Tisp40 prevents cardiac ischemia/reperfusion injury through the hexosamine biosynthetic pathway in male mice

Bag2 protects against doxorubicin-induced cardiotoxicity by maintaining Pink1-mediated mitophagy

The clinical application of Doxorubicin (DOX) is limited due to its cardiotoxicity. Mitophagy dysfunction is the primary cause of DOX-induced cardiotoxicity (DIC). However, the precise mechanism by which DOX regulates mitophagy remains elusive. Bag2 (BCL2-associated athanogene 2) is a cochaperone implicated in multiple pathological states. The aim of this study was to investigate the potential cardio-protective effects of Bag2 in DIC. C57BL/6 mice and AC16 cells were used to establish DIC model. The expression of Bag2 were measured by western blotting and immunohistochemical. The effects of Bag2 on DIC were assessed through functional gain and loss experiments. Through in vitro and in vivo experiments, we found that Bag2 expression was significantly reduced after DOX treatment. Both Bag2 knockdown and DOX administration resulted in apoptosis, mitochondrial dysfunction, and impaired mitophagy. Conversely, Bag2 overexpression exerted protective effects against these phenotypes induced by DOX stimulation. Mechanistically, Bag2 maintained mitophagy activation by binding to Pink1 and protecting it from proteasome-dependent degradation, thereby preserving mitochondrial function and protecting against myocardial lesions. Our findings suggest that Bag2 may serve as a promising therapeutic target for the treatment of DIC.

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

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

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

INTRODUCTION

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

The multifaceted role of intracellular glycosylation in cytoprotection and heart disease

The modification of nuclear, cytoplasmic, and mitochondrial proteins by O-linked β-N-actylglucosamine (O-GlcNAc) is an essential posttranslational modification that is common in metozoans. O-GlcNAc is cycled on and off proteins in response to environmental and physiological stimuli impacting protein function, which, in turn, tunes pathways that include transcription, translation, proteostasis, signal transduction, and metabolism. One class of stimulus that induces rapid and dynamic changes to O-GlcNAc is cellular injury, resulting from environmental stress (for instance, heat shock), hypoxia/reoxygenation injury, ischemia reperfusion injury (heart attack, stroke, trauma hemorrhage), and sepsis. Acute elevation of O-GlcNAc before or after injury reduces apoptosis and necrosis, suggesting that injury-induced changes in O-GlcNAcylation regulate cell fate decisions. However, prolonged elevation or reduction in O-GlcNAc leads to a maladaptive response and is associated with pathologies such as hypertrophy and heart failure. In this review, we discuss the impact of O-GlcNAc in both acute and prolonged models of injury with a focus on the heart and biological mechanisms that underpin cell survival.

Macrod1 suppresses diabetic cardiomyopathy via regulating PARP1-NAD+-SIRT3 pathway

Diabetic cardiomyopathy (DCM), one of the most serious long-term consequences of diabetes, is closely associated with oxidative stress, inflammation and apoptosis in the heart. MACRO domain containing 1 (Macrod1) is an ADP-ribosylhydrolase 1 that is highly enriched in mitochondria, participating in the pathogenesis of cardiovascular diseases. In this study, we investigated the role of Macrod1 in DCM. A mice model was established by feeding a high-fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ). We showed that Macrod1 expression levels were significantly downregulated in cardiac tissue of DCM mice. Reduced expression of Macrod1 was also observed in neonatal rat cardiomyocytes (NRCMs) treated with palmitic acid (PA, 400 μM) in vitro. Knockout of Macrod1 in DCM mice not only worsened glycemic control, but also aggravated cardiac remodeling, mitochondrial dysfunction, NAD+ consumption and oxidative stress, whereas cardiac-specific overexpression of Macrod1 partially reversed these pathological processes. In PA-treated NRCMs, overexpression of Macrod1 significantly inhibited PARP1 expression and restored NAD+ levels, activating SIRT3 to resist oxidative stress. Supplementation with the NAD+ precursor Niacin (50 μM) alleviated oxidative stress in PA-stimulated cardiomyocytes. We revealed that Macrod1 reduced NAD+ consumption by inhibiting PARP1 expression, thereby activating SIRT3 and anti-oxidative stress signaling. This study identifies Macrod1 as a novel target for DCM treatment. Targeting the PARP1-NAD+-SIRT3 axis may open a novel avenue to development of new intervention strategies in DCM. Schematic illustration of macrod1 ameliorating diabetic cardiomyopathy oxidative stress via PARP1-NAD+-SIRT3 axis.

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

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

Roles of O-GlcNAcylation in Mitochondrial Homeostasis and Cardiovascular Diseases

Protein posttranslational modifications are important factors that mediate the fine regulation of signaling molecules. O-linked β-N-acetylglucosamine-modification (O-GlcNAcylation) is a monosaccharide modification on N-acetylglucosamine linked to the hydroxyl terminus of serine and threonine of proteins. O-GlcNAcylation is responsive to cellular stress as a reversible and posttranslational modification of nuclear, mitochondrial and cytoplasmic proteins. Mitochondrial proteins are the main targets of O-GlcNAcylation and O-GlcNAcylation is a key regulator of mitochondrial homeostasis by directly regulating the mitochondrial proteome or protein activity and function. Disruption of O-GlcNAcylation is closely related to mitochondrial dysfunction. More importantly, the O-GlcNAcylation of cardiac proteins has been proven to be protective or harmful to cardiac function. Mitochondrial homeostasis is crucial for cardiac contractile function and myocardial cell metabolism, and the imbalance of mitochondrial homeostasis plays a crucial role in the pathogenesis of cardiovascular diseases (CVDs). In this review, we will focus on the interactions between protein O-GlcNAcylation and mitochondrial homeostasis and provide insights on the role of mitochondrial protein O-GlcNAcylation in CVDs.

Differential effects of four laboratory animal control diets on gut microbiota in mice

BACKGROUND

The gut microbiota is intricate and susceptible to multiple factors, with diet being a major contributor. The present study aimed to investigate the impact of four commonly used laboratory animal control diets, namely Keao Xieli's maintenance diet (KX), HFK's 1025 (HF), Research Diets' D12450B (RD), and Lab Diet's 5CC4 (LD), on the gut microbiota of mice.

RESULTS

A total of 40 mice were randomly assigned to four groups, and each group was fed one of the four diets for a duration of 8 weeks. The assessment of gut microbiota was conducted using 16S rRNA sequencing both at the beginning of the study (week 0) and the end (week 8), which served as the baseline and endpoint samples, respectively. Following the 8-week feeding period, no significant differences were observed in physiological parameters, including body weight, visceral weight, and blood biochemical indices, across the four groups. Nonetheless, relative to the baseline, discernible alterations in the gut microbiota were observed in all groups, encompassing shifts in beta-diversity, hierarchical clustering, and key genera. Among the four diets, HF diet exhibited a significant influence on alpha-diversity, RD diet brought about notable changes in microbial composition at the phylum level, and LD diet demonstrated an interconnected co-occurrence network. Mantel analysis indicated no significant correlation between physiological parameters and gut microbiota in the four groups.

CONCLUSION

Overall, our study demonstrated that the four control diets had a minimal impact on physiological parameters, while exerting a distinct influence on the gut microbiota after 8 weeks. © 2024 Society of Chemical Industry.

Tectorigenin protects against cardiac fibrosis in diabetic mice heart via activating the adiponectin receptor 1-mediated AMPK pathway

Diabetic cardiomyopathy (DCM) is a common severe complication of diabetes that occurs independently of hypertension, coronary artery disease, and valvular cardiomyopathy, eventually leading to heart failure. Previous studies have reported that Tectorigenin (TEC) possesses extensive anti-inflammatory and anti-oxidative stress properties. In this present study, the impact of TEC on diabetic cardiomyopathy was examined. The model of DCM in mice was established with the combination of a high-fat diet and STZ treatment. Remarkably, TEC treatment significantly attenuated cardiac fibrosis and improved cardiac dysfunction. Concurrently, TEC was also found to mitigate hyperglycemia and hyperlipidemia in the DCM mouse. At the molecular level, TEC is involved in the activation of AMPK, both in vitro and in vivo, by enhancing its phosphorylation. This is achieved through the regulation of endothelial-mesenchymal transition via the AMPK/TGFβ/Smad3 pathway. Furthermore, it was demonstrated that the level of ubiquitination of the adiponectin receptor 1 (AdipoR1) protein is associated with TEC-mediated improvement of cardiac dysfunction in DCM mice. Notably the substantial reduction of myocardial fibrosis. In conclusion, TEC improves cardiac fibrosis in DCM mice by modulating the AdipoR1/AMPK signaling pathway. These findings suggest that TEC could be an effective therapeutic agent for the treatment of diabetic cardiomyopathy.

MG53: A new protagonist in the precise treatment of cardiomyopathies

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

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

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

The efferocytosis process in aging: Supporting evidence, mechanisms, and therapeutic prospects for age-related diseases

BACKGROUND

Aging is characterized by an ongoing struggle between the buildup of damage caused by a combination of external and internal factors. Aging has different effects on phagocytes, including impaired efferocytosis. A deficiency in efferocytosis can cause chronic inflammation, aging, and several other clinical disorders.

AIM OF REVIEW

Our review underscores the possible feasibility and extensive scope of employing dual targets in various age-related diseases to reduce the occurrence and progression of age-related diseases, ultimately fostering healthy aging and increasing lifespan. Key scientific concepts of review Hence, the concurrent implementation of strategies aimed at augmenting efferocytic mechanisms and anti-aging treatments has the potential to serve as a potent intervention for extending the duration of a healthy lifespan. In this review, we comprehensively discuss the concept and physiological effects of efferocytosis. Subsequently, we investigated the association between efferocytosis and the hallmarks of aging. Finally, we discuss growing evidence regarding therapeutic interventions for age-related disorders, focusing on the physiological processes of aging and efferocytosis.

O-GlcNAcylation: a pro-survival response to acute stress in the cardiovascular and central nervous systems

O-GlcNAcylation is a unique monosaccharide modification that is ubiquitously present in numerous nucleoplasmic and mitochondrial proteins. The hexosamine biosynthesis pathway (HBP), which is a key branch of glycolysis, provides the unique sugar donor UDP-GlcNAc for the O-GlcNAc modification. Thus, HBP/O-GlcNAcylation can act as a nutrient sensor to perceive changes in nutrient levels and trigger O-GlcNAc modifications of functional proteins in cellular (patho-)physiology, thereby regulating diverse metabolic processes. An imbalance in O-GlcNAcylation has been shown to be a pathogenic contributor to dysfunction in metabolic diseases, including type 2 diabetes, cancer, and neurodegeneration. However, under acute stress conditions, protein O-GlcNAc modification exhibits rapid and transient upregulation, which is strongly correlated with stress tolerance and cell survival. In this context, we discuss the metabolic, pharmacological and genetic modulation of HBP/O-GlcNAc modification in the biological system, the beneficial role of O-GlcNAcylation in regulating stress tolerance for cardioprotection, and neuroprotection, which is a novel and rapidly growing field. Current evidence suggests that transient activation of the O-GlcNAc modification represents a potent pro-survival signalling pathway and may provide a promising strategy for stress-related disorder therapy.

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

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

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

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

PKD knockdown mitigates Ang II-induced cardiac hypertrophy and ferroptosis via the JNK/P53 signaling pathway

BACKGROUND

Cardiac hypertrophy is studied in relation to energy metabolism, autophagy, and ferroptosis, which are associated with cardiovascular adverse events and chronic heart failure. Protein kinase D (PKD) has been shown to play a degenerative role in cardiac hypertrophy. However, the role of ferroptosis in PKD-involved cardiac hypertrophy remains unclear.

METHODS

A cardiac hypertrophy model was induced by a subcutaneous injection of angiotensin II (Ang II) for 4 weeks. Adeno-associated virus serotype 9 (AAV9)-PKD or AAV9-Negative control were injected through the caudal vein 2 weeks prior to the injection of Ang II. The degree of cardiac hypertrophy was assessed using echocardiography and by observing cardiomyocyte morphology. Levels of ferroptosis and protein expression in the Jun N-terminal kinase (JNK)/P53 signaling pathway were measured both in vivo and in vitro.

RESULTS

The results indicated that PKD knockdown reduces Ang II-induced cardiac hypertrophy, enhances cardiac function and inhibits ferroptosis. The involvement of the JNK/P53 pathway in this process was further confirmed by in vivo and in vitro experiments.

CONCLUSION

In conclusion, our findings suggest that PKD knockdown mitigates Ang II-induced cardiac hypertrophy and ferroptosis via the JNK/P53 signaling pathway.

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.

Bisdemethoxycurcumin alleviates LPS-induced acute lung injury via activating AMPKα pathway

OBJECTIVE

Inflammation and oxidative stress contribute to the pathogenesis of acute lung injury (ALI), and subsequently result in rapid deterioration in health. Considering the indispensable role of bisdemethoxycurcumin (BDMC) in inflammation and oxidative stress, the present study aims to examine the effect of BDMC on sepsis-related ALI.

METHODS

C57BL/6 mice were administered with BDMC (100 mg/kg) or an equal volume of vehicle, and then injected with lipopolysaccharides (LPS) to induce ALI. We assessed the parameters of lung injury, inflammatory response and oxidative stress in lung tissues. Consistently, the macrophages with or without BDMC treatment were exposed to LPS to verify the effect of BDMC in vitro.

RESULTS

BDMC suppressed LPS-induced lung injury, inflammation and oxidative stress in vivo and in vitro. Mechanistically, BDMC increased the phosphorylation of AMPKα in response to LPS stimulation, and AMPK inhibition with Compound C almost completely blunted the protective effect of BDMC in LPS-treated mice and macrophages. Moreover, we demonstrated that BDMC activated AMPKα via the cAMP/Epac pathway.

CONCLUSION

Our study identifies the protective effect of BDMC against LPS-induced ALI, and the underlying mechanism may be related to the activation of cAMP/Epac/AMPKα signaling pathway.

The role of glycolytic metabolic pathways in cardiovascular disease and potential therapeutic approaches

Cardiovascular disease (CVD) is a major threat to human health, accounting for 46% of non-communicable disease deaths. Glycolysis is a conserved and rigorous biological process that breaks down glucose into pyruvate, and its primary function is to provide the body with the energy and intermediate products needed for life activities. The non-glycolytic actions of enzymes associated with the glycolytic pathway have long been found to be associated with the development of CVD, typically exemplified by metabolic remodeling in heart failure, which is a condition in which the heart exhibits a rapid adaptive response to hypoxic and hypoxic conditions, occurring early in the course of heart failure. It is mainly characterized by a decrease in oxidative phosphorylation and a rise in the glycolytic pathway, and the rise in glycolysis is considered a hallmark of metabolic remodeling. In addition to this, the glycolytic metabolic pathway is the main source of energy for cardiomyocytes during ischemia-reperfusion. Not only that, the auxiliary pathways of glycolysis, such as the polyol pathway, hexosamine pathway, and pentose phosphate pathway, are also closely related to CVD. Therefore, targeting glycolysis is very attractive for therapeutic intervention in CVD. However, the relationship between glycolytic pathway and CVD is very complex, and some preclinical studies have confirmed that targeting glycolysis does have a certain degree of efficacy, but its specific role in the development of CVD has yet to be explored. This article aims to summarize the current knowledge regarding the glycolytic pathway and its key enzymes (including hexokinase (HK), phosphoglucose isomerase (PGI), phosphofructokinase-1 (PFK1), aldolase (Aldolase), phosphoglycerate metatase (PGAM), enolase (ENO) pyruvate kinase (PKM) lactate dehydrogenase (LDH)) for their role in cardiovascular diseases (e.g., heart failure, myocardial infarction, atherosclerosis) and possible emerging therapeutic targets.

Dapagliflozin protects against doxorubicin-induced nephrotoxicity associated with nitric oxide pathway-A translational study

Doxorubicin (Dox) is a potent anticancer agent, but its associated organ toxicity, including nephrotoxicity, restricts clinical applications. Dapagliflozin (DAPA), a sodium-glucose cotransporter-2 inhibitor, has been shown to slow the progression of kidney disease in patients with and without diabetes. However, the effect of DAPA to counteract Dox-induced nephrotoxicity remains uncertain. Therefore, in this study, we aimed to elucidate the effects of DAPA in mitigating Dox-induced nephrotoxicity. We analyzed the Taiwan National Health Insurance Database to evaluate the incidence of renal failure among breast cancer patients receiving Dox treatment compared to those without. After adjusting for age and comorbidities, we found that the risk of renal failure was significantly higher in Dox-treated patients (incidence rate ratio, 2.45; confidence interval, 1.41-4.26; p = 0.0014). In a parallel study, we orally administered DAPA to Sprague-Dawley rats for 6 weeks, followed by Dox for 4 weeks. DAPA ameliorated Dox-induced glomerular atrophy, renal fibrosis, and dysfunction. Furthermore, DAPA effectively suppressed Dox-induced apoptosis and reactive oxygen species production. On a cellular level, DAPA in HK-2 cells mitigated Dox-mediated suppression of the endothelial NOS pathway and reduced Dox-induced activities of reactive oxygen species and apoptosis-associated proteins. DAPA improved Dox-induced apoptosis and renal dysfunction, suggesting its potential utility in preventing nephrotoxicity in patients with cancer undergoing Dox treatment.

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.

CNIH4 governs cervical cancer progression through reducing ferroptosis

Cervical cancer is one of the most leading causes of cancer death worldwide, and ferroptosis is implicated in the progression of cervical cancer. Cornichon family AMPA receptor auxiliary protein 4 (CNIH4) is involved in the progression of various human cancers; however, its function in cervical cancer remains unclear. The present study aims to investigate the role and mechanism of CNIH4 in cervical cancer using gain- and loss-of-function studies in vitro. SiHa and CaSki cells were infected with lentiviral vectors to manipulate the expression of CNIH4 in vitro, and cell viability, migration, invasion as well as ferroptosis were evaluated. Transcriptome sequencing analysis was performed to further validate the mechanism through which CNIH4 regulated the progression of cervical cancer. The expression of CNIH4 was upregulated in human cervical cancer tissues and cells, and strongly correlated with the decreases in overall survival and disease free survival rates of cervical cancer patients. CNIH4 silence inhibited, while CNIH4 overexpression facilitated the survival of human cervical cancer cells. Mechanistically, CNIH4 elevated solute carrier family 7 member 11 (SLC7A11)-mediated cystine import, and subsequently increased intracellular glutathione synthesis and glutathione peroxidase 4 activity, thereby inhibiting ferroptosis of human cervical cancer cells. SLC7A11 silence significantly abolished CNIH4-mediated inhibition of ferroptosis in cervical cancer cells in vitro. Our study for the first time reveals that CNIH4 inhibits ferroptosis of human cervical cancer cells through upregulating SLC7A11, defining CNIH4 as an attractive therapeutic and prognostic target for cervical cancer.

ANGPTL2 aggravates LPS-induced septic cardiomyopathy via NLRP3-mediated inflammasome in a DUSP1-dependent pathway

Angiopoietin-like protein 2 (ANGPTL2) was implicated in various cardiovascular diseases; however, its role in lipopolysaccharide (LPS)-related septic cardiomyopathy remains unclear. Herein, mice were exposed to LPS to generate septic cardiomyopathy, and adeno-associated viral vector was employed to overexpress ANGPTL2 in the myocardium. Besides, mice were treated with adenoviral vector to knock down ANGPTL2 in hearts. ANGPTL2 expressions in hearts and cardiomyocytes were upregulated by LPS challenge. ANGPTL2 overexpression aggravated, while ANGPTL2 silence ameliorated LPS-associated cardiac impairment and inflammation. Mechanically, we found that ANGPTL2 activated NLRP3 inflammasome via suppressing DUSP1 signaling, and NLRP3 knockdown abrogated the detrimental role of ANGPTL2 in aggravating LPS-induced cardiac inflammation. Furthermore, DUSP1 overexpression significantly inhibited ANGPTL2-mediated NLRP3 activation, and subsequently improved LPS-related cardiac dysfunction. In summary, ANGPTL2 exacerbated septic cardiomyopathy via activating NLRP3-mediated inflammation in a DUSP1-dependent manner, and our study uncovered a promising therapeutic target in preventing septic cardiomyopathy.