VEGF-B gene therapy inhibits doxorubicin-induced cardiotoxicity by endothelial protection

Cancer Therapy and Exercise Intolerance: The Heart Is But a Part: JACC: CardioOncology State-of-the-Art Review

The landscape of cancer therapeutics is continually evolving, with successes in improved survivorship and reduced disease progression for many patients with cancer. Improved cancer outcomes expose competing comorbidities, some of which may be exacerbated by cancer therapies. The leading cause of disability and death for many early-stage cancers is cardiovascular disease (CVD), which is often attributed to direct or indirect cardiac injury from cancer therapy. In this review, the authors propose that toxicities related to conventional and novel cancer therapeutics should be considered beyond the heart. The authors provide a framework using the oxygen pathway to understand the impact of cancer treatment on peak oxygen uptake, a marker of integrative cardiopulmonary function and CVD risk. Peripheral toxicities and the impact on oxygen transport are discussed. Consideration for the broad effects of cancer therapies will improve the prediction and identification of cancer survivors at risk for CVD, functional disability, and premature mortality and those who would benefit from therapeutic intervention, ultimately improving patient outcomes.

Anticancer drugs and cardiotoxicity: the role of cardiomyocyte and non-cardiomyocyte cells

Cardiotoxicity can be defined as "chemically induced heart disease", which can occur with many different drug classes treating a range of diseases. It is the primary cause of drug attrition during pre-clinical development and withdrawal from the market. Drug induced cardiovascular toxicity can result from both functional effects with alteration of the contractile and electrical regulation in the heart and structural changes with morphological changes to cardiomyocytes and other cardiac cells. These adverse effects result in conditions such as arrhythmia or a more serious reduction in left ventricular ejection fraction (LVEF), which can lead to heart failure and death. Anticancer drugs can adversely affect cardiomyocyte function as well as cardiac fibroblasts and cardiac endothelial cells, interfering in autocrine and paracrine signalling between these cell types and ultimately altering cardiac cellular homeostasis. This review aims to highlight potential toxicity mechanisms involving cardiomyocytes and non-cardiomyocyte cells by first introducing the physiological roles of these cells within the myocardium and secondly, identifying the physiological pathways perturbed by anticancer drugs in these cells.

A longitudinal evaluation of oxidative stress - mitochondrial dysfunction - ferroptosis genes in anthracycline-induced cardiotoxicity

BACKGROUND

Antineoplastic medications, including doxorubicin, idarubicin, and epirubicin, have been found to adversely affect the heart due to oxidative stress - mitochondrial dysfunction - ferroptosis (ORMFs), which act as contributing attributes to anthracycline-induced cardiotoxicity. To better understand this phenomenon, the time-resolved measurements of ORMFS genes were analyzed in this study.

METHODS

The effect of three anthracycline drugs on ORMFs genes was studied using a human 3D cardiac microtissue cell model. Transcriptome data was collected over 14 days at two doses (therapeutic and toxic). WGCNA identified key module-related genes, and functional enrichment analysis investigated the biological processes quantified by ssGSEA, such as immune cell infiltration and angiogenesis. Biopsies were collected from heart failure patients and control subjects. GSE59672 and GSE2965 were collected for validation. Molecular docking was used to identify anthracyclines's interaction with key genes.

RESULTS

The ORMFs genes were screened in vivo or in vitro. Using WGCNA, six co-expressed gene modules were grouped, with MEblue emerging as the most significant module. Eight key genes intersecting the blue module with the dynamic response genes were obtained: CD36, CDH5, CHI3L1, HBA2, HSD11B1, OGN, RPL8, and VWF. Compared with control samples, all key genes except RPL8 were down-regulated in vitro ANT treatment settings, and their expression levels varied over time. According to functional analyses, the key module-related genes were engaged in angiogenesis and the immune system pathways. In all ANT-treated settings, ssGSEA demonstrated a significant down-regulation of angiogenesis score and immune cell activity, including Activated CD4 T cell, Immature B cell, Memory B cell, Natural killer cell, Type 1 T helper cell, and Type 2 T helper cell. Molecular docking revealed that RPL8 and CHI3L1 show significant binding affinity for anthracyclines.

CONCLUSION

This study focuses on the dynamic characteristics of ORMFs genes in both human cardiac microtissues and cardiac biopsies from ANT-treated patients. It has been highlighted that ORMFs genes may contribute to immune infiltration and angiogenesis in cases of anthracycline-induced cardiotoxicity. A thorough understanding of these genes could potentially lead to improved diagnosis and treatment of the disease.

Single-Cell Transcriptomic Analysis Reveals Myocardial Fibrosis Mechanism of Doxorubicin-Induced Cardiotoxicity

Myocardial fibrosis is a pathological feature of doxorubicin-induced chronic cardiotoxicity that severely affects the prognosis of oncology patients. However, the specific cellular and molecular mediators driving doxorubicin-induced cardiac fibrosis, and the relative impact of different cell populations on cardiac fibrosis, remain unclear.This study aimed to explore the mechanism of doxorubicin-induced cardiotoxicity and myocardial fibrosis and to find potential therapeutic targets. Single-cell RNA sequencing was used to analyze the transcriptome of non-cardiomyocytes from normal and doxorubicin-induced chronic cardiotoxicity in mouse model heart tissue.We established a mouse model of doxorubicin-induced cardiotoxicity with a well-defined fibrotic phenotype. Analysis of single-cell sequencing results showed that fibroblasts were the major origin of extracellular matrix in doxorubicin-induced myocardial fibrosis. Further resolution of fibroblast subclusters showed that resting fibroblasts were converted to matrifibrocytes and then to myofibroblasts to participate in the myocardial remodeling process in response to doxorubicin treatment. Ctsb expression was significantly upregulated in fibroblasts after doxorubicin-induced.This study provides a comprehensive map of the non-cardiomyocyte landscape at high resolution, reveals multiple cell populations contributing to pathological remodeling of the cardiac extracellular matrix, and identifies major cellular sources of myofibroblasts and dynamic gene-expression changes in fibroblast activation. Finally, we used this strategy to detect potential therapeutic targets and identified Ctsb as a specific target for fibroblasts in doxorubicin-induced myocardial fibrosis.

Cardiomyocytes, cardiac endothelial cells and fibroblasts contribute to anthracycline-induced cardiac injury through RAS-homologous small GTPases RAC1 and CDC42

The clinical use of the DNA damaging anticancer drug doxorubicin (DOX) is limited by irreversible cardiotoxicity, which depends on the cumulative dose. The RAS-homologous (RHO) small GTPase RAC1 contributes to DOX-induced DNA damage formation and cardiotoxicity. However, the pathophysiological relevance of other RHO GTPases than RAC1 and different cardiac cell types (i.e., cardiomyocytes, non-cardiomyocytes) for DOX-triggered cardiac damage is unclear. Employing diverse in vitro and in vivo models, we comparatively investigated the level of DOX-induced DNA damage in cardiomyocytes versus non-cardiomyocytes (endothelial cells and fibroblasts), in the presence or absence of selected RHO GTPase inhibitors. Non-cardiomyocytes exhibited the highest number of DOX-induced DNA double-strand breaks (DSB), which were efficiently repaired in vitro. By contrast, rather low levels of DSB were formed in cardiomyocytes, which however remained largely unrepaired. Moreover, DOX-induced apoptosis was detected only in non-cardiomyocytes but not in cardiomyocytes. Pharmacological inhibitors of RAC1 and CDC42 most efficiently attenuated DOX-induced DNA damage in all cell types examined in vitro. Consistently, immunohistochemical analyses revealed that the RAC1 inhibitor NSC23766 and the pan-RHO GTPase inhibitor lovastatin reduced the level of DOX-induced residual DNA damage in both cardiomyocytes and non-cardiomyocytes in vivo. Overall, we conclude that endothelial cells, fibroblasts and cardiomyocytes contribute to the pathophysiology of DOX-induced cardiotoxicity, with RAC1- and CDC42-regulated signaling pathways being especially relevant for DOX-stimulated DSB formation and DNA damage response (DDR) activation. Hence, we suggest dual targeting of RAC1/CDC42-dependent mechanisms in multiple cardiac cell types to mitigate DNA damage-dependent cardiac injury evoked by DOX-based anticancer therapy.

Voluntary wheel running reduces tumor growth and increases capillarity in the heart during doxorubicin chemotherapy in a murine model of breast cancer

Introduction: The possible beneficial effects of physical activity during doxorubicin treatment of breast cancer need further investigation as many of the existing studies have been done on non-tumor-bearing models. Therefore, in this study, we aim to assess whether short-term voluntary wheel-running exercise during doxorubicin treatment of breast cancer-bearing mice could induce beneficial cardiac effects and enhance chemotherapy efficacy. Methods: Murine breast cancer I3TC cells were inoculated subcutaneously to the flank of female FVB mice (n = 16) that were divided into exercised and non-exercised groups. Two weeks later, doxorubicin treatment was started via intraperitoneal administration (5 mg/kg weekly for 3 weeks). Organs were harvested a day after the last dose. Results: The tumor volume over time was significantly different between the groups, with the exercising group having lower tumor volumes. The exercised group had increased body weight gain, tumor apoptosis, capillaries per cardiomyocytes, and cardiac lactate dehydrogenase activity compared to the unexercised group, but tumor blood vessel density and maturation and tumor and cardiac HIF1-α and VEGF-A levels did not differ from those of the non-exercised group. Discussion: We conclude that even short-term light exercise such as voluntary wheel running exercise can decrease the subcutaneous mammary tumor growth, possibly via increased tumor apoptosis. The increase in cardiac capillaries per cardiomyocytes may also have positive effects on cancer treatment outcomes.

Anthracycline Cardiotoxicity Induces Progressive Changes in Myocardial Metabolism and Mitochondrial Quality Control: Novel Therapeutic Target

Background

Anthracycline-induced cardiotoxicity (AIC) debilitates quality of life in cancer survivors. Serial characterizations are lacking of the molecular processes occurring with AIC.

Objectives

The aim of this study was to characterize AIC progression in a mouse model from early (subclinical) to advanced heart failure stages, with an emphasis on cardiac metabolism and mitochondrial structure and function.

Methods

CD1 mice received 5 weekly intraperitoneal doxorubicin injections (5 mg/kg) and were followed by serial echocardiography for 15 weeks. At 1, 9, and 15 weeks after the doxorubicin injections, mice underwent fluorodeoxyglucose positron emission tomography, and hearts were extracted for microscopy and molecular analysis.

Results

Cardiac atrophy was evident at 1 week post-doxorubicin (left ventricular [LV] mass 117 ± 26 mg vs 97 ± 25 mg at baseline and 1 week, respectively; P < 0.001). Cardiac mass nadir was observed at week 3 post-doxorubicin (79 ± 16 mg; P = 0.002 vs baseline), remaining unchanged thereafter. Histology confirmed significantly reduced cardiomyocyte area (167 ± 19 μm2 in doxorubicin-treated mice vs 211 ± 26 μm2 in controls; P = 0.004). LV ejection fraction declined from week 6 post-doxorubicin (49% ± 9% vs 61% ± 9% at baseline; P < 0.001) until the end of follow-up at 15 weeks (43% ± 8%; P < 0.001 vs baseline). At 1 week post-doxorubicin, when LV ejection fraction remained normal, reduced cardiac metabolism was evident from down-regulated markers of fatty acid oxidation and glycolysis. Metabolic impairment continued to the end of follow-up in parallel with reduced mitochondrial adenosine triphosphate production. A transient early up-regulation of nutrient-sensing and mitophagy markers were observed, which was associated with mitochondrial enlargement. Later stages, when mitophagy was exhausted, were characterized by overt mitochondrial fragmentation.

Conclusions

Cardiac atrophy, global hypometabolism, early transient-enhanced mitophagy, biogenesis, and nutrient sensing constitute candidate targets for AIC prevention.

The VEGFs/VEGFRs system in Alzheimer's and Parkinson's diseases: Pathophysiological roles and therapeutic implications

The vascular endothelial growth factors (VEGFs) and their cognate receptors (VEGFRs), besides their well-known involvement in physiological angiogenesis/lymphangiogenesis and in diseases associated to pathological vessel formation, play multifaceted functions in the central nervous system (CNS). In addition to shaping brain development, by controlling cerebral vasculogenesis and regulating neurogenesis as well as astrocyte differentiation, the VEGFs/VEGFRs axis exerts essential functions in the adult brain both in physiological and pathological contexts. In this article, after describing the physiological VEGFs/VEGFRs functions in the CNS, we focus on the VEGFs/VEGFRs involvement in neurodegenerative diseases by reviewing the current literature on the rather complex VEGFs/VEGFRs contribution to the pathogenic mechanisms of Alzheimer's (AD) and Parkinson's (PD) diseases. Thereafter, based on the outcome of VEGFs/VEGFRs targeting in animal models of AD and PD, we discuss the factual relevance of pharmacological VEGFs/VEGFRs modulation as a novel and potential disease-modifying approach for these neurodegenerative pathologies. Specific VEGFRs targeting, aimed at selective VEGFR-1 inhibition, while preserving VEGFR-2 signal transduction, appears as a promising strategy to hit the molecular mechanisms underlying AD pathology. Moreover, therapeutic VEGFs-based approaches can be proposed for PD treatment, with the aim of fine-tuning their brain levels to amplify neurotrophic/neuroprotective effects while limiting an excessive impact on vascular permeability.

The Transcriptome Analysis of Circular RNAs Between the Doxorubicin- Induced Cardiomyocytes and Bone Marrow Mesenchymal Stem Cells- Derived Exosomes Treated Ones

AIM

To analyze the sequencing results of circular RNAs (circRNAs) in cardiomyocytes between the doxorubicin (DOX)-injured group and exosomes treatment group. Moreover, to offer potential circRNAs possibly secreted by exosomes mediating the therapeutic effect on DOX-induced cardiotoxicity for further study.

METHODS

The DOX-injured group (DOX group) of cardiomyocytes was treated with DOX, while an exosomes-treated group of injured cardiomyocytes were cocultured with bone marrow mesenchymal stem cells (BMSC)-derived exosomes (BEC group). The high-throughput sequencing of circRNAs was conducted after the extraction of RNA from cardiomyocytes. The differential expression of circRNA was analyzed after identifying the number, expression, and conservative of circRNAs. Then, the target genes of differentially expressed circRNAs were predicted based on the targetscan and Miranda database. Next, the GO and KEGG enrichment analyses of target genes of circRNAs were performed. The crucial signaling pathways participating in the therapeutic process were identified. Finally, a real-time quantitative polymerase chain reaction experiment was conducted to verify the results obtained by sequencing.

RESULTS

Thirty-two circRNAs are differentially expressed between the two groups, of which twenty-three circRNAs were elevated in the exosomes-treated group (BEC group). The GO analysis shows that target genes of differentially expressed circRNAs are mainly enriched in the intracellular signalactivity, regulation of nucleic acid-templated transcription, Golgi-related activity, and GTPase activator activity. The KEGG analysis displays that they were involved in the autophagy biological process and NOD-like receptor signaling pathway. The verification experiment suggested that mmu_circ_0000425 (ID: 116324210) was both decreased in the DOX group and elevated in BEC group, which was consistent with the result of sequencing.

CONCLUSION

mmu_circ_0000425 in exosomes derived from bone marrow mesenchymal stem cells (BMSC) may have a therapeutic role in alleviating doxorubicin-induced cardiotoxicity (DIC).

Advances in the study of exosomes in cardiovascular diseases

BACKGROUND

Cardiovascular disease (CVD) has been the leading cause of death worldwide for many years. In recent years, exosomes have gained extensive attention in the cardiovascular system due to their excellent biocompatibility. Studies have extensively researched miRNAs in exosomes and found that they play critical roles in various physiological and pathological processes in the cardiovascular system. These processes include promoting or inhibiting inflammatory responses, promoting angiogenesis, participating in cell proliferation and migration, and promoting pathological progression such as fibrosis.

AIM OF REVIEW

This systematic review examines the role of exosomes in various cardiovascular diseases such as atherosclerosis, myocardial infarction, ischemia-reperfusion injury, heart failure and cardiomyopathy. It also presents the latest treatment and prevention methods utilizing exosomes. The study aims to provide new insights and approaches for preventing and treating cardiovascular diseases by exploring the relationship between exosomes and these conditions. Furthermore, the review emphasizes the potential clinical use of exosomes as biomarkers for diagnosing cardiovascular diseases.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Exosomes are nanoscale vesicles surrounded by lipid bilayers that are secreted by most cells in the body. They are heterogeneous, varying in size and composition, with a diameter typically ranging from 40 to 160 nm. Exosomes serve as a means of information communication between cells, carrying various biologically active substances, including lipids, proteins, and small RNAs such as miRNAs and lncRNAs. As a result, they participate in both physiological and pathological processes within the body.

Early skeletal muscle loss in adolescent and young adult cancer patients treated with anthracycline chemotherapy

BACKGROUND

Early skeletal muscle loss has been observed in adolescent and young adult (AYA) sarcoma patients undergoing treatment. Identification of individuals within the AYA populace that are at greatest risk of anthracycline-induced skeletal muscle loss is unknown. Moreover, investigations which seek out underlying causes of skeletal muscle degradation during chemotherapy are critical for understanding, preventing, and reducing chronic health conditions associated with poor skeletal muscle status.

METHODS

Computed tomography (CT) scans were used to investigate changes in skeletal muscle of 153 AYA sarcoma and Hodgkin lymphoma patients at thoracic vertebra 4 after anthracycline treatment. Images were examined at three time points during the first year of treatment. In parallel, we used translational juvenile mouse models to assess the impact of doxorubicin (DOX) in the soleus and gastrocnemius on muscle wasting.

RESULTS

Significant reductions in total skeletal muscle index and density were seen after chemotherapy in AYA cancer patients (p < 0.01 & p = 0.04, respectively). The severity of skeletal muscle loss varied by subgroup (i.e., cancer type, sex, and treatment). Murine models demonstrated a reduction in skeletal muscle fiber cross-sectional area, increased apoptosis and collagen volume for both the soleus and gastrocnemius after DOX treatment (all p < 0.05). After DOX, hindlimb skeletal muscle blood flow was significantly reduced (p < 0.01).

CONCLUSION

Significant skeletal muscle loss is experienced early during treatment in AYA cancer patients. Reductions in skeletal muscle blood flow may be a key contributing factor to anthracycline doxorubicin induced skeletal muscle loss.

A TRANSCRIPTOMIC APPRECIATION OF CHILDHOOD MENINGOCOCCAL AND POLYMICROBIAL SEPSIS FROM A PRO-INFLAMMATORY AND TRAJECTORIAL PERSPECTIVE, A ROLE FOR VASCULAR ENDOTHELIAL GROWTH FACTOR A AND B MODULATION?

ABSTRACT

This study investigated the temporal dynamics of childhood sepsis by analyzing gene expression changes associated with proinflammatory processes. Five datasets, including four meningococcal sepsis shock (MSS) datasets (two temporal and two longitudinal) and one polymicrobial sepsis dataset, were selected to track temporal changes in gene expression. Hierarchical clustering revealed three temporal phases: early, intermediate, and late, providing a framework for understanding sepsis progression. Principal component analysis supported the identification of gene expression trajectories. Differential gene analysis highlighted consistent upregulation of vascular endothelial growth factor A (VEGF-A) and nuclear factor κB1 (NFKB1), genes involved in inflammation, across the sepsis datasets. NFKB1 gene expression also showed temporal changes in the MSS datasets. In the postmortem dataset comparing MSS cases to controls, VEGF-A was upregulated and VEGF-B downregulated. Renal tissue exhibited higher VEGF-A expression compared with other tissues. Similar VEGF-A upregulation and VEGF-B downregulation patterns were observed in the cross-sectional MSS datasets and the polymicrobial sepsis dataset. Hexagonal plots confirmed VEGF-R (VEGF receptor)-VEGF-R2 signaling pathway enrichment in the MSS cross-sectional studies. The polymicrobial sepsis dataset also showed enrichment of the VEGF pathway in septic shock day 3 and sepsis day 3 samples compared with controls. These findings provide unique insights into the dynamic nature of sepsis from a transcriptomic perspective and suggest potential implications for biomarker development. Future research should focus on larger-scale temporal transcriptomic studies with appropriate control groups and validate the identified gene combination as a potential biomarker panel for sepsis.

The Role of Epithelial Mesenchymal Transition (EMT) in Pathogenesis of Cardiotoxicity: Diagnostic & Prognostic Approach

Cancer is one of the diseases, which it is not still completely curable; the existing treatments are associated with many complications, that double its complexity. One of the causes of cancer cell metastasis is Epithelial Mesenchymal Transition (EMT). Recently study demonstrated that EMT cause cardiotoxicity and heart diseases such as heart failure, hypertrophy and fibrosis. This study evaluated molecular and signaling pathway, which lead to cardiotoxicity via EMT. It was demonstrated that the processes of inflammation, oxidative stress and angiogenesis were involved in EMT and cardiotoxicity. The pathways related to these processes act as a double-edged sword. In relation to inflammation and oxidative stress, molecular pathways caused apoptosis of cardiomyocytes and cardiotoxicity induction. While the angiogenesis process inhibits cardiotoxicity despite the progression of EMT. On the other hand, some molecular pathways such as PI3K/mTOR despite causing the progression of EMT lead to the proliferation of cardiomyocytes and prevent cardiotoxicity. Therefore, it was concluded that the identification of molecular pathways can help in designing therapeutic and preventive strategies to increase patients' survival.

VEGF-B prevents excessive angiogenesis by inhibiting FGF2/FGFR1 pathway

Although VEGF-B was discovered as a VEGF-A homolog a long time ago, the angiogenic effect of VEGF-B remains poorly understood with limited and diverse findings from different groups. Notwithstanding, drugs that inhibit VEGF-B together with other VEGF family members are being used to treat patients with various neovascular diseases. It is therefore critical to have a better understanding of the angiogenic effect of VEGF-B and the underlying mechanisms. Using comprehensive in vitro and in vivo methods and models, we reveal here for the first time an unexpected and surprising function of VEGF-B as an endogenous inhibitor of angiogenesis by inhibiting the FGF2/FGFR1 pathway when the latter is abundantly expressed. Mechanistically, we unveil that VEGF-B binds to FGFR1, induces FGFR1/VEGFR1 complex formation, and suppresses FGF2-induced Erk activation, and inhibits FGF2-driven angiogenesis and tumor growth. Our work uncovers a previously unrecognized novel function of VEGF-B in tethering the FGF2/FGFR1 pathway. Given the anti-angiogenic nature of VEGF-B under conditions of high FGF2/FGFR1 levels, caution is warranted when modulating VEGF-B activity to treat neovascular diseases.

An integrative review of nonobvious puzzles of cellular and molecular cardiooncology

Oncologic patients are subjected to four major treatment types: surgery, radiotherapy, chemotherapy, and immunotherapy. All nonsurgical forms of cancer management are known to potentially violate the structural and functional integrity of the cardiovascular system. The prevalence and severity of cardiotoxicity and vascular abnormalities led to the emergence of a clinical subdiscipline, called cardiooncology. This relatively new, but rapidly expanding area of knowledge, primarily focuses on clinical observations linking the adverse effects of cancer therapy with deteriorated quality of life of cancer survivors and their increased morbidity and mortality. Cellular and molecular determinants of these relations are far less understood, mainly because of several unsolved paths and contradicting findings in the literature. In this article, we provide a comprehensive view of the cellular and molecular etiology of cardiooncology. We pay particular attention to various intracellular processes that arise in cardiomyocytes, vascular endothelial cells, and smooth muscle cells treated in experimentally-controlled conditions in vitro and in vivo with ionizing radiation and drugs representing diverse modes of anti-cancer activity.

Reduction-responsive dextran-based Pt(IV) nano-prodrug showed a synergistic effect with doxorubicin for effective melanoma treatment

Melanoma, the deadliest skin cancer with high metastasis potential, has posed a great threat to human health. Accordingly, early efficient blocking of melanoma progression is vital in antitumor treatment. Herein, a reduction-responsive dextran-based Pt(IV) nano-prodrug (PDPN) was synthesized and used for doxorubicin (DOX) delivery to combat melanoma synergistically. First, PDPN was prepared by one-pot chemical coupling of carboxylated methoxy poly(ethylene glycol) (mPEG), dextran (Dex), and the crosslinking agent cisPt (IV)-COOH. PDPN had a spherical structure (R_h = 34 ± 11.3 nm). Then, DOX was encapsulated into the PDPN core to form DOX-loaded PDPN (PDPN-DOX). The obtained PDPN-DOX displayed reduction-responsive release of DOX and Pt, thus showing a synergistic anticancer effect in B16F10 cells (combination index, 0.46). Furthermore, in vivo experiments demonstrated that PDPN-DOX was effective for the synergistic treatment of subcutaneous melanoma. Collectively, the as-prepared PDPN could serve as a promising and versatile nano-prodrug carrier for the co-delivery of chemotherapeutics in tumor combination therapy.

Therapeutic opportunities for senolysis in cardiovascular disease

Cellular senescence within the cardiovascular system has, until recently, been understudied and unappreciated as a factor in the development of age-related cardiovascular diseases such as heart failure, myocardial infarction and atherosclerosis. This is in part due to challenges with defining senescence within post-mitotic cells such as cardiomyocytes. However, recent evidence has demonstrated senescent-like changes, including a senescence-associated secretory phenotype (SASP), in cardiomyocytes in response to ageing and cell stress. Other replicating cells, including fibroblasts and vascular smooth muscle cells, within the cardiovascular system have also been shown to undergo senescence and contribute to disease pathogenesis. These findings coupled with the emergence of senolytic therapies, to target and eliminate senescent cells, have provided fascinating new avenues for management of several age-related cardiovascular diseases with high prevalence. In this review, we discuss the role of senescent cells within the cardiovascular system and highlight the contribution of senescence cells to common cardiovascular diseases. We discuss the emerging role for senolytics in cardiovascular disease management while highlighting important aspects of senescence biology which must be clarified before the potential of senolytics can be fully realized.

Endothelial-to-Mesenchymal Transition: Potential Target of Doxorubicin-Induced Cardiotoxicity

The use of chemotherapeutic agents is becoming more frequent as the proportion of new oncology patients increases worldwide, with prolonged survival after treatment. As one of the most popular chemotherapy drugs, doxorubicin plays a substantial role in the treatment of tumors. Unfortunately, the use of doxorubicin is associated with several adverse effects, particularly severe cardiotoxicity that can be life-threatening, which greatly limits its clinical use. For decades, scientists have tried to explore many cardioprotective agents and therapeutic approaches, but their efficacy remains controversial, and some drugs have even brought about significant adverse effects. The concrete molecular mechanism of doxorubicin-induced cardiotoxicity is still to be unraveled, yet endothelial damage is gradually being identified as an important mechanism triggering the development and progression of doxorubicin-induced cardiotoxicity. Endothelial-to-mesenchymal transition (EndMT), a fundamental process regulating morphogenesis in multicellular organisms, is recognized to be associated with endothelial damage repair and acts as an important factor in the progression of cardiovascular diseases, tumors, and rheumatic immune diseases. Mounting evidence suggests that endothelial-mesenchymal transition may play a non-negligible role in doxorubicin-induced cardiotoxicity. In this paper, we reviewed the molecular mechanisms and signaling pathways of EndMT and outlined the molecular mechanisms of doxorubicin-induced cardiotoxicity and the current therapeutic advances. Furthermore, we summarized the basic principles of doxorubicin-induced endothelial-mesenchymal transition that lead to endothelial dysfunction and cardiotoxicity, aiming to provide suggestions or new ideas for the prevention and treatment of doxorubicin-induced endothelial and cardiac injury.

Early and dynamic detection of doxorubicin induced cardiotoxicity by myocardial contrast echocardiography combined with two-dimensional speckle tracking echocardiography in rats

Background

Anthracycline-induced cardiotoxicity is well-known as a side effect of chemotherapy. Currently, clinical imaging techniques are not capable to detect doxorubicin (DOX)-induced cardiotoxicity before a functional decline. The purpose of this study was to evaluate whether myocardial contrast echocardiography (MCE) can dynamically monitor the cardiac changes in the early stage in the DOX-induced rat model of cardiotoxicity.

Methods

A weekly injection of 2.5 mg/kg of DOX was used to generate a rat model of cardiotoxicity. All groups underwent ultrasonic examinations including standard echocardiography, 2D speckle tracking echocardiography (2D-STE), and MCE. Then all rats were sacrificed immediately for histopathological evaluation.

Results

A total of eight control rats and 32 DOX-treated rats were included in the study and grouped according to their treatment period. Decreased quantitative parameters of myocardial blood flow (MBF) (control vs. group 1: 133.31 ± 20.23 dB/s vs. 103.35 ± 21.60 dB/s, P = 0.048) and β (control vs. group 2: 11.17 ± 1.48/s vs. 7.15 ± 1.23/s, P < 0.001) were observed after 2 and 4 weeks of treatment, respectively, while left ventricular global strain (control vs. group 3: -23.67 ± 3.92% vs. -16.01 ± 3.40%, P = 0.002) decreased after 6 weeks of treatment and left ventricular ejection fraction (LVEF) (control vs. group 4: 82.41 ± 3.20% vs. 70.89 ± 9.30%, P = 0.008) decreased after 8 weeks of treatment. The main histopathological features are increased myocardial vacuolization and interstitial fibrosis and decreased myocardial microvessel density.

Conclusion

Compared with standard echocardiography and 2D-STE, MCE can accurately and non-invasively detect changes in early myocardial perfusion, demonstrating the clinical potential of continuous and dynamic monitoring of DOX-induced cardiotoxicity.

Metformin Alleviates Epirubicin-Induced Endothelial Impairment by Restoring Mitochondrial Homeostasis

Vascular endothelial injury is important in anthracycline-induced cardiotoxicity. Anthracyclines seriously damage the mitochondrial function and mitochondrial homeostasis. In this study, we investigated the damage of epirubicin to vascular endothelial cells and the protective role of metformin from the perspective of mitochondrial homeostasis. We found that epirubicin treatment resulted in DNA double-strand breaks (DSB), elevated reactive oxygen species (ROS) production, and excessive Angiotensin II release in HUVEC cells. Pretreatment with metformin significantly mitigated the injuries caused by epirubicin. In addition, inhibited expression of Mitochondrial transcription factor A (TFAM) and increased mitochondria fragmentation were observed in epirubicin-treated cells, which were partially resumed by metformin pretreatment. In epirubicin-treated cells, knockdown of TFAM counteracted the attenuated DSB formation due to metformin pretreatment, and inhibition of mitochondrial fragmentation with Mdivi-1 decreased DSB formation but increased TFAM expression. Furthermore, epirubicin treatment promoted mitochondrial fragmentation by stimulating the expression of Dynamin-1-like protein (DRP1) and inhibiting the expression of Optic atrophy-1(OPA1) and Mitofusin 1(MFN1), which could be partially prevented by metformin. Finally, we found metformin could increase TFAM expression and decrease DRP1 expression in epirubicin-treated HUVEC cells by upregulating the expression of calcineurin/Transcription factor EB (TFEB). Taken together, this study provided evidence that metformin treatment was an effective way to mitigate epirubicin-induced endothelial impairment by maintaining mitochondrial homeostasis.

Smad3 promotes adverse cardiovascular remodeling and dysfunction in doxorubicin-treated hearts

Many anticancer therapies cause serious cardiovascular complications that degrade quality of life and cause early mortality in treated patients. Specifically, doxorubicin is known as an effective anticancer agent that causes cardiomyopathy in treated patients. There has been growing interest in defining the role of endothelial cells in cardiac damage by doxorubicin. We have shown in the present study that endothelial nuclei accumulate more intravenously administered doxorubicin than other cardiac cell types. Doxorubicin enhanced cardiac production of the transforming growth factor-β (TGF-β) ligands and nuclear translocation of phospho-Smad3 in both cultured and in vivo cardiac endothelial cells. To examine the role of the TGF-β/mothers against decapentaplegic homolog 3 (Smad3) pathway in cardiac damage by doxorubicin, we used both Smad3 shRNA stable endothelial cell lines and Smad3-knockout mice. We demonstrated using endothelial transcriptome analysis that upregulation of the TGF-β and inflammatory cytokine/cytokine receptor pathways, as well as suppression of cell cycle and angiogenesis by doxorubicin, were alleviated in Smad3-deficient endothelial cells. The results of transcriptomic analysis were validated using qPCR, immunoblotting, and ex vivo aortic ring sprouting assays. Similarly, increased cardiac expression of cytokines and chemokines observed in treated wild-type mice was diminished in treated Smad3-knockout animals. We also detected increased end-diastolic diameter and depressed systolic function in doxorubicin-treated wild-type but not Smad3-knockout mice. This work provides evidence for the critical role of the canonical TGF-β/Smad3 pathway in cardiac damage by doxorubicin.NEW & NOTEWORTHY Microvascular endothelial cells in the heart accumulate more intravenously administered doxorubicin than nonendothelial cardiac cell types. The treatment enhanced the TGF-β/Smad3 pathway and elicited endothelial cell senescence and inflammatory responses followed by adverse cardiac remodeling and dysfunction in wild-type but not Smad3-deficient animals. Our study suggests that the TGF-β/Smad3 pathway contributes to the development of doxorubicin cardiomyopathy and the potential value of novel approaches to ameliorate cardiotoxicity by targeting the Smad3 transcription factor.

Role of non-cardiomyocytes in anticancer drug-induced cardiotoxicity: A systematic review

Cardiotoxicity induced by anticancer drugs interferes with the continuation of optimal treatment, inducing life-threatening risks or leading to long-term morbidity. The heart is a complex pluricellular organ comprised of cardiomyocytes and non-cardiomyocytes. Although the study of these cell populations has been often focusing on cardiomyocytes, the contributions of non-cardiomyocytes to development and disease are increasingly being appreciated as both dynamic and essential. This review summarized the role of non-cardiomyocytes in anticancer drug-induced cardiotoxicity, including the mechanism of direct damage to resident non-cardiomyocytes, cardiomyocytes injury caused by paracrine modality, myocardial inflammation induced by transient cell populations and the protective agents that focused on non-cardiomyocytes.

Integrated multi-omics analysis of adverse cardiac remodeling and metabolic inflexibility upon ErbB2 and ERRα deficiency

Functional oncogenic links between ErbB2 and ERRα in HER2+ breast cancer patients support a therapeutic benefit of co-targeted therapies. However, ErbB2 and ERRα also play key roles in heart physiology, and this approach could pose a potential liability to cardiovascular health. Herein, using integrated phosphoproteomic, transcriptomic and metabolic profiling, we uncovered molecular mechanisms associated with the adverse remodeling of cardiac functions in mice with combined attenuation of ErbB2 and ERRα activity. Genetic disruption of both effectors results in profound effects on cardiomyocyte architecture, inflammatory response and metabolism, the latter leading to a decrease in fatty acyl-carnitine species further increasing the reliance on glucose as a metabolic fuel, a hallmark of failing hearts. Furthermore, integrated omics signatures of ERRα loss-of-function and doxorubicin treatment exhibit common features of chemotherapeutic cardiotoxicity. These findings thus reveal potential cardiovascular risks in discrete combination therapies in the treatment of breast and other cancers.

Murine hearts deficient in ErbB2 and/or ERRα are used to profile the adverse cardiac remodeling associated with potential targeted breast cancer treatments by phosphoproteomic, transcriptomic and metabolomic profiling.

Long noncoding RNA NONMMUT015745 inhibits doxorubicin-mediated cardiomyocyte apoptosis by regulating Rab2A-p53 axis

Doxorubicin (DOX) is an efficacious and widely used drug for human malignancy treatment, but its clinical application is limited due to side effects, especially cardiotoxicity. Our present study revealed that DOX could induce apoptosis in cardiomyocytes. Herein, we screened the dysregulated long noncoding RNAs (lncRNAs) in DOX-treated cardiomyocytes. Notably, overexpression of lncRNA NONMMUT015745 (lnc5745) could alleviate DOX-induced cardiomyocyte apoptosis both in vitro and in vivo. Conversely, silencing lnc5745 promotes cardiomyocyte apoptosis. Moreover, Rab2A, a direct target of lnc5745, possesses a protective effect in DOX-induced cardiotoxicity once knocked down. Importantly, we verified that the p53-related apoptotic signalling pathway was responsible for the lnc5745-mediated protective role against DOX-induced cardiomyocyte apoptosis. Mechanistically, Rab2A interacts with p53 and phosphorylated p53 on Ser 33 (p53 (Phospho-Ser 33)), promotes p53 phosphorylation, thereby activating the apoptotic pathway. Taken together, our results suggested that lnc5745 protects against DOX-induced cardiomyocyte apoptosis through suppressing Rab2A expression, modifying p53 phosphorylation, thereby regulating p53-related apoptotic signalling pathway. Our findings establish the functional mode of the lnc5745-Rab2A-p53 axis in DOX-induced cardiotoxicity. The development of new strategies targeting the lnc5745-Rab2A-p53 axis could attenuate DOX-induced cardiotoxicity, which is beneficial to its clinical anti-tumour application.

Role of VEGFB in electrical pulse stimulation inhibits apoptosis in C2C12 myotubes

Skeletal muscle is the major effector organ for exercise. It has been proposed that VEGFB is significantly related to apoptosis in various cell types but not yet in skeletal muscle. We hypothesize that the decrease of VEGFB in skeletal muscle participates in the occurrence of skeletal muscle apoptosis and that exercise inhibits apoptosis by elevating the expression of VEGFB in skeletal muscle cells. Based on this hypothesis, we developed in vitro experiments to mimic the effect of exercise through electrical pulse stimulation (EPS) to observe the effect of EPS on apoptosis and the change in VEGFB expression in differentiated myotubes. In addition, we employed RNA interference to explore whether VEGFB is directly involved in the regulation of myotube apoptosis during EPS. Our results showed that exogenous VEGFB₁₆₇ significantly inhibited C2C12 myotube apoptosis induced by TNF-α treatment and that endogenous VEGFB in differentiated C2C12 myotubes was significantly upregulated by EPS. In addition, EPS significantly changed the expression of the apoptotic indicators Bax and Bcl-2 at the mRNA level and downregulated the protein expression of cleaved caspase-3. The antiapoptotic effect of EPS weakened substantially as VEGFB in C2C12 myotubes was inhibited. Taken together, these results indicate that exercise-like EPS inhibits apoptosis by increasing the expression of C2C12 myotube-derived VEGFB.

Doxorubicin-Induced Cardiotoxicity May Be Alleviated by Bone Marrow Mesenchymal Stem Cell-Derived Exosomal lncRNA via Inhibiting Inflammation

Purpose

To explore the therapeutic mechanism of bone marrow mesenchymal stem cells derived exosomes (BMSC-Exos) for doxorubicin (DOX)-induced cardiotoxicity (DIC) and identify the long noncoding RNAs’ (lncRNAs’) anti-inflammation function derived by BMSC-Exos.

Materials and Methods

High-throughput sequencing and transcriptome bioinformatics analysis of lncRNA were performed between DOX group and BEC (bone marrow mesenchymal stem cells derived exosomes coculture) group. Elevated lncRNA (ElncRNA) in the cardiomyocytes of BEC group compared with DOX group were confirmed. Based on the location and co-expression relationship between ElncRNA and its target genes, we predicted two target genes of ElncRNA, named cis_targets and trans_targets. The target genes were analyzed by enrichment analyses. Then, we identified the key cellular biological pathways regulating DIC. Experiments were performed to verify the therapeutic effects of exosomes and the origin of lncRNAs in vitro and in vivo.

Results

Three hundred and one lncRNAs were differentially expressed between DOX and BEC groups (fold change >1.5 and p < 0.05), of which 169 lncRNAs were elevated in the BEC group compared with the DOX group. GO enrichment analysis of target genes of ElncRNAs showed that they were predominantly involved in inflammation-associated processes. KEGG analysis indicated that their regulatory pathways were mainly involved in oxidative stress-induced inflammation and proliferation of cardiomyocyte. The verification experiments in vitro showed that the oxidative stress and cell deaths were decreased in BEC groups. Moreover, from the top 10 ElncRNAs identified in the sequencing results, MSTRG.98097.4 and MSTRG.58791.2 were both decreased in the DOX group and elevated in BEC group. While in verification experiments in vivo, only the expression of MSTRG.58791.2 is consistent with the result in vitro.

Conclusion

Our results show that ElncRNA, MSTRG.58791.2, is possibly secreted by the BMSC-Exos and able to alleviate DIC by suppressing inflammatory response and inflammation-related cell death.

Novel Cardiac Computed Tomography Methods for the Assessment of Anthracycline Induced Cardiotoxicity

Anthracyclines are among the most frequently utilized anti-cancer therapies; however, their use is frequently associated with off-target cardiotoxic effects. Cardiac computed tomography (CCT) is a validated and rapidly evolving technology for the evaluation of cardiac structures, coronary anatomy and plaque, cardiac function and preprocedural planning. However, with emerging new techniques, CCT is rapidly evolving to offer information beyond the evaluation of cardiac structure and epicardial coronary arteries to provide details on myocardial deformation, extracellular volume, and coronary vasoreactivity. The potential for molecular imaging in CCT is also growing. In the current manuscript we review these emerging computed tomography techniques and their potential role in the evaluation of anthracycline-induced cardiotoxicity.

Elabela ameliorates doxorubicin-induced cardiotoxicity by promoting autophagic flux through TFEB pathway

Doxorubicin (DOX) is a widely used and effective antineoplastic drug; however, its clinical application is limited by cardiotoxicity. A safe and effective strategy to prevent from doxorubicin-induced cardiotoxicity (DIC) is still beyond reach. Elabela (ELA), a new APJ ligand, has exerted cardioprotective effect against multiple cardiovascular diseases. Here, we asked whether ELA alleviates DIC. Mice were injected with DOX to established acute DIC. In vivo studies were assessed with echocardiography, serum cTnT and CK-MB, HW/BW ratio and WGA staining. Cell death and atrophy were measured by AM/PI staining and phalloidin staining respectively in vitro. Autophagic flux was monitored with Transmission electron microscopy in vivo, as well as LysoSensor and mRFP-GFP-LC3 puncta in vitro. Our results showed that ELA improved cardiac dysfunction in DIC mice. ELA administration also attenuated cell death and atrophy in DOX-challenged neonatal rat cardiomyocytes (NRCs). Additionally, we found that ELA restored DOX-induced autophagic flux blockage, which was evidenced by the reverse of p62 and LC3II, improvement of lysosome function and accelerated degradation of accumulated autolysosomes. Chloroquine, a classical autophagic flux inhibitor, blunted the improvement of ELA on cardiac dysfunction. At last, we revealed that ELA reversed DOX-induced downregulation of transcription factor EB (TFEB), and silencing TFEB by siRNA abrogated the effects of ELA on autophagic flux as well as cell death and atrophy in NRCs. In conclusion, this study indicated that ELA ameliorated DIC through enhancing autophagic flux via activating TFEB. ELA may become a potential target against DIC.

Multimodality Advanced Cardiovascular and Molecular Imaging for Early Detection and Monitoring of Cancer Therapy-Associated Cardiotoxicity and the Role of Artificial Intelligence and Big Data

Cancer mortality has improved due to earlier detection via screening, as well as due to novel cancer therapies such as tyrosine kinase inhibitors and immune checkpoint inhibitions. However, similarly to older cancer therapies such as anthracyclines, these therapies have also been documented to cause cardiotoxic events including cardiomyopathy, myocardial infarction, myocarditis, arrhythmia, hypertension, and thrombosis. Imaging modalities such as echocardiography and magnetic resonance imaging (MRI) are critical in monitoring and evaluating for cardiotoxicity from these treatments, as well as in providing information for the assessment of function and wall motion abnormalities. MRI also allows for additional tissue characterization using T1, T2, extracellular volume (ECV), and delayed gadolinium enhancement (DGE) assessment. Furthermore, emerging technologies may be able to assist with these efforts. Nuclear imaging using targeted radiotracers, some of which are already clinically used, may have more specificity and help provide information on the mechanisms of cardiotoxicity, including in anthracycline mediated cardiomyopathy and checkpoint inhibitor myocarditis. Hyperpolarized MRI may be used to evaluate the effects of oncologic therapy on cardiac metabolism. Lastly, artificial intelligence and big data of imaging modalities may help predict and detect early signs of cardiotoxicity and response to cardioprotective medications as well as provide insights on the added value of molecular imaging and correlations with cardiovascular outcomes. In this review, the current imaging modalities used to assess for cardiotoxicity from cancer treatments are discussed, in addition to ongoing research on targeted molecular radiotracers, hyperpolarized MRI, as well as the role of artificial intelligence (AI) and big data in imaging that would help improve the detection and prognostication of cancer-treatment cardiotoxicity.

Current insights into cellular senescence and myotoxicity induced by doxorubicin

Doxorubicin is an anti-neoplasmic drug that prevents DNA replication but induces senescence and cellular toxicity. Intensive research has focused on strategies to alleviate the doxorubicin-induced skeletal myotoxicity. The aim of the present review is to critically discuss the relevant scientific evidence about the role of exercise and growth factor administration and offer novel insights about newly developed-tools to combat the adverse drug reactions of doxorubicin treatment on skeletal muscle. In the first part, we discuss current data and mechanistic details on the impact of doxorubicin on skeletal myotoxicity. We next, review key aspects about the role of regular exercise and the impact of growth factors either administered pharmacologically or via genetic interventions. Future strategies such as combination of exercise and growth factor administration remain to be established to combat the pharmacologically-induced myotoxicity.

Cardiomyocyte Atrophy, an Underestimated Contributor in Doxorubicin-Induced Cardiotoxicity

Left ventricular (LV) mass loss is prevalent in doxorubicin (DOX)-induced cardiotoxicity and is responsible for the progressive decline of cardiac function. Comparing with the well-studied role of cell death, the part of cardiomyocyte atrophy (CMA) playing in the LV mass loss is underestimated and the knowledge of the underlying mechanism is still limited. In this review, we summarized the recent advances in the DOX-induced CMA. We found that the CMA caused by DOX is associated with the upregulation of FOXOs and “atrogenes,” the activation of transient receptor potential canonical 3-NADPH oxidase 2 (TRPC3-Nox2) axis, and the suppression of IGF-1-PI3K signaling pathway. The imbalance of anabolic and catabolic process may be the common final pathway of these mechanisms. At last, we provided some strategies that have been demonstrated to alleviate the DOX-induced CMA in animal models.

Novel Mechanisms of Anthracycline-Induced Cardiovascular Toxicity: A Focus on Thrombosis, Cardiac Atrophy, and Programmed Cell Death

Anthracycline antineoplastic agents such as doxorubicin are widely used and highly effective component of adjuvant chemotherapy for breast cancer and curative regimens for lymphomas, leukemias, and sarcomas. The primary dose-limiting adverse effect of anthracyclines is cardiotoxicity that typically manifests as cardiomyopathy and can progress to the potentially fatal clinical syndrome of heart failure. Decades of pre-clinical research have explicated the complex and multifaceted mechanisms of anthracycline-induced cardiotoxicity. It is well-established that oxidative stress contributes to the pathobiology and recent work has elucidated important central roles for direct mitochondrial injury and iron overload. Here we focus instead on emerging aspects of anthracycline-induced cardiotoxicity that may have received less attention in other recent reviews: thrombosis, myocardial atrophy, and non-apoptotic programmed cell death.

Potential Applications for Targeted Gene Therapy to Protect Against Anthracycline Cardiotoxicity: JACC: CardioOncology Primer

Anthracyclines are associated with risk of significant dose-dependent cardiotoxicity. Conventional heart failure therapies have neither ameliorated declining cardiac function nor addressed the underlying cause. Gene therapy may confer long-term cardioprotection by rendering the heart resistant to anthracyclines after 1 treatment, although the optimal therapeutic target remains to be elucidated. Recombinant adeno-associated virus is now clinically approved for the treatment of lipoprotein lipase deficiency, spinal muscular atrophy, and hereditary transthyretin amyloidosis. High-throughput methods allow selection of recombinant adeno-associated virus capsids that facilitate efficient gene delivery to specific target cells. Vector safety is enhanced by incorporating cardiac-specific promoters into vector design and localizing delivery to reduce off-target risk. Any cardioprotective transgene may bear a degree of risk as they may play as yet unknown roles, which require careful assessment using clinically relevant models. The innovative technologies outlined here make gene therapy a promising proof of principle, with potential further application to nonanthracycline chemotherapeutics.

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Protection against anthracycline cardiotoxicity may be achieved by gene delivery to the heart.

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The optimal cardioprotective target gene remains to be identified.

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Targeted gene expression in human myocytes can now be achieved with advances in AAV vectorology.

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It is critical to minimize risk of off-target effects which may impede anthracycline oncotherapy.

Establishment of an in vitro safety assessment model for lipid-lowering drugs using same-origin human pluripotent stem cell-derived cardiomyocytes and endothelial cells

Cardiovascular safety assessment is vital for drug development, yet human cardiovascular cell models are lacking. In vitro mass-generated human pluripotent stem cell (hPSC)-derived cardiovascular cells are a suitable cell model for preclinical cardiovascular safety evaluations. In this study, we established a preclinical toxicology model using same-origin hPSC-differentiated cardiomyocytes (hPSC-CMs) and endothelial cells (hPSC-ECs). For validation of this cell model, alirocumab, a human antibody against proprotein convertase subtilisin kexin type 9 (PCSK9), was selected as an emerging safe lipid-lowering drug; atorvastatin, a common statin (the most effective type of lipid-lowering drug), was used as a drug with reported side effects at high concentrations, while doxorubicin was chosen as a positive cardiotoxic drug. The cytotoxicity of these drugs was assessed using CCK8, ATP, and lactate dehydrogenase release assays at 24, 48, and 72 h. The influences of these drugs on cardiomyocyte electrophysiology were detected using the patch-clamp technique, while their effects on endothelial function were determined by tube formation and Dil-acetylated low-density lipoprotein (Dil-Ac-LDL) uptake assays. We showed that alirocumab did not affect the cell viability or cardiomyocyte electrophysiology in agreement with the clinical results. Atorvastatin (5-50 μM) dose-dependently decreased cardiovascular cell viability over time, and at a high concentration (50 μM, ~100 times the normal peak serum concentration in clinic), it affected the action potentials of hPSC-CMs and damaged tube formation and Dil-Ac-LDL uptake of hPSC-ECs. The results demonstrate that the established same-origin hPSC-derived cardiovascular cell model can be used to evaluate lipid-lowering drug safety in cardiovascular cells and allow highly accurate preclinical assessment of potential drugs.

REDD1 is a determinant of low-dose metronomic doxorubicin-elicited endothelial cell dysfunction through downregulation of VEGFR-2/3 expression

Low-dose metronomic chemotherapy (LDMC) inhibits tumor angiogenesis and growth by targeting tumor-associated endothelial cells, but the molecular mechanism has not been fully elucidated. Here, we examined the functional role of regulated in development and DNA damage responses 1 (REDD1), an inhibitor of mammalian target of rapamycin complex 1 (mTORC1), in LDMC-mediated endothelial cell dysfunction. Low-dose doxorubicin (DOX) treatment induced REDD1 expression in cultured vascular and lymphatic endothelial cells and subsequently repressed the mRNA expression of mTORC1-dependent translation of vascular endothelial growth factor receptor (Vegfr)-2/3, resulting in the inhibition of VEGF-mediated angiogenesis and lymphangiogenesis. These regulatory effects of DOX-induced REDD1 expression were additionally confirmed by loss- and gain-of-function studies. Furthermore, LDMC with DOX significantly suppressed tumor angiogenesis, lymphangiogenesis, vascular permeability, growth, and metastasis in B16 melanoma-bearing wild-type but not Redd1-deficient mice. Altogether, our findings indicate that REDD1 is a crucial determinant of LDMC-mediated functional dysregulation of tumor vascular and lymphatic endothelial cells by translational repression of Vegfr-2/3 transcripts, supporting the potential therapeutic properties of REDD1 in highly progressive or metastatic tumors.

Breast cancer chemotherapy vascular toxicity: a review of mediating mechanisms and exercise as a potential therapeutic

Breast cancer chemotherapy, although very potent against tumour tissue, results in significant cardiovascular toxicity. The focus of research in this area has been predominantly towards cardiotoxicity. There is limited evidence detailing the impact of such treatment on the vasculature despite its central importance within the cardiovascular system and resultant detrimental effects of damage and dysfunction. This review highlights the impact of chemotherapy for breast cancer on the vascular endothelium. We consider the most likely mechanisms of endothelial toxicity to be through direct damage and dysfunction of the endothelium. There are sharp consequences of these detrimental effects as they can lead to cardiovascular disease. However, there is potential for exercise to alleviate some of the vascular toxicity of chemotherapy, and the evidence for this is provided. The potential role of exercise in protecting against vascular toxicity is explained, highlighting the recent in-human and animal model exercise interventions. Lastly, the mediating mechanisms of exercise protection of endothelial health is discussed, focusing on the importance of exercise for endothelial health, function, repair, inflammation and hyperlipidaemia, angiogenesis, and vascular remodelling. These are all important counteracting measures against chemotherapy-induced toxicity and are discussed in detail.

Irisin ameliorates doxorubicin-induced cardiac perivascular fibrosis through inhibiting endothelial-to-mesenchymal transition by regulating ROS accumulation and autophagy disorder in endothelial cells

The dose-dependent toxicity to cardiomyocytes has been well recognized as a central characteristic of doxorubicin (DOX)-induced cardiotoxicity (DIC), however, the pathogenesis of DIC in the cardiac microenvironment remains elusive. Irisin is a new hormone-like myokine released into the circulation in response to exercise with distinct functions in regulating apoptosis, inflammation, and oxidative stress. Recent advances revealed the role of irisin as a novel therapeutic method and an important mediator of the beneficial effects of exercise in cardioprotection. Here, by using a low-dose long-term mouse DIC model, we found that the perivascular fibrosis was involved in its myocardial toxicity with the underlying mechanism of endothelial-to-mesenchymal transition (EndMT). Irisin treatment could partially reverse DOX-induced perivascular fibrosis and cardiotoxicity compared to endurance exercise. Mechanistically, DOX stimulation led to excessive accumulation of ROS, which activated the NF-κB-Snail pathway and resulted in EndMT. Besides, dysregulation of autophagy was also found in DOX-treated endothelial cells. Restoring autophagy flux could ameliorate EndMT and eliminate ROS. Irisin treatment significantly alleviated ROS accumulation, autophagy disorder, NF-κB-Snail pathway activation as well as the phenotype of EndMT by targeting uncoupling protein 2 (UCP2). Our results also initially found that irisin was mainly secreted by cardiomyocytes in the cardiac microenvironment, which was significantly reduced by DOX intervention, and had a protective effect on endothelial cells in a paracrine manner. In summary, our study indicated that DOX-induced ROS accumulation and autophagy disorders caused an EndMT in CMECs, which played a role in the perivascular fibrosis of DIC. Irisin treatment could partially reverse this phenomenon by regulating UCP2. Cardiomyocytes were the main source of irisin in the cardiac microenvironment. The current study provides a novel perspective elucidating the pathogenesis and the potential treatment of DIC.

Low-dose metronomic doxorubicin inhibits mobilization and differentiation of endothelial progenitor cells through REDD1-mediated VEGFR-2 downregulation

Low-dose metronomic chemotherapy has been introduced as a less toxic and effective strategy to inhibit tumor angiogenesis, but its anti-angiogenic mechanism on endothelial progenitor cells (EPCs) has not been fully elucidated. Here, we investigated the functional role of regulated in development and DNA damage response 1 (REDD1), an endogenous inhibitor of mTORC1, in low-dose doxorubicin (DOX)-mediated dysregulation of EPC functions. DOX treatment induced REDD1 expression in bone marrow mononuclear cells (BMMNCs) and subsequently reduced mTORC1-dependent translation of endothelial growth factor (VEGF) receptor (Vegfr)-2 mRNA, but not that of the mRNA transcripts for Vegfr-1, epidermal growth factor receptor, and insulin-like growth factor-1 receptor. This selective event was a risk factor for the inhibition of BMMNC differentiation into EPCs and their angiogenic responses to VEGF-A, but was not observed in Redd1-deficient BMMNCs. Low-dose metronomic DOX treatment reduced the mobilization of circulating EPCs in B16 melanoma-bearing wild-type but not Redd1-deficient mice. However, REDD1 overexpression inhibited the differentiation and mobilization of EPCs in both wild-type and Redd1-deficient mice. These data suggest that REDD1 is crucial for metronomic DOX-mediated EPC dysfunction through the translational repression of Vegfr-2 transcript, providing REDD1 as a potential therapeutic target for the inhibition of tumor angiogenesis and tumor progression.

Low-dose metronomic doxorubicin inhibits mobilization and differentiation of endothelial progenitor cells through REDD1-mediated VEGFR-2 downregulation

Low-dose metronomic chemotherapy has been introduced as a less toxic and effective strategy to inhibit tumor angiogenesis, but its anti-angiogenic mechanism on endothelial progenitor cells (EPCs) has not been fully elucidated. Here, we investigated the functional role of regulated in development and DNA damage response 1 (REDD1), an endogenous inhibitor of mTORC1, in low-dose doxorubicin (DOX)-mediated dysregulation of EPC functions. DOX treatment induced REDD1 expression in bone marrow mononuclear cells (BMMNCs) and subsequently reduced mTORC1-dependent translation of endothelial growth factor (VEGF) receptor (Vegfr)-2 mRNA, but not that of the mRNA transcripts for Vegfr-1, epidermal growth factor receptor, and insulin-like growth factor-1 receptor. This selective event was a risk factor for the inhibition of BMMNC differentiation into EPCs and their angiogenic responses to VEGF-A, but was not observed in Redd1-deficient BMMNCs. Low-dose metronomic DOX treatment reduced the mobilization of circulating EPCs in B16 melanoma-bearing wild-type but not Redd1-deficient mice. However, REDD1 overexpression inhibited the differentiation and mobilization of EPCs in both wild-type and Redd1-deficient mice. These data suggest that REDD1 is crucial for metronomic DOX-mediated EPC dysfunction through the translational repression of Vegfr-2 transcript, providing REDD1 as a potential therapeutic target for the inhibition of tumor angiogenesis and tumor progression. [BMB Reports 2021; 54(9): 470-475].

Updates on Anticancer Therapy-Mediated Vascular Toxicity and New Horizons in Therapeutic Strategies

Vascular toxicity is a frequent adverse effect of current anticancer chemotherapies and often results from endothelial dysfunction. Vascular endothelial growth factor inhibitors (VEGFi), anthracyclines, plant alkaloids, alkylating agents, antimetabolites, and radiation therapy evoke vascular toxicity. These anticancer treatments not only affect tumor vascularization in a beneficial manner, they also damage ECs in the heart. Cardiac ECs have a vital role in cardiovascular functions including hemostasis, inflammatory and coagulation responses, vasculogenesis, and angiogenesis. EC damage can be resulted from capturing angiogenic factors, inhibiting EC proliferation, survival and signal transduction, or altering vascular tone. EC dysfunction accounts for the pathogenesis of myocardial infarction, atherothrombosis, microangiopathies, and hypertension. In this review, we provide a comprehensive overview of the effects of chemotherapeutic agents on vascular toxicity leading to hypertension, microvascular rarefaction thrombosis and atherosclerosis, and affecting drug delivery. We also describe the potential therapeutic approaches such as vascular endothelial growth factor (VEGF)-B and prokineticin receptor-1 agonists to maintain endothelial function during or following treatments with chemotherapeutic agents, without affecting anti-tumor effectiveness.

Molecular mechanisms of anthracycline cardiovascular toxicity

Anthracyclines are effective chemotherapeutic agents, commonly used in the treatment of a variety of hematologic malignancies and solid tumors. However, their use is associated with a significant risk of cardiovascular toxicities and may result in cardiomyopathy and heart failure. Cardiomyocyte toxicity occurs via multiple molecular mechanisms, including topoisomerase II-mediated DNA double-strand breaks and reactive oxygen species (ROS) formation via effects on the mitochondrial electron transport chain, NADPH oxidases (NOXs), and nitric oxide synthases (NOSs). Excess ROS may cause mitochondrial dysfunction, endoplasmic reticulum stress, calcium release, and DNA damage, which may result in cardiomyocyte dysfunction or cell death. These pathophysiologic mechanisms cause tissue-level manifestations, including characteristic histopathologic changes (myocyte vacuolization, myofibrillar loss, and cell death), atrophy and fibrosis, and organ-level manifestations including cardiac contractile dysfunction and vascular dysfunction. In addition, these mechanisms are relevant to current and emerging strategies to diagnose, prevent, and treat anthracycline-induced cardiomyopathy. This review details the established and emerging data regarding the molecular mechanisms of anthracycline-induced cardiovascular toxicity.

Potential of exosomes as diagnostic biomarkers and therapeutic carriers for doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is a kind of representative anthracyclines. It has greatly prolonged lifespan of cancer patients. However, a long course of DOX chemotherapy could induce various forms of deaths of cardiomyocytes, such as apoptosis, pyroptosis and ferroptosis, contributing to varieties of cardiac complications called cardiotoxicity. It has become a major concern considering the large number of cancer patients' worldwide and increased survival rates after chemotherapy. Exosomes, a subgroup of extracellular vesicles (EVs), are secreted by nearly all cells and consist of lipid bilayers, nucleic acids and proteins. They can serve as mediators between intercellular communication via the transfer of bioactive molecules from secretory to recipient cells, modulating multiple pathophysiological processes. It has been proven that exosomes in body fluids can serve as biomarkers for doxorubicin-induced cardiotoxicity (DIC). Moreover, exosomes have attracted considerable attention because of their capacity as carriers of certain proteins, genetic materials (miRNA and lncRNA), and chemotherapeutic drugs to decrease the dosage of DOX and alleviate cardiotoxicity. This review briefly describes the characteristics of exosomes and highlights their clinical application potential as diagnostic biomarkers and drug delivery vehicles for DIC, thus providing a strategy for addressing it based on exosomes.

Vascular endothelial growth factor B exerts lipid-lowering effect by activating AMPK via VEGFR1

As an ambiguous member of vascular endothelial growth factor family, VEGF-B has long been poorly understood in its function. Recent researches showed VEGF-B isoforms exerted their metabolic effect through indirectly activating the VEGF-A/VEGFR2 pathway. Here, we report the lipid-lowing effect of VEGF-B via VEGFR1. We investigated the effect of VEGF-B on lipid metabolism in vivo and in vitro approaches. Treatment of mice with VEGF-B recombinant protein repressed HFD-induced body weight gain. This treatment also alleviated obesity associated hyperlipidemia and fatty liver disease. In the muscle and liver of VEGF-B-treated HFD mice were observed increased protein expression of carnitine palmitoyltransferase-1 (CPT-1) and the phosphorylation of ACC and AMP-activated protein kinase (AMPK). This effect was confirmed in HepG2 cells incubated with VEFG-B in which the increased AMPK activation and CPT-1 expression occurs due to activation of Calcium/calmodulin-dependent Protein Kinase β (CaMKKβ) by VEFG-B. VEGF-B increased expression of key genes responsible for lipid oxidation while reducing those for fatty acid synthesis in vivo and in vitro. In addition, the selective inhibitor of VEGFR1 blocked the lipid clearance effect of VEGF-B in HepG2. Our study unraveled unknown role of VEGF-B/VEGFR1 signaling in regulating lipid metabolism. Furthermore, our findings indicate that VEGF-B may have beneficial effects for the treatment of dyslipidemia.

Antioxidant Approach as a Cardioprotective Strategy in Chemotherapy-Induced Cardiotoxicity

Significance: Chemotherapy-induced cardiotoxicity (CTX) has been associated with redox signaling imbalance. In fact, redox reactions are crucial for normal heart physiology, whereas excessive oxidative stress can cause cardiomyocyte structural damage. Recent Advances: An antioxidant approach as a cardioprotective strategy in this setting has shown encouraging results in preventing anticancer drug-induced CTX. Critical Issues: In fact, traditional heart failure drugs as well as many other compounds and nonpharmacological strategies, with a partial effect in reducing oxidative stress, have been shown to counterbalance chemotherapy-induced CTX in this setting to some extent. Future Directions: Given the various pathways of toxicity involved in different chemotherapeutic schemes, interactions with redox balance need to be fine-tuned and a personalized cardioprotective approach seems to be required.

Targeting the Activin Receptor Signaling to Counteract the Multi-Systemic Complications of Cancer and Its Treatments

Muscle wasting, i.e., cachexia, frequently occurs in cancer and associates with poor prognosis and increased morbidity and mortality. Anticancer treatments have also been shown to contribute to sustainment or exacerbation of cachexia, thus affecting quality of life and overall survival in cancer patients. Pre-clinical studies have shown that blocking activin receptor type 2 (ACVR2) or its ligands and their downstream signaling can preserve muscle mass in rodents bearing experimental cancers, as well as in chemotherapy-treated animals. In tumor-bearing mice, the prevention of skeletal and respiratory muscle wasting was also associated with improved survival. However, the definitive proof that improved survival directly results from muscle preservation following blockade of ACVR2 signaling is still lacking, especially considering that concurrent beneficial effects in organs other than skeletal muscle have also been described in the presence of cancer or following chemotherapy treatments paired with counteraction of ACVR2 signaling. Hence, here, we aim to provide an up-to-date literature review on the multifaceted anti-cachectic effects of ACVR2 blockade in preclinical models of cancer, as well as in combination with anticancer treatments.

Protective Effects of Oroxylin A against Doxorubicin-Induced Cardiotoxicity via the Activation of Sirt1 in Mice

Doxorubicin- (DOX-) related cardiac injury impairs the life quality of patients with cancer. This largely limited the clinical use of DOX. It is of great significance to find a novel strategy to reduce DOX-related cardiac injury. Oroxylin A (OA) has been identified to exert beneficial effects against inflammatory diseases and cancers. Here, we investigated whether OA could attenuate DOX-induced acute cardiotoxicity in mice. A single dose of DOX was used to induce acute cardiac injury in mice. To explore the protective effects, OA was administered to mice for ten days beginning from five days before DOX injection. The data in our study indicated that OA inhibited DOX-induced heart weight loss, reduction in cardiac function, and the elevation in myocardial injury markers. DOX injection resulted in increased oxidative damage, inflammation accumulation, and myocardial apoptosis in vivo and in vitro, and these pathological alterations were alleviated by treatment of OA. OA activated the sirtuin 1 (Sirt1) signaling pathway via the cAMP/protein kinase A, and its protective effects were blocked by Sirt1 deficiency. OA treatment did not affect the tumor-killing action of DOX in tumor-bearing mice. In conclusion, OA protected against DOX-related acute cardiac injury via the regulation of Sirt1.

Cardiotoxic effects of angiogenesis inhibitors

The development of new therapies for cancer has led to dramatic improvements in survivorship. Angiogenesis inhibitors represent one such advancement, revolutionising treatment for a wide range of malignancies. However, these drugs are associated with cardiovascular toxicities which can impact optimal cancer treatment in the short-term and may lead to increased morbidity and mortality in the longer term. Vascular endothelial growth factor inhibitors (VEGFIs) are associated with hypertension, left ventricular systolic dysfunction (LVSD) and heart failure as well as arterial and venous thromboembolism, QTc interval prolongation and arrhythmia. The mechanisms behind the development of VEGFI-associated LVSD and heart failure likely involve the combination of a number of myocardial insults. These include direct myocardial effects, as well as secondary toxicity via coronary or peripheral vascular damage. Cardiac toxicity may result from the 'on-target' effects of VEGF inhibition or 'off-target' effects resulting from inhibition of other tyrosine kinases. Similar mechanisms may be involved in the development of VEGFI-associated right ventricular (RV) dysfunction. Some VEGFIs can be associated with QTc interval prolongation and an increased risk of ventricular and atrial arrhythmia. Further pre-clinical and clinical studies and trials are needed to better understand the impact of VEGFI on the cardiovascular system. Once mechanisms are elucidated, therapies can be investigated in clinical trials and surveillance strategies for identifying VEGFI-associated cardiovascular complications can be developed.

Towards the use of localised delivery strategies to counteract cancer therapy-induced cardiotoxicities

Cancer therapies have significantly improved cancer survival; however, these therapies can often result in undesired side effects to off target organs. Cardiac disease ranging from mild hypertension to heart failure can occur as a result of cancer therapies. This can warrant the discontinuation of cancer treatment in patients which can be detrimental, especially when the treatment is effective. There is an urgent need to mitigate cardiac disease that occurs as a result of cancer therapy. Delivery strategies such as the use of nanoparticles, hydrogels, and medical devices can be used to localise the treatment to the tumour and prevent off target side effects. This review summarises the advancements in localised delivery of anti-cancer therapies to tumours. It also examines the localised delivery of cardioprotectants to the heart for patients with systemic disease such as leukaemia where localised tumour delivery might not be an option.

Dual Angiotensin Receptor-Neprilysin Inhibition With Sacubitril/Valsartan Attenuates Systolic Dysfunction in Experimental Doxorubicin-Induced Cardiotoxicity

BACKGROUND

Doxorubicin (DOX) induces cardiotoxicity in part by activation of matrix metalloproteinases (MMPs). Sacubitril/valsartan (Sac/Val) exerts additive cardioprotective actions over renin-angiotensin-aldosterone inhibitors in preclinical models of myocardial infarction and in heart failure patients. We hypothesized that Sac/Val would be more cardioprotective than Val in a rodent model of progressive DOX-induced cardiotoxicity, and this benefit would be associated with modulation of MMP activation.

OBJECTIVES

We sought to investigate the efficacy of Sac/Val for the treatment of anthracycline-induced cardiotoxicity.

METHODS

Male Wistar rats received DOX intraperitoneally (15 mg/kg cumulative) or saline over 3 weeks. Following the first treatment, control animals were gavaged daily with water (n = 25), while DOX-treated animals were gavaged daily with water (n = 25), Val (31 mg/kg; n = 25) or Sac/Val (68 mg/kg; n = 25) for either 4 or 6 weeks. Echocardiography was performed at baseline, and 4 and 6 weeks after DOX initiation. In addition, myocardial MMP activity was assessed with 99mTc-RP805, and cardiotoxicity severity was assessed by histology at these time points in a subgroup of animals.

RESULTS

Left ventricular ejection fraction decreased by 10% at 6 weeks in DOX and DOX + Val rats (both p < 0.05), while this reduction was attenuated in DOX + Sac/Val rats. MMP activity was increased at 6 weeks by 76% in DOX-alone rats, and tended to increase in DOX + Val rats (36%; p = 0.051) but was similar in DOX + Sac/Val rats as compared with time-matched control animals. Both therapies attenuated histological evidence of cellular toxicity and fibrosis (p < 0.05).

CONCLUSIONS

Sac/Val offers greater protection against left ventricular remodeling and dysfunction compared with standard angiotensin receptor blocker therapy in a rodent model of progressive DOX-induced cardiotoxicity.

Plumbagin protects the myocardial damage by modulating the cardiac biomarkers, antioxidants, and apoptosis signaling in the doxorubicin-induced cardiotoxicity in rats

Cardiovascular disease created enormous health and economic burdens worldwide, which is responsible for the highest mobility and mortality that results in nearly 6.2% of in-hospital deaths every year. Plumbagin is a major bioactive compound that occurs in the Plumbago indica and P. zeylanica with numerous therapeutic benefits. The current research exploration was planned to investigate the therapeutic role of plumbagin against doxorubicin stimulated cardiotoxicity in rats. The cardiotoxicity was stimulated to the rats by administering the 2.5 mg/kg of doxorubicin for 14 days with concurrent supplementation with plumbagin. The hemodynamic parameters were studied by using the tail-cuff plethysmography. The lipid peroxidation and antioxidant status was examined by the standard procedures. The myocardial function and damage markers were assessed with the help of commercial kits. The expression status of inflammatory markers and PI3K/Akt signaling markers were investigated by reverse transcription polymerase chain reaction (RT-PCR) and western blotting analysis, respectively. The plumbagin supplementation appreciably regained the body weight and heart weight of the investigational animals. Hemodynamic parameters and antioxidants statuses were escalated by the plumbagin treatment. The severe elevation in the cardiac damage markers and inflammatory markers were noticeably ameliorated by the plumbagin treatment. The plumbagin treatment also assuaged the overexpression of inflammatory and apoptotic proteins in the heart tissues of doxorubicin-challenged rats. The histopathological analysis revealed that the plumbagin appreciably protected the heart tissues from the doxorubicin-induced damages. The findings of this exploration evidenced that plumbagin treatment attenuated the doxorubicin-stimulated cardiotoxicity in rats.