An Integrated Network Pharmacology and RNA-seq Approach for Exploring the Protective Effect of Andrographolide in Doxorubicin-Induced Cardiotoxicity.

PURPOSE: Doxorubicin (Dox) is clinically limited due to its dose-dependent cardiotoxicity. Andrographolide (Andro) has been confirmed to exert cardiovascular protective activities. This study aimed to investigate protective effects of Andro in Dox-induced cardiotoxicity (DIC). METHODS: The cardiotoxicity models were induced by Dox in vitro and in vivo. The viability and apoptosis of H9c2 cells and the myocardial function of c57BL/6 mice were accessed with and without Andro pretreatment. Network pharmacology and RNA-seq were employed to explore the mechanism of Andro in DIC. The protein levels of Bax, Bcl2, NLRP3, Caspase-1 p20, and IL-1ß were qualified as well. RESULTS: In vitro, Dox facilitated the downregulation of cell viability and upregulation of cell apoptosis, after Andro pretreatment, the above symptoms were remarkably reversed. In vivo, Andro could alleviate Dox-induced cardiac dysfunction and apoptosis, manifesting elevation of LVPWs, LVPWd, EF% and FS%, suppression of CK, CK-MB, c-Tnl and LDH, and inhibition of TUNEL-positive cells. Using network pharmacology, we collected and visualized 108 co-targets of Andro and DIC, which were associated with apoptosis, PI3K-AKT signaling pathway, and others. RNA-seq identified 276 differentially expressed genes, which were enriched in response to oxidative stress, protein phosphorylation, and others. Both network pharmacology and RNA-seq analysis identified Tap1 and Timp1 as key targets of Andro in DIC. RT-QPCR validation confirmed that the mRNA levels of Tap1 and Timp1 were consistent with the sequenced results. Moreover, the high expression of NLRP3, Caspase-1 p20, and IL-1ß in the Dox group was reduced by Andro. CONCLUSIONS: Andro could attenuate DIC through suppression of Tap1 and Timp1 and inhibition of NLRP3 inflammasome activation, serving as a promising cardioprotective drug.

Metabolic activation of tyrosine kinase inhibitors: recent advance and further clinical practice.

At present, receptor tyrosine kinase signaling-related pathways have been successfully mediated to inhibit tumor proliferation and promote anti-angiogenesis effects for cancer therapy. Tyrosine kinase inhibitors (TKIs), a group of novel chemotherapeutic agents, have been applied to treat diverse malignant tumors effectively. However, the latent toxic and side effects of TKIs, such as hepatotoxicity and cardiotoxicity, limit their use in clinical practice. Metabolic activation has the potential to lead to toxic effects. Numerous TKIs have been demonstrated to be transformed into chemically reactive/potentially toxic metabolites following cytochrome P450-catalyzed activation, which causes severe adverse reactions, including hepatotoxicity, cardiotoxicity, skin toxicity, immune injury, mitochondria injury, and cytochrome P450 inactivation. However, the precise mechanisms of how these chemically reactive/potentially toxic species induce toxicity remain poorly understood. In addition, we present our viewpoints that regulating the production of reactive metabolites may decrease the toxicity of TKIs. Exploring this topic will improve understanding of metabolic activation and its underlying mechanisms, promoting the rational use of TKIs. This review summarizes the updated evidence concerning the reactive metabolites of TKIs and the associated toxicities. This paper provides novel insight into the safe use of TKIs and the prevention and treatment of multiple TKIs adverse effects in clinical practice.

Hyperoside Protects Trastuzumab-Induced Cardiotoxicity via Activating the PI3K/Akt Signaling Pathway.

PURPOSE: Trastuzumab is a landmark agent in the treatment of human epidermal growth factor receptor-2(HER2)-positive breast cancer. Nevertheless, trastuzumab also comes with unexpected cardiac side effects. Hyperoside is a natural product that serves beneficial roles in cardiovascular disease. This study aimed to explore the effect and mechanism of hyperoside in trastuzumab-induced cardiotoxicity. METHODS: A female C57BL/6 mice cardiotoxicity model was established via intraperitoneally injecting with trastuzumab (10 mg/kg/day, once every other day, cumulative dosage to 40 mg/kg) with or without hyperoside (15 or 30 mg/kg/day) administration. In vitro, the H9c2 cells were exposed to 1 µM trastuzumab with or without hyperoside (100 or 200 µM) administration. Cardiac function was evaluated by echocardiographic, myocardial enzymes levels, and pathological section examinations. TUNEL staining and Annexin V-FITC/ propidium iodide flow cytometry were used to analyze the cardiomyocyte apoptosis. RESULTS: Compared to the control group, the LVEF, LVFS was decreased and the concentrations of cTnT, CK, CK-MB and LDH in mice were significantly increased after treatment with trastuzumab. Collagen deposition and cardiomyocyte hypertrophy were observed in the myocardium of the trastuzumab group. However, these changes were all reversed by different doses of hyperoside. In addition, hyperoside attenuated trastuzumab-induced myocardium apoptosis and H9c2 cells apoptosis through inhibiting the expressions of cleaved caspase-3 and Bax. Trastuzumab abolished the PI3K/Akt signaling pathway in mice and H9c2 cells, while co-treatment of hyperoside effectively increased the ratio of p-Akt/Akt. CONCLUSION: Hyperoside inhibited trastuzumab-induced cardiotoxicity through activating the PI3K/Akt signaling pathway. Hyperoside may be a promising therapeutic approach to trastuzumab-induced cardiotoxicity.

Hyperoside prevents doxorubicin-induced cardiotoxicity by inhibiting NOXs/ROS/NLRP3 inflammasome signaling pathway.

Clinical application of doxorubicin (Dox) in cancer chemotherapy is limited by its cardiotoxicity. Present study aimed to demonstrate the effect and mechanism of hyperoside in Dox-induced cardiotoxicity. C57BL/6 mice were injected with 12 mg/kg of Dox, and 1 µM Dox was exposed to primary cardiomyocytes. Cardiac function was evaluated by echocardiographic and myocardial enzyme levels. Cardiomyocyts apoptosis was analyzed by TUNEL staining and flow cytometry. Network pharmacology and molecular docking were utilized to explore potential targets of hyperoside. Protein expressions were detected by western blot and enzyme activities were determined by colorimetry. Cardiac dysfunction and cardiomyocyte apoptosis induced by Dox were attenuated by hyperoside. Mechanism of hyperoside was mainly related to "oxidative stress" pathway. Hyperoside exhibited strong binding activities with nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs, the main source of ROS in cardiomyocytes) and cyclooxygenases (COXs). Experiments proved that hyperoside suppressed the ROS generation and the elevated activities of NOXs and COXs induced by Dox. Dox also triggered the activation of NLRP3 inflammasome, which was reversed by hyperoside. Hyperoside bound to NOXs and COXs, which prevents Dox-induced cardiotoxicity by inhibiting NOXs/ROS/NLRP3 inflammasome signaling pathway. Hyperoside holds promise as a therapeutic strategy for Dox-induced cardiotoxicity.

Enhanced protection against hypoxia/reoxygenation-induced apoptosis in H9c2 cells by puerarin-loaded liposomes modified with matrix metalloproteinases-targeting peptide and triphenylphosphonium.

Based on the inhibition of mitochondrial permeability transition pore (mPTP) opening, puerarin (PUE) has a good potential to reduce myocardial ischemia/reperfusion injury (MI/RI). However, the lack of targeting of free PUE makes it difficult to reach the mitochondria. In this paper, we constructed matrix metalloproteinase-targeting peptide (MMP-TP) and triphenylphosphonium (TPP) cation co-modified liposomes loaded with PUE (PUE@T/M-L) for mitochondria-targeted drug delivery. PUE@T/M-L had a favorable particle size of 144.9 ± 0.8 nm, an encapsulation efficiency of 78.9 ± 0.6%, and a sustained-release behavior. The results of cytofluorimetric experiments showed that MMP-TP and TPP double-modified liposomes (T/M-L) enhanced intracellular uptake, escaped lysosomal capture, and promoted drug targeting into mitochondria. In addition, PUE@T/M-L enhanced the viability of hypoxia-reoxygenation (H/R) injured H9c2 cells by inhibiting mPTP opening and reactive oxygen species (ROS) production, reducing Bax expression and increasing Bcl-2 expression. It was inferred that PUE@T/M-L delivered PUE into the mitochondria of H/R injured H9c2 cells, resulting in a significant increase in cellular potency. Based on the ability of MMP-TP to bind the elevated expression of matrix metalloproteinases (MMPs), T/M-L had excellent tropism for Lipopolysaccharide (LPS) -stimulated macrophages and can significantly reduce TNF-α and ROS levels, thus allowing both drug accumulation in ischemic cardiomyocytes and reducing inflammatory stimulation during MI/RI. Fluorescence imaging results of the targeting effect using a DiR probe also indicated that DiR@T/M-L could accumulate and retain in the ischemic myocardium. Taken together, these results demonstrated the promising application of PUE@T/M-L for mitochondria-targeted drug delivery to achieve maximum therapeutic efficacy of PUE.

The role and mechanisms of Microglia in Neuromyelitis Optica Spectrum Disorders.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune neurological disease that can cause blindness and disability. As the major mediators in the central nervous system, microglia plays key roles in immunological regulation in neuroinflammatory diseases, including NMOSD. Microglia can be activated by interleukin (IL)-6 and type I interferons (IFN-Is) during NMOSD, leading to signal transducer and activator of transcription (STAT) activation. Moreover, complement C3a secreted from activated astrocytes may induce the secretion of complement C1q, inflammatory cytokines and progranulin (PGRN) by microglia, facilitating injury to microglia, neurons, astrocytes and oligodendrocytes in an autocrine or paracrine manner. These processes involving activated microglia ultimately promote the pathological course of NMOSD. In this review, recent research progress on the roles of microglia in NMOSD pathogenesis is summarized, and the mechanisms of microglial activation and microglial-mediated inflammation, and the potential research prospects associated with microglial activation are also discussed.

A UPLC-MS/MS method for simultaneous quantification of sildenafil and N-desmethyl sildenafil applied in pharmacokinetic and bioequivalence studies in a Chinese population.

OBJECTIVE: To evaluate the pharmacokinetic parameters and bioequivalence of two sildenafil tablets (20 mg) in healthy Chinese subjects. MATERIALS AND METHODS: A random, crossover, self-control design was used. 20 healthy subjects including males and females were randomized into two groups. A single oral dose of the trial or reference preparation was given to the two groups of subjects after an overnight fast of 10 hours. Blood samples were taken at scheduled time points. Plasma concentrations of sildenafil and N-desmethyl sildenafil were measured by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). ANOVA was used to check the difference of the mean values of the pharmacokinetic parameters between the two preparations. Bioequivalence was determined by two one-sided t-tests and 90% confidence intervals. RESULTS: The quantitative range of sildenafil and N-desmethyl sildenafil was 2.000 - 200.0 ng/mL and 0.800 - 80.00 ng/mL, respectively. Plasma samples were stable, and there was no mutual interference between the analyte and internal standard. With the 90% confidence limit, the trial preparations AUC0→t and Cmax fall within 80.00 - 125.00% of the reference preparation's AUC0→t and Cmax. The tmax of sildenafil and N-desmethyl sildenafil was ~ 0.9 hours and 1 hour, and the T1/2 was 2.4 hours and 3.7 hours, respectively. The relative bioavailability of sildenafil and N-desmethyl sildenafil was 99.28 ± 3.30% and 99.20 ± 3.39%. No significant difference was found in every factor between the trial preparation and the reference preparation. CONCLUSION: The UPLC-MS/MS method was successfully established to evaluate the pharmacokinetic parameters of sildenafil in healthy Chinese subjects. The trial preparation was bioequivalent to the reference preparation.

Identification of the protective effect of Polygonatum sibiricum polysaccharide on d-galactose-induced brain ageing in mice by the systematic characterization of a circular RNA-associated ceRNA network.

CONTEXT: Polygonatum sibiricum polysaccharide (PSP), derived from Polygonatum sibiricum Delar. ex Redoute (Liliaceae), is known to be able to delay the ageing process. However, the specific mechanisms underlying these effects are not clear. OBJECTIVE: To investigate the mechanisms underlying the effects of PSP treatment on brain ageing by the application of transcriptomic analysis. MATERIALS AND METHODS: Forty Kunming mice were randomly divided into four groups (control, d-galactose, low-dose PSP, high-dose PSP). Mice were administered d-galactose (50 mg/kg, hypodermic injection) and PSP (200 or 400 mg/kg, intragastric administration) daily for 60 days. Behavioural responses were evaluated with the Morris water maze and the profiles of circRNA, miRNA, and mRNA, in the brains of experimental mice were investigated during the ageing process with and without PSP treatment. RESULTS: PSP improved cognitive function during brain ageing, as evidenced by a reduced escape latency time (p < 0.05) and an increase in the number of times mice crossed the platform (p < 0.05). A total of 37, 13, and 679, circRNAs, miRNAs, and mRNAs, respectively, were significantly altered by PSP treatment (as evidenced by a fold change ≥2 and p < 0.05). These dysregulated RNAs were closely associated with synaptic activity. PSP regulated regulate nine mRNAs (Slc6a5, Bean1, Ace, Samd4, Olfr679, Olfr372, Dhrs9, Tsc1, Slc12a6), three miRNAs (mmu-miR-5110, mmu-miR-449a-5p, mmu-miR-1981-5p), and two circRNAs (2:29227578|29248878 and 5:106632925|106666845) in the competing endogenous RNA (ceRNA) network. DISCUSSION AND CONCLUSIONS: Our analyses showed that multiple circRNAs, miRNAs, and mRNAs responded to PSP treatment in mice experiencing brain ageing.

Tanshinone â ¡A inhibits homocysteine-induced proliferation of vascular smooth muscle cells via miR-145/CD40 signaling.

Tanshinone IIA (Tan IIA), isolated from the traditional Chinese herb Danshen, exhibits broad cardiovascular protective effects. However, the effect of Tan IIA on Homocysteine (Hcy)-induced proliferation of vascular smooth muscle cells (VSMCs) remains unknown. We herein determined whether Tan IIA exerted anti-proliferative effect in Hcy-treating VSMCs, and further investigated the underlying mechanism (miR-145/CD40 signaling). The results showed that Tan IIA significantly inhibited VSMCs proliferation induced by Hcy in a dose-dependent manner, and reversed the VSMCs injury as indicated by decreased KLF4 and increased Calponin expression. In view of the key role of miR-145 in VSMCs, we further explored the role of miR-145 on the protective effect of Tan IIA against Hcy-induced VSMCs proliferation. The miR-145 expression was down-regulated and its targeted gene CD40 was up-regulated in Hcy-treating VSMCs, while the Tan IIA reversed the effect of Hcy, suggesting the miR-145/CD40 may be involve in the protective effect of Tan IIA. To determine the speculation, miR-145 inhibitor was used to inhibit miR-145 expression. The results indicated that miR-145 inhibitor can suppress the protective effects of Tan IIA against Hcy-induced VSMCs proliferation. Collectively, present study demonstrates that Tan IIA inhibits Hcy-induced proliferation of VSMCs via miR-145/CD40 signaling.

The critical role of microRNAs in stress response: Therapeutic prospect and limitation.

Stress response refers to the systemic nonspecific response upon exposure to strong stimulation or chronic stress, such as severe trauma, shock, infection, burn, major surgery or improper environment, which disturb organisms and damage their physical and psychological health. However, the pathogenesis of stress induced disorder remains complicated and diverse under different stress exposure. Recently, studies have revealed a specific role of microRNAs (miRNAs) in regulating cellular function under different types of stress, suggesting a significant role in the treatment and prevention of stress-related diseases, such as stress ulcer, posttraumatic stress disorder, stress-induced cardiomyopathy and so on. This paper have reviewed the literature on microRNA related stress diseases in different databases including PubMed, Web of Science, and the MiRbase. It considers only peer-reviewed papers published in English between 2004 and 2018. This review summarizes new advances in principles and mechanisms of miRNAs regulating stress signalling pathway and the role of miRNAs in human stress diseases. This comprehensive review is to provide an integrated account of how different stresses affect miRNAs and how stress-miRNA pathways may, in turn, be linked with disease, which offers some potential strategies for stress disorder treatment. Furthermore, the limitation of current studies and challenges for clinical use are discussed.

Perspectives on biologically active camptothecin derivatives.

Camptothecins (CPTs) are cytotoxic natural alkaloids that specifically target DNA topoisomerase I. Research on CPTs has undergone a significant evolution from the initial discovery of CPT in the late 1960s through the study of synthetic small-molecule derivatives to investigation of macromolecular constructs and formulations. Over the past years, intensive medicinal chemistry efforts have generated numerous CPT derivatives. Three derivatives, topotecan, irinotecan, and belotecan, are currently prescribed as anticancer drugs, and several related compounds are now in clinical trials. Interest in other biological effects, besides anticancer activity, of CPTs is also growing exponentially, as indicated by the large number of publications on the subject during the last decades. Therefore, the main focus of the present review is to provide an ample but condensed overview on various biological activities of CPT derivatives, in addition to continued up-to-date coverage of anticancer effects.

Involvement of glutamate-cystine/glutamate transporter system in aspirin-induced acute gastric mucosa injury.

Large-dose or long-term use of aspirin tends to cause gastric mucosa injury, which is recognized as the major side effect of aspirin. It has been demonstrated that glutamate exerts a protective effect on stomach, and the level of glutamate is critically controlled by cystine/glutamate transporter (Xc(-)). In the present study, we investigated the role of glutamate-cystine/glutamate transporter system in aspirin-induced acute gastric mucosa injury in vitro and in vivo. Results showed that in human gastric epithelial cells, aspirin incubation increased the activity of LDH and the number of apoptotic cells, meanwhile down-regulated the mRNA expression of Xc(-) accompanied with decreased glutamate release. Similar results were seen in a rat model. In addition, exogenous l-glutamate attenuated the gastric mucosa injury and cell damage induced by aspirin both in vitro and in vivo. Taken together, our results demonstrated that acute gastric mucosa injury induced by aspirin is related to reduction of glutamate-cystine/glutamate transporter system activity.

Synthesis of novel spin-labeled podophyllotoxin derivatives as potential antineoplastic agents: Part XXV.

A series of novel spin-labeled 4ß-[(4-substituted)-1,2,3-triazol-1-yl]podophyllotoxin derivatives (17a-h) were firstly designed and synthesized with significant regioselectivity by employing Cu(I) catalyzed click approach, and evaluated for cytotoxicity against four human tumor cell lines (A-549, DU145, KB, and KBvin). Among them, compound 17h displayed the highest cytotoxic activity against the tumor cell lines tested. Significantly, compound 17h showed superior cytotoxic activity compared with etoposide (IC50 6.30 to>10 µM), a clinically available anticancer drug. Significant activity toward the drug resistant KBvin cell line revealed promising future for compound 17h as a new generation of epipodophyllotoxin-derived antitumor clinical trial candidate.

Multiple delivery strategies of nanocarriers for myocardial ischemia-reperfusion injury: current strategies and future prospective.

Acute myocardial infarction, characterized by high morbidity and mortality, has now become a serious health hazard for human beings. Conventional surgical interventions to restore blood flow can rapidly relieve acute myocardial ischemia, but the ensuing myocardial ischemia-reperfusion injury (MI/RI) and subsequent heart failure have become medical challenges that researchers have been trying to overcome. The pathogenesis of MI/RI involves several mechanisms, including overproduction of reactive oxygen species, abnormal mitochondrial function, calcium overload, and other factors that induce cell death and inflammatory responses. These mechanisms have led to the exploration of antioxidant and inflammation-modulating therapies, as well as the development of myocardial protective factors and stem cell therapies. However, the short half-life, low bioavailability, and lack of targeting of these drugs that modulate these pathological mechanisms, combined with liver and spleen sequestration and continuous washout of blood flow from myocardial sites, severely compromise the expected efficacy of clinical drugs. To address these issues, employing conventional nanocarriers and integrating them with contemporary biomimetic nanocarriers, which rely on passive targeting and active targeting through precise modifications, can effectively prolong the duration of therapeutic agents within the body, enhance their bioavailability, and augment their retention at the injured myocardium. Consequently, these approaches significantly enhance therapeutic effectiveness while minimizing toxic side effects. This article reviews current drug delivery systems used for MI/RI, aiming to offer a fresh perspective on treating this disease.

Noncoding RNA-associated competing endogenous RNA networks in trastuzumab-induced cardiotoxicity.

Trastuzumab-induced cardiotoxicity (TIC) is a common and serious disease with abnormal cardiac function. Accumulating evidence has indicated certain non-coding RNAs (ncRNAs), functioning as competing endogenous RNAs (ceRNAs), impacting the progression of cardiovascular diseases. Nonetheless, the specific involvement of ncRNA-mediated ceRNA regulatory mechanisms in TIC remains elusive. The present research aims to comprehensively investigate changes in the expressions of all ncRNA using whole-transcriptome RNA sequencing. The sequencing analysis unveiled significant dysregulation, identifying a total of 43 circular RNAs (circRNAs), 270 long noncoding RNAs (lncRNAs), 12 microRNAs (miRNAs), and 4131 mRNAs in trastuzumab-treated mouse hearts. Subsequently, circRNA-based ceRNA networks consisting of 82 nodes and 91 edges, as well as lncRNA-based ceRNA networks comprising 111 nodes and 112 edges, were constructed. Using the CytoNCA plugin, pivotal genes-miR-31-5p and miR-644-5p-were identified within these networks, exhibiting potential relevance in TIC treatment. Additionally, KEGG and GO analyses were conducted to explore the functional pathways associated with the genes within the ceRNA networks. The outcomes of the predicted ceRNAs and bioinformatics analyses elucidated the plausible involvement of ncRNAs in TIC pathogenesis. This insight contributes to a better understanding of underlying mechanisms and aids in identifying promising targets for effective prevention and treatment strategies.

Puerarin-Loaded Liposomes Co-Modified by Ischemic Myocardium-Targeting Peptide and Triphenylphosphonium Cations Ameliorate Myocardial Ischemia-Reperfusion Injury.

Purpose: Mitochondrial damage may lead to uncontrolled oxidative stress and massive apoptosis, and thus plays a pivotal role in the pathological processes of myocardial ischemia-reperfusion (I/R) injury. However, it is difficult for the drugs such as puerarin (PUE) to reach the mitochondrial lesion due to lack of targeting ability, which seriously affects the expected efficacy of drug therapy for myocardial I/R injury. Methods: We prepared triphenylphosphonium (TPP) cations and ischemic myocardium-targeting peptide (IMTP) co-modified puerarin-loaded liposomes (PUE@T/I-L), which effectively deliver the drug to mitochondria and improve the effectiveness of PUE in reducing myocardial I/R injury. Results: In vitro test results showed that PUE@T/I-L had sustained release and excellent hemocompatibility. Fluorescence test results showed that TPP cations and IMTP double-modified liposomes (T/I-L) enhanced the intracellular uptake, escaped lysosomal capture and promoted drug targeting into the mitochondria. Notably, PUE@T/I-L inhibited the opening of the mitochondrial permeability transition pore, reduced intracellular reactive oxygen species (ROS) levels and increased superoxide dismutase (SOD) levels, thereby decreasing the percentage of Hoechst-positive cells and improving the survival of hypoxia-reoxygenated (H/R)-injured H9c2 cells. In a mouse myocardial I/R injury model, PUE@T/I-L showed a significant myocardial protective effect against myocardial I/R injury by protecting mitochondrial integrity, reducing myocardial apoptosis and decreasing infarct size. Conclusion: This drug delivery system exhibited excellent mitochondrial targeting and reduction of myocardial apoptosis, which endowed it with good potential extension value in the precise treatment of myocardial I/R injury.

Design, synthesis and potent cytotoxic activity of novel podophyllotoxin derivatives.

Twenty new acyl thiourea derivatives of podophyllotoxin and 4'-demethylepipodophyllotoxin were prepared and screened for their cytotoxicity against four human tumor cell lines, A-549, DU-145, KB, and KBvin. With IC50 values of 0.098-1.13 µM, compounds 13b, 13c, and 13o displayed much better cytotoxic activity than the control etoposide. Most importantly, 13b and 13o exhibited promising cytotoxicity against the drug resistant tumor cell line KBvin with IC50 values of 0.098 and 0.13 µM, respectively, while etoposide lost activity completely. Structure-activity relationship (SAR) correlations of the new derivatives have been established. Compounds 13b and 13o merit further development as a new generation of epipodophyllotoxin-derived antitumor clinical trial candidates.

Phloretin alleviates doxorubicin-induced cardiotoxicity through regulating Hif3a transcription via targeting transcription factor Fos.

BACKGROUND: Doxorubicin (Dox), a chemotherapeutic agent known for its efficacy, has been associated with the development of severe cardiotoxicity, commonly referred to as doxorubicin-induced cardiotoxicity (DIC). The role and mechanism of action of phloretin (Phl) in cardiovascular diseases are well-established; however, its specific function and underlying mechanism in the context of DIC have yet to be fully elucidated. OBJECTIVE: This research aimed to uncover the protective effect of Phl against DIC in vivo and in vitro, while also providing a comprehensive understanding of the underlying mechanisms involved. METHODS: DIC cell and murine models were established. The action targets and mechanism of Phl against DIC were comprehensively examined by systematic network pharmacology, molecular docking, transcriptomics technologies, transcription factor (TF) prediction, and experimental validation. RESULTS: Phl relieved Dox-induced cell apoptosis in vitro and in vivo. Through network pharmacology analysis, a total of 554 co-targeted genes of Phl and Dox were identified. Enrichment analysis revealed several key pathways including the PI3K-Akt signaling pathway, Apoptosis, and the IL-17 signaling pathway. Protein-protein interaction (PPI) analysis identified 24 core co-targeted genes, such as Fos, Jun, Hif1a, which were predicted to bind well to Phl based on molecular docking. Transcriptomics analysis was performed to identify the top 20 differentially expressed genes (DEGs), and 202 transcription factors (TFs) were predicted for these DEGs. Among these TFs, 10 TFs (Fos, Jun, Hif1a, etc.) are also the co-targeted genes, and 3 TFs (Fos, Jun, Hif1a) are also the core co-targeted genes. Further experiments validated the finding that Phl reduced the elevated levels of Hif3a (one of the top 20 DEGs) and Fos (one of Hif3a's predicted TFs) induced by Dox. Moreover, the interaction between Fos protein and the Hif3a promoter was confirmed through luciferase reporter assays. CONCLUSION: Phl actively targeted and down-regulated the Fos protein to inhibit its binding to the promoter region of Hif3a, thereby providing protection against DIC.

Trastuzumab potentiates doxorubicin-induced cardiotoxicity via activating the NLRP3 inflammasome in vivo and in vitro.

Trastuzumab (Tra), the first humanized monoclonal antibody that targets human epidermal growth factor receptor 2 (HER2), is commonly used alongside doxorubicin (Dox) as a combination therapy in HER2-positive breast cancer. Unfortunately, this leads to a more severe cardiotoxicity than Dox alone. NLRP3 inflammasome is known to be involved in Dox-induced cardiotoxicity and multiple cardiovascular diseases. However, whether the NLRP3 inflammasome contributes to the synergistic cardiotoxicity of Tra has not been elucidated. In this study, primary neonatal rat cardiomyocyte (PNRC), H9c2 cells and mice were treated with Dox (15 mg/kg in mice or 1 µM in cardiomyocyte) or Tra (15.75 mg/kg in mice or 1 µM in cardiomyocyte), or Dox combined Tra as cardiotoxicity models to investigate this question. Our results demonstrated that Tra significantly potentiated Dox-induced cardiomyocyte apoptosis and cardiac dysfunction. These were accompanied by the increased expressions of NLRP3 inflammasome components (NLRP3, ASC and cleaved caspase-1), the secretion of IL-ß and the pronounced production of ROS. Inhibiting the activation of NLRP3 inflammasome by NLRP3 silencing significantly reduced cell apoptosis and ROS production in Dox combined Tra-treated PNRC. Compared with the wild type mice, the systolic dysfunction, myocardial hypertrophy, cardiomyocyte apoptosis and oxidative stress induced by Dox combined Tra were alleviated in NLRP3 gene knockout mice. Our data revealed that the co-activation of NLRP3 inflammasome by Tra promoted the inflammation, oxidative stress and cardiomyocytes apoptosis in Dox combined Tra-induced cardiotoxicity model both in vivo and in vitro. Our results suggest that NLRP3 inhibition is a promising cardioprotective strategy in Dox/Tra combination therapy.

Recent progress in the role of endogenous metal ions in doxorubicin-induced cardiotoxicity.

Doxorubicin is a widely used anticancer drug in clinical practice for the treatment of various human tumors. However, its administration is associated with cardiotoxicity. Administration of doxorubicin with low side effects for cancer treatment and prevention are, accordingly, urgently required. The human body harbors various endogenous metal ions that exert substantial influences. Consequently, extensive research has been conducted over several decades to investigate the potential of targeting endogenous metal ions to mitigate doxorubicin's side effects and impede tumor progression. In recent years, there has been a growing body of research indicating the potential efficacy of metal ion-associated therapeutic strategies in inhibiting doxorubicin-induced cardiotoxicity (DIC). These strategies offer a combination of favorable safety profiles and potential clinical utility. Alterations in intracellular levels of metal ions have been found to either facilitate or mitigate the development of DIC. For instance, ferroptosis, a cellular death mechanism, and metal ions such as copper, zinc, and calcium have been identified as significant contributors to DIC. This understanding can contribute to advancements in cancer treatment and provide valuable insights for mitigating the cardiotoxic effects of other therapeutic drugs. Furthermore, potential therapeutic strategies have been investigated to alleviate DIC in clinical settings. The ultimate goal is to improve the efficacy and safety of Dox and offer valuable insights for future research in this field.