SIRT1 in the cardiomyocyte counteracts doxorubicin-induced cardiotoxicity via regulating histone H2AX

Inhibition of the Sp1/PI3K/AKT signaling pathway exacerbates doxorubicin-induced cardiomyopathy

OBJECTIVE

This study aimed to investigate the interaction and underlying mechanisms between specificity protein 1 (Sp1) and the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling pathway in the context of doxorubicin-induced cardiomyopathy (DIC).

METHODS

A rat model of DIC was established by intraperitoneal injection of doxorubicin (1 mg/kg) twice a week for eight weeks. Cardiac function was evaluated using echocardiography, and myocardial histopathology was assessed by hematoxylin-eosin (HE) staining. In vitro, H9c2 cardiomyocytes were treated with doxorubicin (2 μmol/L) to induce cardiotoxicity, followed by co-treatment with the Sp1 inhibitor plicamycin or the PI3K/AKT inhibitor LY294002. Cell viability was measured by the CCK-8 assay. Oxidative stress markers, including reactive oxygen species (ROS) and lactate dehydrogenase (LDH), were quantified using flow cytometry and colorimetric assays. Apoptosis was detected via TUNEL staining, and protein expression of Sp1, PI3K, AKT, and Caspase-3 was analyzed by Western blotting.

RESULTS

Doxorubicin treatment significantly impaired cardiac function in rats, as evidenced by an increase in both left ventricular internal diameters during diastole (LVIDd) and systole (LVIDs), along with decreased ejection fraction (EF) and fractional shortening (FS) (p < 0.01). Myocardial HE staining in doxorubicin-treated rats revealed disorganized cardiomyocyte structures, edema, and cellular necrosis. In vitro, doxorubicin exposure led to reduced H9c2 cell viability, elevated ROS and LDH levels, and increased apoptosis rates (p < 0.01). Western blotting demonstrated that doxorubicin significantly downregulated the expression of Sp1, PI3K, and AKT while upregulating Caspase-3. Inhibition of Sp1 or PI3K/AKT exacerbated these effects, resulting in further cardiac dysfunction, oxidative stress, and apoptosis. Moreover, Sp1 inhibition led to decreased PI3K/AKT pathway activation, while PI3K/AKT inhibition reciprocally suppressed Sp1 expression, indicating a bidirectional regulatory relationship.

CONCLUSION

Doxorubicin induces cardiotoxicity by promoting oxidative stress and apoptosis through the downregulation of the Sp1/PI3K/AKT signaling pathway. Inhibition of this pathway exacerbates cardiac injury, suggesting that targeting Sp1 and PI3K/AKT may offer novel therapeutic strategies for the prevention and treatment of DIC.

Enhanced SIRT1-TFEB Interaction Promotes Lysosome Biogenesis and Autophagy by Reducing TFEB Acetylation: Revealing the Enterotoxicity Disparity of Deoxynivalenol and T-2 Toxin

Multiple environmental factors contribute to digestive system damage caused by food contamination in both humans and animals. Mycotoxins, such as deoxynivalenol (DON) and T-2 toxin, have emerged as the most significant factors due to their extensive contamination and difficulty in removal. Transcription factor EB (TFEB) serves as a crucial transcriptional regulator governing lysosomal biogenesis and autophagy, a lysosomal-driven degradation system that safeguards cells against harmful stressors. However, little is known about whether the post-translational modification of TFEB affects autophagy activity, which could explain the toxicity disparity between DON and T-2 toxin. Here, we discovered that T-2 toxin induces excessive autophagy by significantly reducing TFEB acetylation, whereas DON surprisingly inhibits autophagy activity via maintaining high TFEB acetylation, which impairs lysosomal biogenesis, thereby boosting their respective toxicity. Mechanically, the T-2 toxin decreases TFEB acetylation via enhanced SIRT1-TFEB interaction and SIRT1 deacetylase activity, while DON maintains high TFEB acetylation by reversing the process. Together, our study revealed that the acetylation state of TFEB mediated by SIRT1 alters autophagy phenotypes in intestinal cells, shedding light on the various toxicological mechanisms and an important target of DON and T-2 toxin.

SIRT5 modulates mitochondria function via mitophagy and antioxidant mechanisms to facilitate oocyte maturation in mice

Mitochondrial homeostasis, closely associated with mitophagy and antioxidant mechanisms, is essential for proper meiotic spindle assembly and chromosome segregation during oocyte maturation. SIRT5, known to modulate mitochondrial function under various conditions, has been shown to impact oocyte quality when inhibited, however, the precise mechanisms linking SIRT5 to mitochondrial homeostasis during meiotic progression remain unclear. In this study, we demonstrate that SIRT5 localizes predominantly at the periphery of the meiotic spindle and is enriched on chromosomes during oocyte maturation. Inhibition of SIRT5 led to significant meiotic defects, including disrupted spindle organization and chromosome misalignment. These defects were associated with increased histone acetylation, which impaired kinetochore-microtubule attachments. Moreover, SIRT5 inhibition resulted in mitochondrial dysfunction, subsequently elevating ROS levels and triggering oxidative stress, which further exacerbated meiotic abnormalities. Mechanistically, SIRT5 inhibition disrupted the balance of Parkin-dependent mitophagy by inducing ULK phosphorylation. Additionally, it activated the PI3K/Akt signaling pathway, which increased NADPH consumption and reduced GSH levels. Collectively, these findings reveal that SIRT5 plays dual roles in maintaining mitochondrial homeostasis during oocyte maturation: (1) by regulating Parkin-dependent mitophagy to prevent excessive mitochondrial clearance, and (2) by preserving the NADPH/GSH antioxidant system to ensure redox balance. These insights provide potential targets for improving oocyte quality and addressing mitochondrial dysfunction-related reproductive disorders in females.

IDH1 regulates human erythropoiesis by eliciting chromatin state reprogramming

Isocitrate dehydrogenase 1 (IDH1) is the key enzyme that can modulate cellular metabolism, epigenetic modification, and redox homeostasis. Gain-of-function mutations and decreased expression of IDH1 have been demonstrated to be associated with pathogenesis of various myeloid malignancies characterized by ineffective erythropoiesis, such as acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). However, the function and mechanism of IDH1 in human erythropoiesis still remains unclear. Here, utilizing the human erythropoiesis system, we present an evidence of IDH1-mediated chromatin state reprogramming besides its well-characterized metabolism effects. We found that knockdown IDH1 induced chromatin reorganization and subsequently led to abnormalities biological events in erythroid precursors, which could not be rescued by addition of reactive oxygen species (ROS) scavengers or supplementation of α-ketoglutarate (α-KG).We further revealed that knockdown IDH1 induces genome-wide changes in distribution and intensity of multiple histone marks, among which H3K79me3 was identified as a critical factor in chromatin state reprogramming. Integrated analysis of ChIP-seq, ATAC-seq, and RNA-seq recognized that SIRT1 was the key gene affected by IDH1 deficiency. Thus, our current work provided novel insights for further clarifying fundamental biological function of IDH1 which has substantial implications for an in-depth understanding of pathogenesis of diseases with IDH1 dysfunction and accordingly development of therapeutic strategies.

Cardiac protection of wogonin in mice with pulmonary fibrosis by regulating Sirt1/ γ-H2AX pathway

Background

Clinical evidence suggests that pulmonary fibrosis (PF) and heart failure (HF) often co-exist; however, the specific impact of PF on HF remains underexplored. This gap in understanding complicates the management and treatment of HF in patients with PF.

Objectives

To investigate the effects of PF on cardiac function and myocardial fibrosis using a mouse PF model and evaluate the therapeutic potential of wogonin, a flavonoid compound known for its anti-PF properties.

Methods

A PF mouse model was established via intratracheal administration of bleomycin (BLM). Starting on day 8 post-BLM treatment, wogonin (50 mg/kg) was intraperitoneally administered every 2 days for 2 weeks. Cardiac function was assessed using echocardiography, while myocardial fibrosis was evaluated through Masson staining. In vitro, H9C2 cardiomyocytes were exposed to CoCl2 or H2O2 for 24 h with or without wogonin (20 μM) treatment. Apoptosis and DNA damage markers were analysed using immunofluorescence, immunoblotting, and the Comet assay. The interaction between wogonin and Sirt1 was examined using biotin-affinity pulldown assays and molecular docking simulations.

Results

Mice with PF exhibited significant cardiac dysfunction and myocardial fibrosis. Wogonin treatment markedly improved ejection fraction and attenuated myocardial fibrosis in PF mice. Mechanistic studies revealed that wogonin alleviated DNA damage and cardiomyocyte apoptosis by upregulating Sirt1 and downregulating γ-H2AX expression. Docking simulations predicted that wogonin forms a stable complex with Sirt1 through hydrogen-bonding and hydrophobic interactions, which was further validated by biotin-affinity pulldown assays.

Conclusion

Wogonin exerts protective effects against cardiac dysfunction and fibrosis in PF mice by modulating Sirt1/γ-H2AX-mediated pathways to reduce DNA damage and apoptosis. These findings suggest the potential of wogonin as a therapeutic agent for managing HF associated with PF.

Sirtuin1 mitigates hypoxia-induced cardiomyocyte apoptosis in myocardial infarction via PHD3/HIF-1α

BACKGROUND

Acute myocardial infarction (AMI) is a leading cause of mortality, characterized by myocardial ischemia that induces cardiomyocyte apoptosis and subsequent cardiac dysfunction. Sirtuin 1 (Sirt1) has emerged as a key regulator of cell survival and apoptosis, particularly under hypoxic conditions.

METHODS

An AMI animal model was established via ligation of the left anterior descending (LAD) coronary artery. Gene expression in the infarcted region was evaluated at various time points. Sirt1 overexpression and control lentivirus were administered to the peri-infarct region of mice heart. After LAD ligation, assessment on myocardial infarct size, cardiac function, and cardiomyocyte apoptosis were performed. In vitro, primary mouse cardiomyocytes subjected to hypoxia were analyzed for gene expression, while interactions among Sirt1, Phd3, and Hif-1α were explored using diverse treatment approaches.

RESULTS

A significant reduction in Sirt1 and Phd3 expression, along with an increase in Hif-1α and cleaved caspase-3, was observed in a time-dependent manner post-myocardial infarction (MI). In vitro findings revealed that hypoxia decreased nuclear Sirt1 and cytoplasmic Phd3 levels while promoting a time-dependent increase in Hif-1α and cleaved caspase-3. Furthermore, Sirt1 overexpression enhanced Phd3 expression in cardiomyocytes, suppressed Hif-1α and cleaved caspase-3 levels, and alleviated hypoxia-induced cardiomyocyte apoptosis. Notably, knockdown of Phd3 negated Sirt1's inhibitory effect on Hif-1α, whereas Hif-1α knockdown promoted Sirt1 expression. Sirt1 overexpression reduced infarct size, decreased cardiomyocyte apoptosis, and improved cardiac function.

CONCLUSIONS

Sirt1 effectively reduces cardiomyocyte apoptosis and myocardial infarction size while enhancing cardiac function post-MI, primarily through the Phd3/Hif-1α signaling pathway.

Kartogenin Improves Doxorubicin-Induced Cardiotoxicity by Alleviating Oxidative Stress and Protecting Mitochondria

Doxorubicin (DOX) is a common antitumor drug in clinical practice, but its clinical use is limited due to its cardiotoxic side effects. Oxidative stress and mitochondrial damage are involved in DOX-induced cardiotoxicity (DIC). Kartogenin (KGN) has been shown to have a potent ability to resist oxidative stress and maintain mitochondrial homeostasis. But the impact of KGN on DIC has not been reported. This study explores the potential protective effect of KGN on DIC. The effect of KGN on DIC was studied by establishing in vivo and in vitro DIC models. KGN reduced DOX-induced cardiac insufficiency, myocardial injury, oxidative stress damage, and mitochondrial dysfunction. Through network pharmacology and RNA sequencing (RNA-seq), the mechanism of KGN anti-DIC was highly correlated with oxidative stress and mitochondria. These findings suggest that KGN is a valuable and promising strategy for the prevention of doxorubicin cardiotoxicity.

CDC20 protects the heart from doxorubicin-induced cardiotoxicity by modulating CCDC69 degradation

AIMS

Doxorubicin (DOX) is a potent anticancer drug; however, it is associated with significant cardiotoxicity. CDC20 is an E3 ubiquitin ligase that plays a role in cell cycle progression and apoptosis in various types of cancers. The involvement of CDC20 in DOX-induced cardiotoxicity (DIC) is poorly understood. Hence, this study aimed to explore the potential role of CDC20 in the development of DIC and assess whether CDC20 influences the antitumor effects of DOX.

METHODS AND RESULTS

H9C2 cells were treated with DOX, followed by transcriptomic analysis to identify differentially expressed genes. C57BL/6 mice were treated with DOX for 4 weeks after tail vein injection of CDC20 myocardial-specific knockout mice, AAV9-cTNT-(si) CDC20, or intraperitoneal injection of apcin. Cardiac function and pathological changes were evaluated by echocardiography and pathological staining, respectively. The influence of CDC20 on DOX-induced tumor inhibition was assessed in tumor-bearing mice. In vitro analysis involved treating cardiomyocytes with the Ad-CDC20 adenovirus and DOX, followed by proteomic and ubiquitination-related assays to identify potential downstream ubiquitinated CDC20 proteins. Additionally, we investigated the effect of CCDC69 on CDC20-mediated protection against DOX-induced apoptosis using CCDC69 shRNA. Transcriptome analysis revealed that DOX effectively suppressed the expression of CDC20. Cardiomyocyte-specific overexpression of CDC20 in a DOX-induced mouse model of myocardial injury effectively mitigated cardiomyocyte apoptosis, inflammation, fibrosis, and cell atrophy. Our mechanistic investigation revealed that CDC20 attenuates DOX-induced apoptosis by downregulating CCDC69 expression. Moreover, cardiomyocyte-specific overexpression of CDC20 had no effect on the therapeutic efficacy of DOX against tumors.

CONCLUSION

Our findings indicate that CDC20 safeguards the heart against DOX-induced cardiotoxicity by modulating CCDC69 degradation without compromising the antitumor efficacy of DOX.

Curcumin attenuates myocardial ischemia‑reperfusion‑induced autophagy‑dependent ferroptosis via Sirt1/AKT/FoxO3a signaling

Curcumin (Cur) effectively attenuates myocardial ischemia/reperfusion injury (MIRI). MIRI has a complex mechanism and is associated with autophagy‑dependent ferroptosis. Therefore, the present study aimed to determine whether autophagy‑dependent ferroptosis occurs in MIRI and assess the mechanism of Cur in attenuating MIRI. The study was conducted on a Sprague‑Dawley rat MIRI model and H9c2 cell anoxia/reoxygenation (A/R) injury model. The effect of Cur pretreatment on A/R or MIRI induced autophagy‑dependent ferroptosis and its molecular mechanism were investigated. Protein expression, lysosomal, reactive oxygen species, Fe2+, oxidative systems, mitochondrial function, subcellular localization of molecules, and cardiac function assays will be employed. Cur decreased MIRI; improved myocardial histopathology; increased cardiomyocyte viability; inhibited ferroptosis, apoptosis and autophagy; reduced infarct size and maintained cardiac function. MIRI decreased silent information regulator 1 (Sirt1), decreased AKT and forkhead box O3A (FoxO3a) phosphorylation, leading to FoxO3a entry into the nucleus to activate translation of autophagy‑related genes and inducing ferroptosis, apoptosis and autophagy. However, Cur pretreatment activated AKT and FoxO3a phosphorylation via Sirt1, thereby transporting FoxO3a out of the nucleus, reducing autophagy‑related gene translation and attenuating MIRI‑induced ferroptosis, apoptosis and autophagy. Of note, the silencing of Sirt1 and administration of triciribine (an AKT inhibitor) both eliminated the protective effect of Cur. Thus, Cur maintained cardiomyocyte function by inhibiting autophagy‑dependent ferroptosis via Sirt1/AKT/FoxO3a signaling.

Activation and inhibition of sirtuins: From bench to bedside

The sirtuin family comprises seven NAD+-dependent enzymes which catalyze protein lysine deacylation and mono ADP-ribosylation. Sirtuins act as central regulators of genomic stability and gene expression and control key processes, including energetic metabolism, cell cycle, differentiation, apoptosis, and aging. As a result, all sirtuins play critical roles in cellular homeostasis and organism wellness, and their dysregulation has been linked to metabolic, cardiovascular, and neurological diseases. Furthermore, sirtuins have shown dichotomous roles in cancer, acting as context-dependent tumor suppressors or promoters. Given their central role in different cellular processes, sirtuins have attracted increasing research interest aimed at developing both activators and inhibitors. Indeed, sirtuin modulation may have therapeutic effects in many age-related diseases, including diabetes, cardiovascular and neurodegenerative disorders, and cancer. Moreover, isoform selective modulators may increase our knowledge of sirtuin biology and aid to develop better therapies. Through this review, we provide critical insights into sirtuin pharmacology and illustrate their enzymatic activities and biological functions. Furthermore, we outline the most relevant sirtuin modulators in terms of their modes of action, structure-activity relationships, pharmacological effects, and clinical applications.

SIRT1: a potential therapeutic target for coronary heart disease combined with anxiety or depression

Coronary heart disease (CHD) combined with anxiety or depression is increasingly receiving attention in the clinical field of cardiology, and exploring the comorbidity pathological mechanisms of cardiovascular disease combined with psychological disorders is a hot research topic for scholars in this field. Current research suggests that Silent Information Regulatory Factor 1 (SIRT1) may serve as a potential biomarker for the comorbidity mechanism and treatment of CHD with anxiety or depression. SIRT1 is considered a promising therapeutic target for CHD combined with anxiety or depression, with the ability to regulate inflammatory cytokine levels, alleviate oxidative stress damage, activate multiple signalling pathways, reduce platelet hyperresponsiveness, and exert neuroprotective and cardioprotective effects. In this comprehensive review, we deeply studied the structure, function, and mechanism of SIRT1, and discussed its protective effects in the cardiovascular and nervous system. The latest progress in the mechanism of SIRT1's role in CHD combined with anxiety or depression was emphasised, including its specific mechanisms in regulating inflammatory response, alleviating oxidative stress, and mediating various signalling pathways. In addition, this article also summarises the therapeutic potential of SIRT1 as a potential biomarker in patients with CHD combined with anxiety or depression.

Roles of Sirtuins in Cardiovascular Diseases: Mechanisms and Therapeutics

Cardiovascular diseases (CVDs) are experiencing a rapid surge and are widely recognized as the leading cause of mortality in the current aging society. Given the multifactorial etiology of CVDs, understanding the intricate molecular and cellular mechanisms is imperative. Over the past 2 decades, many scientists have focused on Sirtuins, a family of nicotinamide adenine dinucleotide-dependent deacylases. Sirtuins are highly conserved across species, from yeasts to primates, and play a crucial role in linking aging and diseases. Sirtuins participate in nearly all key physiological and pathological processes, ranging from embryogenic development to stress response and aging. Abnormal expression and activity of Sirtuins exist in many aging-related diseases, while their activation has shown efficacy in mitigating these diseases (eg, CVDs). In terms of research, this field has maintained fast, sustained growth in recent years, from fundamental studies to clinical trials. In this review, we present a comprehensive, up-to-date discussion on the biological functions of Sirtuins and their roles in regulating cardiovascular biology and CVDs. Furthermore, we highlight the latest advancements in utilizing Sirtuin-activating compounds and nicotinamide adenine dinucleotide boosters as potential pharmacological targets for preventing and treating CVDs. The key unresolved issues in the field-from the chemicobiological regulation of Sirtuins to Sirtuin-targeted CVD investigations-are also discussed. This timely review could be critical in understanding the updated knowledge of Sirtuin biology in CVDs and facilitating the clinical accessibility of Sirtuin-targeting interventions.

The role and mechanism of epigenetics in anticancer drug-induced cardiotoxicity

Cardiovascular disease is the main factor contributing to the global burden of diseases, and the cardiotoxicity caused by anticancer drugs is an essential component that cannot be ignored. With the development of anticancer drugs, the survival period of cancer patients is prolonged; however, the cardiotoxicity caused by anticancer drugs is becoming increasingly prominent. Currently, cardiovascular disease has emerged as the second leading cause of mortality among long-term cancer survivors. Anticancer drug-induced cardiotoxicity has become a frontier and hot topic. The discovery of epigenetics has given the possibility of environmental changes in gene expression, protein synthesis, and traits. It has been found that epigenetics plays a pivotal role in promoting cardiovascular diseases, such as heart failure, coronary heart disease, and hypertension. In recent years, increasing studies have underscored the crucial roles played by epigenetics in anticancer drug-induced cardiotoxicity. Here, we provide a comprehensive overview of the role and mechanisms of epigenetics in anticancer drug-induced cardiotoxicity.

Palmitic Acid Accelerates Endothelial Cell Injury and Cardiovascular Dysfunction via Palmitoylation of PKM2

High serum level of palmitic acid(PA) is implicated in pathogenesis of cardiovascular diseases. PA serves as the substrate for protein palmitoylation. However, it is still unknown whether palmitoylation is involved in PA-induced cardiovascular dysfunction. Here, in clinical cohort studies of 1040 patients with coronary heart disease, high level of PA is associated with risk of major adverse cardiovascular events (MACE) and death. In ApoE-/-mice, 10 mg/kg-1 PA treatment induces blood pressure elevation, cardiac contractile dysfunction, endothelial dysfunction and atherosclerotic plaqueformation. In endothelial cells, inhibition of palmitoylation bypalmitoyl-transferase inhibitor 2-BP eliminates PA-induced endothelial injury, whereas promotion of palmitoylation by depalmitoylase inhibitor ML349 exacerbates the harmful effect of PA. Palmitoyl-proteomics analysis identifies pyruvate kinase isozyme type M2 (PKM2) as the palmitoylated protein responsible for PA-induced endothelial injury, and Cys31 as the predominant palmitoylated site. PKM2-C31S mutants (cysteine replaced by serine) prevents PA-induced endothelial injury. Endothelial-specific AAV-C31S PKM2endo ameliorates cardiovascular dysfunction caused by PA in ApoE-/- mice. Mechanistically, PKM2-C31 palmitoylation impairs PKM2 tetramerization to inhibit its pyruvate kinase activity and endothelial glycolysis. Finally, zDHHC13 is identified as the palmitoyl acyltransferase of PKM2. In conclusion, these findings suggest that PKM2-C31 palmitoylation contributes to PA-induced endothelial injury and cardiovascular dysfunction.

HDAC6 Facilitates PRV and VSV Infection by Inhibiting Type I Interferon Production

HDAC6 modulates viral infection through diverse mechanisms. Here, we investigated the role of HDAC6 in influencing viral infection in pig cells with the aim of exploiting the potential antiviral gene targets in pigs. Using gene knockout and overexpression strategies, we found that HDAC6 knockout greatly reduced PRV and VSV infectivity, whereas HDAC6 overexpression increased their infectivity in PK15 cells. Mechanistic studies identified HDAC6 as a DNA damage inhibitor in PK15 cells. HDAC6 overexpression attenuated DNA damage levels, which can further reduce type I IFN production to promote viral infection. Conversely, HDAC6 deficiency can limit viral infection by increasing DNA damage-mediated type I IFN production. This work demonstrates that HDAC6 affects the infection process of multiple viruses by modulating type I IFN production, highlighting a regulatory role of HDAC6 linking host immune response and viral infection levels in pig cells.

Rnd3 protects against doxorubicin-induced cardiotoxicity through inhibition of PANoptosis in a Rock1/Drp1/mitochondrial fission-dependent manner

Doxorubicin, a representative drug of the anthracycline class, is widely used in cancer treatment. However, Doxorubicin-induced cardiotoxicity (DIC) presents a significant challenge in its clinical application. Mitochondrial dysfunction plays a central role in DIC, primarily through disrupting mitochondrial dynamics. This study aimed to investigate the impact of Rnd3 (a Rho family GTPase 3) on DIC, with a focus on mitochondrial dynamics. Cardiomyocyte-specific Rnd3 transgenic mice (Rnd3-Tg) and Rnd3LSP/LSP mice (N-Tg) were established for in vivo experiments, and adenoviruses harboring Rnd3 (Ad-Rnd3) or negative control (Ad-Control) were injected in the myocardium for in vitro experiments. The DIC model was established using wild-type, N-Tg, and Rnd3-Tg mice, with subsequent intraperitoneal injection of Dox for 4 weeks. The molecular mechanism was explored through RNA sequencing, immunofluorescence staining, co-immunoprecipitation assay, and protein-protein docking. Dox administration induced significant mitochondrial injury and cardiac dysfunction, which was ameliorated by Rnd3 overexpression. Further, the augmentation of Rnd3 expression mitigated mitochondrial fragmentation which is mediated by dynamin-related protein 1 (Drp1), thereby ameliorating the PANoptosis (pyroptosis, apoptosis, and necroptosis) response induced by Dox. Mechanically, the interaction between Rnd3 and Rho-associated kinase 1 (Rock1) may impede Rock1-induced Drp1 phosphorylation at Ser616, thus inhibiting mitochondrial fission and dysfunction. Interestingly, Rock1 knockdown nullified the effects of Rnd3 on cardiomyocytes PANoptosis, as well as Dox-induced cardiac remodeling and dysfunction elicited by Rnd3. Rnd3 enhances cardiac resilience against DIC by stabilizing mitochondrial dynamics and reducing PANoptosis. Our findings suggest that the Rnd3/Rock1/Drp1 signaling pathway represents a novel target for mitigating DIC, and modulating Rnd3 expression could be a strategic approach to safeguarding cardiac function in patients undergoing Dox treatment. The graphical abstract illustrated the cardioprotective role of Rnd3 in DIC. Rnd3 directly binds to Rock1 in cytoplasm and ameliorates mitochondrial fission by inhibiting Drp1 phosphorylation at ser616, thereby alleviating PANoptosis (apoptosis, pyroptosis, and necroptosis) in DIC.

Resveratrol promotes autophagosome elimination via SIRT1 in cardiomyocytes

The processes of autophagy, including autophagosome formation, fusion of autophagosomes with lysosomes, and degradation of autophagosomes by lysosomes, are regulated by various mechanisms. We recently found that treatment with resveratrol, an activator of the NAD+-dependent protein deacetylase Sirtuin-1 (SIRT1), in a mouse model prevented autophagosome accumulation in the heart with high mTORC1 activity. In this study, we investigated whether SIRT1 mediates the effects of resveratrol on autophagosome elimination using a cardiomyocyte model. In H9c2 cardiomyocytes, treatment with the mTORC1 activator MHY1485 induced autophagosome accumulation accompanied by increases in fragmented mitochondria within the autophagosomes and levels of intracellular reactive oxygen species (ROS), indicative of impaired autophagy-mediated elimination of mitochondria and resultant oxidative stress. MHY1485 suppressed the fusion of autophagosomes with lysosomes. Co-treatment with resveratrol attenuated the MHY1485-induced increases in autophagosomes, mitochondria within autophagosomes, and levels of ROS. Knockdown of Sirt1 reversed the reductions in autophagosomes and ROS levels induced by resveratrol under the condition of MHY1485 treatment. Neither resveratrol treatment nor Sirt1 knockdown modulated the phosphorylation levels of UVRAG, a target of mTORC1 for suppression of autophagosome-lysosome fusion. Our findings suggest that SIRT1 mediates the resveratrol-induced promotion of autophagosome elimination in cells with high mTORC1 activity.

CHK1 attenuates cardiac dysfunction via suppressing SIRT1-ubiquitination

BACKGROUND

Mitochondrial dysfunction is linked to myocardial ischemia-reperfusion (I/R) injury. Checkpoint kinase 1 (CHK1) could facilitate cardiomyocyte proliferation, however, its role on mitochondrial function in I/R injury remains unknown.

METHODS

To investigate the role of CHK1 on mitochondrial function following I/R injury, cardiomyocyte-specific knockout/overexpression mouse models were generated. Adult mouse cardiomyocytes (AMCMs) were isolated for in vitro study. Mass spectrometry-proteomics analysis and protein co-immunoprecipitation assays were conducted to dissect the molecular mechanism.

RESULTS

CHK1 was downregulated in myocardium post I/R and AMCMs post oxygen-glucose deprivation/re‑oxygenation (OGD/R). In vivo, CHK1 overexpression protected against I/R induced cardiac dysfunction, while heterogenous CHK1 knockout exacerbated cardiomyopathy. In vitro, CHK1 inhibited OGD/R-induced cardiomyocyte apoptosis and bolstered cardiomyocyte survival. Mechanistically, CHK1 attenuated oxidative stress and preserved mitochondrial metabolism in cardiomyocytes under I/R. Moreover, disrupted mitochondrial homeostasis in I/R myocardium was restored by CHK1 through the promotion of mitochondrial biogenesis and mitophagy. Through mass spectrometry analysis following co-immunoprecipitation, SIRT1 was identified as a direct target of CHK1. The 266-390 domain of CHK1 interacted with the 160-583 domain of SIRT1. Importantly, CHK1 phosphorylated SIRT1 at Thr530 residue, thereby inhibiting SMURF2-mediated degradation of SIRT1. The role of CHK1 in maintaining mitochondrial dynamics control and myocardial protection is abolished by SIRT1 inhibition, while inactivated mutation of SIRT1 Thr530 fails to reverse the impaired mitochondrial dynamics following CHK1 knockdown. CHK1 Δ390 amino acids (aa) mutant functioned similarly to full-length CHK1 in scavenging ROS and maintaining mitochondrial dynamics. Consistently, cardiac-specific SIRT1 knockdown attenuated the protective role of CHK1 in I/R injury.

CONCLUSIONS

Our findings revealed that CHK1 mitigates I/R injury and restores mitochondrial dynamics in cardiomyocytes through a SIRT1-dependent mechanism.

Epigenetic modifications and emerging therapeutic targets in cardiovascular aging and diseases

The complex mechanisms underlying the development of cardiovascular diseases remain not fully elucidated. Epigenetics, which modulates gene expression without DNA sequence changes, is shedding light on these mechanisms and their heritable effects. This review focus on epigenetic regulation in cardiovascular aging and diseases, detailing specific epigenetic enzymes such as DNA methyltransferases (DNMTs), histone acetyltransferases (HATs), and histone deacetylases (HDACs), which serve as writers or erasers that modify the epigenetic landscape. We also discuss the readers of these modifications, such as the 5-methylcytosine binding domain proteins, and the erasers ten-eleven translocation (TET) proteins. The emerging role of RNA methylation, particularly N6-methyladenosine (m6A), in cardiovascular pathogenesis is also discussed. We summarize potential therapeutic targets, such as key enzymes and their inhibitors, including DNMT inhibitors like 5-azacytidine and decitabine, HDAC inhibitors like belinostat and givinotide, some of which have been approved by the FDA for various malignancies, suggesting their potential in treating cardiovascular diseases. Furthermore, we highlight the role of novel histone modifications and their associated enzymes, which are emerging as potential therapeutic targets in cardiovascular diseases. Thus, by incorporating the recent studies involving patients with cardiovascular aging and diseases, we aim to provide a more detailed and updated review that reflects the advancements in the field of epigenetic modification in cardiovascular diseases.

Polydatin-Induced Shift of Redox Balance and Its Anti-Cancer Impact on Human Osteosarcoma Cells

Cancer cells demonstrate remarkable resilience by adapting to oxidative stress and undergoing metabolic reprogramming, making oxidative stress a critical target for cancer therapy. This study explores, for the first time, the redox-dependent anticancer effects of Polydatin (PD), a glucoside derivative of resveratrol, on the human Osteosarcoma (OS) cells SAOS-2 and U2OS. Using cell-based biochemical assays, we found that cytotoxic doses of PD (100-200 µM) promote ROS production, deplete glutathione (GSH), and elevate levels of both total iron and intracellular malondialdehyde (MDA), which are key markers of ferroptosis. Notably, the ROS scavenger N-acetylcysteine (NAC) and the ferroptosis inhibitor ferrostatin-1 (Fer-1) partially reverse PD's cytotoxic effects. Interestingly, PD's ability to hinder cell adhesion and migration appears independent of its pro-oxidant effect. Analysis of the oxidative stress regulators SIRT1 and Nrf2 at the gene and protein levels using real-time PCR and Western blot indicates an early oxidative response to PD treatment. PD remains effective under tumor-like conditions of hypoxia and serum starvation, and sensitizes OS cells to ROS-inducing chemotherapeutics like doxorubicin (DOX) and cisplatin (CIS). Importantly, PD exhibits minimal toxicity to non-tumorigenic cells (hFOB), suggesting a favorable therapeutic profile. Overall, our findings underscore that PD-induced redox imbalance plays a crucial role in its anti-OS effects, warranting further exploration into the molecular mechanisms behind its pro-oxidant activity.

Doxorubicin-Induced Cardiotoxicity Through SIRT1 Loss Potentiates Overproduction of Exosomes in Cardiomyocytes

Mutual interaction between doxorubicin (DOX) and cardiomyocytes is crucial for cardiotoxicity progression. Cardiomyocyte injury is an important pathological feature of DOX-induced cardiomyopathy, and its molecular pathogenesis is multifaceted. In addition to the direct toxic effects of DOX on cardiomyocytes, DOX-induced exosomes in the extracellular microenvironment also regulate the pathophysiological states of cardiomyocytes. However, the mechanisms by which DOX regulates exosome secretion and subsequent pathogenesis remain incompletely understood. Here, we found that DOX significantly increased exosome secretion from cardiomyocytes, and inhibiting this release could alleviate cardiomyocyte injury. DOX promoted exosome secretion by reducing cardiomyocyte silencing information regulator 1 (SIRT1) expression, exacerbating cardiotoxicity. DOX impaired lysosomal acidification in cardiomyocytes, reducing the degradation of intracellular multivesicular bodies (MVBs), resulting in an increase in MVB volume before fusing with the plasma membrane to release their contents. Mechanistically, SIRT1 loss inhibited lysosomal acidification by reducing the expression of the ATP6V1A subunit of the lysosomal vacuolar-type H+ ATPase (V-ATPase) proton pump. Overexpressing SIRT1 increased ATP6V1A expression, improved lysosomal acidification, inhibited exosome secretion, and thereby alleviated DOX-induced cardiotoxicity. Interestingly, DOX also induced mitochondrial-derived vesicle formation in cardiomyocytes, which may further increase the abundance of MVBs and promote exosome release. Collectively, this study identified SIRT1-mediated impairment of lysosomal acidification as a key mechanism underlying the increased exosome secretion from cardiomyocytes induced by DOX, providing new insights into DOX-induced cardiotoxicity pathogenesis.

Mitophagy Unveiled: Exploring the Nexus of Mitochondrial Health and Neuroendocrinopathy

Mitochondria play a pivotal role in cellular metabolism, energy production, and apoptotic signaling, making mitophagy, the selective degradation of damaged mitochondria, crucial for mitochondrial health. Dysregulation of mitophagy has been implicated in various neuroendocrinopathies, yet the mechanisms linking these processes remain poorly understood. This review aims to explore the intersection between mitophagy and neuroendocrinopathy, addressing the critical gaps in knowledge regarding how mitochondrial dysfunction may contribute to the pathophysiology of neuroendocrine disorders. We conducted a comprehensive literature review of studies published on mitophagy and neuroendocrinopathies, focusing on data that elucidate the pathways involved and the clinical implications of mitochondrial health in neuroendocrine contexts. Our findings indicate that altered mitophagy may lead to the accumulation of dysfunctional mitochondria, contributing to neuroendocrine dysregulation. We present evidence linking impaired mitochondrial clearance to disease models of conditions such as metabolic syndrome, depression, and stress-related disorders, highlighting the potential for therapeutic interventions targeting mitophagy. While significant advances have been made in understanding mitochondrial biology, the direct interplay between mitophagy and neuroendocrinopathies remains underexplored. This review underscores the necessity for further research to elucidate these connections, which may offer novel insights into disease mechanisms and therapeutic strategies for treating maladaptive neuroendocrine responses.

Inhibiting H2AX Can Ameliorate Myocardial Ischemia/Reperfusion Injury by Regulating P53/JNK Signaling Pathway

Myocardial ischemia-reperfusion (I/R) injury is a significant area of focus in cardiovascular disease research. I/R injury can increase intracellular oxidative stress, leading to DNA damage. H2AX plays a crucial role in DNA repair. This study utilized mouse and cell models of myocardial I/R to investigate the impact of H2AX on cardiomyocytes during I/R. This study initially assessed the expression of H2AX in MI/R mice compared to a sham surgery group. Subsequently, cardiac function, infarct area, and mitochondrial damage were evaluated after inhibiting H2AX in MI/R mice and a negative control group. Furthermore, the study delved into the molecular mechanisms by analyzing the expression of H2AX, P53, p-JNK, SHP2, p-SHP2, p-RAS, parkin, Drp1, Cyt-C, Caspase-3, and Caspase-8 in cardiomyocytes following the addition of JNK or P53 agonists. The results from western blotting in vivo indicated significantly higher H2AX expression in the MI/R group compared to the sham group. Inhibiting H2AX improved cardiac function, reduced myocardial infarct area, and mitigated mitochondrial damage in the MI/R group. In vitro experiments demonstrated that inhibiting H2AX could attenuate mitochondrial damage and apoptosis in myocardial cells by modulating the P53 and JNK signaling pathways. These findings suggested that inhibiting H2AX may alleviate myocardial I/R injury through the regulation of the P53/JNK pathway, highlighting H2AX as a potential target for the treatment of myocardial ischemia/reperfusion injury.

The Multifaceted Role of Endothelial Sirt1 in Vascular Aging: An Update

NAD+-dependent deacetylase sirtuin-1 (Sirt1) belongs to the sirtuins family, known to be longevity regulators, and exerts a key role in the prevention of vascular aging. By aging, the expression levels of Sirt1 decline with a severe impact on vascular function, such as the rise of endothelial dysfunction, which in turn promotes the development of cardiovascular diseases. In this context, the impact of Sirt1 activity in preventing endothelial senescence is particularly important. Given the key role of Sirt1 in counteracting endothelial senescence, great efforts have been made to deepen the knowledge about the intricate cross-talks and interactions of Sirt1 with other molecules, in order to set up possible strategies to boost Sirt1 activity to prevent or treat vascular aging. The aim of this review is to provide a proper background on the regulation and function of Sirt1 in the vascular endothelium and to discuss the recent advances regarding the therapeutic strategies of targeting Sirt1 to counteract vascular aging.

Momordica charantia L.-derived exosome-like nanovesicles stabilize p62 expression to ameliorate doxorubicin cardiotoxicity

BACKGROUND

Doxorubicin (DOX) is a first-line chemotherapeutic drug for various malignancies that causes cardiotoxicity. Plant-derived exosome-like nanovesicles (P-ELNs) are growing as novel therapeutic agents. Here, we investigated the protective effects in DOX cardiotoxicity of ELNs from Momordica charantia L. (MC-ELNs), a medicinal plant with antioxidant activity.

RESULTS

We isolated MC-ELNs using ultracentrifugation and characterized them with canonical mammalian extracellular vesicles features. In vivo studies proved that MC-ELNs ameliorated DOX cardiotoxicity with enhanced cardiac function and myocardial structure. In vitro assays revealed that MC-ELNs promoted cell survival, diminished reactive oxygen species, and protected mitochondrial integrity in DOX-treated H9c2 cells. We found that DOX treatment decreased the protein level of p62 through ubiquitin-dependent degradation pathway in H9c2 and NRVM cells. However, MC-ELNs suppressed DOX-induced p62 ubiquitination degradation, and the recovered p62 bound with Keap1 promoting Nrf2 nuclear translocation and the expressions of downstream gene HO-1. Furthermore, both the knockdown of Nrf2 and the inhibition of p62-Keap1 interaction abrogated the cardioprotective effect of MC-ELNs.

CONCLUSIONS

Our findings demonstrated the therapeutic beneficials of MC-ELNs via increasing p62 protein stability, shedding light on preventive approaches for DOX cardiotoxicity.

Sodium-glucose cotransporter 2 inhibitor dapagliflozin prevents ejection fraction reduction, reduces myocardial and renal NF-κB expression and systemic pro-inflammatory biomarkers in models of short-term doxorubicin cardiotoxicity

Background

Anthracycline-mediated adverse cardiovascular events are among the leading causes of morbidity and mortality in patients with cancer. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) exert multiple cardiometabolic benefits in patients with/without type 2 diabetes, chronic kidney disease, and heart failure with reduced and preserved ejection fraction. We hypothesized that the SGLT2i dapagliflozin administered before and during doxorubicin (DOXO) therapy could prevent cardiac dysfunction and reduce pro-inflammatory pathways in preclinical models.

Methods

Cardiomyocytes were exposed to DOXO alone or combined with dapagliflozin (DAPA) at 10 and 100 nM for 24 h; cell viability, iATP, and Ca++ were quantified; lipid peroxidation products (malondialdehyde and 4-hydroxy 2-hexenal), NLRP3, MyD88, and cytokines were also analyzed through selective colorimetric and enzyme-linked immunosorbent assay (ELISA) methods. Female C57Bl/6 mice were treated for 10 days with a saline solution or DOXO (2.17 mg/kg), DAPA (10 mg/kg), or DOXO combined with DAPA. Systemic levels of ferroptosis-related biomarkers, galectin-3, high-sensitivity C-reactive protein (hs-CRP), and pro-inflammatory chemokines (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL17-α, IL-18, IFN-γ, TNF-α, G-CSF, and GM-CSF) were quantified. After treatments, immunohistochemical staining of myocardial and renal p65/NF-kB was performed.

Results

DAPA exerts cytoprotective, antioxidant, and anti-inflammatory properties in human cardiomyocytes exposed to DOXO by reducing iATP and iCa++ levels, lipid peroxidation, NLRP-3, and MyD88 expression. Pro-inflammatory intracellular cytokines were also reduced. In preclinical models, DAPA prevented the reduction of radial and longitudinal strain and ejection fraction after 10 days of treatment with DOXO. A reduced myocardial expression of NLRP-3 and MyD-88 was seen in the DOXO-DAPA group compared to DOXO mice. Systemic levels of IL-1β, IL-6, TNF-α, G-CSF, and GM-CSF were significantly reduced after treatment with DAPA. Serum levels of galectine-3 and hs-CRP were strongly enhanced in the DOXO group; on the other hand, their expression was reduced in the DAPA-DOXO group. Troponin-T, B-type natriuretic peptide (BNP), and N-Terminal Pro-BNP (NT-pro-BNP) were strongly reduced in the DOXO-DAPA group, revealing cardioprotective properties of SGLT2i. Mice treated with DOXO and DAPA exhibited reduced myocardial and renal NF-kB expression.

Conclusion

The overall picture of the study encourages the use of DAPA in the primary prevention of cardiomyopathies induced by anthracyclines in patients with cancer.

The SP1/SIRT1/ACLY signaling axis mediates fatty acid oxidation in renal ischemia-reperfusion-induced renal fibrosis

BACKGROUND

Renal ischemia-reperfusion is the primary cause of acute kidney injury (AKI). Clinically, most patients who experience ischemia-reperfusion injury eventually progress gradually to renal fibrosis and chronic kidney disease (CKD). However, the underlying mechanism for AKI to CKD transition remain absent. Our study demonstrated that the downregulation of sirtuin 1 (Sirt1)-mediated fatty acid oxidation (FAO) facilitates IRI-induced renal fibrosis.

METHODS

The IRI animal model was established, and ribonucleic acid (RNA) sequencing was used to explore potential differentially expressed genes (DEGs) and pathways. The SIRT1 knockout mice were generated, and a recombinant adeno-associated virus that overexpresses SIRT1 was injected into mice to explore the function of SIRT1 in renal fibrosis induced by renal IRI. In vitro, hypoxia/reoxygenation (H/R) was used to establish the classical model of renal IRI and overexpression or knockdown of SIRT1 to investigate the SIRT1 function through lentiviral plasmids. The underlying molecular mechanism was explored through RNA sequencing, bioinformatics analysis, and chromatin immunoprecipitation assay.

RESULTS

RNA sequencing analysis and western blot demonstrated that the expression of SIRT1 was significantly decreased in IRI mice. Overexpression of SIRT1 improved renal function and reduced lipid deposition and renal fibrosis. On the contrary, knockout of SIRT1 aggravated kidney injury and renal fibrosis. RNA sequencing, bioinformatics analysis, and chromatin immunoprecipitation assay mechanistically revealed that SIRT1 impairs the acetylation of histone H3K27 on the promoter region of ACLY, thereby impeding FAO activity and promoting renal fibrosis. Additionally, SP1 regulated FAO by directly modulating SIRT1 expression.

CONCLUSION

Our findings highlight that downregulation of SIRT1-modulated FAO facilitated by the SP1/SIRT1/ACLY axis in the kidney increases IRI, suggesting SIRT1 to be a potential therapeutic target for renal fibrosis induced by renal IRI.

Mechano-induced cell metabolism disrupts the oxidative stress homeostasis of SAOS-2 osteosarcoma cells

There has been an increasing focus on cancer mechanobiology, determining the underlying-induced changes to unlock new avenues in the modulation of cell malignancy. Our study used LC-MS untargeted metabolomic approaches and real-time polymerase chain reaction (PCR) to characterize the molecular changes induced by a specific moderate uniaxial stretch regimen (i.e., 24 h-1 Hz, cyclic stretch 0,5% elongation) on SAOS-2 osteosarcoma cells. Differential metabolic pathway analysis revealed that the mechanical stimulation induces a downregulation of both glycolysis and the tricarboxylic acid (TCA) cycle. At the same time, the amino acid metabolism was found to be dysregulated, with the mechanical stimulation enhancing glutaminolysis and reducing the methionine cycle. Our findings showed that cell metabolism and oxidative defense are tightly intertwined in mechanically stimulated cells. On the one hand, the mechano-induced disruption of the energy cell metabolism was found correlated with an antioxidant glutathione (GSH) depletion and an accumulation of reactive oxygen species (ROS). On the other hand, we showed that a moderate stretch regimen could disrupt the cytoprotective gene transcription by altering the expression levels of manganese superoxide dismutase (SOD1), Sirtuin 1 (SIRT1), and NF-E2-related factor 2 (Nrf2) genes. Interestingly, the cyclic applied strain could induce a cytotoxic sensitization (to the doxorubicin-induced cell death), suggesting that mechanical signals are integral regulators of cell cytoprotection. Hence, focusing on the mechanosensitive system as a therapeutic approach could potentially result in more effective treatments for osteosarcoma in the future.

Modulation of the Sirtuin-1 signaling pathway in doxorubicin-induced nephrotoxicity (synergistic amelioration by resveratrol and pirfenidone)

The current study was conducted to determine the precise mechanisms of Sirtuin-1 (Sirt-1), TGF- β (Transforming Growth Factor-β), and long non-coding RNA Metastasis Associated Lung Adenocarcinoma Transcript 1 (LncRNA MALAT-1) in signaling pathways in doxorubicin (DOX)-induced nephrotoxicity. The potential therapeutic effect of Resveratrol and Pirfenidone in DOX toxicity was also assessed. Thirty-six male adult rats were evenly distributed into four groups: Group 1: control rats. Group 2: DOX exposed rats' group, each animal received 7.5 mg/kg DOX as a single intravenous dose, Group 3: DOX exposed group subjected to oral resveratrol (20 mg/kg/daily for two weeks), Group 4: DOX exposed group subjected to oral Pirfenidone (200 mg/kg once daily for 10 days). At the planned time, animals were sacrificed. Renal tissue was collected to assess matrix metalloproteinase-9 (MMP9), inflammatory and apoptotic markers: tumor necrosis factor-alpha (TNF- β, caspase-3, cyclo-oxygenase-2 (COX-2), and oxidative stress markers: nitric oxide (NO), Glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD). Sirtuin-1 (Sirt-1), TGF-β, and LncRNA MALAT-1 were quantitatively assessed by real-time RT-PCR in the whole blood. Results showed that the DOX group exhibited a significant increase in oxidative stress markers, and inflammatory, and apoptotic markers in the renal tissue. Histologically, the renal tubule lining cells exhibited vacuolar alterations in the cytoplasm, glomerular atrophy, and vascular congestion. Furthermore, renal degeneration was evident, as confirmed by the heightened immuno-expression of MMP9. Exposure to DOX resulted in a significant decrease in Sirtuin-1 (Sirt-1) with a significant increase in the TGFβ, and LncRNA MALAT-1 gene expression. However, pre-treatment with either resveratrol/or Pirefenidone ameliorated the histological renal alterations, regulated the pathways of Sirt-1, TGFβ, and LncRNA MALAT-1, and decreased all oxidative stress, inflammatory and apoptotic markers. In conclusion, DOX exposure leads to renal toxicity by inducing renal degeneration, oxidative stress, and apoptosis. Administration of either resveratrol or Pirfenidone counteracted these changes and protected the kidney against DOX-induced renal damage.

Bardoxolone methyl attenuates doxorubicin-induced cardiotoxicity by inhibiting the TXNIP-NLRP3 pathway through Nrf2 activation

Bardoxolone methyl, which triggers nuclear factor erythroid 2-related factor (Nrf2), has therapeutic effects against myocardial infarction, heart failure, and other diseases. Nrf2 can inhibit the activation of the thioredoxin-interacting protein (TXNIP)/NLR family pyrin domain-containing protein 3 (NLRP3) pathway. Doxorubicin is an anthracycline chemotherapeutic drug associated with cardiotoxicity, limiting its clinical use. In this study, we explored the specific mechanism of the Nrf2-TXNIP-NLRP3 pathway in doxorubicin-induced cardiotoxicity using bardoxolone methyl in animal and cell models. Using in vivo and in vitro experiments, we show that doxorubicin can induce oxidative stress and pyroptosis in the heart. Western blot and co-immunoprecipitation experimental results found that doxorubicin can reduce the interaction between TXNIP and TRX, increase the interaction between TXNIP and NLRP3, and activate the pyroptosis process. Bardoxolone methyl reduces the accumulation of reactive oxygen species in cardiomyocytes through the Nrf2 pathway, inhibits the interaction between TXNIP and NLRP3, and alleviates the progression of myocardial damage and cardiac fibrosis. Bardoxolone methyl lost its therapeutic effect when the expression of Nrf2 was decreased. Additionally, repressing the expression of TXNIP can inhibit the activation of NLRP3 and alleviate myocardial damage caused by doxorubicin. Collectively, our findings confirm that bardoxolone methyl alleviates doxorubicin-induced cardiotoxicity by activating Nrf2 and inhibiting the TXNIP-NLRP3 pathway.

Sirtuins in intervertebral disc degeneration: current understanding

BACKGROUND

Intervertebral disc degeneration (IVDD) is one of the etiologic factors of degenerative spinal diseases, which can lead to a variety of pathological spinal conditions such as disc herniation, spinal stenosis, and scoliosis. IVDD is a leading cause of lower back pain, the prevalence of which increases with age. Recently, Sirtuins/SIRTs and their related activators have received attention for their activity in the treatment of IVDD. In this paper, a comprehensive systematic review of the literature on the role of SIRTs and their activators on IVDD in recent years is presented. The molecular pathways involved in the regulation of IVDD by SIRTs are summarized, and the effects of SIRTs on senescence, inflammatory responses, oxidative stress, and mitochondrial dysfunction in myeloid cells are discussed with a view to suggesting possible solutions for the current treatment of IVDD.

PURPOSE

This paper focuses on the molecular mechanisms by which SIRTs and their activators act on IVDD.

METHODS

A literature search was conducted in Pubmed and Web of Science databases over a 13-year period from 2011 to 2024 for the terms "SIRT", "Sirtuin", "IVDD", "IDD", "IVD", "NP", "Intervertebral disc degeneration", "Intervertebral disc" and "Nucleus pulposus".

RESULTS

According to the results, SIRTs and a large number of activators showed positive effects against IVDD.SIRTs modulate autophagy, myeloid apoptosis, oxidative stress and extracellular matrix degradation. In addition, they attenuate inflammatory factor-induced disc damage and maintain homeostasis during disc degeneration. Several clinical studies have reported the protective effects of some SIRTs activators (e.g., resveratrol, melatonin, honokiol, and 1,4-dihydropyridine) against IVDD.

CONCLUSION

The fact that SIRTs and their activators play a hundred different roles in IVDD helps to better understand their potential to develop further treatments for IVDD.

NOVELTY

This review summarizes current information on the mechanisms of action of SIRTs in IVDD and the challenges and limitations of translating their basic research into therapy.

Sirtuins in kidney diseases: potential mechanism and therapeutic targets

Sirtuins, which are NAD+-dependent class III histone deacetylases, are involved in various biological processes, including DNA damage repair, immune inflammation, oxidative stress, mitochondrial homeostasis, autophagy, and apoptosis. Sirtuins are essential regulators of cellular function and organismal health. Increasing evidence suggests that the development of age-related diseases, including kidney diseases, is associated with aberrant expression of sirtuins, and that regulation of sirtuins expression and activity can effectively improve kidney function and delay the progression of kidney disease. In this review, we summarise current studies highlighting the role of sirtuins in renal diseases. First, we discuss sirtuin family members and their main mechanisms of action. We then outline the possible roles of sirtuins in various cell types in kidney diseases. Finally, we summarise the compounds that activate or inhibit sirtuin activity and that consequently ameliorate renal diseases. In conclusion, targeted modulation of sirtuins is a potential therapeutic strategy for kidney diseases. Video Abstract.

SIRT1/SREBPs-mediated regulation of lipid metabolism

Sirtuins, also called silent information regulator 2, are enzymes that rely on nicotinamide adenine dinucleotide (NAD+) to function as histone deacetylases. Further investigation is warranted to explore the advantageous impacts of Sirtuin 1 (SIRT1), a constituent of the sirtuin group, on lipid metabolism, in addition to its well-researched involvement in extending lifespan. The regulation of gene expression has been extensively linked to SIRT1. Sterol regulatory element-binding protein (SREBP) is a substrate of SIRT1 that has attracted significant interest due to its role in multiple cellular processes including cell cycle regulation, DNA damage repair, and metabolic functions. Hence, the objective of this analysis was to investigate and elucidate the correlation between SIRT1 and SREBPs, as well as assess the contribution of SIRT1/SREBPs in mitigating lipid metabolism dysfunction. The objective of this research was to investigate whether SIRT1 and SREBPs could be utilized as viable targets for therapeutic intervention in managing complications associated with diabetes.

Protection against cancer therapy-induced cardiovascular injury by planed-derived polyphenols and nanomaterials

Cancer therapy-induced heart injury is a significant concern for cancer patients undergoing chemotherapy, radiotherapy, immunotherapy, and also targeted molecular therapy. The use of these treatments can lead to oxidative stress and cardiomyocyte damage in the heart, which can result in heart failure and other cardiac complications. Experimental studies have revealed that chemotherapy drugs such as doxorubicin and cyclophosphamide can cause severe side effects such as cardiac fibrosis, electrophysiological remodeling, chronic oxidative stress and inflammation, etc., which may increase risk of cardiac disorders and attacks for patients that underwent chemotherapy. Similar consequences may also be observed for patients that undergo radiotherapy for left breast or lung malignancies. Polyphenols, a group of natural compounds with antioxidant and anti-inflammatory properties, have shown the potential in protecting against cancer therapy-induced heart injury. These compounds have been found to reduce oxidative stress, necrosis and apoptosis in the heart, thereby preserving cardiac function. In recent years, nanoparticles loaded with polyphenols have also provided for the delivery of these compounds and increasing their efficacy in different organs. These nanoparticles can improve the bioavailability and efficacy of polyphenols while minimizing their toxicity. This review article summarizes the current understanding of the protective effects of polyphenols and nanoparticles loaded with polyphenols against cancer therapy-induced heart injury. The article discusses the mechanisms by which polyphenols protect the heart, including antioxidant and anti-inflammation abilities. The article also highlights the potential benefits of using nanoparticles for the delivery of polyphenols.

Bibliometric and visual analysis of doxorubicin-induced cardiotoxicity

Background: Doxorubicin-induced cardiotoxicity represents a prevalent adverse effect encountered in patients undergoing treatment with doxorubicin. To date, there has been no bibliometric study to summarize the field of doxorubicin-induced cardiotoxicity. In our study, we aim to determine the current status and frontiers of doxorubicin-induced cardiotoxicity by bibliometric analysis. Methods: The documents concerning doxorubicin-induced cardiotoxicity are obtained from the Web of Science Core Collection database (WOSCC), and VOSviewer 1.6.16, CiteSpace 5.1.3 and the WOSCC's literature analysis wire were used to conduct the bibliometric analysis. Results: In total, 7,021 publications were encompassed, which are produced by 37,152 authors and 6,659 organizations, 1,323 journals, and 101 countries/regions. The most productive author, institution, country and journal were Bonnie Ky with 35 publications, University of Texas with 190 documents, the United States with 1,912 publications, and PLOS ONE with 120 documents. The first high-cited article was published in the NEJM with 8,134 citations authored by DJ Slamon et al., in 2001. For keyword analysis, there are four clusters depicted in distinct directions. The keywords in the red cluster are oxidative stress, apoptosis, and cardiomyopathy. The keywords in the green cluster are cardiotoxicity, heart failure, and anthracycline. The keywords in the blue cluster are chemotherapy, trastuzumab, and paclitaxel. The keywords in the purple cluster are doxorubicin, adriamycin, and cancer. Most of the documents were derived from the United States, China and Italy (4,080/7,021, 58.1%). The number of studies from other countries should be increased. Conclusion: In conclusion, the main research hotspots and frontiers in the field of doxorubicin-induced cardiotoxicity include the role of doxorubicin in cardiotoxicity, the mechanisms underlying doxorubicin-induced cardiotoxicity, and the development of treatment strategies for doxorubicin-induced cardiotoxicity. More studies are needed to explore the mechanisms and treatment of doxorubicin-induced cardiotoxicity.

SIRT1 reduction contributes to doxorubicin-induced oxidative stress and meiotic failure in mouse oocytes

Impaired fertility is the major side effect of chemotherapy for female cancer patients, accumulated evidence indicates this is associated with damage on oocyte quality, but the underlying mechanisms remain unclear. Previously we reported that doxorubicin (DXR) exposure, one of the most widely used chemotherapy drugs, disrupted mouse oocyte meiotic maturation in vitro. In the current study, we identified that SIRT1 expression was remarkably reduced in DXR exposure oocytes. Next, we found that increasing SIRT1 expression by resveratrol partially alleviated the effects of DXR exposure on oocyte maturation, which was counteracted by SIRT1 inhibition. Furthermore, we revealed that increasing SIRT1 expression mitigated DXR induced oocyte damage through reducing ROS levels, increasing antioxidant enzyme MnSOD expression, and preventing spindle and chromosome disorganization, lowering the incidence of aneuploidy. Importantly, by performing in vitro fertilization and embryo transfer assays, we demonstrated that increasing SIRT1 expression significantly improved the fertilization ability, developmental competence of oocytes and early embryos. In summary, our data uncover that SIRT1 reduction represents one mechanism that mediates the effects of DXR exposure on oocyte quality.

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.

RGS7 balances acetylation/de-acetylation of p65 to control chemotherapy-dependent cardiac inflammation

Cardiotoxicity remains a major limitation in the clinical utility of anthracycline chemotherapeutics. Regulator of G-protein Signaling 7 (RGS7) and inflammatory markers are up-regulated in the hearts of patients with a history of chemotherapy particularly those with reduced left-ventricular function. RGS7 knockdown in either the murine myocardium or isolated murine ventricular cardiac myocytes (VCM) or cultured human VCM provided marked protection against doxorubicin-dependent oxidative stress, NF-κB activation, inflammatory cytokine production, and cell death. In exploring possible mechanisms causally linking RGS7 to pro-inflammatory signaling cascades, we found that RGS7 forms a complex with acetylase Tip60 and deacetylase sirtuin 1 (SIRT1) and controls the acetylation status of the p65 subunit of NF-κB. In VCM, the detrimental impact of RGS7 could be mitigated by inhibiting Tip60 or activating SIRT1, indicating that the ability of RGS7 to modulate cellular acetylation capacity is critical for its pro-inflammatory actions. Further, RGS7-driven, Tip60/SIRT1-dependent cytokines released from ventricular cardiac myocytes and transplanted onto cardiac fibroblasts increased oxidative stress, markers of transdifferentiation, and activity of extracellular matrix remodelers emphasizing the importance of the RGS7-Tip60-SIRT1 complex in paracrine signaling in the myocardium. Importantly, while RGS7 overexpression in heart resulted in sterile inflammation, fibrotic remodeling, and compromised left-ventricular function, activation of SIRT1 counteracted the detrimental impact of RGS7 in heart confirming that RGS7 increases acetylation of SIRT1 substrates and thereby drives cardiac dysfunction. Together, our data identify RGS7 as an amplifier of inflammatory signaling in heart and possible therapeutic target in chemotherapeutic drug-induced cardiotoxicity.

Columbianadin attenuates doxorubicin-induced cardiac injury, oxidative stress, and apoptosis via Sirt1/FOXO1 signaling pathway

PURPOSE

Oxidative stress and apoptosis contribute to the pathological basis of doxorubicin (DOX)-induced cardiotoxicity. Columbianadin (CBN) is one of the main bioactive constituents isolated from the root of Angelica pubescens. Herein, we intended to explore the potential role and molecular basis of CBN in DOX-induced cardiotoxicity.

METHODS

C57BL/6 mice were subjected to DOX (15 mg/kg/day, i.p.) to generate DOX-induced cardiotoxicity. CBN (10 mg/kg/day, i.p.) was administered for four week following DOX injection.

RESULTS

DOX administered markedly dampened cardiac function, increased cardiac injury, excessive reactive oxygen species (ROS) production, and cardiomyocyte loss. These alterations induced by DOX significantly alleviated by CBN treatment. Mechanistically, our results demonstrated that the CBN exerts cardioprotection role against DOX by up-regulating silent information regulator 1 (Sirt1) and decreasing acetylation of forkhead box O1 (FOXO1). Moreover, Sirt1 inhibition with Ex-527 significantly blunt the beneficial effect of CBN on DOX-induced cardiotoxicity, including cardiac dysfunction, ROS, and apoptosis.

CONCLUSION

Collectively, CBN attenuated oxidative stress and cardiomyocyte apoptosis in DOX-induced cardiotoxicity through maintaining Sirt1/FOXO1 signaling pathway. Our results demonstrated that CBN might be used to treat DOX-related cardiotoxicity.

Resveratrol, a SIRT1 activator, attenuates aging-associated alterations in skeletal muscle and heart in mice

Aging is associated with impairment of multiple organs, including skeletal muscle and heart. In this study, we investigated whether resveratrol, an activator of an NAD⁺-dependent protein deacetylase Sirtuin-1 (SIRT1), attenuates age-related sarcopenia and cardiomyocyte hypertrophy in mice. Treatment of mice with resveratrol (0.4 g/kg diet) from 28 weeks of age for 32 weeks prevented aging-associated shortening of rotarod riding time. In the tibialis anterior (TA) muscle, histogram analysis showed that the atrophic muscle was increased in 60-week-old (wo) mice compared with 20-wo mice, which was attenuated by resveratrol. In the heart, resveratrol attenuated an aging-associated increase in the cardiomyocyte diameter. Acetylated proteins were increased and autophagic activity was reduced in the TA muscle of 60-wo mice compared with those of 20-wo mice. Resveratrol treatment reduced levels of acetylated proteins and restored autophagic activity in the TA muscle. Aging-related reduction in myocardial autophagy was also suppressed by resveratrol. Skeletal muscle-specific SIRT1 knockout mice showed increases in acetylated proteins and atrophic muscle fibers and reduced autophagic activity in the TA muscle. These results suggest that activation of SIRT1 by treatment with resveratrol suppresses sarcopenia and cardiomyocyte hypertrophy by restoration of autophagy in mice.

Anthracycline Therapy Modifies Immune Checkpoint Signaling in the Heart

Cancer survival rates have increased significantly because of improvements in therapy regimes and novel immunomodulatory drugs. Recently, combination therapies of anthracyclines and immune checkpoint inhibitors (ICIs) have been proposed to maximize neoplastic cell removal. However, it has been speculated that a priori anthracycline exposure may prone the heart vulnerable to increased toxicity from subsequent ICI therapy, such as an anti-programmed cell death protein 1 (PD1) inhibitor. Here, we used a high-dose anthracycline mouse model to characterize the role of the PD1 immune checkpoint signaling pathway in cardiac tissue using flow cytometry and immunostaining. Anthracycline treatment led to decreased heart function, increased concentration of markers of cell death after six days and a change in heart cell population composition with fewer cardiomyocytes. At the same time point, the number of PD1 ligand (PDL1)-positive immune cells and endothelial cells in the heart decreased significantly. The results suggest that PD1/PDL1 signaling is affected after anthracycline treatment, which may contribute to an increased susceptibility to immune-related adverse events of subsequent anti-PD1/PDL1 cancer therapy.

Research progress of therapeutic drugs for doxorubicin-induced cardiomyopathy

Doxorubicin (DOX), as a kind of chemotherapy agent with remarkable therapeutic effect, can be used to treat diverse malignant tumors clinically. Dose-dependent cardiotoxicity is the most serious adverse reaction after DOX treatment, which eventually leads to cardiomyopathy and greatly limits the clinical application of DOX. DOX-induced cardiomyopathy is not a result of a single mechanistic action, and multiple mechanisms have been discovered and demonstrated experimentally, such as oxidative stress, inflammation, mitochondrial damage, calcium homeostasis disorder, ferroptosis, autophagy and apoptosis. Dexrazoxane (DEX) is the only protective agent approved by FDA for the treatment of DOX cardiomyopathy, but its clinical treatment still has some limitations. Therefore, we need to find other effective therapeutic drugs as soon as possible. In this paper, the drugs that effectively improve cardiomyopathy in recent years are mainly described from the aspects of natural drugs, endogenous substances, new dosage forms, herbal medicines, chemical modification and marketed drugs. The aim of the present study is to evaluate the effects of these drugs on DOX-induced anticancer and cardiomyopathy curative effects, so as to provide some reference value for clinical treatment of DOX-induced cardiomyopathy in the future.

OUP accepted manuscript

Cardiovascular diseases (CVDs) arise from a complex interplay among genomic, proteomic, and metabolomic abnormalities. Emerging evidence has recently consolidated the presence of robust DNA damage in a variety of cardiovascular disorders. DNA damage triggers a series of cellular responses termed DNA damage response (DDR) including detection of DNA lesions, cell cycle arrest, DNA repair, cellular senescence, and apoptosis, in all organ systems including hearts and vasculature. Although transient DDR in response to temporary DNA damage can be beneficial for cardiovascular function, persistent activation of DDR promotes the onset and development of CVDs. Moreover, therapeutic interventions that target DNA damage and DDR have the potential to attenuate cardiovascular dysfunction and improve disease outcome. In this review, we will discuss molecular mechanisms of DNA damage and repair in the onset and development of CVDs, and explore how DDR in specific cardiac cell types contributes to CVDs. Moreover, we will highlight the latest advances regarding the potential therapeutic strategies targeting DNA damage signalling in CVDs.