Doxorubicin Cardiotoxicity Research Articles

Pyridoxamine Attenuates Doxorubicin-Induced Cardiomyopathy without Affecting Its Antitumor Effect on Rat Mammary Tumor Cells.

Doxorubicin (DOX) is commonly used in cancer treatment but associated with cardiotoxicity. Pyridoxamine (PM), a vitamin B6 derivative, could be a cardioprotectant. This study investigated the effect of PM on DOX cardiotoxicity and DOX antitumor effectiveness. Sprague Dawley rats were treated intravenously with DOX (2 mg/kg/week) or saline over eight weeks. Two other groups received PM via oral intake (1 g/L in water bottles) next to DOX or saline. Echocardiography was performed after eight weeks. PM treatment significantly attenuated the DOX-induced reduction in left ventricular ejection fraction (72 ± 2% vs. 58 ± 3% in DOX; p < 0.001) and increase in left ventricular end-systolic volume (0.24 ± 0.02 µL/cm2 vs. 0.38 ± 0.03 µL/cm2 in DOX; p < 0.0001). Additionally, LA7 tumor cells were exposed to DOX, PM, or DOX and PM for 24 h, 48 h, and 72 h. Cell viability, proliferation, cytotoxicity, and apoptosis were assessed. DOX significantly reduced LA7 cell viability and proliferation (p < 0.0001) and increased cytotoxicity (p < 0.05) and cleaved caspase-3 (p < 0.001). Concomitant PM treatment did not alter the DOX effect on LA7 cells. In conclusion, PM attenuated DOX-induced cardiomyopathy in vivo without affecting the antitumor effect of DOX in vitro, highlighting PM as a promising cardioprotectant for DOX-induced cardiotoxicity.

Electrocardiographic, biochemical, and scintigraphic evidence for the cardioprotective effect of paricalcitol and vitamin D3 on doxorubicin-induced acute cardiotoxicity in rats.

We aimed to investigate the possible cardioprotective effects of paricalcitol (PR), its vitamin Dreceptor agonist, and vitamin D3 (VIT-D3) on an experimental model of doxorubicin (DX) cardiotoxicity by 99mTc-PYP scintigraphy, electrocardiographic (ECG) and biochemical methods. Forty-two male Wistar/Albino rats (250‒300 g; aged 10‒12 weeks) were randomly separated into six groups, namely into control (CN), doxorubicin (DX), paricalcitol (PR), vitamin D3 (VIT-D3), paricalcitol + doxorubicin (PR+DX), and vitamin D3 + doxorubicin (VIT-D3+DX) groups. Cardiotoxicity was induced by three doses of DX (18 mg/kg, i.p.) at 24-hour intervals on days 18, 19 and 20. PR (0.5 ug/ kg, i.p) and VIT-D3 (5,000IU/kg, i.p) were injected for 20 days before and after the application of DX (18 mg/kg, i.p.). On day 21 of the experiment, biochemical parameters [tumor necrosis factor TNF-alpha (TNF-α); interleukin-6 (IL-6), nitric oxide (NO), and cardiac troponin T(cTnT)], as well as ECG and scintigraphic (99mTc-PYP) features were assessed. Compared to CN, DX significantly raised TNF-α, IL-6, and NO in heart tissue, cTnT in serum, 99mTc-PYP uptake in the myocardium, and ECG parameters, specifically QRS complex duration, QT interval duration, and ST-segment amplitude, while also reducing heart rate (p<0.001). Pretreatment with PR and VIT-D3 mitigated these abnormalities produced by DX in the heart (p<0.001). Results show that vitamin Dreceptor agonist paricalcitol and vitamin Dprotect against DX-induced cardiotoxicity through anti-inflammatory and antioxidant effects (Fig. 4, Ref. 59). Text in PDF www.elis.sk Keywords: paricalcitol, doxorubicin, vitamin D, ECG, 99mTc-PYP scintigraphy, cardiotoxicity, inflammation.

Carnosic acid mitigates doxorubicin-induced cardiac toxicity: Evidence from animal and cell model investigations.

Utilization of doxorubicin (DOX) as a chemotherapy medication is limited due to its cardiotoxic effects. Carnosic acid exerts antioxidant, anti-inflammatory, besides cytoprotective effects. The objective of this study was to investigate the ability of carnosic acid to protect rat hearts and the MCF7 cell line against cardiotoxicity induced by DOX. The study involved the classification of male Wistar rats into seven groups: 1) Control 2) DOX (2 mg/kg, every 48h, IP, 12d), 3-5) Carnosic acid (10, 20, 40 mg/kg/day, IP, 16d)+ DOX, 6) Vitamin E (200 mg/kg, every 48h, IP, 16d)+ DOX 7) Carnosic acid (40 mg/kg/day, IP, 16d). Finally, cardiac histopathological alterations, ECG factors, carotid blood pressure, left ventricular function, heart-to-body weight ratio, oxidative (MDA, GSH), inflammatory (IL-1β, TNF-α), plus apoptosis (caspase 3, 8, 9, Bcl-2, Bax) markers were evaluated. DOX toxicity and carnosic acid ameliorative effect were evaluated on MCF7 cells using the MTT assay. DOX augmented the QRS duration, QA, RRI, STI, and heart-to-body weight ratio, and reduced HR, LVDP, Min dP/dt, Max dP/dt, blood pressure, boosted MDA, TNF-α, IL1-β, caspase 3,8,9, Bax/Bcl-2 ratio, decreased GSH content, caused fibrosis, necrosis, and cytoplasmic vacuolization in cardiac tissue but carnosic acid administration reduced the toxic effects of DOX. The cytotoxic effects of DOX were not affected by carnosic acid at concentrations of 5 and 10 μM. Carnosic acid as an anti-inflammatory and antioxidant substance is effective in reducing DOX-induced damage by enhancing antioxidant defense and modifying inflammatory signal pathway activity and can be used as an adjunct in treating DOX cardiotoxicity.

Upregulation of TRIM16 mitigates doxorubicin-induced cardiotoxicity by modulating TAK1 and YAP/Nrf2 pathways in mice

The clinic application of doxorubicin (DOX) is severely limited by its severe cardiotoxicity. Tripartite motif-containing protein 16 (TRIM16) has E3 ubiquitin ligase activity and is upregulated in cardiomyocytes under pathological stress, yet its role in DOX-induced cardiotoxicity remains elusive. This study aims to investigate the role and mechanism of TRIM16 in DOX cardiotoxicity. Following TRIM16 overexpression in hearts with AAV9-TRIM16, mice were intravenously administered DOX at a dose of 4 mg/kg/week for 4 weeks to assess the impact of TRIM16 on doxorubicin-induced cardiotoxicity. Transfection of OE-TRIM16 plasmids and siRNA-TRIM16 was performed in neonatal rat cardiomyocytes (NRCMs). Our results revealed that DOX challenge elicited a significant upregulation of TRIM16 proteins in cardiomyocytes. TRIM16 overexpression efficiently ameliorated cardiac function while suppressing inflammation, ROS generation, apoptosis and fibrosis provoked by DOX in the myocardium. TRIM16 knockdown exacerbated these alterations caused by DOX in NRCMs. Mechanistically, OE-TRIM16 augmented the ubiquitination and degradation of p-TAK1, thereby arresting JNK and p38MAPK activation evoked by DOX in cardiomyocytes. Furthermore, DOX enhanced the interaction between p-TAK1 and YAP1 proteins, resulting in a reduction in YAP and Nrf2 proteins in cardiomyocytes. OE-TRIM16 elevated YAP levels and facilitated its nuclear translocation, thereby promoting Nrf2 expression and mitigating oxidative stress and inflammation. This effect was nullified by siTRIM16 or TAK1 inhibitor Takinib. Collectively, the current study elaborates that upregulating TRIM16 mitigates DOX-induced cardiotoxicity through anti-inflammation and anti-oxidative stress by modulating TAK1-mediated p38 and JNK as well as YAP/Nrf2 pathways, and targeting TRIM16 may provide a novel strategy to treat DOX-induced cardiotoxicity.

Comparison of bolus administration and short-term infusion versus long-term infusion of doxorubicin in terms of cardiotoxicity and efficacy.

Cardiotoxicity caused by anthracyclines chemotherapy is one of the leading causes of mortality and morbidity in cancer survivors. Continuous infusion (CI) instead of bolus (BOL) injection is one of the methods that seem to be effective in reducing doxorubicin (DOX) cardiotoxicity. Due to the variety of results, we decided to compare these two approaches regarding toxicity and efficacy and report the final results for different cancers. We included 21 studies (four preclinical and seventeen clinical trials) up to May 15, 2023. In children with acute lymphoblastic leukemia (ALL) and adults with chronic lymphoblastic leukemia (CLL) and gastric cancer, results were in favor of BOL injection, without increase in cardiotoxicity. On the other hand, CI showed to be better option in patients with small-cell lung cancer (SCLC) and breast cancer. Various results were also observed in adult patients with sarcoma. Overall, it can be concluded that the benefits of CI, especially in adults, outweigh its disadvantages. However, due to the variety of results and heterogeneity of studies, further clinical trials with a larger sample size and a longer duration of follow-up are needed to make a more accurate comparison between CI and BOL injection.

CYP2J2-derived epoxyeicosatrienoic acids protect against doxorubicin-induced cardiotoxicity by reducing oxidative stress and apoptosis via activation of the AMPK pathway

ObjectiveDespite the widespread use of doxorubicin (DOX) in chemotherapy, it can cause cardiotoxicity, which severely limits its potential clinical use. CYP2J2-derived epoxyeicosatrienoic acids (EETs) exert cardioprotective effects by maintaining cardiac homeostasis. The roles and latent mechanisms of EETs in DOX cardiotoxicity remain uncertain. We investigated these aspects using mouse tissue and cell culture models. MethodsC57BL/6J mice were injected with rAAV9-CYP2J2 or a control vector via the caudal vein. A five-week intraperitoneal course of DOX (5 mg/kg per week) was administered. After pretreatment with 14,15-EET, H9C2 cells were treated for 24-h with DOX, to use as a cell model to verify the role of EETs in cardiotoxicity in vitro. ResultsCYP2J2 overexpression mitigated DOX-induced cardiotoxicity, as shown by the diminished cardiac injury marker levels, improved heart function, reduced oxidative stress, and inhibition of myocardial apoptosis in vivo. These protective roles are associated with the enhancement of antioxidant and anti-apoptotic abilities and the activation of the AMPK pathway. 14,15-EET suppresses DOX-induced oxidative stress, mitochondrial dysfunction, and apoptosis in H9C2 cells. AMPK knockdown partially abolished the cardioprotective effects of 14,15-EET against oxidative damage and apoptosis in DOX-treated cells, suggesting that AMPK is responsible for EET-mediated protection against cardiotoxicity. ConclusionCYP2J2-derived EETs confer myocardial protection against DOX-induced toxicity by activating the AMPK pathway, which reduces oxidative stress, mitochondrial dysfunction, and apoptosis.

Protective Effect of Beta-CasomorPhin-7 on Oxidative Stress and Inflammatory Response in Adriamycin Cardiomyopathy

Adriamycin (ADR) is an anthracycline antibiotic with the advantages of wide anti-tumor spectrum and strong anti-tumor activity. It is one of the most effective anti-tumor drugs at present, and is widely used in the treatment of leukemia and various entities. Tumor. However, cardiotoxicity of doxorubicin can lead to irreversible myocardial damage, ultimately leading to dilated cardiomyopathy (DCM) or congestive heart failure (CHF). Therefore, to explore the mechanism of ADR-induced myocardial injury, and to find effective and effective protective drugs for the clinical expansion of doxorubicin application range is of great significance. We simulated the ADR myocardial injury model by in vivo and in vitro, and the degree of damage of cardiomyocytes by ADR was observed by detecting the corresponding biochemical indicators and tissue staining. And the expression levels of oxidative stress and inflammatory factors were detected by Western blotting and others methods. Beta-casomorPhin-7 can alleviate myocardial damage caused by ADR, inhibit the expression of oxidative stress and inflammation-related factors, and activate TLR4-MyD88-NF-κB signaling pathway. β-CM-7 inhibits ADR-induced cardiomyocyte oxidative stress and inflammatory responses by activating the TLR4-MyD88-NF-κB signaling pathway. This will provide a new intervention target for the treatment of DCM.

Recent Advances in the Mechanisms of Cell Death and Dysfunction in Doxorubicin Cardiotoxicity.

Despite recent advances in cancer therapy, anthracycline-based combination therapy remains the standardized first-line strategy and has been found to have effective antitumor actions. Anthracyclines are extremely cardiotoxic, which limits the use of these powerful chemotherapeutic agents. Although numerous studies have been conducted on the cardiotoxicity of anthracyclines, the precise mechanisms by which doxorubicin causes cardiomyocyte death and myocardial dysfunction remain incompletely understood. This review highlights recent updates in mechanisms and therapies involved in doxorubicin-induced cardiomyocyte death, including autophagy, ferroptosis, necroptosis, pyroptosis, and apoptosis, as well as mechanisms of cardiovascular dysfunction resulting in myocardial atrophy, defects in calcium handling, thrombosis, and cell senescence. We sought to uncover potential therapeutic approaches to manage anthracycline cardiotoxicity via manipulation of crucial targets involved in doxorubicin-induced cardiomyocyte death and dysfunction.

The Metabolic Fingerprint of Doxorubicin-Induced Cardiotoxicity in Male CD-1 Mice Fades Away with Time While Autophagy Increases.

The cardiotoxicity of doxorubicin (DOX) may manifest at the beginning/during treatment or years after, compromising patients' quality of life. We intended to study the cardiac pathways one week (short-term, control 1 [CTRL1] and DOX1 groups) or five months (long-term, CTRL2 and DOX2 groups) after DOX administration in adult male CD-1 mice. Control groups were given saline, and DOX groups received a 9.0 mg/Kg cumulative dose. In the short-term, DOX decreased the content of AMP-activated protein kinase (AMPK) while the electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) increased compared to CTRL1, suggesting the upregulation of fatty acids oxidation. Moreover, mitofusin1 (Mfn1) content was decreased in DOX1, highlighting decreased mitochondrial fusion. In addition, increased B-cell lymphoma-2 associated X-protein (BAX) content in DOX1 pointed to the upregulation of apoptosis. Conversely, in the long-term, DOX decreased the citrate synthase (CS) activity and the content of Beclin1 and autophagy protein 5 (ATG5) compared to CTRL2, suggesting decreased mitochondrial density and autophagy. Our study demonstrates that molecular mechanisms elicited by DOX are modulated at different extents over time, supporting the differences on clinic cardiotoxic manifestations with time. Moreover, even five months after DOX administration, meaningful heart molecular changes occurred, reinforcing the need for the continuous cardiac monitoring of patients and determination of earlier biomarkers before clinical cardiotoxicity is set.

SGLT2i Dapagliflozin decreases NLRP3, IL-1 and PCSK9 expression in preclinical models of short-term doxorubicin cardiotoxicity

Abstract Background Anthracyclines are an effective and widely used chemotherapy agent in the treatment of multiple solid organ tumors and hematologic malignancies. The use of anthracyclines as a standard cancer therapy is limited by the potential for the development of cardiac dysfunction, arrhythmias, and clinical heart failure. In recent five years, it was demonstrated that proprotein convertase subtilisin/kexin type 9 (PCSK9), a lipid metabolism-related protein, is a key orchestrator of immune infiltration in myocardial and cancer tissues and could regulate cardiac fibrosis and inflammation. PCSK9 is a protein with key roles in hepatic low density lipoprotein (LDL) homeostasis. PCSK9 systemic levels are associated to HOMA score and high insulin levels. Dapagliflozin exerts systemic ant-inflammatory properties and cardioprotective effects in diabetic and non-diabetic patients. Purpose We hypothesized that Dapagliflozin, administered during doxorubicin, could reduce PCSK9 systemic levels in preclinical models. Methods Female C57Bl/6 mice were untreated (Sham, n=6) or treated for 10 days with doxorubicin i.p at 2.17 mg/kg (DOXO, n=6), DAPA at 12 mg/kg (DAPA, n=6) or doxorubicin combined to DAPA (DOXO-DAPA, n=6). After treatments, plasma levels of PCSK9, IL-1β and CRP were analyzed through selective anti-mouse ELISA methods. Myocardial and liver expression of NLRP3-inflammasome and IL-1β were analyzed through ELISA method in tissue lysates after treatments. Results DAPA associated to DOXO reduces significantly systemic levels of PCSK9 ( -37,5% vs DOXO group, p&amp;lt;0,001). IL-1β and CRP levels were also reduced ( -47,3 and – 28,5 %, respectively; p&amp;lt;0.05 for both). Myocardial and liver IL-1β and NLRP3 inflammasome expression were also reduced in DAPA/DOXO group vs DOXO and control, indicated beneficial metabolic and anti-inflammatory effects of SGLT2i. Conclusion DAPA has been shown to reduce systemic levels of PCSK9 in preclinical models of short-term DOXO cardiotoxicity. To the best of our knowledge, this is the first evidence of SGLT-2/PCSK9 crass-talk in cardioncology therefore the overall picture of the study open a new window on the beneficial properties of DAPA against anthracyclines side effects.

Abstract 15199: Pyridoxamine Limits Mitochondria-Dependent Ferroptosis in a Rat Model of Doxorubicin-Induced Cardiotoxicity

Background: The use of doxorubicin (DOX) chemotherapy is limited by cardiotoxicity characterized by mitochondrial iron accumulation and ferroptosis, both interesting targets for cardioprotection. We found that pyridoxamine (PM) protects against DOX cardiotoxicity in rats. In this study, we hypothesized that PM is cardioprotective by restoring iron regulation and limiting mitochondria-dependent ferroptosis. Methods: Female Sprague Dawley rats of six weeks old were divided into a DOX group (2 mg/kg/week, 8 weeks, IV, N=7) or control group (CTRL, saline, N=7). Others were treated with PM via drinking water (1 g/L) while receiving DOX or saline (DOX+PM, N=9 and CTRL+PM, N=8). Iron regulation, lipid peroxidation and mitochondrial damage in cardiac tissue were evaluated by qPCR, 4-hydroxynonenal (4-HNE) staining and transmission electron microscopy. Data were compared by 1-way ANOVA or Kruskal-Wallis test with posthoc tests. P values are presented with a mean difference (MD) and [95% CI] or mean rank difference (MRD). Results: DOX significantly increased ZIP14 (P=0.049 vs CTRL, 11.20 MRD) and mitoferrin-1 expression (P=0.0002 vs CTRL, 1.49 MD [0.71, 2.28]), indicating increased cytosolic and mitochondrial iron import. The DOX group showed features of ferroptosis including swollen mitochondria with disrupted cristae (Fig. 1), decreased mitochondrial density (P=0.085 vs CTRL, –0.12 MD [–0.24, 0.01]) and increased 4-HNE levels (P=0.029 vs CTRL, 6.90 MD [0.56, 13.24]). PM treatment significantly decreased ZIP14 (P=0.0055 vs DOX, –12.90 MRD) and mitoferrin-1 expression (P=0.0008 vs DOX, –1.17 MD, [–1.88, –0.46]), indicating restored iron regulation. PM also significantly increased mitochondrial density (P=0.0028 vs DOX, 0.22 MD [0.06, 0.37]) and limited mitochondrial damage (Fig. 1). Conclusion: In conclusion, we show that PM limits DOX-induced mitochondria-dependent ferroptosis, and could be a promising cardioprotective strategy for cancer patients.

Abstract 12306: CREG1 Attenuates Doxorubicin-Induced Cardiotoxicity via Inhibiting the Ferroptosis of Cardiomyocytes

Introduction: Doxorubicin (DOX) is currently one of the most used anthracycline anticancer drugs. However, the cardiotoxicity of DOX limits its application in cancer patients. Cellular repressor of E1A-stimulated genes (CREG1) is an important cardioprotective factor. Hypothesis: We investigated the underlying effects and mechanism of of CREG1 in DOX-induced cardiotoxicity have not been reported. Methods: In vivo, a mouse DOX-induced cardiotoxicity model was established by DOX intraperitoneal injection, the mRNA and protein expression of CREG1 in the myocardium was examined using real-time PCR and western blot. CREG1 transgenic mice and cardiac-specific CREG1 knockout mice were used to establish DOX-induced cardiotoxicity model. HE staining, Masson staining, WGA staining and western blot were applied to examine fibrosis, myocardial hypertrophy and ferroptosis. In vitro, neonatal mouse cardiomyocytes (NMCMs) were stimulated with DOX, CREG1 overexpression adenovirus and small interfering RNA was used to examine the role of CREG1 on the ferroptosis of NMCMs. Results: In vivo, the mRNA and protein expression of CREG1 were significantly reduced in DOX-treated myocardium. CREG1 overexpression alleviated the myocardial damage induced by DOX, and CREG1 deficiency aggravated the DOX-induced cardiotoxicity. The abnormal increase in ferroptosis was shown in the DOX-treated heart tissues. CREG1 overexpression inhibited the ferroptosis, and CREG1 deficiency aggravated the ferroptosis induced by DOX. In vitro, the mRNA and protein of CREG1 was reduced in DOX-treated NMCMs. CREG1 overexpression reduced the ferroptosis of cardiomyocytes, CREG1 knockdown aggravated the ferroptosis of cardiomyocytes induced by DOX. Mechanically, CREG1 inhibited the mRNA and protein expression of pyruvate dehydrogenase kinase 4 (PDK4). The effect of CREG1 overexpression on ferroptosis of cardiomyocytes was reversed by PDK4 overexpression. Conclusion: CREG1 alleviated DOX-induced cardiotoxicity by inhibiting ferroptosis of cardiomyocytes. Our findings might help clarify new roles of CREG1 in the development of DOX-induced cardiotoxicity.

Sexual dimorphism in doxorubicin cardiotoxicity: two sides of a complex coin.

Sexual dimorphism in doxorubicin cardiotoxicity: two sides of a complex coin.

The Essential Strategies to Mitigate Cardiotoxicity Caused by Doxorubicin.

The study of mechanisms underlying cardiotoxicity of doxorubicin and the development of strategies to mitigate doxorubicin-induced cardiotoxicity are the most relevant issues of modern cardio-oncology. This is due to the high prevalence of cancer in the population and the need for frequent use of highly effective chemotherapeutic agents, in particular anthracyclines, for optimal management of cancer patients. However, while being a potent agent to counteract cancer, doxorubicin also affects the cardiovascular systems of patients undergoing chemotherapy in a significant and unfavorable fashion. Consecutively reviewed in this article are risk factors and mechanisms of doxorubicin cardiotoxicity, and the essential strategies to mitigate cardiotoxic effects of doxorubicin treatment in cancer patients are discussed.

Metformin mitigates doxorubicin-induced cardiotoxicity via the AMPK pathway

To explore whether metformin reduces cardiotoxicity of doxorubicin through the AMPK pathway. We analyzed the data of 123 patients with myeloid leukemia, non-Hodgkin's lymphoma, or breast cancer receiving doxorubicin for phased chemotherapy, including 43 patients receiving combined treatment with metformin (test group) and 80 without metformin treatment (control group). The changes in plasma levels of CK-MB, LDH, and BNP, left ventricular ejection fraction (EF) and left ventricular fractional shortening (FS) of the patients were observed. The effect of treatments with metformin and doxorubicin, alone or in combination, on myocardial damage, cardiac function and myocardial cell apoptosis were also observed in C57BL/6 mice with AMPKα2 gene knockout (AKO). CK-MB, LDH and BNP levels increased and EF and FS decreased significantly in the control group after chemotherapy (P<0.05). In the test group, CK-MB, LDH and BNP levels were significantly lowered after the combined treatment (P<0.05), while EF and FS did not undergo obvious changes (P>0.05). CK-MB, LDH and BNP levels were lower and EF and FS were higher significantly in the test group than in the control group after the treatment (P<0.05). Doxorubicin treatment reduced FS in both wild-type and AKO mice, but the reduction was less obvious in AKO group (P<0.05). The combined treatment restored FS in wild-type mice (P<0.05) but not in AKO mice. Doxorubicin significantly increased LDH and cTnI levels in both wild-type and AKO mice, but with smaller increments in the latter (P<0.05); The combined treatment with metformin reduced doxorubicin-induced elevation of LDH and cTnI levels in the wild-type mice (P<0.05) but not in AKO group (P>0.05). Doxorubicin increased myocardial cell apoptosis in both mice (P<0.01) but less strongly in AKO mice (P<0.05). Chemotherapy with doxorubicin causes cardiotoxicity, which can be mitigated by combined treatment with metformin possibly through a mechanism involving the AMPK pathway.

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.Graphical

Assessing the cardioprotective effect of necrosulfonamide in doxorubicin-induced cardiotoxicity in mice.

This study aimed to determine the cardioprotective effect of necrosulfonamide (NSA), a pyroptosis and necroptosis inhibitor, against acute doxorubicin cardiotoxicity. Fifteen male mice were divided into three groups (n=5/group). Cardiotoxicity was induced by a single intraperitoneal injection of 20 mg/kg of DOX on the 3rd day of the experiment. The control group received daily intraperitoneal (i.p.) injections of 5% DMSO for five consecutive days. The second group, the DOX group, received a single i.p. injection of 20 mg/kg DOX on the third day of the experiment. The third group, the DOX plus necrosulfonamide (NSA) group, received DOX injections like the second group and 5 mg/kg of NSA i.p. daily for five days, starting two days before the DOX injection. At the end of the study, animals were euthanized, and blood and tissue samples were collected. Various parameters, including cardiac troponin I (cTnI), TNF-α, IL-1β, caspase-1, glutathione peroxidase-4 (GPX-4), and hemeoxygenase 1 (Hmox-1), were measured using ELISA. Cardiac expression of the NF-κB gene was determined by RT-qPCR. A histopathological assessment of myocardial lesions was also performed. DOX administration significantly increased serum cTnI levels and tissue inflammatory biomarkers (TNF-α, IL-1β, caspase-1) while reducing tissue antioxidant enzymes (GPX-4, Hmox-1). In addition, it significantly increased nuclear factor-κB (NF-κB) gene expression compared to the control (about 10.5-fold elevation). Histopathological analysis revealed marked vacuolization and necrosis. However, pretreatment with NSA dramatically altered these findings, with serum cTnI levels significantly lower in this group compared to DOX. Inflammatory indicators decreased, and antioxidant enzymes were restored to varying degrees. NSA pretreatment downregulated NF-κβ gene expression and preserved near-normal myocardial morphology. Our results showed that NSA protected against DOX-induced cardiotoxicity, an effect likely mediated by its anti-pyroptotic, anti-necroptotic, and antioxidant properties.

TBC1D15 deficiency protects against doxorubicin cardiotoxicity via inhibiting DNA-PKcs cytosolic retention and DNA damage

Clinical application of doxorubicin (DOX) is heavily hindered by DOX cardiotoxicity. Several theories were postulated for DOX cardiotoxicity including DNA damage and DNA damage response (DDR), although the mechanism(s) involved remains to be elucidated. This study evaluated the potential role of TBC domain family member 15 (TBC1D15) in DOX cardiotoxicity. Tamoxifen-induced cardiac-specific Tbc1d15 knockout (Tbc1d15CKO) or Tbc1d15 knockin (Tbc1d15CKI) male mice were challenged with a single dose of DOX prior to cardiac assessment 1 week or 4 weeks following DOX challenge. Adenoviruses encoding TBC1D15 or containing shRNA targeting Tbc1d15 were used for Tbc1d15 overexpression or knockdown in isolated primary mouse cardiomyocytes. Our results revealed that DOX evoked upregulation of TBC1D15 with compromised myocardial function and overt mortality, the effects of which were ameliorated and accentuated by Tbc1d15 deletion and Tbc1d15 overexpression, respectively. DOX overtly evoked apoptotic cell death, the effect of which was alleviated and exacerbated by Tbc1d15 knockout and overexpression, respectively. Meanwhile, DOX provoked mitochondrial membrane potential collapse, oxidative stress and DNA damage, the effects of which were mitigated and exacerbated by Tbc1d15 knockdown and overexpression, respectively. Further scrutiny revealed that TBC1D15 fostered cytosolic accumulation of the cardinal DDR element DNA-dependent protein kinase catalytic subunit (DNA-PKcs). Liquid chromatography–tandem mass spectrometry and co-immunoprecipitation denoted an interaction between TBC1D15 and DNA-PKcs at the segment 594–624 of TBC1D15. Moreover, overexpression of TBC1D15 mutant (∆594–624, deletion of segment 594–624) failed to elicit accentuation of DOX-induced cytosolic retention of DNA-PKcs, DNA damage and cardiomyocyte apoptosis by TBC1D15 wild type. However, Tbc1d15 deletion ameliorated DOX-induced cardiomyocyte contractile anomalies, apoptosis, mitochondrial anomalies, DNA damage and cytosolic DNA-PKcs accumulation, which were canceled off by DNA-PKcs inhibition or ATM activation. Taken together, our findings denoted a pivotal role for TBC1D15 in DOX-induced DNA damage, mitochondrial injury, and apoptosis possibly through binding with DNA-PKcs and thus gate-keeping its cytosolic retention, a route to accentuation of cardiac contractile dysfunction in DOX-induced cardiotoxicity.

The role of inflammation and antioxidant defenses in the cardiotoxicity of doxorubicin in elderly CD-1 male mice

Doxorubicin (DOX) is a potent chemotherapeutic agent used against several cancer types. However, due to its cardiotoxic adverse effects, the use of this drug may be also life-threatening. Although most cancer patients are elderly, they are poorly represented and evaluated in pre-clinical and clinical studies. Considering this, the present work aims to evaluate inflammation and oxidative stress as the main mechanisms of DOX-induced cardiotoxicity, in an innovative approach using an experimental model constituted of elderly animals treated with a clinically relevant human cumulative dose of DOX. Elderly (18–20 months) CD-1 male mice received biweekly DOX administrations, for 3 weeks, to reach a cumulative dose of 9.0 mg/kg. One week (1W) or two months (2 M) after the last DOX administration, the heart was collected to determine both drug’s short and longer cardiac adverse effects. The obtained results showed that DOX causes cardiac histological damage and fibrosis at both time points. In the 1W-DOX group, the number of nuclear factor kappa B (NF-κB) p65 immunopositive cells increased and a trend toward increased NF-κB p65 expression was seen. An increase of inducible nitric oxide synthase (iNOS) and interleukin (IL)-33 and a trend toward increased IL-6 and B-cell lymphoma-2-associated X (Bax) expression were seen after DOX. In the same group, a decrease in IL-1β, p62, and microtubule-associated protein 1A/1B-light chain 3 (LC3)-I, p38 mitogen-activated protein kinase (MAPK) expression was observed. Contrariwise, the animals sacrificed 2 M after DOX showed a significant increase in glutathione peroxidase 1 and Bax expression with persistent cardiac damage and fibrosis, while carbonylated proteins, erythroid-2-related factor 2 (Nrf2), NF-κB p65, myeloperoxidase, LC3-I, and LC3-II expression decreased. In conclusion, our study demonstrated that in an elderly mouse population, DOX induces cardiac inflammation, autophagy, and apoptosis in the heart in the short term. When kept for a longer period, oxidative-stress-linked pathways remained altered, as well as autophagy markers and tissue damage after DOX treatment, emphasizing the need for continuous post-treatment cardiac monitoring.

Anthracycline cardiotoxicity is exacerbated by global p38b genetic ablation in a sexually dimorphic manner but unaltered by cardiomyocyte-specific p38a loss.

Severe cardiotoxic effects limit the efficacy of doxorubicin (DOX) as a chemotherapeutic agent. Activation of intracellular stress signaling networks, including p38 mitogen-activated protein kinase (MAPK), have been implicated in DOX-induced cardiotoxicity (DIC). However, the roles of the individual p38 isoforms in DIC remain incompletely elucidated. We recently reported that global p38d deletion protected female but not male mice from DIC, while global p38g deletion did not significantly modulate it. Here we studied the in vivo roles of p38a and p38b in acute DIC. Male and female mice with cardiomyocyte-specific deletion of p38a or global deletion of p38b and their wild-type counterparts were injected with DOX. Survival and health were tracked for 10 days post-injection. Cardiac function was assessed by echocardiography and electrocardiography, and fibrosis by Picro Sirius Red staining. Expression and activation of signaling proteins and inflammatory markers were measured by western blot, phosphorylation array and chemokine/cytokine array, respectively. Global p38b deletion significantly aggravated DIC and worsened cardiac electrical and mechanical function deterioration in female mice. Mechanistically, DIC in p38b-null female mice correlated with increased autophagy, sustained hyperactivation of pro-apoptotic JNK signaling, as well as remodeling of myocardial inflammatory environment. In contrast, cardiomyocyte-specific deletion of p38a improved survival of DOX30-treated male mice 5 days post-treatment but did not influence cardiac function in DOX-treated male or female mice. Our data highlight the sex- and isoform-specific roles of p38a and p38b MAPKs in DOX-induced cardiac injury and suggest a novel in vivo function of p38b in protecting female mice from DIC.