various screening and separating techniques which led to the discovery of biologically active small molecules from natural products. Preclinical studies testing the antitumor activities of these agents against tumor cell lines and xenograft animal models were the gateway to the clinical trials in humans leading to the approval of these agents that are in clinical use today. This review summarizes how various chemotherapeutic agents were discovered from products of natural origin, their preclinical development, and their indications in both pediatric and adult oncology. Many of these natural products have contributed to the very high cure rates of both pediatric leukemias and solid tumors.

Tenofovir alone or combined with doxorubicin abrogates DMBA-induced mammary cell carcinoma: An insight into its modulatory impact on oxidative/Notch/apoptotic signaling

AIMS

Breast cancer incidence keeps on growing and emerging as one of the major global challenges, therefore, the introduction of new approaches is of great demand. Drug repurposing is crucial to faster and cheaper discovery of anti-cancer drugs. The antiviral tenofovir disproxil fumarate (TF) was reported to decrease hepatocellular carcinoma risk by interfering with cell cycle and proliferation. This study aimed to scrutinize the role of TF alone or combined with doxorubicin (DOX) in 7,12-dimethylbenz (a) anthracene (DMBA)-induced breast carcinoma rat model.

MATERIALS AND METHODS

Breast carcinoma was induced by DMBA (7.5 mg/kg, twice/week, SC into mammary gland) for 4 successive weeks. TF (25 and 50 mg/kg/day) was given orally and DOX (2 mg/kg) was injected once/week by tail vein starting from day 1.

KEY FINDINGS

The anti-cancerous effect of TF was mediated by suppression of oxidative stress markers and Notch signaling proteins (Notch1, JAG1, and HES1), attenuation of tumor proliferation markers (cyclin-D1 and Ki67), and boosting of apoptosis (P53 and Caspase3) and autophagy biomarkers (Beclin1 and LC3). In parallel, histopathological assessment displayed that mammary glands from animals treated with TF alone or combined with DOX showed better histopathological scores. Interestingly, TF and DOX co-treatment markedly decreased myocardial injury markers (AST, LDH, and CK-MB), restored the balance between GSH and ROS, prohibited lipid peroxidation, and preserved microscopic myocardial architecture.

SIGNIFICANCE

TF elicited antitumor activity via multiple molecular mechanisms. Moreover, combining TF with DOX might be a potential novel strategy to enhance DOX-anticancer activity and decrease its cardiac side effects.

Thrombin-mediated activation of PAR1 enhances doxorubicin-induced cardiac injury in mice

The chemotherapeutic drug doxorubicin is cardiotoxic and can cause irreversible heart failure. In addition to being cardiotoxic, doxorubicin also induces the activation of coagulation. We determined the effect of thrombin-mediated activation of protease-activated receptor 1 (PAR1) on doxorubicin-induced cardiac injury. Administration of doxorubicin to mice resulted in a significant increase in plasma prothrombin fragment 1+2, thrombin-antithrombin complexes, and extracellular vesicle tissue factor activity. Doxorubicin-treated mice expressing low levels of tissue factor, but not factor XII-deficient mice, had reduced plasma thrombin-antithrombin complexes compared to controls. To evaluate the role of thrombin-mediated activation of PAR1, transgenic mice insensitive to thrombin (Par1R41Q) or activated protein C (Par1R46Q) were subjected to acute and chronic models of doxorubicin-induced cardiac injury and compared with Par1 wild-type (Par1+/+) and PAR1 deficient (Par1-/-) mice. Par1R41Q and Par1-/- mice, but not Par1R46Q mice, demonstrated similar reductions in the cardiac injury marker cardiac troponin I, preserved cardiac function, and reduced cardiac fibrosis compared to Par1+/+ controls after administration of doxorubicin. Furthermore, inhibition of Gαq signaling downstream of PAR1 with the small molecule inhibitor Q94 significantly preserved cardiac function in Par1+/+ mice, but not in Par1R41Q mice subjected to the acute model of cardiac injury when compared to vehicle controls. In addition, mice with PAR1 deleted in either cardiomyocytes or cardiac fibroblasts demonstrated reduced cardiac injury compared to controls. Taken together, these data suggest that thrombin-mediated activation of PAR1 contributes to doxorubicin-induced cardiac injury.

Hyperoside alleviates doxorubicin-induced myocardial cells apoptosis by inhibiting the apoptosis signal-regulating kinase 1/p38 pathway

Background

Cardiotoxicity is a side effect of the anthracycline broad-spectrum anti-tumor agent, doxorubicin (DOX). Hyperoside, a flavonoid glycoside extracted from many herbs, has anti-apoptotic and anticancer properties. However, its impact on the alleviation of DOX-induced apoptosis in cardiomyocytes remains elusive.

Methods

The HL-1 cell line was treated with 100 µ M hyperoside for 1 h prior to treatment with 100 µ M hyperoside and 1 µ M DOX for 24 h. The cell counting kit-8 (CCK-8) assay was used to detect cell viability; DCFH-DA fluorescent probe was used to detect (reactive oxygen species) ROS; biochemical methods were used to detect the activity of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA); the degree of apoptosis following DOX insult was assessed using immunofluorescence staining and terminal deoxynucleotidyl transferase mediated deoxy uridine triphosphate nick end labeling (TUNEL) assay; the change in protein expression of apoptosis signal-regulating kinase 1 (ASK1), p38, and apoptosis markers was determined using western blot.

Results

Hyperoside ameliorated DOX-induced oxidative stress in HL-1 cells, up-regulated GSH, SOD and CAT activity, reduced ROS production and inhibited MDA overproduction. Moreover, in addition to promoting HL-1 cell apoptosis, DOX administration also increased B-cell lymphoma (Bcl)-2-associated X-protein and cleaved caspase-3 protein levels and decreased Bcl-2 protein level. Hyperoside therapy, however, significantly reversed the impact of DOX on the cardiomyocytes. Mechanically, DOX treatment increased the phosphorylation of the ASK1/p38 axis whereas hyperoside treatment attenuated those changes. In a further step, hyperoside synergizes with DOX to kill MDA-MB-231 cells.

Conclusions

Hyperoside protects HL-1 cells from DOX-induced cardiotoxicity by inhibiting the ASK1/p38 signaling pathway. Meanwhile, hyperoside maintained the cytotoxicity of DOX in MDA-MB-231 cells.

Protective Effects of Omega-3 Supplementation against Doxorubicin-Induced Deleterious Effects on the Liver and Kidneys of Rats

Anthracycline doxorubicin (DOX) is still widely used as a chemotherapeutic drug for some solid tumors. Although DOX is highly effective, its side effects are limiting factors, such as cardio, nephro and hepatotoxicity. As such, approaches used to mitigate these adverse effects are highly encouraged. Omega 3 (ω-3), which is a class of long-chain polyunsaturated fatty acids, has been shown to have anti-inflammatory and antioxidant effects in preclinical bioassays. Thus, we evaluated the protective effects of ω-3 supplementation on hepatotoxicity and nephrotoxicity induced by multiple DOX administrations in rodents. Male Wistar rats (10 rats/group) were treated daily with ω-3 (400 mg/kg/day) by gavage for six weeks. Two weeks after the first ω-3 administration, the rats received DOX (3.5 mg/kg, intraperitoneal, 1×/week) for four weeks. DOX treatment reduced body weight gain increased systemic genotoxicity and caused liver-related (increase in serum ALT levels, thickness of the Glisson’s capsule, compensatory proliferation and p65 levels) and kidney-related (increase in serum urea and creatinine levels, and incidence of tubular dilatation) deleterious outcomes. In contrast, ω-3 supplementation was safe and abrogated the DOX-related enhancement of systemic genotoxicity, serum urea and creatinine levels. Furthermore, ω-3 intervention reduced by 50% the incidence of kidney histological lesions while reducing by 40–50% the p65 protein level, and the proliferative response in the liver induced by DOX. Our findings indicate that ω-3 intervention attenuated the DOX-induced deleterious effects in the liver and kidney. Therefore, our findings may inspire future mechanistical investigations and clinical interventions with ω-3 on the reported outcomes.

MicroRNA in the Diagnosis and Treatment of Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX), a broad-spectrum chemotherapy drug, is widely applied to the treatment of cancer; however, DOX-induced cardiotoxicity (DIC) limits its clinical therapeutic utility. However, it is difficult to monitor and detect DIC at an early stage using conventional detection methods. Thus, sensitive, accurate, and specific methods of diagnosis and treatment are important in clinical practice. MicroRNAs (miRNAs) belong to non-coding RNAs (ncRNAs) and are stable and easy to detect. Moreover, miRNAs are expected to become biomarkers and therapeutic targets for DIC; thus, there are currently many studies focusing on the role of miRNAs in DIC. In this review, we list the prominent studies on the diagnosis and treatment of miRNAs in DIC, explore the feasibility and difficulties of using miRNAs as diagnostic biomarkers and therapeutic targets, and provide recommendations for future research.

The Role of Autophagy and Apoptosis in the Combined Action of Plasma-Treated Saline, Doxorubicin, and Medroxyprogesterone Acetate on K562 Myeloid Leukaemia Cells

The anti-cancer properties of plasma-treated solutions (PTS) and their interaction with drugs are one of the most popular topics in modern plasma medicine. Our research involved comparing the effects of four physiological saline solutions (0.9% NaCl, Ringer’s solution, Hank’s Balanced Salt Solution, Hank’s Balanced Salt Solution with amino acids added in concentrations observed in the human blood) treated with cold atmospheric plasma and studying the combined cytotoxic effect of PTS with doxorubicin and medroxyprogesterone acetate (MPA). Analysis of the effect of the studied agents on the formation of radicals in the incubation medium, the vitality of K562 myeloid leukaemia cells, and the processes of autophagy and apoptosis in them revealed two key findings. The first is that when using PTS and doxorubicin-containing PTS, autophagy is the predominant process in cancer cells. The second is that combining PTS with MPA enhances apoptotic processes. It was hypothesised that while autophagy is stimulated by the accumulation of reactive oxygen species in the cell, apoptosis is stimulated through specific cell progesterone receptors.

Biodegradable porous polymeric drug as a drug delivery system: alleviation of doxorubicin-induced cardiotoxicity via passive targeted release

Doxorubicin (DOX) is an effective chemotherapeutic drug developed against a broad range of cancers, and its clinical applications are greatly restricted by the side effects of severe cardiotoxicity during tumour treatment. Herein, the DOX-loaded biodegradable porous polymeric drug, namely, Fc-Ma-DOX, which was stable in the circulation, but easy to compose in the acidic medium, was used as the drug delivery system avoiding the indiscriminate release of DOX. Fc-Ma was constructed via the copolymerization of 1,1'-ferrocenecarbaldehyde with d-mannitol (Ma) through the pH-sensitive acetal bonds. Echocardiography, biochemical parameters, pathological examination, and western blot results showed that DOX treatment caused increased myocardial injury and oxidative stress damage. In contrast, treatment with Fc-Ma-DOX significantly reduced myocardial injury and oxidative stress by DOX treatment. Notably, in the Fc-Ma-DOX treatment group, we observed a significant decrease in the uptake of DOX by H9C2 cells and a significant decrease in reactive oxygen species (ROS) production.

Tubeimoside I Ameliorates Doxorubicin-Induced Cardiotoxicity by Upregulating SIRT3

Cardiotoxicity linked to doxorubicin (DOX) is primarily caused by inflammation, oxidative stress, and apoptosis. The role of tubeimoside I (TBM) in DOX-induced cardiotoxicity remains ambiguous, despite growing evidence that it could reduce inflammation, oxidative stress, and apoptosis in various diseases. This study was designed to investigate the role of TBM in DOX-induced cardiotoxicity and uncover the underlying mechanisms. H9c2 cell line and C57BL/6 mice were used to construct an in vitro and in vivo model of DOX-induced myocardial injury, respectively. We observed that DOX treatment provoked inflammation, oxidative stress, and cardiomyocyte apoptosis, which were significantly alleviated by TBM administration. Mechanistically, TBM attenuated DOX-induced downregulation of sirtuin 3 (SIRT3), and SIRT3 inhibition abrogated the beneficial effects of TBM both in vitro and in vivo. In conclusion, TBM eased inflammation, oxidative stress, and apoptosis in DOX-induced cardiotoxicity by increasing the expression of SIRT3, suggesting that it holds great promise for treating DOX-induced cardiac injury.

Identification of novel biomarkers involved in doxorubicin-induced acute and chronic cardiotoxicity, respectively, by integrated bioinformatics

Background

The mechanisms of doxorubicin (DOX) cardiotoxicity were complex and controversial, with various contradictions between experimental and clinical data. Understanding the differences in the molecular mechanism between DOX-induced acute and chronic cardiotoxicity may be an ideal entry point to solve this dilemma.

Methods

Mice were injected intraperitoneally with DOX [(20 mg/kg, once) or (5 mg/kg/week, three times)] to construct acute and chronic cardiotoxicity models, respectively. Survival record and ultrasound monitored the cardiac function. The corresponding left ventricular (LV) myocardium tissues were analyzed by RNA-seq to identify differentially expressed genes (DEGs). Gene Ontology (GO), Kyoto Encyclopedia of Gene and Genome (KEGG), and Gene Set Enrichment Analysis (GSEA) found the key biological processes and signaling pathways. DOX cardiotoxicity datasets from the Gene expression omnibus (GEO) database were combined with RNA-seq to identify the common genes. Cytoscape analyzed the hub genes, which were validated by quantitative real-time PCR. ImmuCo and ImmGen databases analyzed the correlations between hub genes and immunity-relative markers in immune cells. Cibersort analyzed the immune infiltration and correlations between the hub genes and the immune cells. Logistic regression, receiver operator characteristic curve, and artificial neural network analysis evaluated the diagnosis ability of hub genes for clinical data in the GEO dataset.

Results

The survival curves and ultrasound monitoring demonstrated that cardiotoxicity models were constructed successfully. In the acute model, 788 DEGs were enriched in the activated metabolism and the suppressed immunity-associated signaling pathways. Three hub genes (Alas1, Atp5g1, and Ptgds) were upregulated and were negatively correlated with a colony of immune-activating cells. However, in the chronic model, 281 DEGs showed that G protein-coupled receptor (GPCR)-related signaling pathways were the critical events. Three hub genes (Hsph1, Abcb1a, and Vegfa) were increased in the chronic model. Furthermore, Hsph1 combined with Vegfa was positively correlated with dilated cardiomyopathy (DCM)-induced heart failure (HF) and had high accuracy in the diagnosis of DCM-induced HF (AUC = 0.898, P = 0.000).

Conclusion

Alas1, Atp5g1, and Ptgds were ideal biomarkers in DOX acute cardiotoxicity. However, Hsph1 and Vegfa were potential biomarkers in the myocardium in the chronic model. Our research, first, provided bioinformatics and clinical evidence for the discovery of the differences in mechanism and potential biomarkers of DOX-induced acute and chronic cardiotoxicity to find a therapeutic strategy precisely.

Drug-induced mitochondrial toxicity: Risks of developing glucose handling impairments

Mitochondrial impairment has been associated with the development of insulin resistance, the hallmark of type 2 diabetes mellitus (T2DM). However, the relationship between mitochondrial impairment and insulin resistance is not fully elucidated due to insufficient evidence to support the hypothesis. Insulin resistance and insulin deficiency are both characterised by excessive production of reactive oxygen species and mitochondrial coupling. Compelling evidence states that improving the function of the mitochondria may provide a positive therapeutic tool for improving insulin sensitivity. There has been a rapid increase in reports of the toxic effects of drugs and pollutants on the mitochondria in recent decades, interestingly correlating with an increase in insulin resistance prevalence. A variety of drug classes have been reported to potentially induce toxicity in the mitochondria leading to skeletal muscle, liver, central nervous system, and kidney injury. With the increase in diabetes prevalence and mitochondrial toxicity, it is therefore imperative to understand how mitochondrial toxicological agents can potentially compromise insulin sensitivity. This review article aims to explore and summarise the correlation between potential mitochondrial dysfunction caused by selected pharmacological agents and its effect on insulin signalling and glucose handling. Additionally, this review highlights the necessity for further studies aimed to understand drug-induced mitochondrial toxicity and the development of insulin resistance.

Molecular mechanisms associated with the chemoprotective role of protocatechuic acid and its potential benefits in the amelioration of doxorubicin-induced cardiotoxicity: A review

Since its discovery in the 1960 s, doxorubicin (DOX) has constantly elicited the broadest spectrum of cancerocidal activity against human cancers. However, cardiotoxicity caused by DOX directly as well as its metabolites is a great source of concern over the continuous use of DOX in chemotherapy. While the exact mechanism of DOX-induced cardiotoxicity is yet to be completely understood, recent studies indicate oxidative stress, inflammation, and several forms of cell death as key pathogenic mechanisms that underpin the etiology of doxorubicin-induced cardiotoxicity (DIC). Notably, these key mechanistic events are believed to be negatively regulated by 3,4-dihydroxybenzoic acid or protocatechuic acid (PCA)-a plant-based phytochemical with proven anti-oxidant, anti-inflammatory, and anti-apoptotic properties. Here, we review the experimental findings detailing the potential ameliorative effects of PCA under exposure to DOX. We also discuss molecular insights into the pathophysiology of DIC, highlighting the potential intervention points where the use of PCA as a veritable chemoprotective agent may ameliorate DOX-induced cardiotoxicities as well as toxicities due to other anticancer drugs like cisplatin. While we acknowledge that controlled oral administration of PCA during chemotherapy may be insufficient to eliminate all toxicities due to DOX treatment, we propose that the ability of PCA to block oxidative stress, attenuate inflammation, and abrogate several forms of cardiomyocyte cell death underlines its great promise in the amelioration of DIC.

Prevention of Anthracycline-Induced Cardiotoxicity: The Good and Bad of Current and Alternative Therapies

Doxorubicin (Dox)-induced cardiotoxicity (DIC) remains a serious health burden, especially in developing countries. Unfortunately, the high cost of current preventative strategies has marginalized numerous cancer patients because of socio-economic factors. In addition, the efficacy of these strategies, without reducing the chemotherapeutic properties of Dox, is frequently questioned. These limitations have widened the gap and necessity for alternative medicines, like flavonoids, to be investigated. However, new therapeutics may also present their own shortcomings, ruling out the idea of “natural is safe”. The U.S. Food and Drug Administration (FDA) has stipulated that the concept of drug-safety be considered in all pre-clinical and clinical studies, to explore the pharmacokinetics and potential interactions of the drugs being investigated. As such our studies on flavonoids, as cardio-protectants against DIC, have been centered around cardiac and cancer models, to ensure that the efficacy of Dox is preserved. Our findings thus far suggest that flavonoids of Galenia africana could be suitable candidates for the prevention of DIC. However, this still requires further investigation, which would focus on drug-interactions as well as in vivo experimental models to determine the extent of cardioprotection.

Protective Effects of Amauroderma rugosum on Doxorubicin-Induced Cardiotoxicity through Suppressing Oxidative Stress, Mitochondrial Dysfunction, Apoptosis, and Activating Akt/mTOR and Nrf2/HO-1 Signaling Pathways

Clinical outcomes for doxorubicin (Dox) are limited by its cardiotoxicity but a combination of Dox and agents with cardioprotective activities is an effective strategy to improve its therapeutic outcome. Natural products provide abundant resources to search for novel cardioprotective agents. Ganoderma lucidum (GL) is the most well-known edible mushroom within the Ganodermataceae family. It is commonly used in traditional Chinese medicine or as a healthcare product. Amauroderma rugosum (AR) is another genus of mushroom from the Ganodermataceae family, but its pharmacological activity and medicinal value have rarely been reported. In the present study, the cardioprotective effects of the AR water extract against Dox-induced cardiotoxicity were studied in vitro and in vivo. Results showed that both the AR and GL extracts could potentiate the anticancer effect of Dox. The AR extract significantly decreased the oxidative stress, mitochondrial dysfunction, and apoptosis seen in Dox-treated H9c2 rat cardiomyocytes. However, knockdown of Nrf2 by siRNA abolished the protective effects of AR in these cells. In addition, Dox upregulated the expression of proapoptotic proteins and downregulated the Akt/mTOR and Nrf2/HO-1 signaling pathways, and these effects could be reversed by the AR extract. Consistently, the AR extract significantly prolonged survival time, reversed weight loss, and reduced cardiac dysfunction in Dox-treated mice. In addition, oxidative stress and apoptosis were suppressed, while Nrf2 and HO-1 expressions were elevated in the heart tissues of Dox-treated mice after treatment with the AR extract. However, the GL extract had less cardioprotective effect against Dox in both the cell and animal models. In conclusion, the AR water extract demonstrated a remarkable cardioprotective effect against Dox-induced cardiotoxicity. One of the possible mechanisms for this effect was the upregulation of the mTOR/Akt and Nrf2/HO-1-dependent pathways, which may reduce oxidative stress, mitochondrial dysfunction, and cardiomyocyte apoptosis. These findings suggested that AR may be beneficial for the heart, especially in patients receiving Dox-based chemotherapy.