FNDC5 alleviates oxidative stress and cardiomyocyte apoptosis in doxorubicin-induced cardiotoxicity via activating AKT

Research trends and hotspots of circular RNA in cardiovascular disease: A bibliometric analysis

From a global perspective, cardiovascular diseases (CVDs), the leading factor accounting for population mortality, and circRNAs, RNA molecules with stable closed-loop structures, have been proven to be closely related. The latent clinical value and the potential role of circRNAs in CVDs have been attracting increasing, active research interest, but bibliometric studies in this field are still lacking. Thus, in this study, we conducted a bibliometric analysis by using software such as VOSviewer, CiteSpace, Microsoft Excel, and the R package to determine the current research progress and hotspots and ultimately provide an overview of the development trends and future frontiers in this field. In our study, based on our search strategy, a total of 1206 publications published before July 31, 2023 were accessed from the WOSCC database. According to our findings, there is a notable increasing trend in global publications in the field of circRNA in CVDs. China was found to be the dominant country in terms of publication number, but a lack of high-quality articles was a significant fault. A cluster analysis on the co-cited references indicated that dilated cardiomyopathy, AMI, and cardiac hypertrophy are the greatest objects of concern. In contrast, a keywords analysis indicated that high importance has been ascribed to MI, abdominal aortic aneurysm, cell proliferation, and coronary artery diseases.

Leucine zipper protein 1 attenuates pressure overload-induced cardiac hypertrophy through inhibiting Stat3 signaling

INTRODUCTION

Cardiac hypertrophy is an important contributor of heart failure, and the mechanisms remain unclear. Leucine zipper protein 1 (LUZP1) is essential for the development and function of cardiovascular system; however, its role in cardiac hypertrophy is elusive.

OBJECTIVES

This study aims to investigate the molecular basis of LUZP1 in cardiac hypertrophy and to provide a rational therapeutic approach.

METHODS

Cardiac-specific Luzp1 knockout (cKO) and transgenic mice were established, and transverse aortic constriction (TAC) was used to induce pressure overload-induced cardiac hypertrophy. The possible molecular basis of LUZP1 in regulating cardiac hypertrophy was determined by transcriptome analysis. Neonatal rat cardiomyocytes were cultured to elucidate the role and mechanism of LUZP1 in vitro.

RESULTS

LUZP1 expression was progressively increased in hypertrophic hearts after TAC surgery. Gain- and loss-of-function methods revealed that cardiac-specific LUZP1 deficiency aggravated, while cardiac-specific LUZP1 overexpression attenuated pressure overload-elicited hypertrophic growth and cardiac dysfunction in vivo and in vitro. Mechanistically, the transcriptome data identified Stat3 pathway as a key downstream target of LUZP1 in regulating pathological cardiac hypertrophy. Cardiac-specific Stat3 deletion abolished the pro-hypertrophic role in LUZP1 cKO mice after TAC surgery. Further findings suggested that LUZP1 elevated the expression of Src homology region 2 domain-containing phosphatase 1 (SHP1) to inactivate Stat3 pathway, and SHP1 silence blocked the anti-hypertrophic effects of LUZP1 in vivo and in vitro.

CONCLUSION

We demonstrate that LUZP1 attenuates pressure overload-induced cardiac hypertrophy through inhibiting Stat3 signaling, and targeting LUZP1 may develop novel approaches to treat pathological cardiac hypertrophy.

CREG1 attenuates doxorubicin-induced cardiotoxicity by inhibiting the ferroptosis of cardiomyocytes

OBJECTIVE

Doxorubicin (DOX)-induced cardiotoxicity limits the application of DOX in cancer patients. Currently, there is no effective prevention or treatment for DOX-induced cardiotoxicity. The cellular repressor of E1A-stimulated genes (CREG1) is a cardioprotective factor that plays an important role in the maintenance of cardiomyocytes differentiation and homeostasis. However, the role and mechanism of CREG1 in DOX-induced cardiotoxicity has not yet been elucidated.

METHODS

In vivo, C57BL/6J mice, CREG1 transgenic and cardiac-specific CREG1 knockout mice were used to establish a DOX-induced cardiotoxicity model. H&E staining, Masson's trichrome, WGA staining, real-time PCR, and western blotting were performed to examine fibrosis and ferroptosis in the myocardium. In vitro, neonatal mouse cardiomyocytes (NMCMs) were cultured and stimulated with DOX, CREG1-overexpressed adenovirus, and small interfering RNA was used to establish CREG1 overexpression or knockdown cardiomyocytes. Transcriptomics, real-time PCR, western blotting, and immunoprecipitation were used to examine the roles and mechanisms of CREG1 in cardiomyocytes ferroptosis.

RESULTS

The mRNA and protein levels of CREG1 were reduced in the hearts and NMCMs after DOX treatment. CREG1 overexpression alleviated myocardial damage and inhibited DOX-induced ferroptosis in the myocardium. CREG1 deficiency in the heart aggravated DOX-induced cardiotoxicity and ferroptosis. In vitro, CREG1 overexpression inhibited cardiomyocytes ferroptosis induced by DOX, and CREG1 knockdown aggravated DOX-induced cardiotoxicity. Mechanistically, CREG1 inhibited the mRNA and protein expression of pyruvate dehydrogenase kinase 4 (PDK4) by regulating the F-box and WD repeat domain containing 7 (FBXW7)-forkhead box O1 (FOXO1) pathway. PDK4 deficiency reversed the effects of CREG1 knockdown on cardiomyocytes ferroptosis following DOX treatment.

CONCLUSION

CREG1 alleviated DOX-induced cardiotoxicity by inhibiting ferroptosis in cardiomyocytes. Our findings may help clarify the new roles of CREG1 in the development of DOX-induced cardiotoxicity.

Asiatic acid ameliorates doxorubicin-induced cardiotoxicity by promoting FPN-mediated iron export and inhibiting ferroptosis

Doxorubicin (DOX), a common chemotherapeutic agent in cancer therapy, is accompanied by pronounced cardiotoxicity. Ferroptosis has been implicated in the pathogenesis and therapeutics of DOX-induced cardiotoxicity (DIC). Asiatic acid (AA), a pentacyclic triterpene from the Chinese medicinal herb Centella asiatica, displays antioxidant, anti-inflammatory, and antiapoptotic activities. In this study, we investigated the beneficial effects of AA against DOX-induced ferroptosis and cardiotoxicity and the underlying mechanisms. A chronic DIC model was established by challenging mice with DOX (5 mg/kg, i.p.) once per week for 4 weeks. Concurrent with DOX insult, the mice were administered AA (25 mg·kg-1·d-1, i.g.). Cardiac function and mechanical properties of isolated cardiomyocytes were evaluated at the end of treatment. We showed that AA administration preserved cardiac function, significantly reduced cardiac injury, and improved cardiomyocyte contractile function in DIC mice. The beneficial effects of AA were causally linked to the inhibition of DOX-induced ferroptosis both in vivo and in vitro. We revealed that AA attenuated DOX-induced iron accumulation in HL-1 cells by increasing FPN-mediated iron export, in a Nrf2-dependent manner. AA upregulated Nrf2 expression and promoted Nrf2 nuclear translocation in DOX-treated HL-1 cells. Moreover, AA-offered benefits against DOX-induced cardiac dysfunction and ferroptosis were abolished by Nrf2 inhibitor ML385 (30 mg·kg-1·d-1, i.p.) administrated 30 min before AA in DIC mice. Our data favor that AA promotes FPN-mediated iron export to inhibit iron overload and ferroptosis in DIC, suggesting its therapeutic potential in the treatment of DIC.

The Role of mTOR in the Doxorubicin-Induced Cardiotoxicity: A Systematic Review

Doxorubicin (DOX) is a chemotherapy drug known to induce metabolic changes in the heart, leading to potential heart toxicity. These changes impact various cellular functions and pathways such as disrupting the mechanistic target of rapamycin (mTOR) signaling pathway. The study aimed to investigate the effect of DOX on the mTOR pathway through an in vivo systematic review. Databases were searched on September 11, 2023. We finally included 30 in vivo studies that examined the mTOR expression in cardiac tissue samples. The present study has shown that the PI3K/AKT/mTOR, the AMPK/mTOR, the p53/mTOR signaling, the mTOR/TFEB pathway, the p38 MAPK/mTOR, the sestrins/mTOR, and the KLF15/eNOS/mTORC1 signaling pathways play a crucial role in the development of DOX-induced cardiotoxicity. Inhibition or dysregulation of these pathways can lead to increased oxidative stress, apoptosis, and other adverse effects on the heart. Strategies that target and modulate the mTOR pathways, such as the use of mTOR inhibitors like rapamycin, have the potential to enhance the anticancer effects of DOX while also mitigating its cardiotoxic side effects.

Tirzepatide protects against doxorubicin-induced cardiotoxicity by inhibiting oxidative stress and inflammation via PI3K/Akt signaling

BACKGROUND

Doxorubicin (DOX) is a highly effective and widely used cytotoxic agent with application for various malignancies, but it's clinically limited due to its cardiotoxicity Oxidative stress and inflammation were reported to take part in DOX-induced cardiotoxicity. Tirzepatide, a dual glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist has been approved to treat type 2 diabetes. However, its role in DOX-induced cardiotoxicity and the underlying mechanisms has not been explored.

METHODS

The cardioprotective properties of Tirzepatide against DOX-induced cardiotoxicity are examined in this work both in vivo and in vitro. For four weeks, an intraperitoneal injection of 4 mg/kg DOX was used to cause cardiotoxicity in C57BL/6 mice. To ascertain the cardioprotective function and underlying mechanisms of Tirzepatide against DOX-induced cardiotoxicity, mice and H9c2 cells were treated with and without Tirzepatide.

RESULTS

Tirzepatide treatment significantly inhibited DOX-induced oxidative stress, inflammation and cardiac injury. Mechanistically, PI3K/Akt signaling pathway contributes to the protective effect of Tirzepatide against DOX-induced cardiotoxicity and inhibited PI3K/Akt signaling pathway with LY294002 almost blocked its therapeutic effect.

CONCLUSIONS

Collectively, Tirzepatide could alleviate DOX-induced oxidative stress, inflammation and cardiac injury via activating PI3K/Akt signaling pathway and Tirzepatide may be a novel therapeutic target for DOX-induced cardiotoxicity.

Marein Alleviates Doxorubicin-Induced Cardiotoxicity through FAK/AKT Pathway Modulation while Potentiating its Anticancer Activity

Doxorubicin (DOX) is an effective anticancer agent, yet its clinical utility is hampered by dose-dependent cardiotoxicity. This study explores the cardioprotective potential of Marein (Mar) against DOX-induced cardiac injury and elucidates underlying molecular mechanisms. Neonatal rat cardiomyocytes (NRCMs) and murine models were employed to assess the impact of Mar on DOX-induced cardiotoxicity (DIC). In vitro, cell viability, oxidative stress were evaluated. In vivo, a chronic injection method was employed to induce a DIC mouse model, followed by eight weeks of Mar treatment. Cardiac function, histopathology, and markers of cardiotoxicity were assessed. In vitro, Mar treatment demonstrated significant cardioprotective effects in vivo, as evidenced by improved cardiac function and reduced indicators of cardiac damage. Mechanistically, Mar reduced inflammation, oxidative stress, and apoptosis in cardiomyocytes, potentially via activation of the Focal Adhesion Kinase (FAK)/AKT pathway. Mar also exhibited an anti-ferroptosis effect. Interestingly, Mar did not compromise DOX's efficacy in cancer cells, suggesting a dual benefit in onco-cardiology. Molecular docking studies suggested a potential interaction between Mar and FAK. This study demonstrates Mar's potential as a mitigator of DOX-induced cardiotoxicity, offering a translational perspective on its clinical application. By activating the FAK/AKT pathway, Mar exerts protective effects against DOX-induced cardiomyocyte damage, highlighting its promise in onco-cardiology. Further research is warranted to validate these findings and advance Mar as a potential adjunctive therapy in cancer treatment.

Rejuvenation of the Aging Heart: Molecular Determinants and Applications

In Canada and worldwide, the elderly population (ie, individuals > 65 years of age) is increasing disproportionately relative to the total population. This is expected to have a substantial impact on the health care system, as increased aged is associated with a greater incidence of chronic noncommunicable diseases. Within the elderly population, cardiovascular disease is a leading cause of death, therefore developing therapies that can prevent or slow disease progression in this group is highly desirable. Historically, aging research has focused on the development of anti-aging therapies that are implemented early in life and slow the age-dependent decline in cell and organ function. However, accumulating evidence supports that late-in-life therapies can also benefit the aged cardiovascular system by limiting age-dependent functional decline. Moreover, recent studies have demonstrated that rejuvenation (ie, reverting cellular function to that of a younger phenotype) of the already aged cardiovascular system is possible, opening new avenues to develop therapies for older individuals. In this review, we first provide an overview of the functional changes that occur in the cardiomyocyte with aging and how this contributes to the age-dependent decline in heart function. We then discuss the various anti-aging and rejuvenation strategies that have been pursued to improve the function of the aged cardiomyocyte, with a focus on therapies implemented late in life. These strategies include 1) established systemic approaches (caloric restriction, exercise), 2) pharmacologic approaches (mTOR, AMPK, SIRT1, and autophagy-targeting molecules), and 3) emerging rejuvenation approaches (partial reprogramming, parabiosis/modulation of circulating factors, targeting endogenous stem cell populations, and senotherapeutics). Collectively, these studies demonstrate the exciting potential and limitations of current rejuvenation strategies and highlight future areas of investigation that will contribute to the development of rejuvenation therapies for the aged heart.

Hypoxic-Normoxic Crosstalk Activates Pro-Inflammatory Signaling in Human Cardiac Fibroblasts and Myocytes in a Post-Infarct Myocardium on a Chip

Myocardial infarctions locally deprive myocardium of oxygenated blood and cause immediate cardiac myocyte necrosis. Irreparable myocardium is then replaced with a scar through a dynamic repair process that is an interplay between hypoxic cells of the infarct zone and normoxic cells of adjacent healthy myocardium. In many cases, unresolved inflammation or fibrosis occurs for reasons that are incompletely understood, increasing the risk of heart failure. Crosstalk between hypoxic and normoxic cardiac cells is hypothesized to regulate mechanisms of repair after a myocardial infarction. To test this hypothesis, microfluidic devices are fabricated on 3D printed templates for co-culturing hypoxic and normoxic cardiac cells. This system demonstrates that hypoxia drives human cardiac fibroblasts toward glycolysis and a pro-fibrotic phenotype, similar to the anti-inflammatory phase of wound healing. Co-culture with normoxic fibroblasts uniquely upregulates pro-inflammatory signaling in hypoxic fibroblasts, including increased secretion of tumor necrosis factor alpha (TNF-α). In co-culture with hypoxic fibroblasts, normoxic human induced pluripotent stem cell (hiPSC)-derived cardiac myocytes also increase pro-inflammatory signaling, including upregulation of interleukin 6 (IL-6) family signaling pathway and increased expression of IL-6 receptor. Together, these data suggest that crosstalk between hypoxic fibroblasts and normoxic cardiac cells uniquely activates phenotypes that resemble the initial pro-inflammatory phase of post-infarct wound healing.

RIP3 orchestrates oxidative stress and pyroptosis in doxorubicin-induced cardiotoxicity through regulation of AKT/Nrf2 signaling cascade

This study was designed to explore the role of RIP3 in DOX-induced cardiotoxicity and its underlying molecular mechanisms. Our results demonstrate that RIP3 exacerbates DOX-induced cardiotoxicity through promoting oxidative stress and pyroptosis by regulating the AKT/Nuclear factor erythroid 2-related factor 2 (Nrf2) signal pathway. Inhibition of RIP3 using GSK-872 attenuated DOX-induced cardiac remodeling and contractile dysfunction. Moreover, using GSK-872 in vivo, the results revealed that inhibition of RIP3 alleviated DOX-induced cardiotoxicity by the resulting inhibition of oxidative stress and pyroptosis. In addition, inhibition of RIP3 increased the protein levels of AKT and Nrf2 in DOX-treated mouse hearts. Furthermore, the AKT inhibitor LY294002 lessened RIP3 reduction-offered protection against DOX-induced H9c2 cell injury by moderating oxidative stress and pyroptosis. Taken together, these data demonstrate that RIP3 activation orchestrates DOX-induced cardiotoxicity through elevated oxidative stress and pyroptosis in an AKT/Nrf2-dependent manner. Those findings highlight the clinical relevance and therapeutic potential of targeting RIP3 for the treatment of DOX-induced cardiotoxicity.

Triad3A-Mediated K48-Linked ubiquitination and degradation of TLR9 impairs mitochondrial bioenergetics and exacerbates diabetic cardiomyopathy

INTRODUCTION

Targeted protein degradation represents a promising therapeutic approach, while diabetic cardiomyopathy (DCM) arises as a consequence of aberrant insulin secretion and impaired glucose and lipid metabolism in the heart..

OBJECTIVES

Considering that the Toll-like receptor 9 (TLR9) signaling pathway plays a pivotal role in regulating energy metabolism, safeguarding cardiomyocytes, and influencing glucose uptake, the primary objective of this study was to investigate the impact of TLR9 on diabetic cardiomyopathy (DCM) and elucidate its underlying mechanism.

METHODS

Mouse model of DCM was established using intraperitoneal injection of STZ, and mice were transfected with adeno-associated virus serotype 9-TLR9 (AAV9-TLR9) to assess the role of TLR9 in DCM. To explore the mechanism of TLR9 in regulating DCM disease progression, we conducted interactome analysis and employed multiple molecular approaches.

RESULTS

Our study revealed a significant correlation between TLR9 expression and mouse DCM. TLR9 overexpression markedly mitigated cardiac dysfunction, myocardial fibrosis, oxidative stress, and apoptosis in DCM, while inflammation levels remained relatively unaffected. Mechanistically, TLR9 overexpression positively modulated mitochondrial bioenergetics and activated the AMPK-PGC1a signaling pathway. Furthermore, we identified Triad3A as an interacting protein that facilitated TLR9's proteasomal degradation through K48-linked ubiquitination. Inhibiting Triad3A expression improved cardiac function and pathological changes in DCM by enhancing TLR9 activity.

CONCLUSIONS

The findings of this study highlight the critical role of TLR9 in maintaining cardiac function and mitigating pathological alterations in diabetic cardiomyopathy. Triad3A-mediated regulation of TLR9 expression and function has significant implications for understanding the pathogenesis of DCM. Targeting TLR9 and its interactions with Triad3A may hold promise for the development of novel therapeutic strategies for diabetic cardiomyopathy. Further research is warranted to fully explore the therapeutic potential of TLR9 modulation in the context of cardiovascular diseases.

Protective Effect of Long Noncoding RNA OXCT1-AS1 on Doxorubicin-Induced Apoptosis of Human Myocardial Cells by the Competitive Endogenous RNA Pattern

BACKGROUND

The anthracycline chemotherapeutic antibiotic doxorubicin (DOX) can induce cumulative cardiotoxicity and lead to cardiac dysfunction. Long non-coding RNAs (lncRNAs) can function as important regulators in DOX-induced myocardial injury.

OBJECTIVE

This study aims to investigate the functional role and molecular mechanism of lncRNA OXCT1 antisense RNA 1 (OXCT1-AS1) in DOX-induced myocardial cell injury in vitro.

METHODS

Human cardiomyocytes (AC16) were stimulated with DOX to induce a myocardial cell injury model. OXCT1-AS1, miR-874-3p, and BDH1 expression in AC16 cells were determined by RT-qPCR. AC16 cell viability was measured by XTT assay. Flow cytometry was employed to assess the apoptosis of AC16 cells. Western blotting was used to evaluate protein levels of apoptosis-related markers. Dual-luciferase reporter assay was conducted to verify the binding ability between miR-874-3p and OXCT1-AS1 and between miR-874-3p and BDH1. The value of p<0.05 indicated statistical significance.

RESULTS

OXCT1-AS1 expression was decreased in DOX-treated AC16 cells. Overexpression of OXCT1-AS1 reversed the reduction of cell viability and promotion of cell apoptosis caused by DOX. OXCT1-AS1 is competitively bound to miR-874-3p to upregulate BDH1. BDH1 overexpression restored AC16 cell viability and suppressed cell apoptosis under DOX stimulation. Knocking down BDH1 reversed OXCT1-AS1-mediated attenuation of AC16 cell apoptosis under DOX treatment.

CONCLUSION

LncRNA OXCT1-AS1 protects human myocardial cells AC16 from DOX-induced apoptosis via the miR-874-3p/BDH1 axis.

Follistatin-like protein 1 attenuates doxorubicin-induced cardiomyopathy by inhibiting MsrB2-mediated mitophagy

Doxorubicin (DOX) is a potent chemotherapeutic drug; however, its clinical use is limited due to its cardiotoxicity. Mitochondrial dysfunction plays a vital role in the pathogenesis of DOX-induced cardiomyopathy. Follistatin-like protein 1 (FSTL1) is a potent cardiokine that protects the heart from diverse cardiac diseases, such as myocardial infarction, cardiac ischemia/reperfusion injury, and heart failure. However, its role in DOX-induced cardiomyopathy is unclear. Therefore, the present study investigated whether administering recombinant FSTL1 could mitigate DOX-induced cardiomyopathy and clarified the underlying molecular mechanisms. FSTL1 treatment attenuated DOX-induced cardiac dysfunction, cardiac fibrosis, and cellular apoptosis by inhibiting excess mitochondrial matrix protein methionine sulfoxide reductase B2 (MsrB2)-mediated mitophagy. Furthermore, FSTL1 administration reduced the expression of apoptotic proteins, including MsrB2, Bax, caspase 3, mitochondrial Parkin, and LC3-II, increased myocardial ATP content, and decreased cardiac malondialdehyde levels, thus protecting mitochondrial function against DOX-induced cardiac injury. Furthermore, FSTL1 treatment protected the contractile properties of adult cardiomyocytes against DOX-induced injury in vitro. Furthermore, carbonyl cyanide m-chlorophenylhydrazone, a mitophagy inducer, impaired the protective effects of FSTL1 in DOX-treated H9c2 cardiomyocytes. In conclusion, these results show that FSTL1 is a novel therapeutic agent against DOX-induced cardiotoxicity that improves mitochondrial function and decreases mitophagy.

The NEDD8 activating enzyme inhibitor MLN4924 mitigates doxorubicin-induced cardiotoxicity in mice

Doxorubicin (DOX) is a widely utilized chemotherapeutic agent in clinical oncology for treating various cancers. However, its clinical use is constrained by its significant side effects. Among these, the development of cardiomyopathy, characterized by cardiac remodeling and eventual heart failure, stands as a major concern following DOX chemotherapy. In our current investigation, we have showcased the efficacy of MLN4924 in mitigating doxorubicin-induced cardiotoxicity through direct inhibition of the NEDD8-activating enzyme, NAE. MLN4924 demonstrated the ability to stabilize mitochondrial function post-doxorubicin treatment, diminish cardiomyocyte apoptosis, alleviate oxidative stress-induced damage in the myocardium, enhance cardiac contractile function, mitigate cardiac fibrosis, and impede cardiac remodeling associated with heart failure. At the mechanistic level, MLN4924 intervened in the neddylation process by inhibiting the NEDD8 activating enzyme, NAE, within the murine cardiac tissue subsequent to doxorubicin treatment. This intervention resulted in the suppression of NEDD8 protein expression, reduction in neddylation activity, and consequential manifestation of cardioprotective effects. Collectively, our findings posit MLN4924 as a potential therapeutic avenue for mitigating doxorubicin-induced cardiotoxicity by attenuating heightened neddylation activity through NAE inhibition, thereby offering a viable and promising treatment modality for afflicted patients.

Possible pathogenic mechanisms for doxorubicin-induced splenic atrophy in a human breast cancer xenograft mouse model

Doxorubicin-based chemotherapy is a widely used first-line treatment for breast cancer, yet it is associated with various side effects, including splenic atrophy. However, the pathogenic mechanisms underlying doxorubicin-induced atrophy of the spleen remain unclear. This study investigates that doxorubicin treatment leads to splenic atrophy through several interconnected pathways involving histological changes, an inflammatory response, and apoptosis. Immunohistochemical and western blot analyses revealed reduced size of white and red pulp, decreased cellularity, amyloidosis, and fibrotic remodeling in the spleen following doxorubicin treatment. Additionally, increased secretion of pro-inflammatory cytokines was detected using an antibody array and enzyme-linked immunosorbent assay (ELISA), which triggers inflammation through the regulation of signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappa B (NF-κB) signaling pathways. Further analysis revealed that the loss of regulators and effectors of the oxidative defense system, including sirtuin (Sirt)3, Sirt5, superoxide dismutase (SOD)1, and SOD2, was implicated in the upstream regulation of caspase-dependent cellular apoptosis. These findings provide insights on the pathogenic mechanisms underlying doxorubicin-induced splenic atrophy and suggest that further investigation may be warranted to explore strategies for managing potential side effects in breast cancer patients treated with doxorubicin.

An update of the molecular mechanisms underlying anthracycline induced cardiotoxicity

Anthracycline drugs mainly include doxorubicin, epirubicin, pirarubicin, and aclamycin, which are widely used to treat a variety of malignant tumors, such as breast cancer, gastrointestinal tumors, lymphoma, etc. With the accumulation of anthracycline drugs in the body, they can induce serious heart damage, limiting their clinical application. The mechanism by which anthracycline drugs cause cardiotoxicity is not yet clear. This review provides an overview of the different types of cardiac damage induced by anthracycline-class drugs and delves into the molecular mechanisms behind these injuries. Cardiac damage primarily involves alterations in myocardial cell function and pathological cell death, encompassing mitochondrial dysfunction, topoisomerase inhibition, disruptions in iron ion metabolism, myofibril degradation, and oxidative stress. Mechanisms of uptake and transport in anthracycline-induced cardiotoxicity are emphasized, as well as the role and breakthroughs of iPSC in cardiotoxicity studies. Selected novel cardioprotective therapies and mechanisms are updated. Mechanisms and protective strategies associated with anthracycline cardiotoxicity in animal experiments are examined, and the definition of drug damage in humans and animal models is discussed. Understanding these molecular mechanisms is of paramount importance in mitigating anthracycline-induced cardiac toxicity and guiding the development of safer approaches in cancer treatment.

Semaglutide ameliorates cardiac remodeling in male mice by optimizing energy substrate utilization through the Creb5/NR4a1 axis

Semaglutide, a glucagon-like peptide-1 receptor agonist, is clinically used as a glucose-lowering and weight loss medication due to its effects on energy metabolism. In heart failure, energy production is impaired due to altered mitochondrial function and increased glycolysis. However, the impact of semaglutide on cardiomyocyte metabolism under pressure overload remains unclear. Here we demonstrate that semaglutide improves cardiac function and reduces hypertrophy and fibrosis in a mouse model of pressure overload-induced heart failure. Semaglutide preserves mitochondrial structure and function under chronic stress. Metabolomics reveals that semaglutide reduces mitochondrial damage, lipid accumulation, and ATP deficiency by promoting pyruvate entry into the tricarboxylic acid cycle and increasing fatty acid oxidation. Transcriptional analysis shows that semaglutide regulates myocardial energy metabolism through the Creb5/NR4a1 axis in the PI3K/AKT pathway, reducing NR4a1 expression and its translocation to mitochondria. NR4a1 knockdown ameliorates mitochondrial dysfunction and abnormal glucose and lipid metabolism in the heart. These findings suggest that semaglutide may be a therapeutic agent for improving cardiac remodeling by modulating energy metabolism.

Ohwia caudata inhibits doxorubicin-induced cardiotoxicity by regulating mitochondrial dynamics via the IGF-IIR/p-Drp1/PARP signaling pathway

The most effective drug, doxorubicin (DOX), is widely used worldwide for clinical application as an anticancer drug. DOX-induced cytotoxicity is characterized by mitochondrial dysfunction. There is no alternative treatment against DOX-induced cardiac damage despite intensive research in the present decades. Ohwia caudata has emerged as a potential herbal remedy that prevents from DOX-induced cytotoxicity owing to its pharmacological action of sustaining mitochondrial dynamics by attenuating oxidative stress and inducing cellular longevity. However, its underlying mechanisms are unknown. The novel treatment provided here depends on new evidence from DOX-treated H9c2 cells, which significantly enhanced insulin-like growth factor (IGF) II receptor (IGF-IIR) pathways that activated calcineurin and phosphorylated dynamin-related protein 1 (p-Drp1) at ser616 (p-Drp1[ser616]); cells undergo apoptosis due to these factors, which translocate to mitochondria and disrupt their function and integrity, and in terms of herbal medicine treatment, which significantly blocked these phenomena. Thus, our findings indicate that maintaining integrity of mitochondria is an essential element in lowering DOX-induced cytotoxicity, which further emphasizes that our herbal medicine can successfully block IGF-IIR pathways and could potentially act as an alternative mechanism in terms of cardioprotective against doxorubicin.

Semaglutide attenuates doxorubicin-induced cardiotoxicity by ameliorating BNIP3-Mediated mitochondrial dysfunction

AIMS

Doxorubicin is a powerful chemotherapeutic agent for cancer, whose use is limited due to its potential cardiotoxicity. Semaglutide (SEMA), a novel analog of glucagon-like peptide-1 (GLP-1), has received widespread attention for the treatment of diabetes. However, increasing evidence has highlighted its potential therapeutic benefits on cardiac function. Therefore, the objective of this study was to examine the efficacy of semaglutide in ameliorating doxorubicin-induced cardiotoxicity.

METHODS AND RESULTS

Doxorubicin-induced cardiotoxicity is an established model to study cardiac function. Cardiac function was studied by transthoracic echocardiography and invasive hemodynamic monitoring. The results showed that semaglutide significantly ameliorated doxorubicin-induced cardiac dysfunction. RNA sequencing suggested that Bnip3 is the candidate gene that impaired the protective effect of semaglutide in doxorubicin-induced cardiotoxicity. To determine the role of BNIP3 on the effect of semaglutide in doxorubicin-induced cardiotoxicity, BNIP3 with adeno-associated virus serotype 9 (AAV9) expressing cardiac troponin T (cTnT) promoter was injected into tail vein of C57/BL6J mice to overexpress BNIP3, specifically in the heart. Overexpression of BNIP3 prevented the improvement in cardiac function caused by semaglutide. In vitro experiments showed that semaglutide, via PI3K/AKT pathway, reduced BNIP3 expression in the mitochondria, improving mitochondrial function.

CONCLUSION

Semaglutide ameliorates doxorubicin-induced mitochondrial and cardiac dysfunction via PI3K/AKT pathway, by reducing BNIP3 expression in mitochondria. The improvement in mitochondrial function reduces doxorubicin-mediated cardiac injury and improves cardiac function. Therefore, semaglutide is a potential therapy to reduce doxorubicin-induced acute cardiotoxicity.

New insights into the roles of Irisin in diabetic cardiomyopathy and vascular diseases

Diabetes mellitus (DM) is a prevalent chronic disease in the 21st century due to increased lifespan and unhealthy lifestyle choices. Extensive research indicates that exercise can play a significant role in regulating systemic metabolism by improving energy metabolism and mitigating various metabolic disorders, including DM. Irisin, a well-known exerkine, was initially reported to enhance energy expenditure by indicating the browning of white adipose tissue (WAT) through peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) signaling. In this review, we summarize the potential mechanisms underlying the beneficial effects of Irisin on glucose dysmetabolism, including reducing gluconeogenesis, enhancing insulin energy expenditure, and promoting glycogenesis. Additionally, we highlight Irisin's potential to improve diabetic vascular diseases by stimulating nitric oxide (NO) production, reducing oxidative and nitrosative stress, curbing inflammation, and attenuating endothelial cell aging. Furthermore, we discuss the potential of Irisin to improve diabetic cardiomyopathy by preventing cardiomyocyte loss and reducing myocardial hypertrophy and fibrosis. Given Irisin's promising functions in managing diabetic cardiomyopathy and vascular diseases, targeting Irisin for therapeutic purposes could be a fruitful avenue for future research and clinical interventions.

Follistatin-like 1 protects against doxorubicin-induced cardiotoxicity by preventing mitochondrial dysfunction through the SIRT6/Nrf2 signaling pathway

Mitochondrial dysfunction and myocardial remodeling have been reported to be the main underlying molecular mechanisms of doxorubicin-induced cardiotoxicity. SIRT6 is a nicotinamide adenine dinucleotide-dependent enzyme that plays a vital role in cardiac protection against various stresses. Moreover, previous studies have demonstrated that FSTL1 could alleviate doxorubicin-induced cardiotoxicity by inhibiting autophagy. The present study investigated the probable mechanisms of FSTL1 on doxorubicin-induced cardiotoxicity in vivo and in vitro. We confirmed that FSTL1 exerted a pivotal protective role on cardiac tissue in vivo and on doxorubicin-induced cell injury in vitro. Furthermore, FSTL1 can alleviate doxorubicin-induced mitochondrial dysfunction by inhibiting autophagy and apoptosis. Further studies demonstrated that FSTL1 can activate SIRT6 signaling by restoring the SIRT6 protein expression in doxorubicin-induced myocardial injury. SIRT6 activation elevated the protein expression of Nrf2 in doxorubicin-induced H9C2 injury. Treatment with the Nrf2 inhibitor ML385 partially antagonized the cardioprotective role of SIRT6 on doxorubicin-induced autophagy or apoptosis. These results suggested that the protective mechanism of FSTL1 on doxorubicin-induced cardiotoxicity may be related with the inhibition of autophagy and apoptosis, partly through the activation of SIRT6/Nrf2.

Idebenone alleviates doxorubicin-induced cardiotoxicity by stabilizing FSP1 to inhibit ferroptosis

Doxorubicin (DOX)-mediated cardiotoxicity can exacerbate mortality in oncology patients, but related pharmacotherapeutic measures are relatively limited. Ferroptosis was recently identified as a major mechanism of DOX-induced cardiotoxicity. Idebenone, a novel ferroptosis inhibitor, is a well-described clinical drug widely used. However, its role and pathological mechanism in DOX-induced cardiotoxicity are still unclear. In this study, we demonstrated the effects of idebenone on DOX-induced cardiotoxicity and elucidated its underlying mechanism. A single intraperitoneal injection of DOX (15 mg/kg) was administrated to establish DOX-induced cardiotoxicity. The results showed that idebenone significantly attenuated DOX-induced cardiac dysfunction due to its ability to regulate acute DOX-induced Fe2+ and ROS overload, which resulted in ferroptosis. CESTA and BLI further revealed that idebenone's anti-ferroptosis effect was mediated by FSP1. Interestingly, idebenone increased FSP1 protein levels but did not affect Fsp1 mRNA levels in the presence of DOX. Idebenone could form stable hydrogen bonds with FSP1 protein at K355, which may influence its association with ubiquitin. The results confirmed that idebenone stabilized FSP1 protein levels by inhibiting its ubiquitination degradation. In conclusion, this study demonstrates idebenone attenuated DOX-induced cardiotoxicity by inhibiting ferroptosis via regulation of FSP1, making it a potential clinical drug for patients receiving DOX treatment.

Nanomedicine alleviates doxorubicin-induced cardiotoxicity and enhances chemotherapy synergistic chemodynamic therapy

Doxorubicin (DOX) is widely used in clinic as a broad-spectrum chemotherapy drug, which can enhance the efficacy of chemodynamic therapy (CDT) by interfering tumor-related metabolize to increase H2O2 content. However, DOX can induce serious cardiomyopathy (DIC) due to its oxidative stress in cardiomyocytes. Eliminating oxidative stress would create a significant opportunity for the clinical application of DOX combined with CDT. To address this issue, we introduced sodium ascorbate (AscNa), the main reason is that AscNa can be catalyzed to produce H2O2 by the abundant Fe3+ in the tumor site, thereby enhancing CDT. While the content of Fe3+ in heart tissue is relatively low, so the oxidation of AscNa had tumor specificity. Meanwhile, due to its inherent reducing properties, AscNa could also eliminate the oxidative stress generated by DOX, preventing cardiotoxicity. Due to the differences between myocardial tissue and tumor microenvironment, a novel nanomedicine was designed. MoS2 was employed as a carrier and CDT catalyst, loaded with DOX and AscNa, coating with homologous tumor cell membrane to construct an acid-responsive nanomedicine MoS2-DOX/AscNa@M (MDA@M). In tumor cells, AscNa enhances the synergistic therapy of DOX and MoS2. In cardiomyocytes, AscNa could effectively reduce the cardiomyopathy induced by DOX. Overall, this study enhanced the clinical potential of chemotherapy synergistic CDT.

Exploring Anthracycline-Induced Cardiotoxicity from the Perspective of Protein Quality Control

Anthracyclines are effective anticancer drugs; however, their use is restricted because of their dose-dependent, time-dependent and irreversible myocardial toxicity. The mechanism of anthracycline cardiotoxicity has been widely studied but remains unclear. Protein quality control is crucial to the stability of the intracellular environment and, ultimately, to the heart because cardiomyocytes are terminally differentiated. Two evolutionarily conserved mechanisms, autophagy, and the ubiquitin-proteasome system, synergistically degrade misfolded proteins and remove defective organelles. Recent studies demonstrated the importance of these mechanisms. Further studies will reveal the detailed metabolic pathway and metabolic control of the protein quality control mechanism integrated into anthracycline-induced cardiotoxicity. This review provides theoretical support for clinicians in the application and management of anthracyclines.

FNDC5 prevents oxidative stress and neuronal apoptosis after traumatic brain injury through SIRT3-dependent regulation of mitochondrial quality control

Mitochondrial dysfunction and oxidative stress are important mechanisms for secondary injury after traumatic brain injury (TBI), which result in progressive pathophysiological exacerbation. Although the Fibronectin type III domain-containing 5 (FNDC5) was reported to repress oxidative stress by retaining mitochondrial biogenesis and dynamics, its possible role in the secondary injury after TBI remain obscure. In present study, we observed that the level of serum irisin (the cleavage product of FNDC5) significantly correlated with the neurological outcomes of TBI patients. Knockout of FNDC5 increased the lesion volume and exacerbated apoptosis and neurological deficits after TBI in mice, while FNDC5 overexpression yielded a neuroprotective effect. Moreover, FNDC5 deficiency disrupted mitochondrial dynamics and function. Activation of Sirtuin 3 (SIRT3) alleviated FNDC5 deficiency-induced disruption of mitochondrial dynamics and bioenergetics. In neuron-specific SIRT3 knockout mice, FNDC5 failed to attenuate TBI-induced mitochondrial damage and brain injuries. Mechanically, FNDC5 deficiency led to reduced SIRT3 expression via enhanced ubiquitin degradation of transcription factor Nuclear factor erythroid 2-related factor 2 (NRF2), which contributed to the hyperacetylation and inactivation of key regulatory proteins of mitochondrial dynamics and function, including OPA1 and SOD2. Finally, engineered RVG29-conjugated nanoparticles were generated to selectively and efficiently deliver irisin to the brain of mice, which yielded a satisfactory curative effect against TBI. In conclusion, FNDC5/irisin exerts a protective role against acute brain injury by promoting SIRT3-dependent mitochondrial quality control and thus represents a potential target for neuroprotection after TBI.

Liraglutide Pretreatment Does Not Improve Acute Doxorubicin-Induced Cardiotoxicity in Rats

Doxorubicin is an effective drug for cancer treatment; however, cardiotoxicity limits its use. Cardiotoxicity pathophysiology is multifactorial. GLP-1 analogues have been shown to reduce oxidative stress and inflammation. In this study, we evaluated the effect of pretreatment with liraglutide on doxorubicin-induced acute cardiotoxicity. A total of 60 male Wistar rats were allocated into four groups: Control (C), Doxorubicin (D), Liraglutide (L), and Doxorubicin + Liraglutide (DL). L and DL received subcutaneous injection of liraglutide 0.6 mg/kg daily, while C and D received saline for 2 weeks. Afterwards, D and DL received a single intraperitoneal injection of doxorubicin 20 mg/kg; C and L received an injection of saline. Forty-eight hours after doxorubicin administration, the rats were subjected to echocardiogram, isolated heart functional study, and euthanasia. Liraglutide-treated rats ingested significantly less food and gained less body weight than animals that did not receive the drug. Rats lost weight after doxorubicin injection. At echocardiogram and isolated heart study, doxorubicin-treated rats had systolic and diastolic function impairment. Myocardial catalase activity was statistically higher in doxorubicin-treated rats. Myocardial protein expression of tumor necrosis factor alpha (TNF-α), phosphorylated nuclear factor-κB (p-NFκB), troponin T, and B-cell lymphoma 2 (Bcl-2) was significantly lower, and the total NFκB/p-NFκB ratio and TLR-4 higher in doxorubicin-treated rats. Myocardial expression of OPA-1, MFN-2, DRP-1, and topoisomerase 2β did not differ between groups (p > 0.05). In conclusion, doxorubicin-induced cardiotoxicity is accompanied by decreased Bcl-2 and phosphorylated NFκB and increased catalase activity and TLR-4 expression. Liraglutide failed to improve acute doxorubicin-induced cardiotoxicity in rats.

Hofmann Bowman M, Yan L. S100a8/9 (S100 Calcium Binding Protein a8/9) Promotes Cardiac Hypertrophy Via Upregulation of FGF23 (Fibroblast Growth Factor 23) in Mice

BACKGROUND

S100a8/9 (S100 calcium binding protein a8/9) belongs to the S100 family and has gained a lot of interest as a critical regulator of inflammatory response. Our previous study found that S100a8/9 homolog promoted aortic valve sclerosis in mice with chronic kidney disease. However, the role of S100a8/9 in pressure overload-induced cardiac hypertrophy remains unclear. The present study was to explore the role of S100a8/9 in cardiac hypertrophy.

METHODS AND RESULTS

Cardiomyocyte-specific S100a9 loss or gain of function was achieved using an adeno-associated virus system, and the model of cardiac hypertrophy was established by aortic banding-induced pressure overload. The results indicate that S100a8/9 expression was increased in response to pressure overload. S100a9 deficiency alleviated pressure overload-induced hypertrophic response, whereas S100a9 overexpression accelerated cardiac hypertrophy. S100a9-overexpressed mice showed increased FGF23 (fibroblast growth factor 23) expression in the hearts after exposure to pressure overload, which activated calcineurin/NFAT (nuclear factor of activated T cells) signaling in cardiac myocytes and thus promoted hypertrophic response. A specific antibody that blocks FGFR4 (FGF receptor 4) largely abolished the prohypertrophic response of S100a9 in mice.

CONCLUSIONS

In conclusion, S100a8/9 promoted the development of cardiac hypertrophy in mice. Targeting S100a8/9 may be a promising therapeutic approach to treat cardiac hypertrophy.

FGF17 protects cerebral ischemia reperfusion-induced blood-brain barrier disruption via FGF receptor 3-mediated PI3K/AKT signaling pathway

Maintaining blood-brain barrier (BBB) integrity is critical components of therapeutic approach for ischemic stroke. Fibroblast growth factor 17 (FGF17), a member of FGF8 superfamily, exhibits the strongest expression throughout the wall of all major arteries during development. However, its molecular action and potential protective role on brain endothelial cells after stroke remains unclear. Here, we observed reduced levels of FGF17 in the serum of patients with ischemic stroke, as well as in the brains of mice subjected to middle cerebral artery occlusion (MCAO) injury and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced brain microvascular endothelial cells (bEnd.3) cells. Moreover, treatment with exogenous recombinant human FGF17 (rhFGF17) decreased infarct volume, improved neurological deficits, reduced Evans Blue leakage and upregulated the expression of tight junctions in MCAO-injured mice. Meanwhile, rhFGF17 increased cell viability, enhanced trans-endothelial electrical resistance, reduced sodium fluorescein leakage, and alleviated reactive oxygen species (ROS) generation in OGD/R-induced bEnd.3 cells. Mechanistically, the treatment with rhFGF17 resulted in nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear accumulation and upregulation of heme oxygenase-1 (HO-1) expression. Additionally, based on in-vivo and in-vitro research, rhFGF17 exerted protective effects against ischemia/reperfusion (I/R) -induced BBB disruption and endothelial cell apoptosis through the activation of the FGF receptor 3/PI3K/AKT signaling pathway. Overall, our findings indicated that FGF17 may hold promise as a novel therapeutic strategy for ischemic stroke patients.

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.

Aucubin alleviates doxorubicin-induced cardiotoxicity through crosstalk between NRF2 and HIPK2 mediating autophagy and apoptosis

BACKGROUND

Doxorubicin (DOX) is widely used for the treatment of a variety of cancers. However, its clinical application is limited by dose-dependent cardiotoxicity. Recent findings demonstrated that autophagy inhibition and apoptosis of cardiomyocytes induced by oxidative stress dominate the pathophysiology of DOX-induced cardiotoxicity (DIC), however, there are no potential molecules targeting on these.

PURPOSE

This study aimed to explore whether aucubin (AU) acting on inimitable crosstalk between NRF2 and HIPK2 mediated the autophagy, oxidative stress, and apoptosis in DIC, and provide a new and alternative strategy for the treatment of DIC.

METHODS AND RESULTS

We first demonstrated the protection of AU on cardiac structure and function in DIC mice manifested by increased EF and FS values, decreased serum CK-MB and LDH contents and well-aligned cardiac tissue in HE staining. Furthermore, AU alleviated DOX-induced myocardial oxidative stress, mitochondrial damage, apoptosis, and autophagy flux dysregulation in mice, as measured by decreased ROS, 8-OHdG, and TUNEL-positive cells in myocardial tissue, increased SOD and decreased MDA in serum, aligned mitochondria with reduced vacuoles, and increased autophagosomes. In vitro, AU alleviated DOX-induced oxidative stress, autophagy inhibition, and apoptosis by promoting NRF2 and HIPK2 expression. We also identified crosstalk between NRF2 and HIPK2 in DIC as documented by overexpression of NRF2 or HIPK2 reversed cellular oxidative stress, autophagy blocking, and apoptosis aggravated by HIPK2 or NRF2 siRNA, respectively. Simultaneously, AU promoted the expression and nuclear localization of NRF2 protein, which was reversed by HIPK2 siRNA, and AU raised the expression of HIPK2 protein as well, which was reversed by NRF2 siRNA. Crucially, AU did not affect the antitumor activity of DOX against MCF-7 and HepG2 cells, which made up for the shortcomings of previous anti-DIC drugs.

CONCLUSION

These collective results innovatively documented that AU regulated the unique crosstalk between NRF2 and HIPK2 to coordinate oxidative stress, autophagy, and apoptosis against DIC without compromising the anti-tumor effect of DOX in vitro.

Irisin attenuates type 1 diabetic cardiomyopathy by anti-ferroptosis via SIRT1-mediated deacetylation of p53

BACKGROUND

Diabetic cardiomyopathy (DCM) is a serious complication in patients with type 1 diabetes mellitus (T1DM), which still lacks adequate therapy. Irisin, a cleavage peptide off fibronectin type III domain-containing 5, has been shown to preserve cardiac function in cardiac ischemia-reperfusion injury. Whether or not irisin plays a cardioprotective role in DCM is not known.

METHODS AND RESULTS

T1DM was induced by multiple low-dose intraperitoneal injections of streptozotocin (STZ). Our current study showed that irisin expression/level was lower in the heart and serum of mice with STZ-induced TIDM. Irisin supplementation by intraperitoneal injection improved the impaired cardiac function in mice with DCM, which was ascribed to the inhibition of ferroptosis, because the increased ferroptosis, associated with increased cardiac malondialdehyde (MDA), decreased reduced glutathione (GSH) and protein expressions of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4), was ameliorated by irisin. In the presence of erastin, a ferroptosis inducer, the irisin-mediated protective effects were blocked. Mechanistically, irisin treatment increased Sirtuin 1 (SIRT1) and decreased p53 K382 acetylation, which decreased p53 protein expression by increasing its degradation, consequently upregulated SLC7A11 and GPX4 expressions. Thus, irisin-mediated reduction in p53 decreases ferroptosis and protects cardiomyocytes against injury due to high glucose.

CONCLUSION

This study demonstrated that irisin could improve cardiac function by suppressing ferroptosis in T1DM via the SIRT1-p53-SLC7A11/GPX4 pathway. Irisin may be a therapeutic approach in the management of T1DM-induced cardiomyopathy.

MG53: A new protagonist in the precise treatment of cardiomyopathies

Cardiomyopathies (CMs) are highly heterogeneous progressive heart diseases characterised by structural and functional abnormalities of the heart, whose intricate pathogenesis has resulted in a lack of effective treatment options. Mitsugumin 53 (MG53), also known as Tripartite motif protein 72 (TRIM72), is a tripartite motif family protein from the immuno-proteomic library expressed primarily in the heart and skeletal muscle. Recent studies have identified MG53 as a potential cardioprotective protein that may play a crucial role in CMs. Therefore, the objective of this review is to comprehensively examine the underlying mechanisms mediated by MG53 responsible for myocardial protection, elucidate the potential role of MG53 in various CMs as well as its dominant status in the diagnosis and prognosis of human myocardial injury, and evaluate the potential therapeutic value of recombinant human MG53 (rhMG53) in CMs. It is expected to yield novel perspectives regarding the clinical diagnosis and therapeutic treatment of CMs.

SESN2-Mediated AKT/GSK-3β/NRF2 Activation to Ameliorate Adriamycin Cardiotoxicity in High-Fat Diet-Induced Obese Mice

Aims: Obese patients are highly sensitive to adriamycin (ADR)-induced cardiotoxicity. However, the potential mechanism of superimposed toxicity remains to be elucidated. Sestrin 2 (SESN2), a potential antioxidant, could attenuate stress-induced cardiomyopathy; therefore, this study aims to explore whether SESN2 enhances cardiac resistance to ADR-induced oxidative damage in high-fat diet (HFD)-induced obese mice. Results: The results revealed that obesity decreased SESN2 expression in ADR-exposed heart. And, HFD mice may predispose to ADR-induced cardiotoxicity, which was probably associated with inhibiting protein kinase B (AKT), glycogen synthase kinase-3 beta (GSK-3β) phosphorylation and subsequently blocking nuclear localization of nuclear factor erythroid-2 related factor 2 (NRF2), ultimately resulting in cardiac oxidative damage. However, these destructive cascades and cardiac oxidative damage effects induced by HFD/sodium palmitate combined with ADR were blocked by overexpression of SESN2. Moreover, the antioxidant effect of SESN2 could be largely abolished by sh-Nrf2 or wortmannin. And sulforaphane, an NRF2 agonist, could remarkably reverse cardiac pathological and functional abnormalities caused by ADR in obese mice. Innovation and Conclusion: This study demonstrated that SESN2 might be a promising therapeutic target for improving anthracycline-related cardiotoxicity in obesity by upregulating activity of NRF2 via AKT/GSK-3β/Src family tyrosine kinase signaling pathway. Antioxid. Redox Signal. 40, 598-615.

Eupatilin attenuates doxorubicin-induced cardiotoxicity by activating the PI3K-AKT signaling pathway in mice

Eupatilin is a pharmacologically active flavonoid with a variety of biological activities, such as anticancer, anti-inflammatory, antioxidant, neuroprotective, anti-allergic and cardioprotective effects. However, whether eupatilin has protective effects on doxorubicin-induced cardiotoxicity remains unknown. Thus, this study aimed to investigate the role of eupatilin in doxorubicin-induced cardiotoxicity. Mice were exposed to a single dose of doxorubicin (15 mg/kg) to generate doxorubicin-induced cardiotoxicity or normal saline as a control. To explore the protective effects, mice were intraperitoneally injected with eupatilin daily for 7 days. Then, we examined the changes in cardiac function, inflammation, apoptosis, and oxidative stress to evaluate the effects of eupatilin on doxorubicin-induced cardiotoxicity. Additionally, RNA-seq analysis was introduced to explore the potential molecular mechanisms. Eupatilin ameliorated doxorubicin-induced cardiotoxicity by attenuating inflammation, oxidative stress, and cardiomyocyte apoptosis and ameliorated doxorubicin-induced cardiac dysfunction. Mechanistically, eupatilin activated the PI3K-AKT signaling pathway, as evidenced by RNA-seq analysis and Western blot analysis. This study provides the first evidence that eupatilin ameliorates doxorubicin-induced cardiotoxicity by attenuating inflammation, oxidative stress, and apoptosis. Pharmacotherapy with eupatilin provides a novel therapeutic regimen for doxorubicin-induced cardiotoxicity.

Matrine attenuating cardiomyocyte apoptosis in doxorubicin-induced cardiotoxicity through improved mitochondrial membrane potential and activation of mitochondrial respiratory chain Complex I pathway

The study aimed to demonstrate that matrine can reduce apoptosis in H9c2 cells induced by the cardiotoxic anticancer drug doxorubicin (DOX).The researchers pretreated H9c2 cells with different concentrations of matrine before exposing them to DOX and cultured them for 24 h. They assessed cell survival rates using cell counting kit-8 and MTT assay. Hoechst 33258 dye kits were used to determine apoptosis, while laser confocal JC-1 method was applied to test the mitochondrial membrane potential (MMP). Complex I activities were detected following the manufacturer's protocol. The results indicated that matrine pretreatment significantly increased the survival rate of H9c2 cells injured by DOX. Additionally, matrine reduced apoptosis in H9c2 cells through the improvement of MMP and activity of Complex I, which were damaged by DOX.

Irisin protects against cardiac injury by inhibiting NLRP3 inflammasome-mediated pyroptosis during remodeling after infarction

This study aimed to explore the cardioprotective mechanism of irisin in the context of cardiac injury. Utilizing a myocardial infarction (MI) mouse model, we investigated the therapeutic potential of recombinant human irisin (rhIrisin) administered for 28 days post-infarction. The efficacy of irisin treatment was evaluated through echocardiographic assessment of cardiac function and serum analysis of myocardial injury markers. Our research provided novel insights into the impacts of irisin on the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome activation and pyroptosis, assessed both in vivo in MI mice and in vitro in hypoxia/reoxygenation-treated H9C2 cells. Remarkably, irisin treatment significantly reduced levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), and troponin I, indicating reduced myocardial injury. Echocardiography highlighted substantial improvements in left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), and dimensions (LVIDd and LVIDs) in irisin-treated mice, underscoring enhanced cardiac function. Moreover, irisin was shown to significantly suppress the mRNA and protein expressions of key components involved in NLRP3 inflammasome pathway (NLRP3, ASC, caspase-1 (p20), and interleukin-18 (IL-18)) both in MI-induced mice and hypoxia/reoxygenation-treated cells. This study firstly reveals that the cardioprotective effect of irisin is mediated through the attenuation of NLRP3 inflammasome activation and pyroptosis, positioning irisin as a promising therapeutic agent for cardiac injury.

FNDC5/irisin ameliorates bone loss of type 1 diabetes by suppressing endoplasmic reticulum stress‑mediated ferroptosis

BACKGROUND

Ferroptosis is known to play a crucial role in diabetic osteopathy. However, key genes and molecular mechanisms remain largely unclear. This study aimed to identify a crucial ferroptosis-related differentially expressed gene (FR-DEG) in diabetic osteopathy and investigate its potential mechanism.

METHODS

We identified fibronectin type III domain-containing protein 5 (FNDC5)/irisin as an essential FR-DEG in diabetic osteopathy using the Ferroptosis Database (FerrDb) and GSE189112 dataset. Initially, a diabetic mouse model was induced by intraperitoneal injection of streptozotocin (STZ), followed by intraperitoneal injection of irisin. MC3T3-E1 cells treated with high glucose (HG) were used as an in vitro model. FNDC5 overexpression plasmid was used to explore underlying mechanisms in vitro experiments. Femurs were collected for micro-CT scan, histomorphometry, and immunohistochemical analysis. Peripheral serum was collected for ELISA analysis. Cell viability was assessed using a CCK-8 kit. The levels of glutathione (GSH), malondialdehyde (MDA), iron, reactive oxygen species (ROS), and lipid ROS were detected by the corresponding kits. Mitochondria ultrastructure was observed through transmission electron microscopy (TEM). Finally, mRNA and protein expressions were examined by quantitative real-time PCR (qRT-PCR) and western blot analysis.

RESULTS

The expression of FNDC5 was found to be significantly decreased in both in vivo and in vitro models. Treatment with irisin significantly suppressed ferroptosis and improved bone loss. This was demonstrated by reduced lipid peroxidation and iron overload, increased antioxidant capability, as well as the inhibition of the ferroptosis pathway in bone tissues. Furthermore, in vitro studies demonstrated that FNDC5 overexpression significantly improved HG-induced ferroptosis and promoted osteogenesis. Mechanistic investigations revealed that FNDC5 overexpression mitigated ferroptosis in osteoblasts by inhibiting the eukaryotic initiation factor 2 alpha (eIF2α)/activated transcription factor 4 (ATF4)/C/EBP-homologous protein (CHOP) pathway.

CONCLUSIONS

Collectively, our study uncovered the important role of FNDC5/irisin in regulating ferroptosis of diabetic osteopathy, which might be a potential therapeutic target.

Isoquercitrin alleviates pirarubicin-induced cardiotoxicity in vivo and in vitro by inhibiting apoptosis through Phlpp1/AKT/Bcl-2 signaling pathway

Introduction: Due to the cardiotoxicity of pirarubicin (THP), it is necessary to investigate new compounds for the treatment of THP-induced cardiotoxicity. Isoquercitrin (IQC) is a natural flavonoid with anti-oxidant and anti-apoptosis properties. Thus, the present study aimed to investigate the influence of IQC on preventing the THP-induced cardiotoxicity in vivo and in vitro. Methods: The optimal concentration and time required for IQC to prevent THP-induced cardiomyocyte damage were determined by an MTT assay. The protective effect was further verified in H9c2 and HCM cells using dichlorodihydrofluorescein diacetate fluorescent probes, MitoTracker Red probe, enzyme-linked immunosorbent assay, JC-1 probe, and real time-quantitative polymerase chain reaction (RT-qPCR). Rats were administered THP to establish cardiotoxicity. An electrocardiogram (ECG) was performed, and cardiac hemodynamics, myocardial enzymes, oxidative stress indicators, and hematoxylin-eosin staining were studied. Voltage-dependent anion channel 1 (VDAC1), adenine nucleotide translocase 1 (ANT1), and cyclophilin D (CYPD) were detected by qRT-PCR, and the Phlpp1/AKT/Bcl-2 axis proteins were detected by western blot, confirming that IQC markedly increased cell viability and superoxide dismutase (SOD) levels, diminished the levels of ROS and MDA, and elevated mitochondrial function and apoptosis in vivo and in vitro. Results: Results showed that IQC reduced THP-induced myocardial histopathological injury, electrocardiogram (ECG) abnormalities, and cardiac dysfunction in vivo. IQC also decreased serum levels of MDA, BNP, CK-MB, c-TnT, and LDH, while increasing levels of SOD and GSH. We also found that IQC significantly reduced VDAC1, ANT1, and CYPD mRNA expression. In addition, IQC controlled apoptosis by modulating Phlpp1/AKT/Bcl-2 signaling pathways. IQC markedly increased H9c2 and HCM cell viability and SOD levels, diminished the levels of ROS and MDA, and elevated mitochondrial function in H9c2 and HCM cells to defend against THP-induced cardiomyocyte apoptosis in vitro. The AKT inhibitor IMQ demonstrated that IQC lacked antioxidant and anti-apoptotic properties. Moreover, our data showed that IQC regulates Phlpp1 expression, thereby influencing the expression levels of p-AKT, cytochrome c, caspase-3, caspase-9, Bcl-2, and Bax. Discussion: In conclusion, our results indicate that IQC protects the changes in mitochondrial membrane permeability in cardiomyocytes by regulating the Phlpp1/AKT/Bcl-2 signaling pathway, inhibits the release of cytc from the mitochondrial inner membrane to the cytoplasm, forms apoptotic bodies, induces cell apoptosis, and reduces THP induced cardiotoxicity.

DL-3-n-butylphthalide attenuates doxorubicin-induced acute cardiotoxicity via Nrf2/HO-1 signaling pathway

Doxorubicin (DOX) is a widely used chemotherapeutic drug known to cause dose-dependent myocardial toxicity, which limits its clinical potential. DL-3-n-butylphthalide (NBP), a substance extracted from celery seed species, has a number of pharmacological properties, such as antioxidant, anti-inflammatory, and anti-apoptotic actions. However, whether NBP can protect against DOX-induced acute myocardial toxicity is still unclear. Therefore, this study was designed to investigate the potential protective effects of NBP against DOX-induced acute myocardial injury and its underlying mechanism. By injecting 15 mg/kg of DOX intraperitoneally, eight-week-old male C57BL6 mice suffered an acute myocardial injury. The treatment group of mice received 80 mg/kg NBP by gavage once daily for 14 days. To mimic the cardiotoxicity of DOX, 1uM DOX was administered to H9C2 cells in vitro. In comparison to the DOX group, the results showed that NBP improved cardiac function and decreased serum levels of cTnI, LDH, and CK-MB. Additionally, HE staining demonstrated that NBP attenuated cardiac fibrillar lysis and breakage in DOX-treated mouse hearts. Western blotting assay and immunofluorescence staining suggested that NBP attenuated DOX-induced oxidative stress, apoptosis, and inflammation both in vivo and in vitro. Mechanistically, NBP significantly upregulated the Nrf2/HO-1 signaling pathway, while the Nrf2 inhibitor ML385 prevented NBP from protecting the myocardium from DOX-induced myocardial toxicity in vitro. In conclusion, Our results indicate that NBP alleviates DOX-induced myocardial toxicity by activating the Nrf2/HO-1 signaling pathway.

FLRT2 suppresses bladder cancer progression through inducing ferroptosis

Bladder cancer is a common tumour worldwide and exhibits a poor prognosis. Fibronectin leucine rich transmembrane protein 2 (FLRT2) is associated with the regulation of multiple tumours; however, its function in human bladder cancer remain unclear. Herein, we found that FLRT2 level was reduced in human bladder cancer and that higher FLRT2 level predicted lower survival rate. FLRT2 overexpression inhibited, while FLRT2 silence facilitated tumour cell growth, migration and invasion. Mechanistic studies revealed that FLRT2 elevated acyl-CoA synthetase long-chain family member 4 (ACSL4) expression, increased lipid peroxidation and subsequently facilitated ferroptosis of human bladder cancer cells. In summary, we demonstrate that FLRT2 elevates ACSL4 expression to facilitate lipid peroxidation and subsequently triggers ferroptosis, thereby inhibiting the malignant phenotype of human bladder cancer cells. Overall, we identify FLRT2 as a tumour suppressor gene.

The Role of FNDC5/Irisin in Cardiovascular Disease

Disorders of cardiomyocyte metabolism play a crucial role in many cardiovascular diseases, such as myocardial infarction, heart failure and ischemia-reperfusion injury. In myocardial infarction, cardiomyocyte metabolism is regulated by mitochondrial changes and biogenesis, which allows energy homeostasis. There are many proteins in cells that regulate and control metabolic processes. One of them is irisin (Ir), which is released from the transmembrane protein FNDC5. Initial studies indicated that Ir is a myokine secreted mainly by skeletal muscles. Further studies showed that Ir was also present in various tissues. However, its highest levels were observed in cardiomyocytes. Ir is responsible for many processes, including the conversion of white adipose tissue (WAT) to brown adipose tissue (BAT) by increasing the expression of thermogenin (UCP1). In addition, Ir affects mitochondrial biogenesis. Therefore, the levels of FNDC5/Ir in the blood and myocardium may be important in cardiovascular disease. This review discusses the current knowledge about the role of FNDC5/Ir in cardiovascular disease.

FGF12 restrains mitochondria-dependent ferroptosis in doxorubicin-induced cardiomyocytes through the activation of FGFR1/AMPK/NRF2 signaling

Fibroblast growth factor-12 (FGF12) has been reported to play important role in regulating heart diseases. We aimed to explore the role of FGF12 in doxorubicin (DOX)-induced myocardial injury. DOX-induced mice and DOX-induced HL-1 cells were used as the myocardial injury in vivo and in vitro. Then, FGF12, Anp, Bnp, and Myh7 expression was detected. The pathological injury in myocardium tissue was observed by H&E staining. The levels of markers related to myocardial damage and oxidative stress were assessed. Then, immunohistochemistry and immunofluorescence staining were used to detect FGF12 and 4-HNE expression. Ferroptosis were detected by Prussian blue staining and western blot. The FGFR1/AMPK/NRF2 signaling was measured by western blot. FGF12 expression was downregulated in DOX-induced mice myocardium tissues. FGF12 overexpression alleviated DOX-induced myocardial tissue pathological injury and reduced Anp, Bnp, and Myh7 expression. Additionally, the levels of CK-MB, LDH and cTnT in serum were decreased after FGF12 upregulation in DOX-induced mice. Moreover, FGF12 overexpression reduced the levels of ROS, MDA, and 4-HNE but increased SOD and GSH-Px activities. Meanwhile, FGF12 led to less deposition of iron ion, decreased ACSL4, PTGS2 and increased GPX4, FTH1 expression. Additionally, FGF12 activated the expressions of FGFR1, p-AMPK, and NRF2. Moreover, FGFR1 silencing reversed the protective effects of FGF12 overexpression on cell viability, oxidative stress, ferroptosis, and FGFR1/AMPK/NRF2 pathway. To sum up, FGF12 inhibited mitochondria-dependent ferroptosis in cardiomyocytes induced by DOX through activation of FGFR1/AMPK/NRF2 signaling. These findings clarify a new mechanism of DOX-induced cardiac injury and provide a promising target to limit the disease development.

From Energy Metabolic Change to Precision Therapy: a Holistic View of Energy Metabolism in Heart Failure

Heart failure (HF) is a complex and multifactorial disease that affects millions of people worldwide. It is characterized by metabolic disturbances of substrates such as glucose, fatty acids (FAs), ketone bodies, and amino acids, which lead to changes in cardiac energy metabolism pathways. These metabolic alterations can directly or indirectly promote myocardial remodeling, thereby accelerating the progression of HF, resulting in a vicious cycle of worsening symptoms, and contributing to the increased hospitalization and mortality among patients with HF. In this review, we summarized the latest researches on energy metabolic profiling in HF and provided the related translational therapeutic strategies for this devastating disease. By taking a holistic approach to understanding energy metabolism changes in HF, we hope to provide comprehensive insights into the pathophysiology of this challenging condition and identify novel precise targets for the development of more effective treatments.

Isthmin-1 Improves Aging-Related Cardiac Dysfunction in Mice through Enhancing Glycolysis and SIRT1 Deacetylase Activity

Aging-related cardiac dysfunction poses a major risk factor of mortality for elderly populations, however, efficient treatment for aging-related cardiac dysfunction is far from being known. Isthmin-1 (ISM1) is a novel adipokine that promotes glucose uptake and acts indispensable roles in restraining inflammatory and fibrosis. The present study aims to investigate the potential role and molecular mechanism of ISM1 in aging-related cardiac dysfunction. Aged and matched young mice were overexpressed or silenced with ISM1 to investigate the role of ISM1 in aging-related cardiac dysfunction. Moreover, H9C2 cells were stimulated with D-galactose (D-gal) to examine the role of ISM1 in vitro. Herein, we found that cardiac-specific overexpression of ISM1 significantly mitigated insulin resistance by promoting glucose uptake in aging mice. ISM1 overexpression alleviated while ISM1 silencing deteriorated cellular senescence, cardiac inflammation, and dysfunction in natural and accelerated cardiac aging. Mechanistically, ISM1 promoted glycolysis and activated Sirtuin-1 (SIRT1) through increasing glucose uptake. ISM1 increased glucose uptake via translocating GLUT4 to the surface, thereby enhancing glycolytic flux and hexosamine biosynthetic pathway (HBP) flux, ultimately leading to increased SIRT1 activity through O-GlcNAc modification. ISM1 may serve as a novel potential therapeutic target for preventing aging-related cardiac disease in elderly populations. ISM1 prevents aging-related cardiac dysfunction by promoting glycolysis and enhancing SIRT1 deacetylase activity, making it a promising therapeutic target for aging-related cardiac disease.

Targeting heat shock protein 47 alleviated doxorubicin-induced cardiotoxicity and remodeling in mice through suppression of the NLRP3 inflammasome

AIM

Doxorubicin-induced cardiotoxicity (DIC) is an increasing problem, occurring in many cancer patients receiving anthracycline chemotherapy, ultimately leading to heart failure (HF). Unfortunately, DIC remains difficult to manage due to an ignorance regarding pathophysiological mechanisms. Our work aimed to evaluate the role of HSP47 in doxorubicin-induced HF, and to explore the molecular mechanisms.

METHODS AND RESULTS

Mice were exposed to multi-intraperitoneal injection of doxorubicin (DOX, 4mg/kg/week, for 6 weeks continuously) to produce DIC. HSP47 expression was significantly upregulated in serum and in heart tissue in DOX-treated mice and in isolated cardiomyocytes. Mice with cardiac-specific HSP47 overexpression and knockdown were generated using recombinant adeno-associated virus (rAVV9) injection. Importantly, cardiac-specific HSP47 overexpression exacerbated cardiac dysfunction in DIC, while HSP47 knockdown prevented DOX-induced cardiac dysfunction, cardiac atrophy and fibrosis in vivo and in vitro. Mechanistically, we identified that HSP47 directly interacted with IRE1α in cardiomyocytes. Furthermore, we provided powerful evidence that HSP47-IRE1α complex promoted TXNIP/NLRP3 inflammasome and reinforced USP1-mediated NLRP3 ubiquitination. Moreover, NLRP3 deficiency in vivo conspicuously abolished HSP47-mediated cardiac atrophy and fibrogenesis under DOX condition.

CONCLUSION

HSP47 was highly expressed in serum and cardiac tissue after doxorubicin administration. HSP47 contributed to long-term anthracycline chemotherapy-associated cardiac dysfunction in an NLRP3-dependent manner. HSP47 therefore represents a plausible target for future therapy of doxorubicin-induced HF.

Inhibition of ferroptosis by POLE2 in gastric cancer cells involves the activation of NRF2/GPX4 pathway

Gastric cancer results in great cancer mortality worldwide, and inducing ferroptosis dramatically improves the malignant phenotypes of gastric cancer. DNA polymerase epsilon subunit 2 (POLE2) plays indispensable roles in tumorigenesis; however, its involvement and molecular basis in ferroptosis and gastric cancer are not clear. Human gastric cancer cells were infected with lentiviral vectors to knock down or overexpress POLE2, and cell ferroptosis was detected. To further validate the involvement of nuclear factor erythroid 2-related factor 2 (NRF2) and glutathione peroxidase 4 (GPX4), lentiviral vectors were used. POLE2 expression was elevated in human gastric cancer cells and tissues and closely correlated with clinicopathological features in gastric cancer patients. POLE2 knockdown was induced, while POLE2 overexpression inhibited ferroptosis of human gastric cancer cells, thereby modulating the malignant phenotypes of gastric cancer. Mechanistic studies revealed that POLE2 overexpression elevated NRF2 expression and activity and subsequently activated GPX4, which then prevented lipid peroxidation and ferroptosis in human gastric cancer cells. In contrast, either NRF2 or GPX4 silence significantly prevented POLE2 overexpression-mediated inductions of cell proliferation, migration, invasion and inhibition of ferroptosis. POLE2 overexpression inhibits ferroptosis in human gastric cancer cells through activating NRF2/GPX4 pathway, and inhibiting POLE2 may be a crucial strategy to treat gastric cancer.

Deubiquitinase OTUB1 regulates doxorubicin-induced cardiotoxicity via deubiquitinating c-MYC

BACKGROUND

Doxorubicin (DOX), an anthracycline drug widely used in antitumor therapies, has dose-dependent toxicity that can cause cardiomyocyte apoptosis and oxidative stress, thus limiting its clinical application. OTUB1 (ovarian tumor associated proteinase B1) is an OTU superfamily deubiquitinase that effectively regulates cell proliferation, inflammatory responses, apoptosis, and oxidative stress by specifically removing K48- and K63-linked ubiquitination; however, its role in DOX-induced cardiotoxicity remains unknown.

MATERIALS AND METHODS

A DOX-induced subacute cardiotoxicity mouse model was established by intraperitoneal injection, and cardiac injury was assessed by echocardiography, serum cardiac markers, and histopathological staining. Western blotting, qRT-PCR, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) immunohistochemistry were used to analyze cell apoptosis, tissue oxidative stress was assessed by superoxide dismutase (SOD) activity, malondialdehyde (MDA), and glutathione peroxidase (GSH-PX) activity. Cell counting kit-8 (CCK-8) assay, TUNEL staining, Western blotting, qRT-PCR, and reactive oxygen species (ROS) flow cytometry were applied on isolated neonatal mice cardiomyocytes to assess apoptosis and oxidative stress. Differentially expressed genes were analyzed using RNA sequencing and clustering analyses. c-MYC inhibitor 10,058-F4 and siRNA targeting c-Myc were used to investigate the roles of c-MYC in OTUB1's regulations of DOX-induced cardiotoxicity. Immunoprecipitation and Western blotting were performed to reveal the deubiquitinating effects of OTUB1 on c-MYC expression.

RESULTS

We found that global Otub1-knockdown in vivo alleviated the subacute DOX treatment-induced cardiac dysfunction, fibrosis, and cardiomyocyte atrophy. Mechanistically, unbiased RNA sequencing and molecular biology experiments revealed that cardiomyocyte apoptosis, inflammation, and oxidative stress in DOX-induced cardiotoxicity were significantly compromised in the Otub1-knockdown group. Further in vitro studies have shown that c-MYC, a critical regulator of apoptosis, is indispensable in OTUB1's regulations of DOX-induced cardiotoxicity. Deubiquitinating effects of OTUB1 on K48- and K63-linked ubiquitination of c-MYC protein are essential for promoting cardiomyocyte apoptosis and oxidative responses.

CONCLUSIONS

OTUB1-c-MYC inhibition protected cardiomyocytes against DOX-induced apoptosis and oxidative stress, suggesting that OTUB1 is a potential translational therapeutic target for preventing DOX-induced cardiotoxicity.

Apocynin exerts cytoprotective effects on dexamethasone-induced osteoblasts by inhibiting oxidative stress through the Nrf2 signalling pathway

Steroid-induced femoral head necrosis (SIFHN) is a serious clinical complication that is caused by prolonged or excessive use of glucocorticoids (GCs). Osteoblast apoptosis and osteogenic differentiation dysfunction caused by GC-induced oxidative stress and mitochondrial impairment are strongly implicated in SIFHN. Apocynin (APO) is a kind of acetophenone extracted from an herb. In recent years, APO has received much attention for its antiapoptotic and antioxidant properties. This study aimed to investigate whether APO could protect against SIFHN and explore the mechanism. In our study, low-dose APO had no toxic effects on osteoblasts and restored dexamethasone (Dex)-treated osteoblasts by improving survival, inhibiting OS and restoring mitochondrial dysfunction. Mechanistically, APO alleviated Dex-induced osteoblast injury by activating the Nrf2 pathway, and the use of ML385 to block Nrf2 significantly eliminated the protective effect of APO. In addition, APO could reduce the formation of empty lacunae, restore bone mass and promote the expression of Nrf2 in SIFHN rats. In conclusion, APO protects osteoblasts from Dex-induced oxidative stress and mitochondrial dysfunction through activation of the Nrf2 pathway and may be a beneficial drug for the treatment of SIFHN.

Recent advances in pluripotent stem cell-derived cardiac organoids and heart-on-chip applications for studying anti-cancer drug-induced cardiotoxicity

Cardiovascular disease (CVD) caused by anti-cancer drug-induced cardiotoxicity is now the second leading cause of mortality among cancer survivors. It is necessary to establish efficient in vitro models for early predicting the potential cardiotoxicity of anti-cancer drugs, as well as for screening drugs that would alleviate cardiotoxicity during and post treatment. Human induced pluripotent stem cells (hiPSCs) have opened up new avenues in cardio-oncology. With the breakthrough of tissue engineering technology, a variety of hiPSC-derived cardiac microtissues or organoids have been recently reported, which have shown enormous potential in studying cardiotoxicity. Moreover, using hiPSC-derived heart-on-chip for studying cardiotoxicity has provided novel insights into the underlying mechanisms. Herein, we summarize different types of anti-cancer drug-induced cardiotoxicities and present an extensive overview on the applications of hiPSC-derived cardiac microtissues, cardiac organoids, and heart-on-chips in cardiotoxicity. Finally, we highlight clinical and translational challenges around hiPSC-derived cardiac microtissues/organoids/heart-on chips and their applications in anti-cancer drug-induced cardiotoxicity. • Anti-cancer drug-induced cardiotoxicities represent pressing challenges for cancer treatments, and cardiovascular disease is the second leading cause of mortality among cancer survivors. • Newly reported in vitro models such as hiPSC-derived cardiac microtissues/organoids/chips show enormous potential for studying cardio-oncology. • Emerging evidence supports that hiPSC-derived cardiac organoids and heart-on-chip are promising in vitro platforms for predicting and minimizing anti-cancer drug-induced cardiotoxicity.

Serinc2 deficiency exacerbates sepsis-induced cardiomyopathy by enhancing necroptosis and apoptosis

In critical care medicine, sepsis is a potentially fatal syndrome characterized by multi-organ dysfunction and eventual failure. Sepsis-induced cardiomyopathy (SIC) is characterized by decreased venstricular contractility. Serine incorporator 2 (Serinc2) is a protein involved in phosphatidylserine biosynthesis and membrane incorporation. It may also be a protective factor in septic lung injury. However, it is unknown whether Serinc2 influences SIC onset or progression. In the present study, we found that Serinc2 was downregulated in the cardiomyocytes of cecal ligation and puncture (CLP)-induced SIC and in neonatal rat cardiomyocytes (NRCMs) exposed to lipopolysaccharides (LPS). Serinc2 knockout (KO) exacerbated sepsis-induced myocardial inflammation, necroptosis, apoptosis, myocardial damage, and contractility impairment. Furthermore, the lack of Serinc2 in cardiomyocytes aggravated LPS-induced cardiomyopathic inflammation, necroptosis, and apoptosis. An adenovirus overexpressing Serinc2 inhibited the inflammatory response and favored cardiomyocyte survival. A mechanistic analysis revealed that Serinc2 deficiency exacerbated LPS-induced cardiac dysfunction by inhibiting the protein kinase B (Akt)/glycogen synthase kinase 3 beta (GSK-3β) signaling pathway that regulates necrotic complex formation and apoptotic pathways in cardiomyopathy. The findings of the present work demonstrated that Serinc2 plays an essential role in SIC and is, therefore, promising as a prophylactic and therapeutic target for this condition.