Role of mitochondria in doxorubicin-mediated cardiotoxicity: From molecular mechanisms to therapeutic strategies.

This comprehensive review delves into the pivotal role of mitochondria in doxorubicin-induced cardiotoxicity, a significant complication limiting the clinical use of this potent anthracycline chemotherapeutic agent. Doxorubicin, while effective against various malignancies, is associated with dose-dependent cardiotoxicity, potentially leading to irreversible cardiac damage. The review meticulously dissects the molecular mechanisms underpinning this cardiotoxicity, particularly focusing on mitochondrial dysfunction, a central player in this adverse effect. Central to the discussion is the concept of mitochondrial quality control, including mitochondrial dynamics (fusion/fission balance) and mitophagy. The review presents evidence linking aberrations in these processes to cardiotoxicity in doxorubicin-treated patients. It elucidates how doxorubicin disrupts mitochondrial dynamics, leading to an imbalance between mitochondrial fission and fusion, and impairs mitophagy, culminating in the accumulation of dysfunctional mitochondria and subsequent cardiac cell damage. Furthermore, the review explores emerging therapeutic strategies targeting mitochondrial dysfunction. It highlights the potential of modulating mitochondrial dynamics and enhancing mitophagy to mitigate doxorubicin-induced cardiac damage. These strategies include pharmacological interventions with mitochondrial fission inhibitors, fusion promoters, and agents that modulate mitophagy. The review underscores the promising results from preclinical studies while advocating for more extensive clinical trials to validate these approaches in human patients. In conclusion, this review offers valuable insights into the intricate relationship between mitochondrial dysfunction and doxorubicin-mediated cardiotoxicity. It underscores the need for continued research into targeted mitochondrial therapies as a means to improve the cardiac safety profile of doxorubicin, thereby enhancing the overall treatment outcomes for cancer patients.

Overexpression of multidrug resistance-associated protein 1 protects against cardiotoxicity by augmenting the doxorubicin efflux from cardiomyocytes.

Doxorubicin is a commonly used anti-cancer drug used in treating a variety of malignancies. However, a major adverse effect is cardiotoxicity, which is dose dependent and can be either acute or chronic. Doxorubicin causes injury by DNA damage, the formation of free reactive oxygen radicals and induction of apoptosis. Our aim is to induce expression of the multidrug resistance-associated protein 1 (MRP1) in cardiomyocytes derived from human iPS cells (hiPSC-CM), to determine whether this will allow cells to effectively remove doxorubicin and confer cardioprotection. We generated a lentivirus vector encoding MRP1 (LV.MRP1) and validated its function in HEK293T cells and stem cell-derived cardiomyocytes (hiPSC-CM) by quantitative PCR and western blot analysis. The activity of the overexpressed MRP1 was also tested, by quantifying the amount of fluorescent dye exported from the cell by the transporter. We demonstrated reduced dye sequestration in cells overexpressing MRP1. Finally, we demonstrated that hiPSC-CM transduced with LV.MRP1 were protected against doxorubicin injury. In conclusion, we have shown that we can successfully overexpress MRP1 protein in hiPSC-CM, with functional transporter activity leading to protection against doxorubicin-induced toxicity.

5-Hydroxytryptophan acts as a gap junction inhibitor to limit the spread of chemotherapy-induced cardiomyocyte injury and mitochondrial dysfunction.

Anthracycline chemotherapeutics like doxorubicin (DOX) are widely used against various cancers but are accompanied by severe cardiotoxic effects that can lead to heart failure. Through whole transcriptome sequencing and pathological tissue analysis in a murine model, our study has revealed that DOX impairs collagen expression in the early phase, causing extracellular matrix anomalies that weaken the mechanical integrity of the heart. This results in ventricular wall thinning and dilation, exacerbating cardiac dysfunction. In this work, we have identified 5-hydroxytryptophan (5-HTP) as a potent inhibitor of gap junction communication. This inhibition is key to limiting the spread of DOX-induced cardiotoxicity. Treatment with 5-HTP effectively countered the adverse effects of DOX on the heart, preserving ventricular structure and ejection fraction. Moreover, 5-HTP enhanced mitochondrial respiratory function, as shown by the O2k mitochondrial function assay, by improving mitochondrial complex activity and ATP production. Importantly, the cardioprotective benefits of 5-HTP did not interfere with DOX's ability to combat cancer. These findings shed light on the cardiotoxic mechanisms of DOX and suggest that 5-HTP could be a viable strategy to prevent heart damage during chemotherapy, offering a foundation for future clinical development. This research opens the door for 5-HTP to be considered a dual-purpose agent that can protect the heart without compromising the oncological efficacy of anthracycline chemotherapy.

Integrated Stress Response Potentiates Ponatinib-Induced Cardiotoxicity.

BACKGROUND: Mitochondrial dysfunction is a primary driver of cardiac contractile failure; yet, the cross talk between mitochondrial energetics and signaling regulation remains obscure. Ponatinib, a tyrosine kinase inhibitor used to treat chronic myeloid leukemia, is among the most cardiotoxic tyrosine kinase inhibitors and causes mitochondrial dysfunction. Whether ponatinib-induced mitochondrial dysfunction triggers the integrated stress response (ISR) to induce ponatinib-induced cardiotoxicity remains to be determined. METHODS: Using human induced pluripotent stem cells-derived cardiomyocytes and a recently developed mouse model of ponatinib-induced cardiotoxicity, we performed proteomic analysis, molecular and biochemical assays to investigate the relationship between ponatinib-induced mitochondrial stress and ISR and their role in promoting ponatinib-induced cardiotoxicity. RESULTS: Proteomic analysis revealed that ponatinib activated the ISR in cardiac cells. We identified GCN2 (general control nonderepressible 2) as the eIF2α (eukaryotic translation initiation factor 2α) kinase responsible for relaying mitochondrial stress signals to trigger the primary ISR effector-ATF4 (activating transcription factor 4), upon ponatinib exposure. Mechanistically, ponatinib treatment exerted inhibitory effects on ATP synthase activity and reduced its expression levels resulting in ATP deficits. Perturbed mitochondrial function resulting in ATP deficits then acts as a trigger of GCN2-mediated ISR activation, effects that were negated by nicotinamide mononucleotide, an NAD+ precursor, supplementation. Genetic inhibition of ATP synthase also activated GCN2. Interestingly, we showed that the decreased abundance of ATP also facilitated direct binding of ponatinib to GCN2, unexpectedly causing its activation most likely because of a conformational change in its structure. Importantly, administering an ISR inhibitor protected human induced pluripotent stem cell-derived cardiomyocytes against ponatinib. Ponatinib-treated mice also exhibited reduced cardiac function, effects that were attenuated upon systemic ISRIB administration. Importantly, ISRIB does not affect the antitumor effects of ponatinib in vitro. CONCLUSIONS: Neutralizing ISR hyperactivation could prevent or reverse ponatinib-induced cardiotoxicity. The findings that compromised ATP production potentiates GCN2-mediated ISR activation have broad implications across various cardiac diseases. Our results also highlight an unanticipated role of ponatinib in causing direct activation of a kinase target despite its role as an ATP-competitive kinase inhibitor.

Levocabastine ameliorates cyclophosphamide-induced cardiotoxicity in Swiss albino mice: Targeting TLR4/NF-κB/NLRP3 signaling pathway.

Cyclophosphamide (CP), although a potent anti-cancer drug, causes cardiotoxicity as a side effect that limits its use. Hence, a specific medicine that can lower cardiotoxicity and be utilised as an adjuvant in cancer treatment is very much needed. In this light, we intended to assess the protective potential of levocabastine (LEV) on CP-induced cardiotoxicity in Swiss albino mice. Mice were administered LEV (50 and 100 µg/kg, i.p.) daily for 14 days and CP at 200 mg/kg, intraperitoneally once on the 7th day. On the 15th day, mice were weighed, blood withdrawn then sacrificed and hearts were removed to estimate various biochemical and histopathological parameters. CP 200 mg/kg significantly increased cardiac troponin T, LDH, CK-MB, interleukin-1ß, IL-6, TNF-α, TBARS, nitrite, and decreased CAT, GSH, and SOD levels, thus, manifested cardiac damage, inflammation, oxidative stress, and nitrative stress, cumulatively causing cardiotoxicity. CP also elevated the expression of various markers including cleaved caspase-3, NF-κB, TLR4, NLRP3, and fibrotic lesions in cardiac tissues, whereas decreased hematological parameters (RBCs, platelets, and Hb) to confirm cardiotoxicity. LEV and fenofibrate (FF) treatment reversed these changes towards normal and showed a significant protective effect against CP. The results showed the protective role of LEV in restoring CP-induced cardiotoxicity in terms of inflammation, apoptosis, oxidative stress, cardiac injury and histopathological damage. Thus, levocabastine can be used as an adjuvant to cyclophosphamide in cancer treatment but a thorough study with various animal cancer models is further needed to establish the fact.

Treatment of Internal Mammary Nodes is Associated With Improved Overall Survival in Breast Cancer: A Meta-Analysis.

INTRODUCTION: The role of internal mammary nodal irradiation (IMNI) as a component of regional nodal radiotherapy is a controversial issue in breast radiation oncology with conflicting results presented in recent landmark trials. We thus created a meta-analysis of available data to better ascertain the potential benefit of IMNI. We hypothesize that with the increased power available within a meta-analysis, IMNI will prove to improve overall survival (OS) in breast cancer. METHODS: Literature search was conducted for prospective studies comparing IMNI to no IMNI. Primary endpoint was OS and secondary endpoints included local recurrence, regional recurrence, disease-free survival (DFS), breast cancer mortality (BCM), distant metastasis-free survival (DMFS), grade 2+ skin toxicity, cardiac events, and pneumonitis events. Subgroup analyses were performed for tumor location (medial/central vs. lateral), and nodal status (pN+ vs. pN0). Fixed-effect model was used if there was no heterogeneity, random-effects model otherwise. RESULTS: Four studies with a total of 5258 patients (IMNI: n=2592; control: n=2666) were included in the study. Pooled results showed IMNI significantly improved OS for all-comers (hazard ratio [HR]=0.89; 95% CI 0.81-0.97; P =0.008), as well as subgroups of pN+ with medial/central tumor location (HR=0.84; 95% CI 0.73-0.96; P =0.01) and pN+ with lateral tumor location (HR=0.87; 95% CI 0.77-0.99; P =0.04). There was no significant difference in OS for subgroups of pN0 and medial/central tumor location. There was no difference in local recurrence, but regional recurrence was significantly improved ( P =0.04). Endpoints of DFS (HR 0.91, 95% CI 0.84-0.99 P =0.03), BCM (HR 0.87, 95% CI 0.77-0.98, P =0.03), and DMFS (HR=0.87; 95% CI, 0.78-0.98; P =0.02) were all improved with IMNI. Grade 2+ skin toxicity, cardiac events and pneumonitis events were not significantly different between patient in the IMNI and no IMNI groups. CONCLUSION: Inclusion of IMN irradiation improves OS, DFS, BCM, and DMFS in breast cancer. Largest effect on OS was noted in the subgroup of patients with pN+ and medial/central tumor location.

The Role of Nrf2 and Inflammation on the Dissimilar Cardiotoxicity of Doxorubicin in Two-Time Points: a Cardio-Oncology In Vivo Study Through Time.

Doxorubicin (DOX) is a topoisomerase II inhibitor used in cancer therapy. Despite its efficacy, DOX causes serious adverse effects, such as short- and long-term cardiotoxicity. This work aimed to assess the short- and long-term cardiotoxicity of DOX and the role of inflammation and antioxidant defenses on that cardiotoxicity in a mice model. Adult CD-1 male mice received a cumulative dose of 9.0 mg/kg of DOX (2 biweekly intraperitoneal injections (ip), for 3 weeks). One week (1W) or 5 months (5M) after the last DOX administration, the heart was collected. One week after DOX, a significant increase in p62, tumor necrosis factor receptor (TNFR) 2, glutathione peroxidase 1, catalase, inducible nitric oxide synthase (iNOS) cardiac expression, and a trend towards an increase in interleukin (IL)-6, TNFR1, and B-cell lymphoma 2 associated X (Bax) expression was observed. Moreover, DOX induced a decrease on nuclear factor erythroid-2 related factor 2 (Nrf2) cardiac expression. In both 1W and 5M, DOX led to a high density of infiltrating M1 macrophages, but only the 1W-DOX group had a significantly higher number of nuclear factor κB (NF-κB) p65 immunopositive cells. As late effects (5M), an increase in Nrf2, myeloperoxidase, IL-33, tumor necrosis factor-α (TNF-α), superoxide dismutase 2 (SOD2) expression, and a trend towards increased catalase expression were observed. Moreover, B-cell lymphoma 2 (Bcl-2), cyclooxygenase-2 (COX-2), and carbonylated proteins expression decreased, and a trend towards decreased p38 mitogen-activated protein kinase (MAPK) expression were seen. Our study demonstrated that DOX induces adverse outcome pathways related to inflammation and oxidative stress, although activating different time-dependent response mechanisms.

Resveratrol protects against doxorubicin-induced cardiotoxicity by attenuating ferroptosis through modulating the MAPK signaling pathway.

Doxorubicin (Dox) is a widely used antitumor agent with dose-dependent and cumulative cardiotoxic effects. Resveratrol (Res) is a natural non-flavonoid polyphenol that can potentially provide cardiovascular benefits. We aimed to estimate the protective effect of Res on Dox-induced cardiotoxicity (DIC) and explore whether it was related to attenuating ferroptosis. We established DIC models in C57BL/6 J mice, H9C2 cardiomyoblasts, and neonatal rat cardiomyocytes (NRCMs). We further treated H9C2 cells with RSL3, a ferroptosis agonist, to investigate whether Res exerted protective effects through inhibiting ferroptosis. Ferrostatin-1 (Fer-1) was applied to suppress ferroptosis. Dox treatment caused cardiac dysfunction and resulted in apparent ferroptotic damage in cardiac tissue, involving increased iron accumulation, glutathione depletion, increased expression of ferroptosis-related proteins, and decreased expression of glutathione peroxidase 4, which were alleviated by Fer-1 and Res administration. These findings were also confirmed in Dox-treated H9C2 cells and NRCMs, with Fer-1 and Res effectively attenuating Dox-induced cytotoxicity and ferroptosis. Furthermore, Res protected H9C2 cells from RSL3-induced ferroptotic cell death, and the protective effect was similar to that of Fer-1. Both Dox and RSL3 treatment increased the phosphorylation levels of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinases; however, these changes were hindered by Res. This study demonstrates that Res effectively alleviates DIC by suppressing ferroptosis possibly through modulating the MAPK signaling pathway. Our results highlight that targeting ferroptosis can be a potential cardioprotective strategy for DIC.

Capsaicin alleviates doxorubicin-induced acute myocardial injury by regulating iron homeostasis and PI3K-Akt signaling pathway.

BACKGROUND: Capsaicin (CAP), a frequently occurring alkaloid component found in spicy peppers, has demonstrated therapeutic potential against tumors, metabolic disease, and cardiovascular disorders. Doxorubicin (DOX), a widely used anthracycline drug in chemotherapy, is notorious for its cardiotoxicity. This study aimed to investigate the potential of CAP in mitigating DOX toxicity in mouse hearts and H9C2 cells, as well as to explore the underlying mechanisms. METHODS: In our study, we conducted experiments on both mice and H9C2 cells. The mice were divided into four groups and treated with different substances: normal saline, CAP, DOX and CAP+DOX. We evaluated the induction of ferroptosis by DOX and the remission of ferroptosis by CAP using various methods, including echocardiography, Hematoxylin and Eosin (H&E) staining, Masson's trichrome staining, and determination of ferroptosis metabolites, genes and proteins. Additionally, we employed RNA-seq to identify the inhibitory effect of CAP on DOX-induced myocardial apoptosis, which was further confirmed through western blotting. Similar approaches were applied to H9C2 cells, yielding reliable results. RESULTS: Our study demonstrated that treatment with CAP improved the survival rate of DOX-treated mice and reduced myocardial injury. Mechanistically, CAP downregulated transferrin (Trf) and upregulated solute carrier family 40 member 1 (SLC40A1), which helped maintain iron levels in the cells and prevent ferroptosis. Furthermore, CAP inhibited DOX-induced apoptosis by modulating the phosphoinositide 3-kinase (PI3K)- protein kinase B (Akt) signaling pathway. Specifically, CAP activated the PI3K-Akt pathway and regulated downstream BCL2 and BAX to mitigate DOX-induced apoptosis. Therefore, our results suggest that CAP effectively alleviates acute myocardial injury induced by DOX. CONCLUSION: Our findings demonstrate that CAP has the potential to alleviate DOX-induced ferroptosis by regulating iron homeostasis. Additionally, it can inhibit DOX-induced apoptosis by activating PI3K-Akt signaling pathway.

WGX50 mitigates doxorubicin-induced cardiotoxicity through inhibition of mitochondrial ROS and ferroptosis.

BACKGROUND: Doxorubicin (DOX)-induced cardiotoxicity (DIC) is a major impediment to its clinical application. It is indispensable to explore alternative treatment molecules or drugs for mitigating DIC. WGX50, an organic extract derived from Zanthoxylum bungeanum Maxim, has anti-inflammatory and antioxidant biological activity, however, its function and mechanism in DIC remain unclear. METHODS: We established DOX-induced cardiotoxicity models both in vitro and in vivo. Echocardiography and histological analyses were used to determine the severity of cardiac injury in mice. The myocardial damage markers cTnT, CK-MB, ANP, BNP, and ferroptosis associated indicators Fe2+, MDA, and GPX4 were measured using ELISA, RT-qPCR, and western blot assays. The morphology of mitochondria was investigated with a transmission electron microscope. The levels of mitochondrial membrane potential, mitochondrial ROS, and lipid ROS were detected using JC-1, MitoSOX™, and C11-BODIPY 581/591 probes. RESULTS: Our findings demonstrate that WGX50 protects DOX-induced cardiotoxicity via restraining mitochondrial ROS and ferroptosis. In vivo, WGX50 effectively relieves doxorubicin-induced cardiac dysfunction, cardiac injury, fibrosis, mitochondrial damage, and redox imbalance. In vitro, WGX50 preserves mitochondrial function by reducing the level of mitochondrial membrane potential and increasing mitochondrial ATP production. Furthermore, WGX50 reduces iron accumulation and mitochondrial ROS, increases GPX4 expression, and regulates lipid metabolism to inhibit DOX-induced ferroptosis. CONCLUSION: Taken together, WGX50 protects DOX-induced cardiotoxicity via mitochondrial ROS and the ferroptosis pathway, which provides novel insights for WGX50 as a promising drug candidate for cardioprotection.

Angiotensin IV ameliorates doxorubicin-induced cardiotoxicity by increasing glutathione peroxidase 4 and alleviating ferroptosis.

BACKGROUND: Doxorubicin (DOX)-induced cardiotoxicity is an important cause of poor prognosis in cancer patients treated with DOX. Angiotensin IV (Ang IV) has multiple protective effects against cardiovascular diseases, including diabetic cardiomyopathy and myocardial infarction, but its role in DOX-induced cardiotoxicity is currently unclear. In this study, we investigated the effects of Ang IV on DOX-induced cardiotoxicity. METHODS: The viability of primary cardiomyocytes was measured by Cell Counting Kit-8 assays and Hoechst 33342/propidium iodide staining in vitro. ELISAs (serum cTnT and CK-MB) and echocardiography were performed to assess myocardial injury and cardiac function in vivo. Phalloidin staining, haematoxylin and eosin staining and wheat germ agglutinin staining were conducted to detect cardiomyocyte atrophy. We also performed C11 BODIPY staining, measured the levels of Ptgs2 and malondialdehyde and detected the concentrations of ferrous ions, glutathione and oxidized glutathione to indicate ferroptosis. RESULTS: Ang IV not only attenuated DOX-induced atrophy and cardiomyocyte injury in vitro but also alleviated myocardial injury and improved cardiac function in DOX-treated mice in vivo. Moreover, Ang IV reversed DOX-induced downregulation of glutathione peroxidase 4 (GPX4) and inhibited ferroptosis both in vitro and in vivo. Knockdown of GPX4 by siRNA abolished the cardioprotective effects of Ang IV. Furthermore, Ang IV increased GPX4 levels and ameliorated ferroptosis in RAS-selective lethal 3-treated primary cardiomyocytes. CONCLUSIONS: Ang IV ameliorates DOX-induced cardiotoxicity by upregulating GPX4 and inhibiting ferroptosis. Ang IV may be a promising candidate to protect against DOX-induced cardiotoxicity in the future.

Homotypic targeted nanoplatform enable efficient chemoimmunotherapy and reduced DOX cardiotoxicity in chemoresistant cancer via TGF-ß1 blockade.

Doxorubicin (DOX) with broad-spectrum antitumor activity has been reported to induce effective immunogenic cell death (ICD) effect. However, the serious cardiotoxicity and chemoresistance severely restrict the widely clinical application of DOX. Herein, for the first time, a bio-inspired nanoplatform via co-assembly of DOX-conjugated polyethyleneimine (PEI-DOX), cancer cell membrane (CCM) and TGF-ß1 siRNA (siTGF-ß1) was rationally designed, which can not only overcome the drawbacks of DOX but also display high capability to modulate the tumor microenvironment and prevent the tumor progressing and metastasis. Experimental studies confirmed the pH-sensitivity of PEI-DOX and the homotypic-targeting and immuno-escapable ability of CCM, resulting an enhanced accumulation of DOX and siTGF-ß1 in tumor sites. In addition to this, the bio-inspired nanoplatform could also improve the stability and facilitate the endosomal escape of siTGF-ß1. All these effects ensured the silence efficiency of siTGF-ß1 in tumor sites, which could further modulate the chemoresistant and immunosuppressive tumor microenvironment, resulting a synergistic effect with DOX to prevent tumor progressing and metastasis. Additionally, even trapped in cardiac tissues, siTGF-ß1 could inhibit the production of TGF-ß1 and ROS induced by DOX, resulting a reduced myocardial damage. Therefore, our newly designed bio-inspired nano-delivery system may be a promising nanoplatform with efficient chemoimmunotherapy to ameliorate DOX-induced cardiotoxicity and combat tumor growth and metastasis in chemoresistant cancer.

M2b macrophages protect against doxorubicin induced cardiotoxicity via alternating autophagy in cardiomyocytes.

OBJECTIVE: Doxorubicin (DOX) is an anthracycline antibiotic which is widely used for the treatment of various cancers, while the dose-related cardiotoxicity limits its potential therapeutic application. The underlying mechanism of DOX induced cardiotoxicity is complex and remains elusive. Our previous studies have shown that M2b macrophage plays an important role in reducing inflammation due to ischemic reperfusion injury in the myocardium. The purpose of this study was to investigate the potential protective role of M2b macrophages in DOX induced cardiotoxicity. METHODS: In vivo, we conducted DOX induced cardiac injury in C57BL/6 mice and treated them with M2b macrophages. Then, the mice were examined by echocardiography. The heart specimens were harvested for histological examination, transmission electron microscope analysis, and autophagy molecules evaluation. In vitro, HL-1 cardiac cell lines treated with DOX were cocultured with or without M2b macrophages. Then, Autophagy related genes and protein expression were assessed by real-time quantitative PCR and western blot; cell proliferation was assessed by cell counting kit-8. RESULTS: We found that M2b macrophages can improve cardiac function and alleviate cardiac injury in DOX induced cardiac injury mice. M2b macrophages can enhance cardiac autophagy levels both in vivo and in vitro in DOX induced cardiac injury model. In addition, this protective effect can be blocked by an autophagy inhibitor. CONCLUSION: Our study shows that M2b macrophages can help attenuate the DOX induced cardiotoxicity by regulating the autophagy level of cardiomyocytes.

Identification of Gene Expression Signatures for Phenotype-Specific Drug Targeting of Cardiac Fibrosis.

We have designed translational animal models to investigate cardiac profibrotic gene signatures. Domestic pigs were treated with cardiotoxic drugs (doxorubicin, DOX, n = 5 or Myocet®, MYO, n = 5) to induce replacement fibrosis via cardiotoxicity. Reactive interstitial fibrosis was triggered by LV pressure overload by artificial isthmus stenosis with stepwise developing myocardial hypertrophy and final fibrosis (Hyper, n = 3) or by LV volume overload in the adverse remodeled LV after myocardial infarction (RemoLV, n = 3). Sham interventions served as controls and healthy animals (Control, n = 3) served as a reference in sequencing study. Myocardial samples from the LV of each group were subjected to RNA sequencing. RNA-seq analysis revealed a clear distinction between the transcriptomes of myocardial fibrosis (MF) models. Cardiotoxic drugs activated the TNF-alpha and adrenergic signaling pathways. Pressure or volume overload led to the activation of FoxO pathway. Significant upregulation of pathway components enabled the identification of potential drug candidates used for the treatment of heart failure, such as ACE inhibitors, ARB, ß-blockers, statins and diuretics specific to the distinct MF models. We identified candidate drugs in the groups of channel blockers, thiostrepton that targets the FOXM1-regulated ACE conversion to ACE2, tyrosine kinases or peroxisome proliferator-activated receptor inhibitors. Our study identified different gene targets involved in the development of distinct preclinical MF protocols enabling tailoring expression signature-based approach for the treatment of MF.

Seaweed Sargassum aquifolium extract ameliorates cardiotoxicity induced by doxorubicin in rats.

Doxorubicin (DOX) is a potent anticancer drug with adverse cardiotoxic effects. Alginates are multifunctional biopolymers and polyelectrolytes derived from the cell walls of brown seaweeds. They are nontoxic, biocompatible, and biodegradable, and hence, utilized in several biomedical and pharmaceutical applications. Here, we investigated the potential cardioprotective effect of thermally treated sodium alginate (TTSA), which was extracted and purified from the seaweed Sargassum aquifolium, in treating acute DOX cardiotoxicity and apoptotic pathways in rats. UV-visible spectroscopy, Fourier-transform infrared, and nuclear magnetic resonance (1H-NMR) spectroscopy techniques were used to characterize TTSA. CK-MB and AST levels in sera samples were determined. The expression levels of Erk-2 (MAPK-1) and iNOS genes were investigated by quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression levels of Erk-2, anti-apoptotic p53, and caspase-3 were analyzed using western blotting and ELISA. For the in vivo studies, sixty rats were randomly divided equally into six groups and treated with DOX, followed by TTSA. We revealed that treatment with TTSA, which has low molecular weight and enhanced antioxidant properties, improved DOX-mediated cardiac dysfunction and alleviated DOX-induced myocardial apoptosis. Furthermore, TTSA exhibited a cardioprotective effect against DOX-induced cardiac toxicity, indicated by the increased expression of MAPK-1 (Erk2) and iNOS genes, which are implicated in the adaptive responses regulating DOX-induced myocardial damage. Moreover, TTSA significantly (p < 0.05) suppressed caspase-3 and upregulated anti-apoptotic protein p53 expression. TTSA also rebalanced the cardiomyocyte redox potential by significantly (p < 0.05) increasing the levels of endogenous antioxidant enzymes, including catalase and superoxide dismutase. Our findings suggest that TTSA, particularly at a dose of 400 mg/kg b.w., is a potential prophylactic supplement for treating acute DOX-linked cardiotoxicity.

PTX3 from vascular endothelial cells contributes to trastuzumab-induced cardiac complications.

AIMS: Trastuzumab, the first humanized monoclonal antibody that targets human epidermal growth factor receptor 2 (ERBB2/HER2), is currently used as a first-line treatment for HER2 (+) tumours. However, trastuzumab increases the risk of cardiac complications without affecting myocardial structure, suggesting a distinct mechanism of cardiotoxicity. METHODS AND RESULTS: We used medium from trastuzumab-treated human umbilical vein endothelial cells (HUVECs) to treat CCC-HEH-2 cells, the human embryonic cardiac tissue-derived cell lines, and human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) to assess the crosstalk between vascular endothelial cells (VECs) and cardiomyocytes. Protein mass spectrometry analysis was used to identify the key factors from VECs that regulate the function of cardiomyocytes. We applied RNA-sequencing to clarify the mechanism, by which PTX3 causes cardiac dysfunction. We used an anti-human/rat HER2 (neu) monoclonal antibody to generate a rat model that was used to evaluate the effects of trastuzumab on cardiac structure and function and the rescue effects of lapatinib on trastuzumab-induced cardiac side effects. Medium from trastuzumab-treated HUVECs apparently impaired the contractility of CCC-HEH-2 cells and iPSC-CMs. PTX3 from VECs caused defective cardiomyocyte contractility and cardiac dysfunction in mice, phenocopying trastuzumab treatment. PTX3 affected calcium homoeostasis in cardiomyocytes, which led to defective contractile properties. EGFR/STAT3 signalling in VECs contributed to the increased expression and release of PTX3. Notably, lapatinib, a dual inhibitor of EGFR/HER2, could rescue the cardiac complications caused by trastuzumab by blocking the release of PTX3. CONCLUSION: We identified a distinct mode of cardiotoxicity, wherein the activation of EGFR/STAT3 signalling by trastuzumab in VECs promotes PTX3 excretion, which contributes to the impaired contractility of cardiomyocytes by inhibiting cellular calcium signalling. We confirmed that lapatinib could be a feasible preventive agent against trastuzumab-induced cardiac complications and provided the rationale for the combined application of lapatinib and trastuzumab in cancer therapy.

Impact of Saussurea lappa root extract against copper oxide nanoparticles induced oxidative stress and toxicity in rat cardiac tissues.

Copper oxide nanoparticles (CuO NPs) have developed as a significant class of nanomaterial with potential dangers to organisms and the environment in a variety of applications. This study aimed to investigate the impact of costus root extract against CuO NPs induced oxidative stress, alterations in heart structure and functions. 40 adult male rats were assigned randomly to four groups: first; control, second; costus (300 mg/kg body weight/day) orally for 2 weeks, third; CuO NPs (100 mg/kg body weight/day) intraperitoneally for 4 weeks and fourth; CuO NPs + costus. Current results revealed, significant increases in serum levels of creatine kinase-MB, creatine kinase enzyme, lactate dehydrogenase, myoglobin, aspartate aminotransferase, alkaline phosphatase, cardiac TBIRS, total thiol, nitric oxide, and cardiac proliferating cell nuclear antigen after CuO NPs administration when compared with control group. Conversely, statistical significant decreases were detected in cardiac reduced glutathione, catalase, and superoxide dismutase in CuO NPs group as compared with control group. Interestingly, treatment of CuO NPs with costus root extract was associated with significant improvements of the studied parameters, heart structure and functions. CuO NPs-induced toxicity, injury and oxidative stress in rat heart and treatment with Costus root extract could scavenge free radicals producing beneficial effects against CuO NPs.

Evaluation of Ameliorative Effect of Quercetin and Candesartan in Doxorubicin-Induced Cardiotoxicity.

Background: Several mechanisms have been explored for the anthracycline myocardial toxicity. These are free-radical generation, myocyte apoptosis, lipid peroxidation, mitochondrial deterioration, and direct repression of muscle-specific gene expression. Adriamycin (Doxorubicin) is a potent anti-cancer agent. Adriamycin in prolonged use is fatal and generates free radicals that lead to dose-dependent cardiac toxicity. Objective: The intent of the study was to explore the protective activity of candesartan and quercetin in cardiomyopathy induced by doxorubicin in rats. Methods: To induce cardiac toxicity, rats were intraperitoneally treated with doxorubicin (06 equivalent injections of 2.5 mg/kg, i. p. at 48 hour interval for 02 consecutive weeks to achieve a cumulative dose of 15 mg/kg). Individual and combined oral treatment of candesartan (5 mg/kg/day) and quercetin (10 mg/kg/day) was administered for four weeks. Results: Following cardiomyopathy, heart/body weight ratio (3.526 × 10-3), serum creatine kinase (352.4±16.99 IU/L), lactate dehydrogenase (661.7±20.45 IU/L) levels were elevated in addition to altered lipid profile (TC - 118.4±4.25 mg/dL, TG - 263.3±9.99 mg/dL, VLDL - 52.66±1.99 mg/dL, LDL - 52.99±5.80 mg/dL and HDL - 12.78±0.36 mg/dL). The pre-cotreatment of candesartan and quercetin significantly restored the values to normal. The increased level of lipid peroxides (33.12±1.63 µmol/mg protein), serum troponin-T (1.82 ± 0.11 pg/mL) and nitric oxide (13.33±0.73 nmol/mg protein) level along with attenuating antioxidant profile, ie catalase, glutathione and superoxide dismutase (1.43±0.12 nmol/mg protein, 8.48±0.42 nmol/mg protein and 2.09±0.031 U/mg protein) were reversed to normal. Morphometry and histopathologic changes represented a beneficial effect of single and combination pre-cotreatment of drugs which significantly decreases adriamycin cardiac toxicity. Conclusion: The overall result depicts more beneficial and cardioprotective effect of quercetin and candesartan combination as compared to their individual effects in doxorubicin treated animals. Therefore, this combination might be a suitable option to treat the cardiotoxic effect of doxorubicin.

Dapagliflozin Guards Against Cadmium-Induced Cardiotoxicity via Modulation of IL6/STAT3 and TLR2/TNFα Signaling Pathways.

Cadmium (Cd) is a common environmental pollutant that leads to severe cardiotoxic hazards. Several studies were carried out to protect the myocardium against Cd-induced cardiotoxicity. Up till now, no researches evaluated the protective effect of dapagliflozin (DAP) against Cd induced cardiotoxicity. Thus, we aimed to explore the role of DAP in such model with deep studying of the involved mechanisms. 40 male Wistar albino rats were included in current study. Cd (5 mg/kg/day) was administered orally for 7 days to induce cardiotoxicity with or without co-administration of DAP in three different doses (2.5, 5, 10 mg/kg/day) orally for 7 days. Our data revealed that Cd could induce cardiotoxicity with significant increase in serum cardiac enzymes, heart weight, tissue malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), nuclear factor kappa B (NFκB), toll like receptor2 (TLR2), interleukin 6 (IL6) and caspase3 immunoexpression with abnormal histopathological changes. In addition, Cd significantly decreased the level of heme oxygenase1 (HO1), nuclear factor erythroid 2-related factor 2 (Nrf2), signal transducer and activator of transcription (STAT3), reduced glutathione (GSH), glutathione peroxidase (GPx), and total antioxidant capacity (TAC). Co-administration of DAP could ameliorate Cd cardiotoxicity with significant improvement of the biochemical and histopathological changes. We found that DAP had protective properties against Cd induced cardiotoxicity and this may be due to its anti-oxidant, anti-inflammatory, anti-apoptotic properties and modulation of IL6/STAT3 and TLR2/TNFα-signaling pathways.

[Honokiol reduces doxorubicin-induced cardiotoxicity in vitro by inhibiting pyroptosis via activating AMPK/Nrf2 signaling].

OBJECTIVE: To investigate the effect of honokiol (HKL) for reducing doxorubicin (DOX)-induced cardiotoxicity in H9c2 cells and the underlying mechanisms. METHODS: H9c2 cells were divided into control group, DOX group, HKL + DOX group, and HKL+compound C+DOX group. After 24 h of corresponding treatment, the cells were examined for morphological changes and cell viability using CCK-8 assay. The mRNA expressions of the inflammatory factors including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) were detected by RT-PCR, and the protein levels of cleaved caspase-3, cytochrome c, NOD-like receptor pyrin domain containing 3 (NLRP3), caspase-1, apoptosis-associated speck-like protein containing a CARD (ASC), p-AMPK and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) were detected with Western blotting; the expressions of NLRP3 and p-AMPK also detected with immunofluorescence staining. RESULTS: DOX treatment caused swelling and significantly lowered the viability of H9c2 cells (P < 0.05), resulting also in increased mRNA expressions of TNF-α, IL-6 and IL-1ß (P < 0.05) and protein expressions of cleaved caspase-3, cytochrome c, NLRP3, caspase-1 and ASC (P < 0.05) but reduced protein levels of p-AMPK and Nrf2 (P < 0.05); fluorescence staining showed significantly increased NLRP3 expression and decreased expression of p-AMPK in DOX-treated cells (P < 0.05). All these changes in COX-treated cells were significantly alleviated by HKL treatment (P < 0.05). The application of compound C obviously mitigated the protective effects of HKL against DOX-induced cardiotoxicity in H9c2 cells. CONCLUSIONS: HKL can alleviate DOX-induced cardiotoxicity by inhibiting pyroptosis in H9c2 cells, and this effect is mediated by activation of AMPK to regulate Nrf2 signaling.