LCZ696 Attenuated Doxorubicin-Induced Chronic Cardiomyopathy Through the TLR2-MyD88 Complex Formation

Circ-0006332 stimulates cardiomyocyte pyroptosis via the miR-143/TLR2 axis to promote doxorubicin-induced cardiac damage

Doxorubicin (DOX)-mediated cardiotoxicity can impair the clinical efficacy of chemotherapy, leading to heart failure (HF). Given the importance of circRNAs and miRNAs in HF, this paper intended to delineate the mechanism of the circular RNA 0006332 (circ -0,006,332)/microRNA (miR)-143/Toll-like receptor 2 (TLR2) axis in doxorubicin (DOX)-induced HF. The binding of miR-143 to circ -0,006,332 and TLR2 was assessed with the dual-luciferase assay, and the binding between miR-143 and circ -0,006,332 was determined with FISH, RIP, and RNA pull-down assays. miR-143 and/or circ -0,006,332 were overexpressed in rats and cardiomyocytes, followed by DOX treatment. In cardiomyocytes, miR-143 and TLR2 expression, cell viability, LDH release, ATP contents, and levels of IL-1β, IL-18, TNF-α, and pyroptosis-related molecules were examined. In rats, cardiac function, serum levels of cardiac enzymes, apoptosis, myocardial fibrosis, and levels of IL-1β, IL-18, TNF-α, TLR2, and pyroptosis-related molecules were detected. miR-143 diminished TLR2 expression by binding to TLR2, and circ -0,006,332 bound to miR-143 to downregulate miR-143 expression. miR-143 expression was reduced and TLR2 expression was augmented in DOX-induced cardiomyocytes. miR-143 inhibited DOX-induced cytotoxicity by suppressing pyroptosis in H9C2 cardiomyocytes. In DOX-induced rats, miR-143 reduced cardiac dysfunction, myocardial apoptosis, myocardial fibrosis, TLR2 levels, and pyroptosis. Furthermore, overexpression of circ -0,006,332 blocked these effects of miR-143 on DOX-induced cardiomyocytes and rats. Circ -0,006,332 stimulates cardiomyocyte pyroptosis by downregulating miR-143 and upregulating TLR2, thus promoting DOX-induced cardiac injury.

Role of Oxidative Stress and Inflammation in Doxorubicin-Induced Cardiotoxicity: A Brief Account

Cardiotoxicity is the main side effect of several chemotherapeutic drugs. Doxorubicin (Doxo) is one of the most used anthracyclines in the treatment of many tumors, but the development of acute and chronic cardiotoxicity limits its clinical usefulness. Different studies focused only on the effects of long-term Doxo administration, but recent data show that cardiomyocyte damage is an early event induced by Doxo after a single administration that can be followed by progressive functional decline, leading to overt heart failure. The knowledge of molecular mechanisms involved in the early stage of Doxo-induced cardiotoxicity is of paramount importance to treating and/or preventing it. This review aims to illustrate several mechanisms thought to underlie Doxo-induced cardiotoxicity, such as oxidative and nitrosative stress, inflammation, and mitochondrial dysfunction. Moreover, here we report data from both in vitro and in vivo studies indicating new therapeutic strategies to prevent Doxo-induced cardiotoxicity.

SIRT6 activates PPARα to improve doxorubicin-induced myocardial cell aging and damage

The Sirtuins family, formally known as the Silent Information Regulator Factors, constitutes a highly conserved group of histone deacetylases. Recent studies have illuminated SIRT6's role in doxorubicin (DOX)-induced oxidative stress and apoptosis within myocardial cells. Nevertheless, the extent of SIRT6's impact on DOX-triggered myocardial cell aging and damage remains uncertain, with the associated mechanisms yet to be fully understood. In our research, we examined the influence of SIRT6 on DOX-induced cardiomyocyte senescence using β-galactosidase and γ-H2AX staining. Additionally, we gauged the mRNA expression of senescence-associated genes, namely p16, p21, and p53, through Real-time PCR. Employing ELISA assay kits, MDA, and total SOD activity assay kits, we measured inflammatory factors TNF-α, IL-6, and IL-1β, alongside oxidative stress-related indicators. The results unequivocally indicated that SIRT6 overexpression robustly inhibited DOX-induced cardiomyocyte senescence. Furthermore, we established that SIRT6 overexpression suppressed the inflammatory response and oxidative stress induced by DOX in cardiomyocytes. Conversely, silencing SIRT6 exacerbated DOX-induced cardiomyocyte injury. Our investigations further unveiled that SIRT6 upregulated the expression of genes CD36, CPT1, LCAD, MCAD associated with fatty acid oxidation through its interaction with PPARα, thereby exerting anti-aging effects. In vivo, the overexpression of SIRT6 was observed to restore DOX-induced declines in EF and FS to normal levels in mice. Echocardiography and HE staining revealed the restoration of cardiomyocyte alignment, affording protection against DOX-induced myocardial senescence and injury. The findings from this study suggest that SIRT6 holds significant promise as a therapeutic target for mitigating DOX-induced cardiomyopathy.

The Angiotensin II Receptor Neprilysin Inhibitor LCZ696 Inhibits the NLRP3 Inflammasome By Reducing Mitochondrial Dysfunction in Macrophages and Alleviates Dextran Sulfate Sodium-induced Colitis in a Mouse Model

The intracellular sensor protein complex known as the NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome plays a crucial role in regulating inflammatory diseases by overseeing the production of interleukin (IL)-1β and IL-18. Targeting its abnormal activation with drugs holds significant promise for inflammation treatment. This study highlights LCZ696, an angiotensin receptor-neprilysin inhibitor, as an effective suppressor of NLRP3 inflammasome activation in macrophages stimulated by ATP, nigericin, and monosodium urate. LCZ696 also reduces caspase-11 and GSDMD activation, lactate dehydrogenase release, propidium iodide uptake, and the extracellular release of NLRP3 and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) in ATP-activated macrophages, suggesting a potential mitigation of pyroptosis. Mechanistically, LCZ696 lowers mitochondrial reactive oxygen species and preserves mitochondrial integrity. Importantly, it does not significantly impact NLRP3, proIL-1β, inducible nitric oxide synthase, cyclooxygenase-2 expression, or NF-κB activation in lipopolysaccharide-activated macrophages. LCZ696 partially inhibits the NLRP3 inflammasome through the induction of autophagy. In an in vivo context, LCZ696 alleviates NLRP3-associated colitis in a mouse model by reducing colonic expression of IL-1β and tumor necrosis factor-α. Collectively, these findings suggest that LCZ696 holds significant promise as a therapeutic agent for ameliorating NLRP3 inflammasome activation in various inflammatory diseases, extending beyond its established use in hypertension and heart failure treatment.

Novel pterostilbene derivatives ameliorate heart failure by reducing oxidative stress and inflammation through regulating Nrf2/NF-κB signaling pathway

Pterostilbene is a demethylated resveratrol derivative with attractive anti-inflammatory, anti-tumor and anti-oxidative stress activities. However, the clinical use of pterostilbene is limited by its poor selectivity and druggability. Heart failure is a leading cause of morbidity and mortality worldwide, which is closely related to enhanced oxidative stress and inflammation. There is an urgent need for new effective therapeutic drugs that can reduce oxidative stress and inflammatory responses. Therefore, we designed and synthesized a series of novel pterostilbene chalcone and dihydropyrazole derivatives with antioxidant and anti-inflammatory activities by the molecular hybridization strategy. The preliminary anti-inflammatory activities and structure-activity relationships of these compounds were evaluated by nitric oxide (NO) inhibitory activity in lipopolysaccharide (LPS)-treated RAW264.7 cells, and compound E1 exhibited the most potent anti-inflammatory activities. Furthermore, pretreatment with compound E1 decreased reactive oxygen species (ROS) generation both in RAW264.7 and H9C2 cells by increasing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), as well as downstream antioxidant enzymes superoxide dismutase 1 (SOD1), catalase (CAT) and glutathione peroxidase 1 (GPX1). In addition, compound E1 also significantly inhibited LPS or doxorubicin (DOX)-induced inflammation in both RAW264.7 and H9C2 cells through reducing the expression of inflammatory cytokines by inhibiting nuclear factor-κB (NF-κB) signaling pathway. Moreover, we found that compound E1 improved DOX-induced heart failure by inhibiting inflammation and oxidative stress in mouse model, which is mediated by the potential of antioxidant and anti-inflammatory activities. In conclusion, this study demonstrated the novel pterostilbene dihydropyrazole derivative E1 was identified as a promising agent for heart failure treatment.

Cardiac sirtuin1 deficiency exacerbates ferroptosis in doxorubicin-induced cardiac injury through the Nrf2/Keap1 pathway

Doxorubicin (DOX), a broad-spectrum chemotherapeutic agent for various cancers, has limited clinical application because of its serious cardiotoxicity, which is due to different mechanisms, including cardiac ferroptosis and oxidative stress. Some drugs, such as berberine or dioscin, show efficacy in impeding DOX-induced cardiotoxicity by activating Sirtuin 1 (Sirt1). However, there is no direct evidence to clarify the role of Sirt1 in DOX-induced cardiomyopathy and its underlying role in cardiac ferroptosis. In this study, C57BL/6 and cardiac-specific Sirt1-/- knockout mice were used as a DOX-induced cardiotoxicity model. We found that cardiac Sirt1 was downregulated, oxidative stress was increased and ferroptosis were obviously enhanced, as reflected by decreased Glutathione peroxidase 4 (GPX4) and increased Heme oxygenase 1 (Hmox-1), exposure to DOX treatment in mice and H9c2 cells compared with the control. And Sirt1 activation was resistant to cardiac injury induced by DOX, as observed the improvement of cardiac dysfunction, and the reduction of cardiac fibrosis. However, cardiac Sirt1 deficiency aggravated Dox-induced cardiac dysfunction and cardiac remodeling, further downregulated GPX4, upregulated Hmox-1 expression and increased ROS level. In addition, Sirt1-siRNA exacerbated DOX-induced cardiotoxicity in H9c2 cells, which is similar to the results obtained in vivo. Furthermore, DOX decrease Nrf2 translocation from the cytosol to the nucleus, and Sirt1 deficiency further restrain the process, as well as the downstream Keap1 pathways, in DOX-induced cardiotoxicity. This study provides direct evidence that Sirt1 plays a protective role in DOX-induced cardiotoxicity by mediating ferroptosis reduction via the Nrf2/Keap1 pathway.

Infliximab substantially re-silenced Wnt/β-catenin signaling and ameliorated doxorubicin-induced cardiomyopathy in rats

The release of inflammatory cytokines, namely tumor necrosis factor-α (TNF-α), plays an important role in the pathogenesis of cardiomyopathy. TNF-α increases in plasma and in myocardium of heart failure patients. We aimed to investigate the role of TNF-α inhibitor (infliximab; IFX) in regulating dilated cardiomyopathy (DCM) induced in rats. DCM was induced in rats by doxorubicin (DOX; 3.5 mg. kg-1 , i.p) twice weekly for 3 weeks (21 mg. kg-1 cumulative dose). DCM rats were treated with RPL (1 mg. kg-1 orally, daily), IFX (5 mg. kg-1 ; i.p. once) or their combination for 4 weeks starting next day of last DOX dose. Echocardiography was conducted followed by a collection of blood and left ventricle (LV) for biochemical and histological investigations. DCM rats revealed deteriorated cardiac function (increased CK-MB activity, LVIDs, LVIDd, ESV, and EDV, while decreased EF% and FS%), hypertrophy (increased HW/TL, β-MHC, and α-actin), inflammation (increased IL-1β, IL-6, and TNF-α). The activation of Wnt/β-catenin along with increased gene expression of RAS components (RENIN, ACE, and AT1) were evident. LV architecture also revealed abnormalities and some degree of fibrosis. Treatment with RPL and/or IFX suppressed TNF-α and consequently improved most of these parameters suppressing Wnt/β-catenin/RAS axis. Combined RPL and IFX treatment was the best among all treatments. In conclusion, Wnt/β-catenin/RAS axis is implicated in DOX-induced cardiomyopathy. The upstream TNF-α was proved for the first time in-vivo to stimulate this axis where its inhibition by RPL or IFX prevented DCM. Targeting this axis at two points using RPL and IFX showed better therapeutic efficacy.

Qiangxin recipe improves doxorubicin-induced chronic heart failure by enhancing KLF5-mediated glucose metabolism

BACKGROUND

Qiangxin recipe (QXF) is a well-known Chinese herbal medicine commonly used in Asia for thousands of years to treat cardiovascular diseases, but its underlying mechanism remains unclear.

PURPOSE

This study aimed to illustrate whether Qiangxin Recipe (QXF) induce glucose metabolism and inhibit cardiomyocyte apoptosis by promoting the activation of the transcription factor Krüppel like factor 5 (KLF5).

MATERIAL AND METHODS

In vitro experiments, we constructed an H9C2 cardiomyocyte injury model using doxorubicin and used RNA-seq data analysis to detect the mechanism of QXF. In in vivo experiments, C57 BL/6 mice injected with doxorubicin (4 mg/kg every 6 days, for 30 days) to construct a CHF mouse model and randomly divided into to the normal control group, Dox group and Dox+QXF group (2.12 g/kg/day, 4.24 g/kg/day, for 30 days). Using Echocardiography, serum biochemical indices BNP, cTnl; and histopathological tests involving HE staining, Tunel staining and Immuno-dual fluorescence colocalization to analyze the therapeutic mechanism of QXF.

RESULTS

We verified that the Qiangxin recipe could reverse cardiomyocyte dying through enhancing glucose metabolism and reducing apoptosis to improve CHF. Mechanistically, we discovered that the Qiangxin recipe promoted the activation of transcription factor Krüppel-like factor 5 (KLF5) to induce glucose metabolism and inhibit apoptosis in cardiomyocytes. Further, we identified that KLF5 increased the promoter activity of hexokinase 2 (HK2) and B-cell CLL/lymphoma 2 (BCL2) genes, which further enhanced glucose metabolism and inhibited apoptosis of cardiomyocytes.

CONCLUSIONS

We highlighted the importance of KLF5-mediated signaling pathways in the treatment of CHF as shown by their participation in glucose metabolism and apoptosis in a doxorubicin-induced model of cardiomyocyte injury, as well as show that Qiangxin recipe can be used as a novel targeted therapy for the treatment of CHF. Compared with previous studies, we provide new ideas for the treatment of Doxorubicin-induced CHF from the perspective of energy metabolism.

The history and mystery of sacubitril/valsartan: From clinical trial to the real world

Heart failure is a serious threat to human health, with morbidity and mortality rates increasing despite the existence of multiple treatment options. Therefore, it is necessary to identify new therapeutic targets for this disease. Sacubitril/valsartan is a supramolecular sodium salt complex of the enkephalinase inhibitor prodrug sacubitril and the angiotensin receptor blocker valsartan. Its combined action increases endogenous natriuretic peptides while inhibiting the renin-angiotensin-aldosterone system and exerting cardioprotective effects. Clinical evidence suggests that sacubitril/valsartan is superior to conventional renin-angiotensin-aldosterone inhibitor therapy for patients with reduced ejection fraction heart failure who can tolerate angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. The therapy reduces the risk of heart failure hospitalization, cardiovascular mortality, and all-cause mortality and has a better safety and tolerability record. This review describes the potential pathophysiological mechanisms of cardiomyocyte injury amelioration by sacubitril/valsartan. We explore the protective effects of sacubitril/valsartan and outline the therapeutic value in patients with heart failure by summarizing the results of recent large clinical trials. Furthermore, a preliminary outlook shows that sacubitril/valsartan may be effective at treating other diseases, and provides some exploratory observations that lay the foundation for future studies on this drug.

Role of oxidative stress and inflammation-related signaling pathways in doxorubicin-induced cardiomyopathy

Doxorubicin (DOX) is a powerful and commonly used chemotherapeutic drug, used alone or in combination in a variety of cancers, while it has been found to cause serious cardiac side effects in clinical application. More and more researchers are trying to explore the molecular mechanisms of DOX-induced cardiomyopathy (DIC), in which oxidative stress and inflammation are considered to play a significant role. This review summarizes signaling pathways related to oxidative stress and inflammation in DIC and compounds that exert cardioprotective effects by acting on relevant signaling pathways, including the role of Nrf2/Keap1/ARE, Sirt1/p66Shc, Sirt1/PPAR/PGC-1α signaling pathways and NOS, NOX, Fe²⁺ signaling in oxidative stress, as well as the role of NLRP3/caspase-1/GSDMD, HMGB1/TLR4/MAPKs/NF-κB, mTOR/TFEB/NF-κB pathways in DOX-induced inflammation. Hence, we attempt to explain the mechanisms of DIC in terms of oxidative stress and inflammation, and to provide a theoretical basis or new idea for further drug research on reducing DIC. Video Abstract.

The beneficial role of exercise in preventing doxorubicin-induced cardiotoxicity

Doxorubicin is a highly effective chemotherapeutic agent widely used to treat a variety of cancers. However, the clinical application of doxorubicin is limited due to its adverse effects on several tissues. One of the most serious side effects of doxorubicin is cardiotoxicity, which results in life-threatening heart damage, leading to reduced cancer treatment success and survival rate. Doxorubicin-induced cardiotoxicity results from cellular toxicity, including increased oxidative stress, apoptosis, and activated proteolytic systems. Exercise training has emerged as a non-pharmacological intervention to prevent cardiotoxicity during and after chemotherapy. Exercise training stimulates numerous physiological adaptations in the heart that promote cardioprotective effects against doxorubicin-induced cardiotoxicity. Understanding the mechanisms responsible for exercise-induced cardioprotection is important to develop therapeutic approaches for cancer patients and survivors. In this report, we review the cardiotoxic effects of doxorubicin and discuss the current understanding of exercise-induced cardioprotection in hearts from doxorubicin-treated animals.

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

Background

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

Methods

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

Results

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

Conclusion

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

Neprilysin Inhibition in the Prevention of Anthracycline-Induced Cardiotoxicity

Anthracycline-induced cardiotoxicity (AIC) poses a clinical challenge in the management of cancer patients. AIC is characterized by myocardial systolic dysfunction and remodeling, caused by cardiomyocyte DNA damage, oxidative stress, mitochondrial dysfunction, or renin-angiotensin-aldosterone system (RAAS) dysregulation. In the past decade, after positive results of a PARADIGM-HF trial, a new class of drugs, namely angiotensin receptor/neprilysin inhibitors (ARNi), was incorporated into the management of patients with heart failure with reduced ejection fraction. As demonstrated in a variety of preclinical studies of cardiovascular diseases, the cardioprotective effects of ARNi administration are associated with decreased oxidative stress levels, the inhibition of myocardial inflammatory response, protection against mitochondrial damage and endothelial dysfunction, and improvement in the RAAS imbalance. However, data on ARNi's effectiveness in the prevention of AIC remains limited. Several reports of ARNi administration in animal models of AIC have shown promising results, as ARNi prevented ventricular systolic dysfunction and electrocardiographic changes and ameliorated oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, and the inflammatory response associated with anthracyclines. There is currently an ongoing PRADAII trial aimed to assess the efficacy of ARNi in patients receiving breast cancer treatment, which is expected to be completed by late 2025.

LCZ696 protects against doxorubicin-induced cardiotoxicity by inhibiting ferroptosis via AKT/SIRT3/SOD2 signaling pathway activation

Doxorubicin (DOX) is an effective and widely used anticancer drug but has limited clinical applicability because of its cardiotoxicity. Ferroptosis plays a key role in DOX-induced cardiac damage and cardiomyocyte cell death. The inhibition of ferroptosis reverses DOX-induced cardiotoxicity (DIC). LCZ696, a first-in-class angiotensin receptor neprilysin inhibitor, protects against DIC. However, the mechanism of action of LCZ696, especially its effect on ferroptosis, is incompletely understood. This study investigates the cardioprotective effects of LCZ696 on DIC in vivo and in vitro.Cardiotoxicity was induced in Wistar rats by tail intravenous injection of 2.5 mg/kg DOX once a week for six weeks. Rats and H9c2 cells were treated with or without LCZ696 to determine the cardioprotective role and underlying mechanisms of LCZ696 against DIC. To assess the role of SIRT3 and correlated pathways in ferroptosis, SIRT3 knockout was performed using lentiviral vectors, and AKT was inhibited with LY294002. LCZ696 significantly attenuated DIC by decreasing the concentrations of lipid reactive oxygen species and malondialdehyde and increasing the levels of glutathione peroxidase-4 and reduced glutathione in cells and heart tissues. Moreover, LCZ696 remodeled myocardial structures and improved heart ventricular function in DOX-treated rats. LCZ696 treatment increased SIRT3 expression and deacetylated its target gene SOD2, and these changes were mediated by AKT activation. SIRT3 knockdown and AKT inhibition induced lipid peroxidation and reduced the protective effect of LCZ696 in H9c2 cells. Collectively,LCZ696 prevents DIC by inhibiting ferroptosis via AKT/SIRT3/SOD2 signaling pathway activation. Thus, LZC696 is a potential therapeutic strategy for DIC.

The Innate Immune System in Cardiovascular Diseases and Its Role in Doxorubicin-Induced Cardiotoxicity

Innate immune cells are the early responders to infection and tissue damage. They play a critical role in the initiation and resolution of inflammation in response to insult as well as tissue repair. Following ischemic or non-ischemic cardiac injury, a strong inflammatory response plays a critical role in the removal of cell debris and tissue remodeling. However, persistent inflammation could be detrimental to the heart. Studies suggest that cardiac inflammation and tissue repair needs to be tightly regulated such that the timely resolution of the inflammation may prevent adverse cardiac damage. This involves the recognition of damage; activation and release of soluble mediators such as cytokines, chemokines, and proteases; and immune cells such as monocytes, macrophages, and neutrophils. This is important in the context of doxorubicin-induced cardiotoxicity as well. Doxorubicin (Dox) is an effective chemotherapy against multiple cancers but at the cost of cardiotoxicity. The innate immune system has emerged as a contributor to exacerbate the disease. In this review, we discuss the current understanding of the role of innate immunity in the pathogenesis of cardiovascular disease and dox-induced cardiotoxicity and provide potential therapeutic targets to alleviate the damage.

Gasdermin D mediates doxorubicin-induced cardiomyocyte pyroptosis and cardiotoxicity via directly binding to doxorubicin and changes in mitochondrial damage

Doxorubicin (Dox), as a widely used anthracycline antitumor drug, can cause severe cardiotoxicity. Cardiomyocyte death and inflammation are involved in the pathophysiology of Dox-induced cardiotoxicity (DIC). Gasdermin D (GSDMD) is known as a key executioner of pyroptosis, which is a pro-inflammatory programmed cell death. We aimed to investigate the impact of GSDMD on DIC and systematically reveal its underlying mechanisms. Our findings indicated that Dox induced cardiomyocyte pyroptosis in a GSDMD-dependent manner by utilizing siRNA or overexpression-plasmid technique. We then generated GSDMD global knockout mice via CRISPR/Cas9 system and found that GSDMD deficiency reduced Dox-induced cardiomyopathy. Dox induced the activation of inflammatory caspases, which subsequently mediated GSDMD-N generation indirectly. Using molecular dynamics simulation and cell-free systems, we confirmed that Dox directly bound to GSDMD and facilitated GSDMD-N-mediated pyroptosis. Furthermore, GSDMD also mediated Dox-induced mitochondrial damage via Bnip3 and mitochondrial perforation in cardiomyocytes. These findings provide fresh insights into the mechanism of how Dox-engaged GSDMD orchestrates adverse cardiotoxicity and highlight the prospects of GSDMD as a potential target for DIC.

Ranolazine alleviated cardiac/brain dysfunction in doxorubicin-treated rats

Doxorubicin (Dox), a powerful chemotherapeutic agent, has been shown to cause cardiotoxicity and neurotoxicity. Ranolazine, a drug that is commonly used to treat patients with chronic angina, has been shown to reduce toxicity from Dox therapy. Therefore, the present study aims to investigate the mechanisms behind the protective effects of ranolazine on the heart and brain in Dox-treatment. Twenty-four male Wistar rats received 6 doses of either 0.9% normal saline (0.9% NSS, i.p., n = 8) or Dox (3 mg/kg, i.p., n = 16). All Dox-treated rats were assigned into 2 groups to receive vehicle (0.9% NSS, orally; n = 8) or ranolazine (305 mg/kg/day, orally; n = 8) for 30 consecutive days. Following the treatments, left ventricular (LV) function and cognition were determined. Animals were euthanized, then the heart and brain were collected for further analysis. Dox induced systemic oxidative stress/inflammation, and cardiac injury evidenced by mitochondrial dysfunction, mitochondrial dynamic imbalance, and apoptosis, resulting in LV dysfunction. Ranolazine significantly improved LV function via attenuating cardiac injury. Dox also caused brain pathologies as indicated by increased brain inflammation, impaired blood-brain barrier integrity, brain mitochondrial dysfunction, microglial dysmorphology, hippocampal dysplasticity, and increased apoptosis, resulting in cognitive decline. Ranolazine exerted neuroprotective effects by suppressing brain pathologies and restoring cognitive function. These findings suggest that ranolazine has a potential role in cardio- and neuro-protection against chemotherapy.

Sacubitril/valsartan protects against arsenic trioxide induced cardiotoxicity in vivo and in vitro

The cardiotoxicity induced by arsenic trioxide (ATO) limits its clinical application in acute promyelocytic leukemia treatment. Sacubitril/valsartan (LCZ696) is an effective drug for the treatment of heart failure. In this study, we aimed to investigate the protective effect and mechanisms of LCZ696 against the ATO-induced cardiotoxicity in mice and H9c2 cells. We found that LCZ696 could alleviate the decrease of ejection fraction and fractional shortening induced by ATO, thereby improving mouse cardiac contractile function. LCZ696 could also reduce the myocardial enzyme, resist oxidative stress, mitigate myocardial fibrosis, and ameliorate myocardial structure, thereby alleviating myocardial damage caused by ATO. In addition, LCZ696 could significantly increase the cell viability and reduce the accumulation of reactive oxygen species in ATO-treated H9c2 cells. Besides, in vivo and in vitro studies have been found that LCZ696 could restore the expression of Bcl-2 and reduce Bax and Caspase-3 levels, inhibiting ATO-induced apoptosis. Meanwhile, LCZ696 decreased the levels of IL-1, IL-6, and TNF-α, alleviating the inflammatory injury caused by ATO. Furthermore, LCZ696 prevented NF-κB upregulation induced by ATO. Our findings revealed that LCZ696 has a considerable effect on preventing cardiotoxicity induced by ATO, which attributes to its capability to suppress oxidative stress, inflammation, and apoptosis.

LncRNA HOX transcript antisense RNA mitigates cardiac function injury in chronic heart failure via regulating microRNA-30a-5p to target KDM3A

Long noncoding RNA HOX transcript antisense RNA (HOTAIR) has been studied in multiple diseases, but the role of HOTAIR on chronic heart failure (CHF) through the regulation of microRNA (miR)‐30a‐5p and lysine‐specific demethylase 3A (KDM3A) remains unexplored. This research aims to probe the effects of HOTAIR on CHF progression via modulating miR‐30a‐5p to target KDM3A. CHF mouse model was established by intraperitoneal injection of doxorubicin. The CHF mice were then injected with high‐expressed HOTAIR, miR‐30a‐5p or KDM3A adenovirus vectors to determine the cardiac function, oxidative stress, inflammatory response, pathological change and cardiomyocyte apoptosis. HOTAIR, miR‐30a‐5p, KDM3A and Bcl‐2/adenovirus E1B 19kDa interacting protein 3 (BNIP3) expression in CHF mice was detected. The binding relations among HOTAIR, miR‐30a‐5p and KDM3A were validated. HOTAIR and KDM3A were depleted, while miR‐30a‐5p was augmented in CHF mice. The elevated HOTAIR or KDM3A or could improve cardiac function, mitigate oxidative stress and pathological change, reduce inflammatory factor levels and cardiomyocyte apoptosis, while the increased miR‐30a‐5p exerted opposite effects. The miR‐30a‐5p elevation could reverse the effects of enriched HOTAIR, while BNIP3 reduction abrogated the effects of KDM3A on CHF. HOTAIR sponged miR‐30a‐5p that targeted KDM3A. HOTAIR improves cardiac injury in CHF via modulating miR‐30a‐5p to target KDM3A. This study provides novel therapeutic strategies for CHF treatment.