Proteasomal Degradation of TRAF2 Mediates Mitochondrial Dysfunction in Doxorubicin-Cardiomyopathy

Identification of TRAF2, CAMK2G, and TIMM17A as biomarkers distinguishing mechanical asphyxia from sudden cardiac death base on 4D-DIA Proteomics: A pilot study

In the context of forensic medicine, the differential diagnosis between mechanical asphyxia and sudden cardiac death is very important regarding the establishment of the cause of death. Traditional autopsy findings have generally been very nonspecific; accordingly, highlighting the need for more specific molecular biomarkers. This study employed four-dimensional data-independent acquisition (4D-DIA) proteomics technology, in combination with both animal models and human samples, to conduct a comprehensive protein expression analysis of cardiac tissues, identifying 7557 proteins, among which 142 shared differentially expressed proteins (DEPS) were screened out. Based on the protein interaction network and through rigorous screening, this study identified three proteins, namely TNF receptor-associated factor 2 (TRAF2), Calcium/calmodulin-dependent protein kinase II gamma (CAMK2G), and translocase of inner mitochondrial membrane 17 homolog A (TIMM17A), as biomarkers for differentiating mechanical asphyxia from sudden cardiac death. Further verification using Western Blot (WB) and immunohistochemistry (IHC) proved the differential expression of these biomarkers in both animal and human samples. These findings, besides deepening the molecular understanding of the pathophysiological differences between sudden cardiac death and mechanical asphyxia, also provided new biomarkers for forensic applications that could enable the improvement of accuracy and reliability in the determination of the cause of death.

Targeting FDX1 by trilobatin to inhibit cuproptosis in doxorubicin-induced cardiotoxicity

BACKGROUND AND PURPOSE

Doxorubicin (DOX), an anthracycline chemotherapeutic agent, whose use is limited owing to its dose-dependent cardiotoxicity. Mitochondrial oxidative stress plays a crucial role in the pathogenesis of DOX-induced cardiotoxicity (DIC). Trilobatin (TLB), a naturally occurring food additive, exhibits strong antioxidant properties, but its cardioprotective effects in DIC is unclear. This study investigates the cardioprotective effect of TLB on DIC.

EXPERIMENTAL APPROACH

DOX was used to generate an in vivo and in vitro model of cardiotoxicity. Echocardiography, enzyme-linked immunosorbent assay (ELISA) and haematoxylin and eosin (H&E) staining were used to evaluate the cardiac function in these models. To identify the targets of TLB, RNA-sequence analysis, molecular dynamics simulations, surface plasmon resonance binding assays and protein immunoblotting techniques were used. Transmission electron microscopy, along with dihydroethidium and Mito-SOX staining, was conducted to examine the impact of trilobatin on mitochondrial oxidative stress. SiRNA transfection was performed to confirm the role of ferredoxin 1 (FDX1) in DIC development.

KEY RESULTS

In DIC mice, TLB improved cardiac function in a dose-dependent manner and inhibited myocardial fibrosis in DIC mice. TLB also attenuated DOX-induced mitochondrial dysfunction and reduced cardiac mitochondrial oxidative stress. TLB was found to directly bind to FDX1 and suppresses cuproptosis after DOX treatment, causing significant inhibition of cuproptosis-related proteins.

CONCLUSIONS AND IMPLICATIONS

This is the first study to show that TLB strongly inhibits DIC by reducing mitochondrial oxidative stress and controlling DOX-mediated cuproptosis by targeting FDX1. Therefore, TLB is as a potential phytochemical cardioprotective candidate for ameliorating DIC.

Erythrocyte Membrane-Camouflaged Xanthohumol Nanoparticles Mitigate Doxorubicin-Induced Cardiotoxicity by Inhibiting Ferroptosis

Doxorubicin (DOX) chemotherapy is a cornerstone of cancer treatment, but its clinical application and effectiveness are severely restricted due to its life-threatening cardiotoxicity. Xanthohumol (XH), a compound from traditional Chinese medicine, is noted for its antioxidant properties and the potential to mitigate DOX-induced cardiotoxicity (DIC). However, its poor water solubility results in low biocompatibility, making it susceptible to immune system clearance, which severely restricts its application in vivo. In this study, we first identified and demonstrated that XH can effectively mitigate DIC by inhibiting ferroptosis. We designed a biomimetic nanodelivery system encapsulating XH within porous poly(lactic-co-glycolic acid) (PLGA) nanoparticles, further coated with an erythrocyte membrane (XH-NPs@RBCm). This system offers several advantages, including evasion of macrophage phagocytosis and prolonged circulation time, thereby enhancing the stability and bioavailability of XH in vivo. Treatment with XH-NPs@RBCm significantly reduced reactive oxygen species-dependent ferroptosis, improving the DOX-induced myocardial atrophy and cardiac dysfunction. Our study underscores the therapeutic promise of XH-NPs@RBCm in treating DIC through ferroptosis inhibition, offering key insights into biomimetic nanodelivery system development for DIC management.

Progress of extracellular vesicles-based system for tumor therapy

The increasing number of new cancer cases and cancer-related deaths worldwide highlights the urgent need to develop novel anti-tumor treatment methods to alleviate the current challenging situation. Nearly all organisms are capable of secreting extracellular vesicles (EVs), and these nano-scale EVs carrying biological molecules play an important role in intercellular communication, further affecting various physiological and pathological processes. Notably, EVs from different sources have differences in their characteristics and functions. Consequently, diverse EVs have been utilized as drug or vaccine delivery carriers for improving anti-tumor treatment due to their good safety, ease of modification and unique properties, and achieved satisfactory results. Meanwhile, the clinical trials of EV-based platform for tumor therapy are also continuously being conducted. Therefore, in this review, we summarize the recent research progress of EV-based tumor treatment methods, including the introduction of main sources and unique functions of EVs, the application of EVs in tumor treatment as well as their prospects and challenges. Additionally, considering the unique advantages of artificial EVs over natural EVs, we also highlighted their characteristics and applications in tumor treatments. We believe that this review will help researchers develop novel EV-based anti-tumor platforms through a bottom-up design and accelerate the development in this field.

Sotorasib-impaired degradation of NEU1 contributes to cardiac injury by inhibiting AKT signaling

Sotorasib, the inaugural targeted inhibitor sanctioned for the management of patients afflicted with locally advanced or metastatic non-small cell lung cancer presenting the KRAS G12C mutation, has encountered clinical application constraints due to its potential for cardiac injury as evidenced by safety trials. This investigation has elucidated that the heightened expression of neuraminidase-1 (NEU1) constitutes the principal etiology of cardiac damage induced by sotorasib. Mechanistically, sotorasib treatment inhibited the ubiquitinated degradation of NEU1, leading to its elevated expression, which induced downstream AKT signaling pathway inhibition and mitochondrial dysfunction leading to cardiomyocyte apoptosis. Meanwhile, in vivo and in vitro studies showed that D-pantothenic acid (D-PAC) alleviated sotorasib-induced cardiac damage by promoting NEU1 degradation. In conclusion, this study revealed that NEU1 is a key protein in sotorasib cardiotoxicity and that reducing the level of this protein is a critical strategy for the clinical treatment of sotorasib-induced cardiac injury. Schematic representation of a mechanism.

Expression of PSMD2 gene in hepatocellular carcinoma and its correlation with immune checkpoints and prognosis

Hepatocellular carcinoma (HCC) is a prevalent and fatal tumor globally, characterized by a complex pathogenesis and poor prognosis. Despite significant advancements in the application of immune checkpoint inhibitors (ICIs) for cancer treatment, the efficacy of immunotherapy in HCC remains suboptimal. PSMD2, a crucial regulator of the ubiquitin-proteasome system, has attracted increasing attention for its involvement in various cancers; however, its functions and mechanisms in HCC are still poorly understood. This study aims to investigate the expression of PSMD2 in HCC, its association with prognosis, and its interaction with immune checkpoints, thus establishing a foundation for further exploration of its role in immune evasion in HCC. We analyzed the expression levels of PSMD2 in HCC and adjacent normal tissues utilizing the GEPIA and TIMER databases. Cox regression analysis was performed using R software to evaluate the relationship between PSMD2 expression and prognosis. Furthermore, we assessed the correlation between PSMD2 and immune cell infiltration, as well as immune checkpoints, including PD1, PD-L1, and CTLA-4, using R tools. Additionally, we examined the association between PSMD2 expression and immune therapy response through Tumor Immune Dysfunction and Exclusion (TIDE) analysis. Finally, we constructed a protein-protein interaction (PPI) network using the STRING database and Cytoscape software, followed by Gene Set Enrichment Analysis (GSEA). PSMD2 was significantly overexpressed in HCC and was closely correlated with poor prognosis (HR = 1.61, P = 2.0e-4). Immune infiltration analysis demonstrated that PSMD2 was positively correlated with several immune checkpoint genes, including PD1, PD-L1, and CTLA-4, as well as various immune cell types. TIDE analysis indicated that elevated PSMD2 expression was significantly associated with increased immune evasion potential and a poor response to immunotherapy. Furthermore, GSEA enrichment analysis revealed that PSMD2 is primarily enriched in the p53 signaling pathway, the ubiquitin-mediated proteolysis pathway, and other cancer-related pathways. The elevated expression of PSMD2 in HCC is not only correlated with poor prognosis but may also play a role in immune evasion by modulating tumor immunity, thereby affecting patient responses to immunotherapy. Consequently, PSMD2 presents a promising novel therapeutic target and potential biomarker for immunotherapy in HCC.

1'-Acetoxychavicol Acetate Selectively Downregulates Tumor Necrosis Factor Receptor-Associated Factor 2 (TRAF2) Expression

1'-Acetoxychavicol acetate (ACA) is a natural compound derived from rhizomes of the Zingiberaceae family that suppresses the nuclear factor κB (NF-κB) signaling pathway; however, the underlying mechanisms remain unclear. Therefore, the present study investigated the molecular mechanisms by which ACA inhibits the NF-κB signaling pathway in human lung adenocarcinoma A549 cells. The results obtained showed ACA decreased tumor necrosis factor (TNF)-α-induced intercellular adhesion molecule-1 (ICAM-1) expression in A549 cells. It also inhibited TNF-α-induced ICAM-1 mRNA expression and ICAM-1 promoter-driven and NF-κB-responsive luciferase reporter activities. Furthermore, the TNF-α-induced degradation of the inhibitor of NF-κB α protein in the NF-κB signaling pathway was suppressed by ACA. Although ACA did not affect TNF receptor 1, TNF receptor-associated death domain, or receptor-interacting protein kinase 1 protein expression, it selectively downregulated TNF receptor-associated factor 2 (TRAF2) protein expression. The proteasome inhibitor MG-132, but not inhibitors of caspases or lysosomal degradation, attenuated ACA-induced reductions in TRAF2 expression. ACA also downregulated TRAF2 protein expression in human fibrosarcoma HT-1080 cells. This is the first study to demonstrate that ACA selectively downregulates TRAF2 protein expression.

Resolving the developmental mechanisms of cardiac microthrombosis of SARS-CoV-2 based on single-cell transcriptome analysis

The coronavirus disease 2019 (COVID-19) outbreak caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) developed into a global health emergency. Systemic microthrombus caused by SARS-CoV-2 infection is a common complication in patients with COVID-19. Cardiac microthrombosis as a complication of SARS-CoV-2 infection is the primary cause of cardiac injury and death in patietns with severe COVID-19. In this study, we performed single-cell sequencing analysis of the right ventricular free wall tissue from healthy donors, patients who died during the hypercoagulable period of characteristic coagulation abnormality (CAC), and patients who died during the fibrinolytic period of CAC. We collected 61,187 cells enriched in 24 immune cell subsets and 13 cardiac-resident cell subsets. We found that in the course of SARS-CoV-2 infected heart microthrombus, MYO1EhighRASGEF1Bhighmonocyte-derived macrophages promoted hyperactivation of the immune system and initiated the extrinsic coagulation pathway by activating chemokines CCL3, CCL5. This series of events is the main cause of cardiac microthrombi following SARS-CoV-2 infection. In a SARS-CoV-2 infected heart microthrombus, excessive immune activation is accompanied by an increase in cellular iron content, which in turn promotes oxidative stress and intensifies intercellular competition. This induces cells to alter their metabolic environment, resulting in increased sugar uptake via the glycosaminoglycan synthesis pathway. In addition, high levels of reactive oxygen species generated by elevated iron levels promote increased endogenous malondialdehyde synthesis in a subpopulation of cardiac endothelial cells. This exacerbates endothelial cell dysfunction and exacerbates the coagulopathy process.

Ubiquitylation in the development of somatic diseases: a mechanism of cellular regulation and a new therapeutic target

At the present stage of medical science, an increasing role in the pathogenesis of various groups of diseases is assigned to the mechanisms of epigenetic regulation and posttranslational modifications of proteins. One of these mechanisms is ubiquitylation, which is able to regulate the functional activity of proteins, their stability, and also influence the processes of cell death. Involvement in a large number of metabolic pathways and presently identified associations with oncological, cardiovascular, neurological, and inflammatory diseases makes ubiquitylation of the enzymes involved a promising target to develop new therapy options. In this review, we consider the effect of ubiquitination on the development of diseases of the cardiovascular, nervous systems, diabetes mellitus, as well as the development of possible treatment options.

Interleukin-12p40 deficiency attenuates myocardial ferroptosis in doxorubicin-induced chronic cardiomyopathy by inhibiting Th17 differentiation and interleukin-17A production

AIMS

Interleukin (IL)-12p40 is a common subunit of the bioactive cytokines IL-12 and IL-23, and it also has its own intrinsic functional activity. However, its role in doxorubicin-induced chronic cardiomyopathy (DICCM) as well as the underlying mechanisms are still unknown.

METHODS AND RESULTS

In this study, we used IL-12p40-knockout mice, IL-23p19-knockout mice, Rag1-knockout mice, a ferroptosis inhibitor, recombinant IL-12 (rIL-12), rIL-23, rIL-12p40, rIL-12p80, and anti-IL17A to investigate the effects of IL-12p40 on DICCM and elucidate the underlying mechanisms. We found that myocardial ferroptosis were increased in DICCM and that the inhibition of ferroptosis protected against DICCM. The expression of IL-12p40 was upregulated, and IL-12p40 was predominantly expressed by CD4+ T cells in the hearts of mice with DICCM. IL-12p40 knockout attenuated cardiac dysfunction, fibrosis and ferroptosis in DICCM, and similar results were observed in the context of CD4+ T cell IL-12p40 deficiency in Rag1-/- mice. Treatment with rIL-23, but not rIL-12, rIL-12p40 monomer or rIL-12p80, abolished the protective effects of IL-12p40 knockout. Moreover, rIL-23 treatment and IL-23p19 knockout exacerbated and ameliorated DICCM, respectively. IL-12p40 knockout might protect against DICCM by inhibiting Th17 differentiation and IL-17A production but not Th1, Th2 and Treg differentiation. Neutralizing IL-17A with an antibody also attenuated cardiac dysfunction, fibrosis, and ferroptosis. The IL-12p40/Th17/IL-17A axis might promote cardiomyocyte ferroptosis by activating TNF receptor-associated factor 6 (TRAF6)/mitogen-activated protein kinase (MAPK)/P53 signalling in DICCM.

CONCLUSION

Interleukin-12p40 deficiency protects against DICCM by inhibiting Th17 differentiation and the production of IL-17A, which plays critical roles in cardiomyocyte ferroptosis in DICCM via activating TRAF6/MAPK/P53 signalling. Our study may provide novel insights for the identification of therapeutic targets for treating DICCM in the clinic.

Fasting: A Complex, Double-Edged Blade in the Battle Against Doxorubicin-Induced Cardiotoxicity

In recent years, there has been a surge in the popularity of fasting as a method to enhance one's health and overall well-being. Fasting is a customary practice characterized by voluntary refraining from consuming food and beverages for a specified duration, ranging from a few hours to several days. The potential advantages of fasting, including enhanced insulin sensitivity, decreased inflammation, and better cellular repair mechanisms, have been well documented. However, the effects of fasting on cancer therapy have been the focus of recent scholarly investigations. Doxorubicin (Dox) is one of the most widely used chemotherapy medications for cancer treatment. Unfortunately, cardiotoxicity, which may lead to heart failure and other cardiovascular issues, has been linked to Dox usage. This study aims to comprehensively examine the possible advantages and disadvantages of fasting concerning Dox-induced cardiotoxicity. Researchers have investigated the potential benefits of fasting in lowering the risk of Dox-induced cardiac damage to solve this problem. Nevertheless, new studies indicate that prolonged alternate-day fasting may adversely affect the heart's capacity to manage the cardiotoxic properties of Dox. Though fasting may benefit overall health, it is essential to proceed cautiously and consider the potential risks in certain circumstances.

LncRNA DANCR suppresses acute myocardial infarction in mice via mediating p-RXRA/TRAF2/NIK/IKK/NF-κB signaling pathway

OBJECTIVES

This study aimed to investigate the role of LncRNA differentiation antagonizing non-protein coding RNA (DANCR) in acute myocardial infarction (AMI).

METHODS

A mouse model of AMI was established, and the cardiac contractile function was detected. Next, cardiomyocytes treated with oxygen-glucose deprivation (OGD) were used for gain- and loss-function experiments in vitro. RIP analysis was used to verify the binding of DANCR and Retinoid X receptor alpha (RXRA), and Co-IP assay was used to measure the binding of phosphorylated RXRA to TNF receptor associated factor 2 (TRAF2).

RESULTS

The expression of DANCR in myocardial tissues of AMI mice were significantly downregulated. Overexpression of DANCR decreased myocardial infarct size and enhanced cardiac contractile function in AMI mice. Moreover, overexpression of DANCR promoted proliferation and inhibited apoptosis in OGD-induced cardiomyocytes. Mechanism studies demonstrated that DANCR interacted with RXRA and promoted glycogen synthase kinase 3beta (GSK3β)-mediated phosphorylation of RXRA, and phosphorylated RXRA interacted with TRAF2 protein to downregulate TRAF2 protein level. Bexarotene (Bex), an activator of RXRA, inhibited TRAF2 protein expression, while RXRA overexpression had no effect on TRAF2 protein expression. Bex treatment or silencing TRAF2 promoted proliferation and inhibited apoptosis in cardiomyocytes. In addition, silencing DANCR inhibited cardiomyocyte proliferation and induced apoptosis by activating the NIK/IKK/NF-κB pathway, while B022, an inhibitor of NIK, counteracted the effects of DANCR silencing on cardiomyocytes.

CONCLUSIONS

Studies demonstrated that DANCR suppressed AMI in mice by mediating p-RXRA/TRAF2/NIK/IKK/NF-κB pathway.

Estimating the Number of Polygenic Diseases Among Six Mutually Exclusive Entities of Non-Tumors and Cancer

In the era of precision medicine with increasing amounts of sequenced cancer and non-cancer genomes of different ancestries, we here enumerate the resulting polygenic disease entities. Based on the cell number status, we first identified six fundamental types of polygenic illnesses, five of which are non-cancerous. Like complex, non-tumor disorders, neoplasms normally carry alterations in multiple genes, including in 'Drivers' and 'Passengers'. However, tumors also lack certain genetic alterations/epigenetic changes, recently named 'Goners', which are toxic for the neoplasm and potentially constitute therapeutic targets. Drivers are considered essential for malignant transformation, whereas environmental influences vary considerably among both types of polygenic diseases. For each form, hyper-rare disorders, defined as affecting <1/108 individuals, likely represent the largest number of disease entities. Loss of redundant tumor-suppressor genes exemplifies such a profoundly rare mutational event. For non-tumor, polygenic diseases, pathway-centered taxonomies seem preferable. This classification is not readily feasible in cancer, but the inclusion of Drivers and possibly also of epigenetic changes to the existing nomenclature might serve as initial steps in this direction. Based on the detailed genetic alterations, the number of polygenic diseases is essentially countless, but different forms of nosologies may be used to restrict the number.

Mechanisms of myocardial toxicity of antitumor drugs and potential therapeutic strategies: A review of the literature

With the successive development of chemotherapy drugs, good results have been achieved in clinical application. However, myocardial toxicity is the biggest challenge. Anthracyclines, immune checkpoint inhibitors, and platinum drugs are widely used. Targeted drug delivery, nanomaterials and dynamic imaging evaluation are all emerging research directions. This article reviews the recent literature on the use of targeted nanodrug delivery and imaging techniques to evaluate the myocardial toxicity of antineoplastic drugs, and discusses the potential mechanisms.

The Role of Retinoic-Acid-Related Orphan Receptor (RORs) in Cellular Homeostasis

Retinoic-acid-related orphan receptors (RORs) are transcription factors belonging to the nuclear receptor subfamily consisting of RORα, RORβ, and RORγ. By binding to the ROR response elements (ROREs) on target gene promoters, RORs regulate a wide variety of cellular processes, including autophagy, mitophagy, oxidative stress, and inflammation. The regulatory roles of RORs are observed in cardiac cells, hepatocytes, pulmonary epithelial cells, renal cells, immune cells, and cancer cells. A growing body of clinical and experimental evidence suggests that ROR expression levels are markedly reduced under different pathological and stress conditions, suggesting that RORs may play a critical role in the pathogenesis of a variety of disease states, including myocardial infarction, immune disorders, cancer, and metabolic syndrome. Reductions in RORs are also associated with inhibition of autophagy, increased reactive oxygen species (ROS), and increased cell death, underscoring the importance of RORs in the regulation of these processes. Herein, we highlight the relationship between RORs and homeostatic processes that influence cell viability. Understanding how these intricate processes are governed at the cellular level is of high scientific and clinical importance to develop new therapeutic strategies that modulate ROR expression and disease progression.

Immunoregulation and male reproductive function: Impacts and mechanistic insights into inflammation

This paper investigates the complex relationship between the immune system and male reproductive processes, emphasizing how chronic inflammation can adversely affect male reproductive health. The immune system plays a dual role; it protects and regulates reproductive organs and spermatogenesis while maintaining reproductive health through immune privilege in the testes and the activities of various immune cells and cytokines. However, when chronic inflammation persists or intensifies, it can disrupt this balance, leading to immune attacks on reproductive tissues and resulting in infertility.This study provides a detailed analysis of how chronic inflammation can impair sperm production, sperm quality, and the secretion of gonadal hormones both directly and indirectly. It also delves into the critical roles of testicular immune privilege, various immune cells, and cytokines in sustaining reproductive health and examines the impacts of infections, autoimmune diseases, and environmental factors on male fertility.

Literature review: nuclear factor kappa B (NF-κB) regulation in human cancers mediated by ubiquitin-specific proteases (USPs)

Background and Objective

The nuclear factor kappa B (NF-κB) consists of a group of transcription factors of which its dysregulation is responsible for diseases such as inflammation and cancer. Ubiquitin-specific proteases (USPs) are the most prominent group among the deubiquitinases (DUBs). Their functions include control of protein stability and regulation of signaling transduction. The association between NF-κB activity and human cancer progression is evident. Still, the role of USPs in the NF-κB regulation in human cancers, especially prostate cancer, is not well understood. This review discusses on the role of USP-mediated regulation of the canonical NF-κB signaling pathway in human cancers and provides a prospect of future studies in prostate cancers.

Methods

Within the biomedical literature database, PubMed, our review team searched for keywords including USP, NF-κB signaling pathway, cancer, prostate cancer, and specific USPs such as USP1, USP2, USP3, etc. These keywords were used individually or in combinations. After screening, only mechanistic studies and articles reporting the subsequent changes in cellular behaviors were included for full-text review.

Key Content and Findings

Most USPs function primarily as DUBs to regulate the canonical NF-κB signaling pathway. The typical K48- and K63-linked DUB activities of USPs are the best understood. These USPs are positive and negative regulators of the NF-κB activity. However, their DUB activities against polyubiquitin chains with atypical linkages have not yet been extensively studied. Furthermore, some USPs can regulate the canonical NF-κB signaling pathway via ubiquitin-independent mechanisms.

Conclusions

In the regulation of the canonical NF-κB pathway, the USPs function primarily as DUBs, but they also regulate the p65/p50 by ubiquitin-independent mechanisms. Generally, in human cancer models, USP-mediated elevation and suppression of p65/p50 activity lead to more or less malignant cellular behaviors, respectively. Given the currently unbalanced focus on K48- and K63-linked DUB activities and the context-dependent function of USPs, future research of USP-mediated NF-κB regulation in human cancers should invest more in the DUB activities against the atypical polyubiquitin chains and test known mechanisms in different cancer models.

TRAF2 associates with cullin neddylation complex assembly

Cullin-based RING ligases (CRLs) comprise the largest family of ubiquitin E3 ligases. CRL activity is tightly regulated by cullin neddylation, which has been associated with various diseases. Although inhibitors of CRLs neddylation have been reported, there is a lack of small molecules that can selectively target individual cullins. Here, we identified a natural product, liquidambaric acid (LDA), with relatively selective inhibition properties against cullin (Cul) 2 neddylation, and found that its target, Tumor Necrosis Factor receptor-associated factor 2 (TRAF2) was required for the activity. TRAF2 associates with the Cul2 neddylation complex and regulates the machinery assembly, especially that of E2 (UBC12) and E3 (RBX1) enzymes. In addition, we demonstrated that by intervention of the associations between TRAF2 and the neddylation machinery, LDA disturbed NEDD8 transfer from E1 to E2, therefore blocking Cul2 neddylation. Taken together, we show that TRAF2 plays a positive role in neddylation cascades, and we have identified a small molecule capable of selective modulation of cullin neddylation.

Knocking out USP7 attenuates cardiac fibrosis and endothelial-to-mesenchymal transition by destabilizing SMAD3 in mice with heart failure with preserved ejection fraction

Background: Heart failure with preserved ejection fraction (HFpEF) is a predominant type of heart failure. Exploring new pathogenesis and identifying potential novel therapeutic targets for HFpEF is of paramount importance. Methods: HFpEF mouse model was established by the "Multiple-hit" strategy, in that 18- to 22-month-old female C57B6/J mice fed with a high-fat diet were further challenged with chronic infusion of Angiotensin II. RNA sequencing analysis showed that USP7 was significantly increased in the heart of HFpEF mice. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis, in conjunction with co-immunoprecipitation (Co-IP) techniques, identified expression of SMAD3, the key molecule of endothelial-to-mesenchymal transition (EndMT), was also significantly elevated. USP7 endothelium-specific knockout mice was generated to investigate the involvement of USP7 in HFpEF. The biological significance of the interaction between USP7 and SMAD3 was further explored. Results: USP7 promotes EndMT and cardiac fibrosis by binding to SMAD3 directly via its UBL (Ubiquitin-like) domain and cysteine at position 223 of USP7, leading SMAD3 deubiquitination to maintain the stability of SMAD3 by removing the K63 ubiquitin chain and preventing the degradation of SMAD3 by proteasomal process. USP7 also promotes SMAD3 phosphorylation and nuclear translocation, thereby aggravating EndMT and cardiac fibrosis. Endothelium-specific USP7 knockout led to improvement of HFpEF phenotypes and reduction of cardiac fibrosis. Overexpression of SMAD3 in endothelium-specific knockout HFpEF mice reversed the protective effects of USP7 knockout in this HFpEF mouse model. Conclusion: Our results indicated that USP7 is one of the key pathogenic molecules of HFpEF, and knocking out USP7 could attenuate HFpEF injury by promoting the degradation of SMAD3. USP7 and SMAD3 inhibition might be potential therapeutic options for HFpEF.

Cardiomyocyte-specific Tbk1 deletion aggravated chronic doxorubicin cardiotoxicity via inhibition of mitophagy

Doxorubicin (Dox) use is limited by Dox-induced cardiotoxicity. TANK-blinding kinase 1 (TBK1) is an important kinase involved in the regulation of mitophagy, but the role of TBK1 in cardiomyocytes in chronic Dox-induced cardiomyopathy remains unclear. Cardiomyocyte-specific Tbk1 knockout (Tbk1CKO) mice received Dox (6 mg/kg, injected intraperitoneally) once a week for 4 times, and cardiac assessment was performed 4 weeks after the final Dox injection. Adenoviruses encoding Tbk1 or containing shRNA targeting Tbk1, or a TBK1 phosphorylation inhibitor were used for overexpression or knockdown of Tbk1, or inhibit phosphorylation of TBK1 in isolated primary cardiomyocytes. Our results revealed that moderate Dox challenge decreased TBK1 phosphorylation (with no effect on TBK1 protein levels), resulting in compromised myocardial function, obvious mortality and overt interstitial fibrosis, and the effects were accentuated by Tbk1 deletion. Dox provoked mitochondrial membrane potential collapse and oxidative stress, the effects of which were exacerbated and mitigated by Tbk1 knockdown, specific inhibition of phosphorylation and overexpression, respectively. However, Tbk1 （Ser172A） overexpression did not alleviate these effects. Further scrutiny revealed that TBK1 exerted protective effects on mitochondria via SQSTM1/P62-mediated mitophagy. Tbk1 overexpression mediated cardioprotective effects on Dox-induced cardiotoxicity were cancelled off by Sqstm1/P62 knockdown. Moreover, TBK1-mitophagy-mitochondria cascade was confirmed in heart tissues from dilated cardiomyopathy patients. Taken together, our findings denoted a pivotal role of TBK1 in Dox-induced mitochondrial injury and cardiotoxicity possibly through its phosphorylation and SQSTM1/P62-mediated mitophagy.

Programmed death of cardiomyocytes in cardiovascular disease and new therapeutic approaches

Cardiovascular diseases (CVDs) have a complex pathogenesis and pose a major threat to human health. Cardiomyocytes have a low regenerative capacity, and their death is a key factor in the morbidity and mortality of many CVDs. Cardiomyocyte death can be regulated by specific signaling pathways known as programmed cell death (PCD), including apoptosis, necroptosis, autophagy, pyroptosis, and ferroptosis, etc. Abnormalities in PCD can lead to the development of a variety of cardiovascular diseases, and there are also molecular-level interconnections between different PCD pathways under the same cardiovascular disease model. Currently, the link between programmed cell death in cardiomyocytes and cardiovascular disease is not fully understood. This review describes the molecular mechanisms of programmed death and the impact of cardiomyocyte death on cardiovascular disease development. Emphasis is placed on a summary of drugs and potential therapeutic approaches that can be used to treat cardiovascular disease by targeting and blocking programmed cell death in cardiomyocytes.

Low-dose doxorubicin loaded extracellular vesicles combined Fas/FasL pathway-mediated chemo-sensitization and immunotherapy against tumor

The clinical application of doxorubicin (DOX) is mainly restricted by its serious side effects, poor drug delivery efficiency, and limited immunogenic death (ICD) effect. To improve DOX-based chemotherapy and ameliorate its adverse effects, we utilized 3LL cell-derived extracellular vesicles to encapsulate DOX and sodium nitroprusside (SNP) to obtain DOX/SNP@CM, which could effectively target the tumor site by harnessing the inherent homologous targeting property of tumor cell membranes. DOX performed its role on chemotherapy, and SNP successfully respond to the intracellular GSH to continuously generate nitric oxide (NO). The in situ-produced NO upregulated the Fas expression on the tumor cell surface, thereby sensitizing the Fas/FasL pathway-mediated tumor cell apoptosis of DOX. Furthermore, NO also boosted the intratumoral infiltration of cytotoxic T cells by promoted ICD effect towards tumor cells. Importantly, the anti-tumor immunity tightly cooperated with Fas/FasL mediated tumor cell apoptosis by NO-mediated manipulation on Fas/FasL interaction, collectively making DOX/SNP@CM exert significant tumor growth inhibition with low-dose DOX. Remarkably, DOX and SNP both are widely used clinical medicines, ensuring DOX/SNP@CM a potential opportunity for future practical applications.

Identification of key genes associated with acute myocardial infarction using WGCNA and two-sample mendelian randomization study

OBJECTIVE

Acute myocardial infarction (AMI) is a severe condition with high morbidity and mortality rates. This study aimed to identify hub genes potentially associated with AMI and assess their clinical utility in predicting AMI occurrence.

METHODS

Gene microarray data were obtained from the Gene Expression Omnibus (GEO) database. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were conducted on samples from patients with AMI and control samples to identify modules significantly associated with AMI. GO and KEGG analyses were applied to investigate the potential functions of these hub genes. Lastly, the mendelian randomization (MR) method was applied to analyze the causal relationship between the hub gene TNF and AMI.

RESULTS

285 differentially expressed genes (DEGs) were identified through WCGNA and were clustered into 6 modules. The yellow module appeared most relevant to AMI. Further exploration through GO and KEGG pathway enrichment showed that key hub genes in the yellow module were linked to positive regulation of cytokine production, cytokine receptor binding, NF-kappa B signaling pathway, IL-17 signaling pathway, and TNF signaling pathway. The top 10 genes identified through Cytoscape software analysis were IL1B, TNF, TLR4, TLR2, FCGR3B, MMP9, CXCL8, TLR8, ICAM1, and JUK. Utilizing inverse variance weighting (IVW) analysis, we discovered a significant association between TNF and AMI risk, with an OR of 0.946 (95% CI = 0.911-0.984, p = 0.005).

CONCLUSIONS

The result of this study indicated that TNF, TLR2, TLR4, IL1B and FCGR3B may be potential biodiagnostic markers for AMI. TNF can inhibit inflammatory and oxidative stress responses in AMI, exerting a protective role in the heart.

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.

Ivermectin ameliorates acute myocarditis via the inhibition of importin-mediated nuclear translocation of NF-κB/p65

BACKGROUND

Myocarditis is an important clinical issue which lacks specific treatment by now. Ivermectin (IVM) is an inhibitor of importin α/β-mediated nuclear translocation. This study aimed to explore the therapeutic effects of IVM on acute myocarditis.

METHODS

Mouse models of coxsackie B3 virus (CVB3) infection-induced myocarditis and experimental autoimmune myocarditis (EAM) were established to evaluate the effects of IVM. Cardiac functions were evaluated by echocardiography and Millar catheter. Cardiac inflammatory infiltration was assessed by histological staining. Cytometric bead array and quantitative real-time PCR were used to detect the levels of pro-inflammatory cytokines. The macrophages and their M1/M2 polarization were analyzed via flow cytometry. Protein expression and binding were detected by co-immunoprecipitation, Western blotting and histological staining. The underlying mechanism was verified in vitro using CVB3-infected RAW264.7 macrophages. Cyclic polypeptide (cTN50) was synthesized to selectively inhibit the nuclear translocation of NF-κB/p65, and CVB3-infected RAW264.7 cells were treated with cTN50.

RESULTS

Increased expression of importin β was observed in both models. IVM treatment improved cardiac functions and reduced the cardiac inflammation associated with CVB3-myocarditis and EAM. Furthermore, the pro-inflammatory cytokine (IL-1β/IL-6/TNF-α) levels were downregulated via the inhibition of the nuclear translocation of NF-κB/p65 in macrophages. IVM and cTN50 treatment also inhibited the nuclear translocation of NF-κB/p65 and downregulated the expression of pro-inflammatory cytokines in RAW264.7 macrophages.

CONCLUSIONS

Ivermectin inhibits the nuclear translocation of NF-κB/p65 and the expression of major pro-inflammatory cytokines in myocarditis. The therapeutic effects of IVM on viral and non-viral myocarditis models suggest its potential application in the treatment of acute myocarditis.

AP39 through AMPK-ULK1-FUNDC1 pathway regulates mitophagy, inhibits pyroptosis, and improves doxorubicin-induced myocardial fibrosis

Doxorubicin induces myocardial injury and fibrosis. Still, no effective interventions are available. AP39 is an H2S donor that explicitly targets mitochondria. This study investigated whether AP39 could improve doxorubicin-induced myocardial fibrosis. Doxorubicin induced significant myocardial fibrosis while suppressing mitophagy-related proteins and elevating pyroptosis-related proteins. Conversely, AP39 reverses these effects, enhancing mitophagy and inhibiting pyroptosis. In vitro experiments revealed that AP39 inhibited H9c2 cardiomyocyte pyroptosis, improved doxorubicin-induced impairment of mitophagy, reduced ROS levels, ameliorated the mitochondrial membrane potential, and upregulated AMPK-ULK1-FUNDC1 expression. In contrast, AMPK inhibitor (dorsomorphin) and ULK1 inhibitor (SBI-0206965) reversed AP39 antagonism of doxorubicin-induced FUNDC1-mediated impairment of mitophagy and secondary cardiomyocyte pyroptosis. These results suggest that mitochondria-targeted H2S can antagonize doxorubicin-induced pyroptosis and impaired mitophagy in cardiomyocytes via AMPK-ULK1-FUNDC1 and ameliorated myocardial fibrosis and remodeling.

The role of deubiquitinases in cardiac disease

Deubiquitinases are a group of proteins that identify and digest monoubiquitin chains or polyubiquitin chains attached to substrate proteins, preventing the substrate protein from being degraded by the ubiquitin-proteasome system. Deubiquitinases regulate cellular autophagy, metabolism and oxidative stress by acting on different substrate proteins. Recent studies have revealed that deubiquitinases act as a critical regulator in various cardiac diseases, and control the onset and progression of cardiac disease through a board range of mechanism. This review summarizes the function of different deubiquitinases in cardiac disease, including cardiac hypertrophy, myocardial infarction and diabetes mellitus-related cardiac disease. Besides, this review briefly recapitulates the role of deubiquitinases modulators in cardiac disease, providing the potential therapeutic targets in the future.

IKKβ stabilizes Mitofusin 2 and suppresses doxorubicin cardiomyopathy

AIMS

The mitochondrial dynamics protein Mitofusin 2 (MFN2) coordinates critical cellular processes including mitochondrial bioenergetics, quality control, and cell viability. The NF-κB kinase IKKβ suppresses mitochondrial injury in doxorubicin cardiomyopathy, but the underlying mechanism is undefined.

METHODS AND RESULTS

Herein, we identify a novel signalling axis that functionally connects IKKβ and doxorubicin cardiomyopathy to a mechanism that impinges upon the proteasomal stabilization of MFN2. In contrast to vehicle-treated cells, MFN2 was highly ubiquitinated and rapidly degraded by the proteasomal-regulated pathway in cardiac myocytes treated with doxorubicin. The loss of MFN2 activity resulted in mitochondrial perturbations, including increased reactive oxygen species (ROS) production, impaired respiration, and necrotic cell death. Interestingly, doxorubicin-induced degradation of MFN2 and mitochondrial-regulated cell death were contingent upon IKKβ kinase activity. Notably, immunoprecipitation and proximity ligation assays revealed that IKKβ interacted with MFN2 suggesting that MFN2 may be a phosphorylation target of IKKβ. To explore this possibility, mass spectrometry analysis identified a novel MFN2 phospho-acceptor site at serine 53 that was phosphorylated by wild-type IKKβ but not by a kinase-inactive mutant IKKβK-M. Based on these findings, we reasoned that IKKβ-mediated phosphorylation of serine 53 may influence MFN2 protein stability. Consistent with this view, an IKKβ-phosphomimetic MFN2 (MFN2S53D) was resistant to proteasomal degradation induced by doxorubicin whereas wild-type MFN2 and IKKβ-phosphorylation defective MFN2 mutant (MFNS53A) were readily degraded in cardiac myocytes treated with doxorubicin. Concordantly, gain of function of IKKβ or MFN2S53D suppressed doxorubicin-induced mitochondrial injury and cell death.

CONCLUSIONS

The findings of this study reveal a novel survival pathway for IKKβ that is mutually dependent upon and obligatory linked to the phosphorylation and stabilization of the mitochondrial dynamics protein MFN2.

Alleviation of temporomandibular joint osteoarthritis by targeting RIPK1-mediated inflammatory signalling

Temporomandibular joint osteoarthritis (TMJOA), prevalent in adolescents and the elderly, has serious physical and psychological consequences. TMJOA is a degenerative disease of the cartilage and bone, mostly driven by inflammation, and synoviocytes are the first and most important inflammatory factor releasers. Receptor-interacting serine/threonine-protein kinase (RIPK1) promotes inflammatory response and cell death during an array of illnesses. This research aimed to explore the impacts of RIPK1 inhibitor therapy in TMJOA and the mechanism of RIPK1 in inducing inflammation during TMJOA. Herein, inhibition of RIPK1 suppressed the elevated levels of inflammatory factors, nuclear factor kappa B (NF-κB), along with markers of apoptosis and necroptosis after tumour necrosis factor (TNF)-α/cycloheximide (CHX) treatment in synoviocytes. Moreover, inflammation models were constructed in vivo through complete Freund's adjuvant (CFA) induction and disc perforation, and the findings supported that RIPK1 inhibition protected TMJ articular cartilage against progressive degradation. RIPK1 regulates NF-κB activation via cellular inhibitor of apoptosis proteins (cIAP), apoptosis via caspase-8, and necroptosis via RIPK3/mixed lineage kinase domain-like (MLKL) in synoviocytes, which in turn facilitates TMJOA inflammation progression.

Friend or foe? Reciprocal regulation between E3 ubiquitin ligases and deubiquitinases

Protein ubiquitination is a post-translational modification that entails the covalent attachment of the small protein ubiquitin (Ub), which acts as a signal to direct protein stability, localization, or interactions. The Ub code is written by a family of enzymes called E3 Ub ligases (∼600 members in humans), which can catalyze the transfer of either a single ubiquitin or the formation of a diverse array of polyubiquitin chains. This code can be edited or erased by a different set of enzymes termed deubiquitinases (DUBs; ∼100 members in humans). While enzymes from these distinct families have seemingly opposing activities, certain E3-DUB pairings can also synergize to regulate vital cellular processes like gene expression, autophagy, innate immunity, and cell proliferation. In this review, we highlight recent studies describing Ub ligase-DUB interactions and focus on their relationships.

The E3 ubiquitin ligases regulate inflammation in cardiovascular diseases

Accumulating evidence has illustrated that the E3 ubiquitin ligases critically participate in the development and progression of cardiovascular diseases. Dysregulation of E3 ubiquitin ligases exacerbates cardiovascular diseases. Blockade or activation of E3 ubiquitin ligases mitigates cardiovascular performance. Therefore, in this review, we mainly introduced the critical role and underlying molecular mechanisms of E3 ubiquitin ligase NEDD4 family in governing the initiation and progression of cardiovascular diseases, including ITCH, WWP1, WWP2, Smurf1, Smurf2, Nedd4-1 and Nedd4-2. Moreover, the functions and molecular insights of other E3 ubiquitin ligases, such as F-box proteins, in cardiovascular disease development and malignant progression are described. Furthermore, we illustrate several compounds that alter the expression of E3 ubiquitin ligases to alleviate cardiovascular diseases. Therefore, modulation of E3 ubiquitin ligases could be a novel and promising strategy for improvement of therapeutic efficacy of deteriorative cardiovascular diseases.

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

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

Upregulation of NF-κB by USP24 aggravates ferroptosis in diabetic cardiomyopathy

BACKGROUND

Recent investigations have proposed a potential causal association between the occurrence of ferroptosis, nuclear factor kappa B (NF-κB) and ubiquitin-specific protease 24 (USP24). Nevertheless, the mechanism of USP24 and NF-κB regulation of ferroptosis in the context of diabetic cardiomyopathy (DCM) remain unclear.

METHODS

In this study, a high-fat diet and a streptozotocin-induced mouse DCM model were established, and high glucose and palmitic acid treatment of H9c2 cells and neonatal mouse primary cardiomyocytes (NMPCs) was used as an in vitro DCM models. Utilizing both the in vivo and in vitro DCM models, we assessed of USP24, NF-κB, and ferroptosis levels, and explored the relationship among them.

RESULTS

In in vivo and in vitro DCM models, increased expression of USP24, NF-κB, phosphorylated NF-κB (p-NF-κB) and fatty acid-CoA ligase 4 (FACL4) were detected, along with accumulated iron, as well as reduced ferritin heavy chain 1 (FTH1), solute carrier family 7 member 11 (SLC7A11) and antioxidant capacity. Knockdown of USP24 resulted in a reduction of NF-κB levels, while knockdown of NF-κB did not lead to a decrease in USP24 expression. Moreover, in H9c2 cells, knockdown of USP24 and NF-κB separately resulted in reduced levels of FACL4, increased levels of SLC7A11 and FTH1, as well as improved antioxidant capacity and cell viability. In shUSP24 knockdown H9c2 cells, administration of phorbol 12-myristate 13-acetate (PMA) activated NF-κB, subsequently reversing the previously observed effect caused by USP24 knockdown.

CONCLUSIONS

These findings show that USP24 upregulates NF-κB to promote ferroptosis in DCM.

The Metformin Immunoregulatory Actions in Tumor Suppression and Normal Tissues Protection

The immune system is the key player in a wide range of responses in normal tissues and tumors to anticancer therapy. Inflammatory and fibrotic responses in normal tissues are the main limitations of chemotherapy, radiotherapy, and also some newer anticancer drugs such as immune checkpoint inhibitors (ICIs). Immune system responses within solid tumors including anti-tumor and tumor-promoting responses can suppress or help tumor growth. Thus, modulation of immune cells and their secretions such as cytokines, growth factors and epigenetic modulators, pro-apoptosis molecules, and some other molecules can be suggested to alleviate side effects in normal tissues and drug-resistance mechanisms in the tumor. Metformin as an anti-diabetes drug has shown intriguing properties such as anti-inflammation, anti-fibrosis, and anticancer effects. Some investigations have uncovered that metformin can ameliorate radiation/chemotherapy toxicity in normal cells and tissues through the modulation of several targets in cells and tissues. These effects of metformin may ameliorate severe inflammatory responses and fibrosis after exposure to ionizing radiation or following treatment with highly toxic chemotherapy drugs. Metformin can suppress the activity of immunosuppressive cells in the tumor through the phosphorylation of AMP-activated protein kinase (AMPK). In addition, metformin may stimulate antigen presentation and maturation of anticancer immune cells, which lead to the induction of anticancer immunity in the tumor. This review aims to explain the detailed mechanisms of normal tissue sparing and tumor suppression during cancer therapy using adjuvant metformin with an emphasis on immune system responses.

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.

A CircRNA-miRNA-mRNA Network for Exploring Doxorubicin- and Myocet-Induced Cardiotoxicity in a Translational Porcine Model

Despite the widespread use of doxorubicin (DOX) as a chemotherapeutic agent, its severe cumulative cardiotoxicity represents a significant limitation. While the liposomal encapsulation of doxorubicin (Myocet, MYO) reduces cardiotoxicity, it is crucial to understand the molecular background of doxorubicin-induced cardiotoxicity. Here, we examined circular RNA expression in a translational model of pigs treated with either DOX or MYO and its potential impact on the global gene expression pattern in the myocardium. This study furthers our knowledge about the regulatory network of circRNA/miRNA/mRNA and its interaction with chemotherapeutics. Domestic pigs were treated with three cycles of anthracycline drugs (DOX, n = 5; MYO, n = 5) to induce cardiotoxicity. Untreated animals served as controls (control, n = 3). We applied a bulk mRNA-seq approach and the CIRIquant algorithm to identify circRNAs. The most differentially regulated circRNAs were validated under cell culture conditions, following forecasting of the circRNA-miRNA-mRNA network. We identified eight novel significantly regulated circRNAs from exonic and mitochondrial regions in the porcine myocardium. The forecasted circRNA-miRNA-mRNA network suggested candidate circRNAs that sponge miR-17, miR-15b, miR-130b, the let-7 family, and miR125, together with their mRNA targets. The identified circRNA-miRNA-mRNA network provides an updated, coherent view of the mechanisms involved in anthracycline-induced cardiotoxicity.

Taxifolin protects against doxorubicin-induced cardiotoxicity and ferroptosis by adjusting microRNA-200a-mediated Nrf2 signaling pathway

The chemotherapeutic agent doxorubicin (Dox) is commonly used to treat various types of cancer, even though it can cause life-threatening cardiotoxicity. Clinically, there is no particularly effective way to treat Dox-induced cardiotoxicity. Therefore, it is imperative to identify compounds that can effectively alleviate Dox-induced cardiotoxicity. Ferroptosis and oxidative stress play a key role in Dox-induced cardiotoxicity, and the inhibition of ferroptosis and oxidative stress could effectively protect against doxorubicin-induced cardiotoxicity. Taxifolin (TAX) is a flavonoid commonly found in onions and citrus fruits. In the present study, we evaluated the effects of TAX on Dox-induced cardiac injury and dysfunction and aimed to explore the mechanisms underlying these effects. Using a mouse model of Dox-induced cardiotoxicity, we administered 20 mg/kg/day of TAX by gavage for 2 weeks. A week after the first use of TAX, each mouse was administered a 10 mg/kg dose of Dox. TAX was first evaluated for its cardioprotective properties, and the outcomes showed that TAX significantly reduced the damage caused by Dox to the myocardium in terms of structural and functional damage by effectively inhibiting ferroptosis and oxidative stress. In vivo, echocardiography, histopathologic assay, serum biochemical analysis and western blotting was used to find the results that Dox promoted ferroptosis-induced cardiomyocyte death, while TAX reversed these effects. In vitro, we also found that TAX alleviated Dox-induced cardiotoxicity by using ROS/DHE staining assay, Cellular immunofluorescence and western blotting. TAX increasing expression of microRNA-200a (miR-200a) which affects ferroptosis by activating Nrf2 signaling pathway. We believe that TAX inhibits ferroptosis and is a potential phytochemical that prevents Dox-induced cardiotoxicity.

Doxorubicin-mediated cardiac dysfunction: Revisiting molecular interactions, pharmacological compounds and (nano)theranostic platforms

Although chemotherapy drugs are extensively utilized in cancer therapy, their administration for treatment of patients has faced problems that regardless of chemoresistance, increasing evidence has shown concentration-related toxicity of drugs. Doxorubicin (DOX) is a drug used in treatment of solid and hematological tumors, and its function is based on topoisomerase suppression to impair cancer progression. However, DOX can also affect the other organs of body and after chemotherapy, life quality of cancer patients decreases due to the side effects. Heart is one of the vital organs of body that is significantly affected by DOX during cancer chemotherapy, and this can lead to cardiac dysfunction and predispose to development of cardiovascular diseases and atherosclerosis, among others. The exposure to DOX can stimulate apoptosis and sometimes, pro-survival autophagy stimulation can ameliorate this condition. Moreover, DOX-mediated ferroptosis impairs proper function of heart and by increasing oxidative stress and inflammation, DOX causes cardiac dysfunction. The function of DOX in mediating cardiac toxicity is mediated by several pathways that some of them demonstrate protective function including Nrf2. Therefore, if expression level of such protective mechanisms increases, they can alleviate DOX-mediated cardiac toxicity. For this purpose, pharmacological compounds and therapeutic drugs in preventing DOX-mediated cardiotoxicity have been utilized and they can reduce side effects of DOX to prevent development of cardiovascular diseases in patients underwent chemotherapy. Furthermore, (nano)platforms are used comprehensively in treatment of cardiovascular diseases and using them for DOX delivery can reduce side effects by decreasing concentration of drug. Moreover, when DOX is loaded on nanoparticles, it is delivered into cells in a targeted way and its accumulation in healthy organs is prevented to diminish its adverse impacts. Hence, current paper provides a comprehensive discussion of DOX-mediated toxicity and subsequent alleviation by drugs and nanotherapeutics in treatment of cardiovascular diseases.

Mitochonic acid 5 rescues cardiomyocytes from doxorubicin-induced toxicity via repressing the TNF-α/NF-κB/NLRP3-mediated pyroptosis

AIMS

Doxorubicin (DOX) is an effective anti-tumor drug, but the cardiotoxicity severely limits its clinical use. Interestingly, a hypothesis has emerged suggesting an association between DOX-induced cardiotoxicity and mitochondrial disorders and oxidative stress. The mitochonic acid 5 (MA5) shows promise in alleviating mitochondrial dysfunction by promoting mitochondrial ATP synthesis and reducing reactive oxygen species (ROS) accumulation, though its potential in ameliorating DOX-induced cardiotoxicity remains elusive.

METHODS

Network pharmacology approach, molecular docking techniques, and molecular dynamics simulation (MDS) were used to reveal the specific drug targets and pharmaceutical mechanisms involved in the treatment of DOX-induced cardiotoxicity using MA5. For experimental verification, cardiomyocytes (H9c2) and mice were exposed to DOX in the presence or absence of MA5. Our investigation involved the assessment of echocardiographic parameters, cardiac enzymes, inflammatory factors, mitochondrial function, myocardial structure, and cardiomyocyte pyroptosis.

RESULTS

Among the 100 core targets identified in network pharmacology, MA5 was pharmacologically active against DOX-induced cardiotoxicity via pathways implicated in cancer, prostate cancer, lipids and atherosclerosis. Molecular docking analysis confirmed that MA5 docked well with TNF-α, interleukin-6 (IL-6), and caspase-3. Furthermore, MA5 exhibited a stronger affinity toward TNF-α than IL-6 and caspase-3. Subsequent MDS revealed the stability of binding between MA5 and TNF-α. The DOX-challenged mice also displayed abnormal myocardial enzymogram, disrupted systolic and diastolic function, and elevated inflammation and cardiomyocyte pyroptosis, which could be mitigated by the administration of MA5. Similarly, H9c2 cells exposed to DOX showed increased intracellular ROS production and impaired mitochondrial function, which were relieved by MA5 treatment.

CONCLUSION

Our findings suggest that MA5 attenuates DOX-induced cardiac anomalies through the TNF-α-mediated regulation of inflammation and pyroptosis. These insights offer a potential therapeutic strategy for managing DOX-induced cardiac complications, thereby improving the safety and efficacy of cancer treatments.

Possible correlated signaling pathways with chronic urate nephropathy: A review

Hyperuricemia nephropathy, also known as gouty nephropathy, refers to renal damage induced by hyperuricemia caused by excessive production of serum uric acid or low excretion of uric acid. the persistence of symptoms will lead to changes in renal tubular phenotype and accelerate the progress of renal fibrosis. The existence and progressive aggravation of symptoms will bring a heavy burden to patients, their families and society, affect their quality of life and reduce their well-being. With the increase of reports on hyperuricemia nephropathy, the importance of related signal pathways in the pathogenesis of hyperuricemia nephropathy is becoming more and more obvious, but most studies are limited to the upper and lower mediating relationship between 1 or 2 signal pathways. The research on the comprehensiveness of signal pathways and the breadth of crosstalk between signal pathways is limited. By synthesizing the research results of signal pathways related to hyperuricemia nephropathy in recent years, this paper will explore the specific mechanism of hyperuricemia nephropathy, and provide new ideas and methods for the treatment of hyperuricemia nephropathy based on a variety of signal pathway crosstalk and personal prospects.

Leucine zipper protein 1 prevents doxorubicin-induced cardiotoxicity in mice

OBJECTIVE

Doxorubicin (DOX) is commonly used for chemotherapy; however, its clinical value is extremely dampened because of the fatal cardiotoxicity. Leucine zipper protein 1 (LUZP1) plays critical roles in cardiovascular development, and this study is designed for determining its function and mechanism in DOX-induced cardiotoxicity.

METHODS

Cardiac-specific Luzp1 knockout (cKO) and transgenic (cTG) mice received a single or repeated DOX injections to establish acute and chronic cardiotoxicity. Biomarkers of inflammation, oxidative damage and cell apoptosis were evaluated. Transcriptome and co-immunoprecipitation analysis were used to screen the underlying molecular pathways. Meanwhile, primary cardiomyocytes were applied to confirm the beneficial effects of LUZP1 in depth.

RESULTS

LUZP1 was upregulated in DOX-injured hearts and cardiomyocytes. Cardiac-specific LUZP1 deficiency aggravated, while cardiac-specific LUZP1 overexpression attenuated DOX-associated inflammation, oxidative damage, cell apoptosis and acute cardiac injury. Mechanistic studies revealed that LUZP1 ameliorated DOX-induced cardiotoxicity through activating 5'-AMP-activated protein kinase (AMPK) pathway, and AMPK deficiency abolished the cardioprotection of LUZP1. Further findings suggested that LUZP1 interacted with protein phosphatase 1 to activate AMPK pathway. Moreover, we determined that cardiac-specific LUZP1 overexpression could also attenuate DOX-associated chronic cardiac injury in mice.

CONCLUSION

LUZP1 attenuates DOX-induced inflammation, oxidative damage, cell apoptosis and ventricular impairment through regulating AMPK pathway, and gene therapy targeting LUZP1 may provide novel therapeutic approached to treat DOX-induced cardiotoxicity.

Amentoflavone mitigates doxorubicin-induced cardiotoxicity by suppressing cardiomyocyte pyroptosis and inflammation through inhibition of the STING/NLRP3 signalling pathway

BACKGROUND

Doxorubicin (DOX) is a potent anticancer chemotherapeutic agent whose clinical application is substantially constrained by its cardiotoxicity. The pathophysiology of DOX-induced cardiotoxicity manifests as cardiomyocyte pyroptosis and inflammation. Amentoflavone (AMF) is a naturally occurring biflavone possessing anti-pyroptotic and anti-inflammatory properties. However, the mechanism through which AMF alleviates DOX-induced cardiotoxicity remains undetermined.

PURPOSE

This study aimed at investigating the role of AMF in alleviating DOX-induced cardiotoxicity.

STUDY DESIGN AND METHODS

To assess the in vivo effect of AMF, DOX was intraperitoneally administered into a mouse model to induce cardiotoxicity. To elucidate the underlying mechanisms, the activities of STING/NLRP3 were quantified using the NLRP3 agonist nigericin and the STING agonist amidobenzimidazole (ABZI). Primary cardiomyocytes isolated from neonatal Sprague-Dawley rats were treated with saline (vehicle) or DOX with or without AMF and/or ABZI. The echocardiogram, haemodynamics, cardiac injury markers, heart/body weight ratio, and pathological alterations were monitored; the STING/NLRP3 pathway-associated proteins were detected by western blot and cardiomyocyte pyroptosis was analysed by immunofluorescence staining of cleaved N-terminal GSDMD and scanning electron microscopy. Furthermore, we evaluated the potential of AMF in compromising the anticancer effects of DOX in human breast cancer cell lines.

RESULTS

AMF substantially alleviated cardiac dysfunction and reduced heart/body weight ratio and myocardial damage in mice models of DOX-induced cardiotoxicity. AMF effectively suppressed DOX-mediated upregulation of IL-1β, IL-18, TNF-α, and pyroptosis-related proteins, including NLRP3, cleaved caspase-1, and cleaved N-terminal GSDMD. The levels of apoptosis-related proteins, namely Bax, cleaved caspase-3, and BCL-2 were not affected. In addition, AMF inhibited STING phosphorylation in DOX-affected hearts. Intriguingly, the administration of nigericin or ABZI dampened the cardioprotective effects of AMF. The in vitro anti-pyroptotic effect of AMF was demonstrated in attenuating the DOX-induced reduction in cardiomyocyte cell viability, upregulation of cleaved N-terminal GSDMD, and pyroptotic morphology alteration at the microstructural level. AMF exhibited a synergistic effect with DOX to reduce the viability of human breast cancer cells.

CONCLUSION

AMF alleviates DOX-induced cardiotoxicity by suppressing cardiomyocyte pyroptosis and inflammation via inhibition of the STING/NLRP3 signalling pathway, thereby validating its efficacy as a cardioprotective agent.

Apolipoprotein M Attenuates Anthracycline Cardiotoxicity and Lysosomal Injury

Apolipoprotein M (ApoM) binds sphingosine-1-phosphate (S1P) and is inversely associated with mortality in human heart failure (HF). Here, we show that anthracyclines such as doxorubicin (Dox) reduce circulating ApoM in mice and humans, that ApoM is inversely associated with mortality in patients with anthracycline-induced heart failure, and ApoM heterozygosity in mice increases Dox-induced mortality. In the setting of Dox stress, our studies suggest ApoM can help sustain myocardial autophagic flux in a post-transcriptional manner, attenuate Dox cardiotoxicity, and prevent lysosomal injury.

Ellagic acid inhibits mitochondrial fission protein Drp-1 and cell proliferation in cancer

Anthracyclines such as doxorubicin (Dox) are widely used to treat a variety of adult and childhood cancers, however, a major limitation to many of these compounds is their propensity for inducing heart failure. A naturally occurring polyphenolic compound such as Ellagic acid (EA) has been shown by our laboratory to mitigate the cardiotoxic effects of Dox, however, the effects of EA on cancer cell viability have not been established. In this study, we explored the effects of EA alone and in combination with Dox on cancer cell viability and tumorigenesis. Herein, we show that EA induces cell cycle exit and reduces proliferation in colorectal cancer (HCT116) and breast adenocarcinoma cells (MCF7). We show that EA promotes cell cycle exit by a mechanism that inhibits mitochondrial dynamics protein Drp-1. EA treatment of HCT116 and MCF7 cells resulted in a hyperfused mitochondrial morphology that coincided with mitochondrial perturbations including loss of mitochondrial membrane potential, impaired respiratory capacity. Moreover, impaired mitochondrial function was accompanied by a reduction in cell cycle and proliferation markers, CDK1, Ki67, and Cyclin B. This resulted in a reduction in proliferation and widespread death of cancer cells. Furthermore, while Dox treatment alone promoted cell death in both HCT116 and MCF7 cancer cell lines, EA treatment lowered the effective dose of Dox to promote cell death. Hence, the findings of the present study reveal a previously unreported anti-tumor property of EA that impinges on mitochondrial dynamics protein, Drp-1 which is crucial for cell division and tumorigenesis. The ability of EA to lower the therapeutic threshold of Dox for inhibiting cancer cell growth may prove beneficial in reducing cardiotoxicity in cancer patients undergoing anthracycline therapy.