The molecular mechanisms of ferroptosis and its role in cardiovascular disease

Endonuclear Circ-calm4 regulates ferroptosis via a circR-Loop of the COMP gene in pulmonary artery smooth muscle cells

Pulmonary hypertension (PH) is a serious pulmonary vascular disease characterized by vascular remodeling. Circular RNAs (CircRNAs) play important roles in pulmonary hypertension, but the mechanism of PH is not fully understood, particularly the roles of circRNAs located in the nucleus. Circ-calmodulin 4 (circ-calm4) is expressed in both the cytoplasm and the nucleus of pulmonary arterial smooth muscle cells (PASMCs). This study aimed to investigate the role of endonuclear circ-calm4 in PH and elucidate its underlying signaling pathway in ferroptosis. Immunoblotting, quantitative real-time polymerase chain reaction (PCR), malondialdehyde (MDA) assay, immunofluorescence, iron assay, dot blot, and chromatin immunoprecipitation (ChIP) were performed to investigate the role of endonuclear circ-calm4 in PASMC ferroptosis. Increased endonuclear circ-calm4 facilitated ferroptosis in PASMCs under hypoxic conditions. We further identified the cartilage oligomeric matrix protein (COMP) as a downstream effector of circ-calm4 that contributed to the occurrence of hypoxia-induced ferroptosis in PASMCs. Importantly, we confirmed that endonuclear circ-calm4 formed circR-loops with the promoter region of the COMP gene and negatively regulated its expression. Inhibition of COMP restored the phenotypes related to ferroptosis under hypoxia stimulation combined with antisense oligonucleotide (ASO)-circ-calm4 treatment. We conclude that the circ-calm4/COMP axis contributed to hypoxia-induced ferroptosis in PASMCs and that circ-calm4 formed circR-loops with the COMP promoter in the nucleus and negatively regulated its expression. The circ-calm4/COMP axis may be useful for the design of therapeutic strategies for protecting cellular functionality against ferroptosis and pulmonary hypertension.

The role and mechanism of various trace elements in atherosclerosis

Atherosclerosis is a slow and complex disease that involves various factors, including lipid metabolism disorders, oxygen-free radical production, inflammatory cell infiltration, platelet adhesion and aggregation, and local thrombosis. Trace elements play a crucial role in human health. Many trace elements, especially metallic ones, not only maintain the normal functions of organs but also participate in basic metabolic processes. The latest studies have revealed a close correlation between trace elements and the occurrence and progression of atherosclerosis. The imbalance of these trace elements can induce atherosclerosis or accelerate its progression through various mechanisms, which poses a significant threat to human health. Therefore, exploring the specific mechanism of trace elements on atherosclerosis is highly significant. In this review, we summarized the roles and mechanisms of iron, copper, zinc, magnesium, and selenium homeostasis and imbalance in atherosclerosis development, in order to identify novel targets and therapeutic strategies for treating atherosclerosis.

Inhibition of ubiquitin-specific protease 7 ameliorates ferroptosis-mediated myocardial infarction by contrasting oxidative stress: An in vitro and in vivo analysis

BACKGROUND

Our prior research determined that USP7 exacerbates myocardial injury. Additionally, existing studies indicate a strong connection between USP7 and ferroptosis. However, the influence of USP7 on ferroptosis-mediated myocardial infarction (MI) remains unclear. Given these findings, we are particularly interested in USP7's regulatory role in ferroptosis-mediated MI and its underlying mechanisms.

METHODS

In this study, we established MI models and lentivirus-transfected groups to inhibit USP7 expression both in vivo and in vitro. Cardiac function was detected with Echocardiography. TTC and HE staining were employed to assess myocardial alterations. The expression of ferroptosis markers (PTGS2, ACSL4, GPX4) were analyzed by RT-qPCR and Western blotting. Flow cytometry and ELISA were used for measuring Fe2+, lipid ROS, GSH, and GSSG levels. TEM and Prussian blue staining were used to observe mitochondrial alterations and iron deposition. RT-qPCR, Western blotting, and immunofluorescence were conducted to analyze Keap1, Nrf2, and nuclear Nrf2 expression in vitro and in vivo.

RESULTS

In the MI model group, USP7 expression significantly increased, worsening ferroptosis-mediated MI. Conversely, in the USP7-inhibited group, activation of the Keap1-Nrf2 signaling pathway improved ferroptosis-mediated MI outcomes. In vitro, the MI model exhibited a marked decline in cardiomyocyte viability and notable mitochondrial damage. However, these issues improved in the USP7-inhibited groups. In vivo, USP7 intensified MI and iron deposition within the MI model group, with decreased values of LVEF, LVFS, SV, LVAWd, and LVPWs, all of which showed improvement in the USP7-inhibited group, except for LVPWd and LVPWs, which showed no significant variation. Importantly, both the in vitro and in vivo experiments revealed analogous results: a reduction in Keap1 expression and an increase in both Nrf2 and nuclear Nrf2 post USP7 inhibition. Additionally, GPX4 expression decreased while PTGS2 and ACSL4 expressions increased. Notably, concentrations of Fe2+, lipid ROS, GSH, and GSSG significantly decreased.

CONCLUSION

In vitro and in vivo studies have found that inhibition of USP7 attenuates iron deposition and suppresses oxidative stress, resulting in amelioration of ferroptosis-induced MI.

Elucidating ferroptosis mechanisms in heart failure through transcriptomics, single-cell sequencing, and experimental validation

BACKGROUND

The mechanisms underlying ferroptosis in heart failure (HF) remain incompletely understood.

METHODS

This study analyzed the heart failure dataset from the Gene Expression Omnibus to identify differentially expressed ferroptosis-related genes (DFRGs). Key DFRGs were selected using LASSO regression and SVM-RFE machine learning techniques. Their diagnostic accuracy was evaluated via ROC curve analysis. Single-cell sequencing data, heart failure cell, and mouse models were utilized to validate these key DFRGs. Additionally, potential non-coding RNAs targeting these genes were predicted, and analyses for gene set enrichment, immune cell infiltration, and drug targeting were conducted.

RESULTS

A total of 127 DFRGs were identified, with 83 downregulated and 44 upregulated compared to controls. Seven key DFRGs (PTGS2, BECN1, SLC39A14, QSOX1, MLST8, TMSB4X, KDM4A) were identified, showing high diagnostic accuracy (AUC 0.988) in the GSE5406 dataset. GO and KEGG analyses linked these genes to ferroptosis, FoxO signaling, and autophagy pathways. A ceRNA network identified 217 miRNAs and 243 lncRNAs potentially targeting these genes, and 64 drugs were predicted as potential targets. Single-cell sequencing and in vitro experiments revealed differential expression of SLC39A14 and QSOX1, which was further confirmed in vivo.

CONCLUSION

This study provides novel insights into the role of ferroptosis in heart failure by identifying and validating DFRGs that exhibit differential expression across various cell types. The differential expression patterns of these genes, particularly SLC39A14 and QSOX1, indicate their potential involvement in the pathophysiological mechanisms contributing to HF. These findings offer new insights for the development of targeted therapies for HF.

Biomarkers That Seem to Have the Greatest Impact on Promoting the Formation of Atherosclerotic Plaque in Current Scientific Research

Atherosclerosis is a chronic inflammatory disease that causes degenerative and productive changes in the arteries. The resulting atherosclerotic plaques restrict the vessel lumen, causing blood flow disturbances. Plaques are formed mainly in large- and medium-sized arteries, usually at bends and forks where there is turbulence in blood flow. Depending on their location, they can lead to various disease states such as myocardial infarction, stroke, renal failure, peripheral vascular diseases, or sudden cardiac death. In this work, we reviewed the literature on the early detection of atherosclerosis markers in the application of photodynamic therapy to atherosclerosis-related diseases. Herein, we described the roles of C-reactive protein, insulin, osteopontin, osteoprotegerin, copeptin, the TGF-β cytokine family, and the amino acid homocysteine. Also, we discuss the role of microelements such as iron, copper, zinc, and Vitamin D in promoting the formation of atherosclerotic plaque. Dysregulation of the administered compounds is associated with an increased risk of atherosclerosis. Additionally, taking into account the pathophysiology of atherosclerotic plaque formation, we believe that maintaining homeostasis in the range of biomarkers mentioned in this article is crucial for slowing down the process of atherosclerotic plaque development and the stability of plaque that is already formed.

Shock Wave Therapy Alleviates Hypoxia/Reoxygenation-Induced Cardiomyocyte Injury by Inhibiting Both Apoptosis and Ferroptosis

Shock wave therapy (SWT) is a new alternative therapy for patients with severe coronary artery disease that improves myocardial ischemic symptoms by delivering low-energy shock wave stimulation to ischaemic myocardium with low-energy pulsed waves. However, the specific mechanism of its protective effect is not fully understood, especially for the protective mechanism in cardiomyocytes after hypoxia/reoxygenation (H/R). We selected a rat H9c2 cardiomyocyte cell line to establish a stable H/R cardiomyocyte injury model by hypoxia/reoxygenation, and then used SWT for therapeutic intervention to explore its cardiomyocyte protective mechanisms. The results showed that SWT significantly increased cell viability and GSH levels while decreasing LDH levels, ROS levels, and MDA levels. SWT also improved mitochondrial morphology and function of cells after H/R. Meanwhile, we found that SWT could increase the expression of GPX4, xCT, and Bcl-2, while decreasing the expression of Bax and cleaved caspase-3, and inhibiting cardiomyocyte apoptosis and ferroptosis. Moreover, this protective effect of SWT on cardiomyocytes could be significantly reversed by knockdown of xCT, a key regulator protein of ferroptosis. In conclusion, our study shows that SWT can attenuate hypoxia-reoxygenation-induced myocardial injury and protect cardiomyocyte function by inhibiting H/R-induced apoptosis and ferroptosis, and this therapy may have important applications in the treatment of clinical myocardial ischemic diseases.

Bioinformatics and machine learning approaches reveal key genes and underlying molecular mechanisms of atherosclerosis: A review

Atherosclerosis (AS) causes thickening and hardening of the arterial wall due to accumulation of extracellular matrix, cholesterol, and cells. In this study, we used comprehensive bioinformatics tools and machine learning approaches to explore key genes and molecular network mechanisms underlying AS in multiple data sets. Next, we analyzed the correlation between AS and immune fine cell infiltration, and finally performed drug prediction for the disease. We downloaded GSE20129 and GSE90074 datasets from the Gene expression Omnibus database, then employed the Cell-type Identification By Estimating Relative Subsets Of RNA Transcripts algorithm to analyze 22 immune cells. To enrich for functional characteristics, the black module correlated most strongly with T cells was screened with weighted gene co-expression networks analysis. Functional enrichment analysis revealed that the genes were mainly enriched in cell adhesion and T-cell-related pathways, as well as NF-κ B signaling. We employed the Lasso regression and random forest algorithms to screen out 5 intersection genes (CCDC106, RASL11A, RIC3, SPON1, and TMEM144). Pathway analysis in gene set variation analysis and gene set enrichment analysis revealed that the key genes were mainly enriched in inflammation, and immunity, among others. The selected key genes were analyzed by single-cell RNA sequencing technology. We also analyzed differential expression between these 5 key genes and those involved in iron death. We found that ferroptosis genes ACSL4, CBS, FTH1 and TFRC were differentially expressed between AS and the control groups, RIC3 and FTH1 were significantly negatively correlated, whereas SPON1 and VDAC3 were significantly positively correlated. Finally, we used the Connectivity Map database for drug prediction. These results provide new insights into AS genetic regulation.

Palmitic acid induces β-cell ferroptosis by activating ceramide signaling pathway

Individuals with type 2 diabetes mellitus frequently display heightened levels of palmitic acid (PA) in their serum, which may lead to β-cell damage. The involvement of ferroptosis, a form of oxidative cell death in lipotoxic β-cell injury remains uncertain. Here, we have shown that PA induces intracellular lipid peroxidation, increases intracellular Fe2+ content and decreases intracellular glutathione peroxidase 4 (GPX4) expression. Furthermore, PA causes distinct changes in pancreatic islets and INS-1 cells, such as mitochondrial atrophy and increased membrane density. Furthermore, the presence of the ferroptosis inhibitor has a significant mitigating effect on PA-induced β-cell damage. Mechanistically, PA increased ceramide content and c-Jun N-terminal kinase (JNK) phosphorylation. The ceramide synthase inhibitor effectively attenuated PA-induced β-cell damage and GPX4/Fe2+ abnormalities, while inhibiting JNK phosphorylation. Additionally, the JNK inhibitor SP600125 improved PA-induced cell damage. In conclusion, by promoting ceramide synthesis, PA inhibited GPX4 expression and increased intracellular Fe2+ to induce β-cell ferroptosis. Moreover, JNK may be a downstream mechanism of ceramide-triggered lipotoxic ferroptosis in β-cells.

Construction of the circRNA-miRNA-mRNA axis based on ferroptosis-related gene AKR1C1 to explore the potential pathogenesis of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a cardiovascular disease that seriously threatens human health and brings huge economic burden. At present, its pathogenesis remains unclear and its treatment is limited to surgical treatment. With the deepening and analysis of studies on the mechanism of ferroptosis, a new idea has been provided for the clinical management of AAA patients, including diagnosis, treatment and prevention. Therefore, this paper aims to construct a competitive endogenous RNA (ceRNA) regulatory axis based on ferroptosis to preliminarily explore the pathogenesis and potential therapeutic targets of AAA. We obtained upregulated and downregulated ferroptosis-related DEGs (FRGs) from GSE144431 dataset and 60 known ferroptosis-related genes. Pearson correlation analysis was used to find aldoketone reductase 1C (AKR1C1) in AAA samples. Enrichment analysis of these genes was performed via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Correlation test between immune cells and AKR1C1 was investigated through single-sample gene set enrichment analysis (ssGSEA). The AKR1C1-miRNA pairs were predicted by the TargetScan database and miRWalk database. Circular RNA (CircRNA)-miRNA pairs were selected by the CircInteractome database. Overlapping miRNA between circRNA-miRNA and AKR1C1-miRNA pairs was visualized by Venn diagram. Finally, the circRNA-miRNA-mRNA axis was constructed by searching for upstream circRNA and downstream mRNA of overlapping miRNA. Only one downregulated AKR1C1 gene was found in GSE144431 and 60 ferroptosis-related genes. Functional Enrichment and Pathway Analysis of AKR1C1-related genes were further explored, and it was observed that they were mainly enriched in "response to oxidative stress," "glutathione biosynthetic process" and "nonribosomal peptide biosynthetic process," "Ferroptosis," "Glutathione metabolism" and "Chemical carcinogenesis-reactive oxygen species." They were also found to be significantly associated with most immune cells, including Activated Dendritic cells, CD56dim Natural killer cells, Gamma Delta T cells, Immature B cells, Plasmacytoid dendritic cell, Type 2 T helper cell, Activated CD4 T cell and Type 1 T helper cell. Has_circ_0005073-miRNA-543 and AKR1C1-miRNA-543 were identified by Online Database analysis. Therefore, we have established the has_circ_0005073/miRNA-543/AKR1C1 axis in AAA. We found AKR1C1 was differentially expressed between normal and AAA groups. Based on AKR1C1, we constructed the has_circ_0005073/miRNA-543/AKR1C1 axis to analyze AAA.

Advances in integrating single-cell sequencing data to unravel the mechanism of ferroptosis in cancer

Ferroptosis, a commonly observed type of programmed cell death caused by abnormal metabolic and biochemical mechanisms, is frequently triggered by cellular stress. The occurrence of ferroptosis is predominantly linked to pathophysiological conditions due to the substantial impact of various metabolic pathways, including fatty acid metabolism and iron regulation, on cellular reactions to lipid peroxidation and ferroptosis. This mode of cell death serves as a fundamental factor in the development of numerous diseases, thereby presenting a range of therapeutic targets. Single-cell sequencing technology provides insights into the cellular and molecular characteristics of individual cells, as opposed to bulk sequencing, which provides data in a more generalized manner. Single-cell sequencing has found extensive application in the field of cancer research. This paper reviews the progress made in ferroptosis-associated cancer research using single-cell sequencing, including ferroptosis-associated pathways, immune checkpoints, biomarkers, and the identification of cell clusters associated with ferroptosis in tumors. In general, the utilization of single-cell sequencing technology has the potential to contribute significantly to the investigation of the mechanistic regulatory pathways linked to ferroptosis. Moreover, it can shed light on the intricate connection between ferroptosis and cancer. This technology holds great promise in advancing tumor-wide diagnosis, targeted therapy, and prognosis prediction.

Nanodrug Delivery Systems for Myasthenia Gravis: Advances and Perspectives

Myasthenia gravis (MG) is a rare chronic autoimmune disease caused by the production of autoantibodies against the postsynaptic membrane receptors present at the neuromuscular junction. This condition is characterized by fatigue and muscle weakness, including diplopia, ptosis, and systemic impairment. Emerging evidence suggests that in addition to immune dysregulation, the pathogenesis of MG may involve mitochondrial damage and ferroptosis. Mitochondria are the primary site of energy production, and the reactive oxygen species (ROS) generated due to mitochondrial dysfunction can induce ferroptosis. Nanomedicines have been extensively employed to treat various disorders due to their modifiability and good biocompatibility, but their application in MG management has been rather limited. Nevertheless, nanodrug delivery systems that carry immunomodulatory agents, anti-oxidants, or ferroptosis inhibitors could be effective for the treatment of MG. Therefore, this review focuses on various nanoplatforms aimed at attenuating immune dysregulation, restoring mitochondrial function, and inhibiting ferroptosis that could potentially serve as promising agents for targeted MG therapy.

Construction of ferroptosis-related prediction model for pathogenesis, diagnosis and treatment of ruptured abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a dangerous cardiovascular disease, which often brings great psychological burden and economic pressure to patients. If AAA rupture occurs, it is a serious threat to patients' lives. Therefore, it is of clinical value to actively explore the pathogenesis of ruptured AAA and prevent its occurrence. Ferroptosis is a new type of cell death dependent on lipid peroxidation, which plays an important role in many cardiovascular diseases. In this study, we used online data and analysis of ferroptosis-related genes to uncover the formation of ruptured AAA and potential therapeutic targets. We obtained ferroptosis-related differentially expressed genes (Fe-DEGs) from GSE98278 dataset and 259 known ferroptosis-related genes from FerrDb website. Enrichment analysis of differentially expressed genes (DEGs) was performed by gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG). Receiver Operating characteristic (ROC) curve was employed to evaluate the diagnostic abilities of Fe-DEGs. Transcription factors and miRNAs of Fe-DEGs were identified through PASTAA and miRDB, miRWalk, TargetScan respectively. Single-sample gene set enrichment analysis (ssGSEA) was used to observe immune infiltration between the stable group and the rupture group. DGIdb database was performed to find potential targeted drugs of DEGs. GO and KEGG enrichment analysis found that DEGs mainly enriched in "cellular divalent inorganic cation homeostasis," "cellular zinc ion homeostasis," "divalent inorganic cation homeostasis," "Mineral absorption," "Cytokine - cytokine receptor interaction," "Coronavirus disease - COVID-19." Two up-regulated Fe-DEGs MT1G and DDIT4 were found to further analysis. Both single and combined applications of MT1G and DDIT4 showed good diagnostic efficacy (AUC = 0.8254, 0.8548, 0.8577, respectively). Transcription factors STAT1 and PU1 of MT1G and ARNT and MAX of DDIT4 were identified. Meanwhile, has_miR-548p-MT1G pairs, has_miR-53-3p/has_miR-181b-5p/ has_miR-664a-3p-DDIT4 pairs were found. B cells, NK cells, Th2 cells were high expression in the rupture group compared with the stable group, while DCs, Th1 cells were low expression in the rupture group. Targeted drugs against immunity, GEMCITABINE and INDOMETHACIN were discovered. We preliminarily explored the clinical significance of Fe-DEGs MT1G and DDIT4 in the diagnosis of ruptured AAA, and proposed possible upstream regulatory transcription factors and miRNAs. In addition, we also analyzed the immune infiltration of stable and rupture groups, and found possible targeted drugs for immunotherapy.

Cyclophosphamide activates ferroptosis-induced dysfunction of Leydig cells via SMAD2 pathway†

Cyclophosphamide (CP) is a widely used chemotherapeutic drug and immunosuppressant in the clinic, and the hypoandrogenism caused by CP is receiving more attention. Some studies found that ferroptosis is a new mechanism of cell death closely related to chemotherapeutic drugs and plays a key role in regulating reproductive injuries. The purpose of this study is to explore ferroptosis' role in testicular Leydig cell dysfunction and molecular mechanisms relating to it. In this study, the level of ferroptosis in the mouse model of testicular Leydig cell dysfunction induced by CP was significantly increased and further affected testosterone synthesis. The ferroptosis inhibitors ferrostatin-1 (Fer-1) and iron chelator deferoxamine (DFO) can improve injury induced by CP. The results of immunohistochemistry showed that Fer-1 and DFO could improve the structural disorder of seminiferous tubules and the decrease of the number of Leydig cells in testicular tissue induced by CP. Immunofluorescence and western blot confirmed that Fer-1 and DFO could improve the expression of key enzymes in testosterone synthesis. The activation of SMAD family member 2 (Smad2)/cyclin-dependent kinase inhibitor 1A (Cdkn1a) pathway can improve the ferroptosis of Leydig cells induced by CP and protect the function of Leydig cells. By inhibiting the Smad2/Cdkn1a signal pathway, CP can regulate ferroptosis, resulting in testicular Leydig cell dysfunction. In this study, CP-induced hypoandrogenism is explained theoretically and a potential therapeutic strategy is provided.

The beneficial health effects of puerarin in the treatment of cardiovascular diseases: from mechanisms to therapeutics

Cardiovascular diseases (CVDs) are the leading causes of death globally that seriously threaten human health. Although novel western medicines have continued to be discovered over the past few decades to inhibit the progression of CVDs, new drug research and development for treating CVDs with less side effects and adverse reactions are continuously being desired. Puerarin is a natural product found in a variety of medicinal plants belonging to the flavonoid family with potent biological and pharmacological activities. Abundant research findings in the literature have suggested that puerarin possesses a promising prospect in treating CVDs. In recent years, numerous new molecular mechanisms of puerarin have been explored in experimental and clinical studies, providing new evidence for this plant metabolite to protect against CVDs. This article systematically introduces the history of use, bioavailability, and various dosage forms of puerarin and further summarizes recently published data on the major research advances and their underlying therapeutic mechanisms in treating CVDs. It may provide references for researchers in the fields of pharmacology, natural products, and internal medicine.

Emerging regulatory mechanisms in cardiovascular disease: Ferroptosis

Ferroptosis, distinct from apoptosis, necrosis, autophagy, and other types of cell death, is a novel iron-dependent regulated cell death characterized by the accumulation of lipid peroxides and redox imbalance with distinct morphological, biochemical, and genetic features. Dysregulation of iron homeostasis, the disruption of antioxidative stress pathways and lipid peroxidation are crucial in ferroptosis. Ferroptosis is involved in the pathogenesis of several cardiovascular diseases, including atherosclerosis, cardiomyopathy, myocardial infarction, ischemia-reperfusion injury, abdominal aortic aneurysm, aortic dissection, and heart failure. Therefore, a comprehensive understanding of the mechanisms that regulate ferroptosis in cardiovascular diseases will enhance the prevention and treatment of these diseases. This review discusses the latest findings on the molecular mechanisms of ferroptosis and its regulation in cardiovascular diseases, the application of ferroptosis modulators in cardiovascular diseases, and the role of traditional Chinese medicines in ferroptosis regulation to provide a comprehensive understanding of the pathogenesis of cardiovascular diseases and identify new prevention and treatment options.

GPX4, ferroptosis, and diseases

GPX4 (Glutathione peroxidase 4) serves as a crucial intracellular regulatory factor, participating in various physiological processes and playing a significant role in maintaining the redox homeostasis within the body. Ferroptosis, a form of iron-dependent non-apoptotic cell death, has gained considerable attention in recent years due to its involvement in multiple pathological processes. GPX4 is closely associated with ferroptosis and functions as the primary inhibitor of this process. Together, GPX4 and ferroptosis contribute to the pathophysiology of several diseases, including sepsis, nervous system diseases, ischemia reperfusion injury, cardiovascular diseases, and cancer. This review comprehensively explores the regulatory roles and impacts of GPX4 and ferroptosis in the development and progression of these diseases, with the aim of providing insights for identifying potential therapeutic strategies in the future.

Type 2 diabetic mellitus related osteoporosis: focusing on ferroptosis

With the aging global population, type 2 diabetes mellitus (T2DM) and osteoporosis(OP) are becoming increasingly prevalent. Diabetic osteoporosis (DOP) is a metabolic bone disorder characterized by abnormal bone tissue structure and reduced bone strength in patients with diabetes. Studies have revealed a close association among diabetes, increased fracture risk, and disturbances in iron metabolism. This review explores the concept of ferroptosis, a non-apoptotic cell death process dependent on intracellular iron, focusing on its role in DOP. Iron-dependent lipid peroxidation, particularly impacting pancreatic β-cells, osteoblasts (OBs) and osteoclasts (OCs), contributes to DOP. The intricate interplay between iron dysregulation, which comprises deficiency and overload, and DOP has been discussed, emphasizing how excessive iron accumulation triggers ferroptosis in DOP. This concise overview highlights the need to understand the complex relationship between T2DM and OP, particularly ferroptosis. This review aimed to elucidate the pathogenesis of ferroptosis in DOP and provide a prospective for future research targeting interventions in the field of ferroptosis.

Identification of osteoporosis ferroptosis-related markers and potential therapeutic compounds based on bioinformatics methods and molecular docking technology

RESEARCH BACKGROUND AND PURPOSE

Osteoporosis (OP) is one of the most common bone diseases worldwide, characterized by low bone mineral density and susceptibility to pathological fractures, especially in postmenopausal women and elderly men. Ferroptosis is one of the newly discovered forms of cell death regulated by genes in recent years. Many studies have shown that ferroptosis is closely related to many diseases. However, there are few studies on ferroptosis in osteoporosis, and the mechanism of ferroptosis in osteoporosis is still unclear. This study aims to identify biomarkers related to osteoporosis ferroptosis from the GEO (Gene Expression Omnibus) database through bioinformatics technology, and to mine potential therapeutic small molecule compounds through molecular docking technology, trying to provide a basis for the diagnosis and treatment of osteoporosis in the future.

MATERIALS AND METHODS

We downloaded the ferroptosis-related gene set from the FerrDb database ( http://www.zhounan.org/ferrdb/index.html ), downloaded the data sets GSE56815 and GSE7429 from the GEO database, and used the R software "limma" package to screen differentially expressed genes (DEGs) from GSE56815, and intersected with the ferroptosis gene set to obtain ferroptosis-related DEGs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed by the R software "clusterProfiler" package. The random forest model was further screened to obtain essential ferroptosis genes. R software "corrplot" package was used for correlation analysis of essential ferroptosis genes, and the Wilcox test was used for significance analysis. The lncRNA-miRNA-mRNA-TF regulatory network was constructed using Cytoscape software. The least absolute shrinkage and selection operator (LASSO) was used to construct a disease diagnosis model, and a Receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic performance, and then GSE7429 was used to verify the reliability of the diagnosis model. Molecular docking technology was used to screen potential small molecule compounds from the Drugbank database. Finally, a rat osteoporosis model was constructed, and peripheral blood mononuclear cells were extracted for qRT-PCR detection to verify the mRNA expression levels of crucial ferroptosis genes.

RESULT

Six DEGs related to ferroptosis were initially screened out. GO function and KEGG pathway enrichment analysis showed that ferroptosis-related DEGs were mainly enriched in signaling pathways such as maintenance of iron ion homeostasis, copper ion binding function, and ferroptosis. The random forest model identified five key ferroptosis genes, including CP, FLT3, HAMP, HMOX1, and SLC2A3. Gene correlation analysis found a relatively low correlation between these five key ferroptosis genes. The lncRNA-miRNA-mRNA-TF regulatory network shows that BAZ1B and STAT3 may also be potential molecules. The ROC curve of the disease diagnosis model shows that the model has a good diagnostic performance. Molecular docking technology screened out three small molecule compounds, including NADH, Midostaurin, and Nintedanib small molecule compounds. qRT-PCR detection confirmed the differential expression of CP, FLT3, HAMP, HMOX1 and SLC2A3 between OP and normal control group.

CONCLUSION

This study identified five key ferroptosis genes (CP, FLT3, HAMP, HMOX1, and SLC2A3), they were most likely related to OP ferroptosis. In addition, we found that the small molecule compounds of NADH, Midostaurin, and Nintedanib had good docking scores with these five key ferroptosis genes. These findings may provide new clues for the early diagnosis and treatment of osteoporosis in the future.

Updated mechanisms of MASLD pathogenesis

Metabolic dysfunction-associated steatotic liver disease (MASLD) has garnered considerable attention globally. Changing lifestyles, over-nutrition, and physical inactivity have promoted its development. MASLD is typically accompanied by obesity and is strongly linked to metabolic syndromes. Given that MASLD prevalence is on the rise, there is an urgent need to elucidate its pathogenesis. Hepatic lipid accumulation generally triggers lipotoxicity and induces MASLD or progress to metabolic dysfunction-associated steatohepatitis (MASH) by mediating endoplasmic reticulum stress, oxidative stress, organelle dysfunction, and ferroptosis. Recently, significant attention has been directed towards exploring the role of gut microbial dysbiosis in the development of MASLD, offering a novel therapeutic target for MASLD. Considering that there are no recognized pharmacological therapies due to the diversity of mechanisms involved in MASLD and the difficulty associated with undertaking clinical trials, potential targets in MASLD remain elusive. Thus, this article aimed to summarize and evaluate the prominent roles of lipotoxicity, ferroptosis, and gut microbes in the development of MASLD and the mechanisms underlying their effects. Furthermore, existing advances and challenges in the treatment of MASLD were outlined.

N6-methyladenosine-associated genetic variants in NECTIN2 and HPCAL1 are risk factors for abdominal aortic aneurysm

Although N6-methyladenosine (m6A) modification has been implicated in the pathogenesis of abdominal aortic aneurysm (AAA), the relationship between m6A-associated single nucleotide polymorphisms (m6A-SNPs) and AAA remains unknown. This study used integrative multi-omics analysis and clinical validation approaches to systematically identify potential m6A-SNPs connected with AAA risk. We found that rs6859 and rs10198139 could modulate the expression of local genes, NECTIN2 and HPCAL1, respectively, which exhibited upregulation in AAA tissues, and their risk variants were significantly correlated with an increased susceptibility to AAA. Incorporating rs6859 and rs10198139 improved the efficiency of AAA risk prediction compared to the model considering only conventional risk factors. Additionally, these two SNPs were predicted to be located within the regulatory sequences, and rs6859 showed a substantial impact on m6A modification levels. Our findings suggest that m6A-SNPs rs6859 and rs10198139 confer an elevated risk of AAA, possibly by promoting local gene expression through an m6A-mediated manner.

Deciphering Ferroptosis: From Molecular Pathways to Machine Learning-Guided Therapeutic Innovation

Ferroptosis is a unique form of cell death reliant on iron and lipid peroxidation. It disrupts redox balance, causing cell death by damaging the plasma membrane, with inducers acting through enzymatic pathways or transport systems. In cancer treatment, suppressing ferroptosis or circumventing it holds significant promise. Beyond cancer, ferroptosis affects aging, organs, metabolism, and nervous system. Understanding ferroptosis mechanisms holds promise for uncovering novel therapeutic strategies across a spectrum of diseases. However, detection and regulation of this regulated cell death are still mired with challenges. The dearth of cell, tissue, or organ-specific biomarkers muted the pharmacological use of ferroptosis. This review covers recent studies on ferroptosis, detailing its properties, key genes, metabolic pathways, and regulatory networks, emphasizing the interaction between cellular signaling and ferroptotic cell death. It also summarizes recent findings on ferroptosis inducers, inhibitors, and regulators, highlighting their potential therapeutic applications across diseases. The review addresses challenges in utilizing ferroptosis therapeutically and explores the use of machine learning to uncover complex patterns in ferroptosis-related data, aiding in the discovery of biomarkers, predictive models, and therapeutic targets. Finally, it discusses emerging research areas and the importance of continued investigation to harness the full therapeutic potential of targeting ferroptosis.

The association between ferroptosis and autophagy in cardiovascular diseases

Autophagy is a process in which cells degrade intracellular substances and play a variety of roles in cells, such as maintaining intracellular homeostasis, preventing cell overgrowth, and removing pathogens. It is highly conserved during the evolution of eukaryotic cells. So far, the study of autophagy is still a hot topic in the field of cytology. Ferroptosis is an iron-dependent form of cell death, accompanied by the accumulation of reactive oxygen species and lipid peroxides. With the deepening of research, it has been found that ferroptosis, like autophagy, is involved in the occurrence and development of cardiovascular diseases. The relationship between autophagy and ferroptosis is complex, and the association between the two in cardiovascular disease remains to be clarified. This article reviews the mechanism of autophagy and ferroptosis and their correlation, and discusses the relationship between them in cardiovascular diseases, which is expected to provide new and important treatment strategies for cardiovascular diseases.

LuQi formula attenuates Cardiomyocyte ferroptosis via activating Nrf2/GPX4 signaling axis in heart failure

BACKGROUND

The terminal stage of all cardiovascular diseases typically culminates in heart failure (HF), with no effective intervention available to halt its progression. LuQi formula (LQF) has been employed in clinical for numerous years to significantly ameliorate cardiac function in HF patients. Nevertheless, the underlying mechanism of LQF's efficacy remains inadequately comprehended. Cardiomyocyte ferroptosis has served as a pathogenic mechanism in HF. The goal of the current experiment was to ascertain whether LQF ameliorates HF by preventing cardiomyocyte ferroptosis and to elucidate the intrinsic mechanism involved.

PURPOSE

This research objective is to investigate the impact and underlying mechanism of LQF attenuating cardiomyocyte ferroptosis in heart failure.

METHODS

Transverse aortic constriction (TAC) was performed to construct the HF mouse model. Neonatal rat cardiomyocytes (NRCMs) were subjected to in vitro experiments. High-performance liquid chromatography (HPLC) identified the bioactive compounds in LQF. Transcriptomic and quantitative proteomic analyses revealed the potential targets of LQF anti-HF. Specifically, histological staining evaluated cardiac hypertrophy and fibrosis. Transmission electron microscopy (TEM) observed mitochondrial morphology. The content of Fe2+, ROS, MDA, GSH, and GSSH was detected using kits. Molecular docking evaluated the binding activities between essential active ingredients of LQF and critical proteins of cardiomyocyte ferroptosis. Mechanistically, the expression levels of Nrf2, Keap1, HO-1, SLC7A11, and GPX4 were evaluated using qPCR, Western blot (WB), or immunohistochemical staining.

RESULTS

The primary nine active ingredients in LQF were detected. Transcriptomic and proteomic analyses demonstrated that LQF may ameliorate HF by preventing cardiomyocyte ferroptosis. Histomorphometric analyses revealed that LQF attenuates myocardial hypertrophy and fibrosis. TEM revealed that LQF diminished mitochondrial shrinkage and increased membrane density in myocardial tissue. Additionally, LQF diminished reactive oxygen species (ROS) generation in cardiomyocytes and suppressed cardiomyocyte ferroptosis. Furthermore, the molecular docking technique revealed that the primary active ingredients of LQF had suitable binding activities with Nrf2, GPX4, and SLC7A11. Western analysis further verified that LQF activated the Nrf2/GPX4 signaling axis. decreased SLC7A11 and HO-1 expression.

CONCLUSIONS

These results demonstrated that LQF prevents cardiomyocyte ferroptosis via activating Nrf2/GPX4 signaling axis and suppressing SLC7A11 and HO-1 expression. Concurrently, it contributed to elucidating the intrinsic mechanism of LQF and provided a scientific rationale for its development as a novel cardiovascular therapeutic drug.

The role of ferroptosis in cardio-oncology

With the rapid development of new generations of antitumor therapies, the average survival time of cancer patients is expected to be continuously prolonged. However, these therapies often lead to cardiotoxicity, resulting in a growing number of tumor survivors with cardiovascular disease. Therefore, a new interdisciplinary subspecialty called "cardio-oncology" has emerged, aiming to detect and treat cardiovascular diseases associated with tumors and antitumor therapies. Recent studies have highlighted the role of ferroptosis in both cardiovascular and neoplastic diseases. The balance between intracellular oxidative stress and antioxidant defense is crucial in regulating ferroptosis. Tumor cells can evade ferroptosis by upregulating multiple antioxidant defense pathways, while many antitumor therapies rely on downregulating antioxidant defense and promoting ferroptosis in cancer cells. Unfortunately, these ferroptosis-inducing antitumor therapies often lack tissue specificity and can also cause injury to the heart, resulting in ferroptosis-induced cardiotoxicity. A range of cardioprotective agents exert cardioprotective effects by inhibiting ferroptosis. However, these cardioprotective agents might diminish the efficacy of antitumor treatment due to their antiferroptotic effects. Most current research on ferroptosis only focuses on either tumor treatment or heart protection but rarely considers both in concert. Therefore, further research is needed to study how to protect the heart during antitumor therapies by regulating ferroptosis. In this review, we summarized the role of ferroptosis in the treatment of neoplastic diseases and cardiovascular diseases and also attempted to propose further research directions for ferroptosis in the field of cardio-oncology.

CircCDYL Contributes to Apoptosis, Ferroptosis, and Oxidative Stress of Ang II-Induced Vascular Smooth Muscle Cells in Thoracic Aortic Aneurysm

Circular RNAs (circRNAs) have important regulation in thoracic aortic aneurysm (TAA). The function and mechanism of circCDYL (circ_0008285) was explored in TAA here. Angiotensin II (Ang II) was used to construct a TAA model. Real-time quantitative polymerase chain reaction (RT-qPCR) was performed for the detection of circCDYL, miR-1270, and a disintegrin and metalloproteinase 10 (ADAM10). Cell viability was examined via cell counting kit-8 (CCK-8) assay and proliferation was analyzed using Ethynyl-2'-deoxyuridine (EdU) assay. Apoptosis rate was assessed via flow cytometry. Western blot was used for protein detection. Oxidative stress was evaluated by commercial kits. CircCDYL was upregulated in TAA tissues and Ang II-induced circCDYL upregulation in vascular smooth muscle cells (VSMCs). Knockdown of circCDYL weakened Ang II-aroused inhibition of viability, proliferation, and promotion of apoptosis, ferroptosis, and oxidative stress in VSMCs. CircCDYL served as a miR-1270 sponge. The mitigated regulation of circCDYL knockdown for Ang II-induced injury was restored after miR-1270 downregulation. CircCDYL positively regulated ADAM10 through interacting with miR-1270. Overexpression of miR-1270 abated Ang II-induced injury by downregulating ADAM10. In conclusion, circCDYL was involved in the Ang II-induced VSMC injury in TAA via the miR-1270/ADAM10 axis.

METTL3-mediated m6A modification of NORAD inhibits the ferroptosis of vascular smooth muscle cells to attenuate the aortic dissection progression in an YTHDF2-dependent manner

Ferroptosis of vascular smooth muscle cells (VSMCs) is related to the incidence of aortic dissection (AD). Long non-coding RNA (lncRNA) NORAD plays a crucial role in the progression of various diseases. The present study aimed to investigate the effects of NORAD on the ferroptosis of VSMCs and the molecular mechanisms. The expression of NORAD, HUR, and GPX4 was detected using quantitative real-time PCR (qPCR) or western blot. Ferroptosis was evaluated by detecting lactate dehydrogenase (LDH) activity, lipid reactive oxygen species (ROS), malonaldehyde (MDA) content, L-Glutathione (GSH) level, Fe2+ content, and ferroptosis-related protein levels. The molecular mechanism was assessed using RNA pull-down, RNA-binding protein immunoprecipitation (RIP), and luciferase reporter assay. The histology of aortic tissues was assessed using H&E, elastic Verhoeff-Van Gieson (EVG), and Masson staining assays. The data indicated that NORAD was downregulated in patients with AD and AngII-treated VSMCs. Overexpression of NORAD promoted VSMC growth and inhibited the ferroptosis induced by AngII. Mechanistically, NORAD interacted with HUR, which promoted GPX4 mRNA stability and elevated GPX4 levels. Knockdown of GPX4 abrogated the effects of NORAD on cell growth and ferroptosis of AngII-treated VSMCs. Moreover, METTL3 promoted m6A methylation of NORAD in an YTHDF2-dependent manner. In addition, NORAD attenuated AAD symptoms, incidence, histopathology, inflammation, and ferroptosis in AAD mice. In conclusion, METTL3-mediated NORAD inhibited ferroptosis of VSMCs via the HUR/GPX4 axis and decelerated AAD progression, suggesting that NORAD may be an AD therapeutic target.

ONOO- Activatable Fluorescent Sulfur Dioxide Donor for a More Accurate Assessment of Cell Ferroptosis

Ferroptosis is critical in the treatment of tumor therapies. Thus, monitoring reactive oxygen species (ROS) is of great significance for accurate assessment in ferroptosis without any interference. However, current probes for monitoring ROS during ferroptosis suffer from a drawback in that the probes consume ROS during detection, which inhibits the ferroptosis process and thus affects the accuracy and effectiveness of monitoring the process of ferroptosis. Herein, a new fluorescent donor probe, TFMU-SO2D, with the combination of the moiety of the SO2 donor is designed and synthesized by introducing the aryl boronate moieties that could give it the ability to effectively recognize ONOO-. The released SO2 could consume excess glutathione and regulate oxidative stress by elevating ROS levels, which would offset the ROS depletion by TFMU-SO2D and ensure accuracy in monitoring the ferroptosis process. The experimental results demonstrated that TFMU-SO2D possessed satisfactory performance for monitoring ONOO- as well as simultaneously releasing SO2 in oxidative stress stimulated by monensin and ferroptosis stimulated by erastin and RSL3. Additionally, the capability of SO2 synergized with ferroptosis to inhibit the viability of cancer cells was demonstrated by the CCK8 assay, which may be due to the fact that SO2 can potentiate ferroptosis cell death by increasing the ROS level. Overall, these combined results indicated that TFMU-SO2D possesses the excellent ability to precisely monitor ONOO- during ferroptosis without interference, which is significant for accurately accessing ferroptosis, cancer treatment, and drug development.

Ancient dormant virus remnant ERVW-1 drives ferroptosis via degradation of GPX4 and SLC3A2 in schizophrenia

Human endogenous retroviruses (HERVs) are remnants of retroviral infections in human germline cells from millions of years ago. Among these, ERVW-1 (also known as HERV-W-ENV, ERVWE1, or ENVW) encodes the envelope protein of the HERV-W family, which contributes to the pathophysiology of schizophrenia. Additionally, neuropathological studies have revealed cell death and disruption of iron homeostasis in the brains of individuals with schizophrenia. Here, our bioinformatics analysis showed that differentially expressed genes in the human prefrontal cortex RNA microarray dataset (GSE53987) were mainly related to ferroptosis and its associated pathways. Clinical data demonstrated significantly lower expression levels of ferroptosis-related genes, particularly Glutathione peroxidase 4 (GPX4) and solute carrier family 3 member 2 (SLC3A2), in schizophrenia patients compared to normal controls. Further in-depth analyses revealed a significant negative correlation between ERVW-1 expression and the levels of GPX4/SLC3A2 in schizophrenia. Studies indicated that ERVW-1 increased iron levels, malondialdehyde (MDA), and transferrin receptor protein 1 (TFR1) expression while decreasing glutathione (GSH) levels and triggering the loss of mitochondrial membrane potential, suggesting that ERVW-1 can induce ferroptosis. Ongoing research has shown that ERVW-1 reduced the expression of GPX4 and SLC3A2 by inhibiting their promoter activities. Moreover, Ferrostatin-1 (Fer-1), the ferroptosis inhibitor, reversed the iron accumulation and mitochondrial membrane potential loss, as well as restored the expressions of ferroptosis markers GSH, MDA, and TFR1 induced by ERVW-1. In conclusion, ERVW-1 could promote ferroptosis by downregulating the expression of GPX4 and SLC3A2, revealing a novel mechanism by which ERVW-1 contributes to neuronal cell death in schizophrenia.

Ferrostatin-1 inhibits ferroptosis of vascular smooth muscle cells and alleviates abdominal aortic aneurysm formation through activating the SLC7A11/GPX4 axis

Ferroptosis, a type of iron-catalyzed necrosis, is responsible for vascular smooth muscle cell (VSMC) death and serves as a potential therapeutic target for alleviating aortic aneurysm. Here, our study explored the underlying mechanism of ferroptosis affecting VSMC functions and the resultant formation of AAA using its inhibitor Ferrostatin-1 (Fer-1). Microarray-based gene expression profiling was employed to identify differentially expressed genes related to AAA and ferroptosis. An AAA model was established by angiotensin II (Ang II) induction in apolipoprotein E-knockout (ApoE-/- ) mice, followed by injection of Fer-1 and RSL-3 (ferroptosis inducer). Then, the role of Fer-1 and RSL-3 in the ferroptosis of VSMCs and AAA formation was analyzed in Ang II-induced mice. Primary mouse VSMCs were cultured in vitro and treated with Ang II, Fer-1, sh-SLC7A11, or sh-GPX4 to assess the effect of Fer-1 via the SLC7A11/GPX axis. Bioinformatics analysis revealed that GPX4 was involved in the fibrosis formation of AAA, and there was an interaction between SLC7A11 and GPX4. In vitro assays showed that Fer-1 alleviated Ang II-induced ferroptosis of VSMCs and retard the consequent AAA formation. The mechanism was associated with activation of the SLC7A11/GPX4 pathway. Silencing of SLC7A11 or GPX4 could inhibit the ameliorating effect of Fer-1 on the ferroptosis of VSMCs. In vivo animal studies further demonstrated that Fer-1 inhibited Ang II-induced ferroptosis and vessel wall structural abnormalities in AAA mouse through activation of the SLC7A11/GPX4 pathway. Fer-1 may prevent AAA formation through activation of the SLC7A11/GPX4 pathway.

Adrenomedullin, transcriptionally regulated by vitamin D receptors, alleviates atherosclerosis in mice through suppressing AMPK-mediated endothelial ferroptosis

PURPOSE

Vitamin D receptors (VDR) play important roles in cardiovascular, immune, metabolic and other functions. Activation of VDR may help improve endothelial dysfunction, atherosclerosis, vascular calcification, and cardiac hypertrophy. However, the specific target genes and mechanisms of VDR in improving Human Umbilical Vein Endothelial Cell (HUVEC) functions remain unclear. This study aims to investigate the function and mechanism of VDR in HUVECs.

METHODS

Endothelial dysfunction cell model was constructed by oxidized low-density lipoprotein (ox-LDL). An animal model of atherosclerosis was established in male homozygous Apoe-/- mice (6 weeks) on a high fat diet for 6 weeks. The relationship between VDR and adrenomedullin (ADM) was studied by bioinformatics analysis, ChIP, and luciferase reporter gene analysis. Endothelial cell function was evaluated by Transwell migration and Tube Formation tests. Ferroptosis was detected by measuring intracellular iron content, levels of oxidative stress markers, and ferroptosis related proteins.

RESULTS

Overexpression of VDR in HUVECs inhibits ox-LDL-induced endothelial dysfunction and ferroptosis. VDR binds to the ADM promoter sequence and regulates the transcription of ADM. Inhibition of ADM promotes ox-LDL-induced endothelial dysfunction and ferroptosis. ADM regulates ox-LDL-induced endothelial dysfunction and ferroptosis through the AMPK signaling pathway. Overexpression of VDR in Apoe-/- mice inhibited lipid deposition and plaque area in atherosclerotic mice.

CONCLUSION

VDR inhibits ox-LDL-induced endothelial dysfunction and ferroptosis by regulating ADM transcription and acting on AMPK signaling pathway. Overexpression of VDR in Apoe-/- mice reduced lipid deposition and plaque area in the thoracic aorta of atherosclerotic mice.

PGAM5 expression levels in heart failure and protection ROS-induced oxidative stress and ferroptosis by Keap1/Nrf2

OBJECTIVES

As a common and frequently occurring disease, heart failure has been paid more and more attention, but the mechanism of its occurrence and development is still unclear. This study investigated that PGAM5 expression levels in heart failure and its underlying mechanisms in vivo and in vitro.

METHODS

The inhibition of PGAM5 mRNA expression levels in patients with heart failure was compared with the normal group.

RESULTS

The serum of PGAM5 mRNA expression was negative correlation with collagen I and collagen III in patients with heart failure. PGAM5 mRNA and protein expression in the heart tissue of mice with heart failure were down-regulated at a time-dependent rate. The inhibition of PGAM5 presented heart failure in the model. PGAM5 reduced inflammation and inhibited ROS-induced oxidative stress in models of heart failure. PGAM5 reduced Ferroptosis in models of heart failure. PGAM5 regulated Keap1/Nrf2 signaling pathway. IP also showed that PGAM5 protein combined with the Keap1 protein. PGAM5 could increase Keap1 protein ubiquitination. Keap1 inhibition affected the effects of PGAM5 in model of heart failure.

CONCLUSIONS

We conclude that the protection of PGAM5 reduced ROS-induced oxidative stress and ferroptosis by the Keap1/Nrf2 signaling pathway in heart failure, suggesting that targeting this mechanism of PGAM5 may be a feasible strategy to treat heart failure.

Ferroptosis in cardiac hypertrophy and heart failure

Heart failure has become a public health problem that we cannot avoid choosing to face in today's context. In the case of heart failure, pathological cardiac hypertrophy plays a major role because of its condition of absolute increase in ventricular mass under various stresses. Ferroptosis, it could be defined as regulatory mechanisms that regulate cell death in the absence of apoptosis in iron-dependent cells. This paper introduces various new research findings on the use of different regulatory mechanisms of cellular ferroptosis for the treatment of heart failure and cardiac hypertrophy, providing new therapeutic targets and research directions for clinical treatment. The role and mechanism of ferroptosis in the field of heart failure has been increasingly demonstrated, and the relationship between cardiac hypertrophy, which is one of the causes of heart failure, is also an area of research that we should focus on. In addition, the latest applications and progress of inducers and inhibitors of ferroptosis are reported in this paper, updating the breakthroughs in their fields.

Therapeutic Approaches Targeting Ferroptosis in Cardiomyopathy

The term cardiomyopathy refers to a group of heart diseases that cause severe heart failure over time. Cardiomyopathies have been proven to be associated with ferroptosis, a non-apoptotic form of cell death. It has been shown that some small molecule drugs and active ingredients of herbal medicine can regulate ferroptosis, thereby alleviating the development of cardiomyopathy. This article reviews recent discoveries about ferroptosis, its role in the pathogenesis of cardiomyopathy, and the therapeutic options for treating ferroptosis-associated cardiomyopathy. The article aims to provide insights into the basic mechanisms of ferroptosis and its treatment to prevent cardiomyopathy and related diseases.

Curdione inhibits ferroptosis in isoprenaline-induced myocardial infarction via regulating Keap1/Trx1/GPX4 signaling pathway

Myocardial infarction (MI) is a common disease with high morbidity and mortality. Curdione is a sesquiterpenoid from Radix Curcumae. The current study is aimed to investigate the protective effect and mechanism of curdione on ferroptosis in MI. Isoproterenol (ISO) was used to induce MI injury in mice and H9c2 cells. Curdione was orally given to mice once daily for 7 days. Echocardiography, biochemical kits, and western blotting were performed on the markers of cardiac ferroptosis. Curdione at 50 and 100 mg/kg significantly alleviated ISO-induced myocardial injury. Curdione and ferrostatin-1 significantly attenuated ISO-induced H9c2 cell injury. Curdione effectively suppressed cardiac ferroptosis, evidenced by decreasing malondialdehyde and iron contents, and increasing glutathione (GSH) level, GSH peroxidase 4 (GPX4), and ferritin heavy chain 1 expression. Importantly, drug affinity responsive target stability, molecular docking, and surface plasmon resonance technologies elucidated the direct target Keap1 of curdione. Curdione disrupted the interaction between Keap1 and thioredoxin1 (Trx1) but enhanced the Trx1/GPX4 complex. In addition, curdione-derived protection against ISO-induced myocardial ferroptosis was blocked after overexpression of Keap1, while enhanced after Keap1 silence in H9c2 cells. These findings demonstrate that curdione inhibited ferroptosis in ISO-induced MI via regulating Keap1/Trx1/GPX4 signaling pathway.

The Chains of Ferroptosis Interact in the Whole Progression of Atherosclerosis

Atherosclerosis (AS), a category of cardiovascular disease (CVD) that can cause other more severe disabilities, increasingly jeopardizes human health. Owing to its imperceptible and chronic symptoms, it is hard to determine the pathogenesis and precise therapeutics for AS. A novel type of programmed cell death called ferroptosis was discovered in recent years that is distinctively different from other traditional cell death pathways in morphological and biochemical aspects. Characterized by iron overload, redox disequilibrium, and accumulation of lipid hydroperoxides (L-OOH), ferroptosis influences endothelial cells, vascular smooth muscle cells (VSMCs), and macrophages, as well as inflammation, partaking in the pathology of many cardiovascular diseases such as atherosclerosis, stroke, ischemia-reperfusion injury, and heart failure. The mechanisms behind ferroptosis are so sophisticated and interwoven that many molecules involved in this procedure are unknown. This review systematically depicts the initiation and modulation of ferroptosis and summarizes the contribution of ferroptosis to AS, which may open a feasible approach for target treatment in the alleviation of AS progression.

Identication and validation of cell senescence biomarkers in idiopathic pulmonary hypertension via integrated transcriptome analyses and machine learning

BACKGROUND

Idiopathic pulmonary hypertension (IPAH) is a rare and severe disease that affects the pulmonary vasculature. As the diagnosis of IPAH requires invasive right heart catheterization surgery, early detection of this condition is notoriously challenging. Therefore, it is of utmost importance to investigate biomarkers present in peripheral blood that could aid physicians in the early identification and management of IPAH.

METHOD

We speculate that cellular senescence may be involved in the occurrence and development of IPAH through various pathways. In this study, we utilized integrated transcriptome analyses and machine learning-based approach to develop a diagnostic model for IPAH cell senescence. To select genetic features, we employed two machine learning algorithms: the Least Absolute Shrinkage and Selection Operator (LASSO) and Random Forest (RF). Additionally, we validated our findings through both external data sets and qRT-PCR experiments.

RESULTS

The resulting diagnostic nomogram was able to identify five important biomarkers that can aid in the diagnosis of IPAH, including TNFRSF1B, CCL16, GCLM, IL15, and SOD1. These genes are primarily associated with the immune system, as well as with cell senescence and apoptosis.

CONCLUSION

Our study demonstrates the utility of machine learning algorithms in making accurate diagnoses of IPAH, providing clinicians with a more directed approach to the diagnosis and treatment of this disease.

miR-432-5p Inhibits the Ferroptosis in Cardiomyocytes Induced by Hypoxia/Reoxygenation via Activating Nrf2/SLC7A11 Axis by Degrading Keap1

Early reperfusion into the myocardium after ischemia causes myocardial ischemia-reperfusion (I/R) injury and ferroptosis was involved. Ischemia activates the expression of a series of oxidative stress genes and their downstream regulatory genes, including ferroptosis-related genes such as nuclear factor E2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4), and SLC7A11. This study adopted primary cardiomyocytes and I/R in rats to evaluate the ferroptosis and changing of Nrf2-SLC7A11/heme oxygenase-1 (HO-1) in vitro and in vivo. Online analysis tools were used to predict the possible target Kelch-like ECH-associated protein 1 (Keap1) of miR-432-5p. The mimic of miR-432-5p plasmid was constructed to verify the effect of miR-432-5p on ferroptosis. We found that hypoxia/reoxygenation (H/R) in cardiomyocytes and I/R in rats induced lipid peroxidation and ferroptosis in cardiomyocytes. The activation of the Nrf2-SLC7A11/HO-1 pathway protects cardiomyocytes from ferroptosis. Downregulation of miR-432-5p has been confirmed in H/R cardiomyocytes (in vitro) and cardiomyocytes in myocardial infarction rats (in vivo). Upregulation of miR-432-5p inhibited ferroptosis of cardiomyocytes induced by RAS-selective lethal 3 (RSL3), an inhibitor of GPX4 and ferroptosis inducer through decreasing the binding protein of Nrf2, Keap1, which was confirmed by bioinformatics and mutation assay. Knockdown Nrf2 attenuates the protection effect of miR-432-5p on H/R cardiomyocytes. Intravenous delivery of liposome carriers of miR-432-5p remarkably ameliorated cardiomyocyte impairment in the I/R animal model. In conclusion, miR-432-5p inhibits the ferroptosis in cardiomyocytes induced by H/R by activating Nrf2/SLC7A11 axis by degrading Keap1 and is a potential drug target for clinical myocardial infarction treatment.

Resveratrol inhibits ferroptosis and decelerates heart failure progression via Sirt1/p53 pathway activation

Resveratrol is an organic compound widely studied for its therapeutic uses. We investigated whether resveratrol exerts cardioprotective effects by inhibiting ferroptosis via the Sirt1/p53 pathway. A heart failure model was established by aortic coarctation in Sirt1 knockout mice. The superoxide dismutase (SOD), glutathione (GSH) levels and mitochondrial morphology in murine heart tissues were assessed at different time points to determine the role of ferroptosis in heart failure progression. The cardiac function of mice with heart failure was evaluated by determining the brain natriuretic peptide (BNP) and sST2 concentration and conducting echocardiography. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were transfected with the p53 K382R mutant and Sirt1 interference lentiviral vectors. Immunoprecipitation (IP) experiments were performed to investigate whether Sirt1 influences ferroptosis via p53 K382 acetylation and SLC7A11 expression modulation. Resveratrol improved cardiac function in mice and decelerated ferroptosis and fibrosis progression in heart failure. However, the ability of resveratrol to prevent ferroptosis and treat heart failure was lost after silencing Sirt1. Sirt1 reduced ferroptosis by diminishing the levels of p53 K382 acetylation, reducing the degradation of SLC7A11, and increasing the levels of GSH and glutathione peroxidase 4 (GPX4) in cells. In conclusion, by activating the Sirt1/p53 pathway in heart failure, resveratrol decreased the depletion of SLC7A11, inhibited ferroptosis, and improved cardiac function.

Ferroptosis: a new strategy for cardiovascular disease

Cardiovascular disease (CVD) is currently one of the prevalent causes of human death. Iron is one of the essential trace elements in the human body and a vital component of living tissues. All organ systems require iron for various metabolic processes, including myocardial and skeletal muscle metabolism, erythropoiesis, mitochondrial function, and oxygen transport. Its deficiency or excess in the human body remains one of the nutritional problems worldwide. The total amount of iron in a normal human body is about 3-5 g. Iron deficiency may cause symptoms such as general fatigue, pica, and nerve deafness, while excessive iron plays a crucial role in the pathophysiological processes of the heart through ferroptosis triggered by the Fenton reaction. It differs from other cell death modes based on its dependence on the accumulation of lipid peroxides and REDOX imbalance, opening a new pathway underlying the pathogenesis and mechanism of CVDs. In this review, we describe the latest research progress on the mechanism of ferroptosis and report its crucial role and association with miRNA in various CVDs. Finally, we summarise the potential therapeutic value of ferroptosis-related drugs or ferroptosis inhibitors in CVDs.

A bibliometric analysis of myocardial ischemia/reperfusion injury from 2000 to 2023

Background

Myocardial ischemia/reperfusion injury (MIRI) refers to the more severe damage that occurs in the previously ischemic myocardium after a short-term interruption of myocardial blood supply followed by restoration of blood flow within a certain period of time. MIRI has become a major challenge affecting the therapeutic efficacy of cardiovascular surgery.

Methods

A scientific literature search on MIRI-related papers published from 2000 to 2023 in the Web of Science Core Collection database was conducted. VOSviewer was used for bibliometric analysis to understand the scientific development and research hotspots in this field.

Results

A total of 5,595 papers from 81 countries/regions, 3,840 research institutions, and 26,202 authors were included. China published the most papers, but the United States had the most significant influence. Harvard University was the leading research institution, and influential authors included Lefer David J., Hausenloy Derek J., Yellon Derek M., and others. All keywords can be divided into four different directions: risk factors, poor prognosis, mechanisms and cardioprotection.

Conclusion

Research on MIRI is flourishing. It is necessary to conduct an in-depth investigation of the interaction between different mechanisms and multi-target therapy will be the focus and hotspot of MIRI research in the future.

Age-related changes in adipose tissue metabolomics and inflammation, cardiolipin metabolism, and ferroptosis markers in female aged rat model

Aging adipose tissue exhibits elevated inflammation and oxidative stress that are major sources of age-related metabolic dysfunction. However, the exact metabolic changes associated with inflammation and oxidative stress are unclear. To address this topic, we assessed variation in metabolic phenotypes of adipose tissue from 18 months adult sedentary (ASED), 26 months old sedentary (OSED), and 8 months young sedentary (YSED). The results of metabolomic analysis showed that ASED and OSED group had higher palmitic acid, elaidic acid, 1-heptadecanol, and α-tocopherol levels than YSED, but lower sarcosine levels. Furthermore, stearic acid was specifically elevated in ASED compared with YSED. Cholesterol was upregulated specifically in the OSED group compared with YSED, whereas linoleic acid was downregulated. In addition, ASED and OSED had more inflammatory cytokines, lower antioxidant capacity, and higher expression of ferroptosis-related genes than YSED. Moreover, mitochondrial dysfunction associated with abnormal cardiolipin synthesis was more pronounced in the OSED group. In conclusion, both ASED and OSED can affect the FA metabolism and increase oxidative stress in adipose tissue, leading to inflammation. In particular, linoleic acid content specifically decreases in OSED, which associated with abnormal cardiolipin synthesis and mitochondrial dysfunction in adipose tissue.

Curcumin Attenuates Periodontal Injury via Inhibiting Ferroptosis of Ligature-Induced Periodontitis in Mice

Periodontitis is a chronic infectious disease characterized by the destruction of connective tissue and alveolar bone that eventually leads to tooth loss. Ferroptosis is an iron-dependent regulated cell death and is involved in ligature-induced periodontitis in vivo. Studies have demonstrated that curcumin has a potential therapeutic effect on periodontitis, but the mechanism is still unclear. The purpose of this study was to investigate the protective effects of curcumin on alleviating ferroptosis in periodontitis. Ligature-induced periodontal-diseased mice were used to detect the protective effect of curcumin. The level of superoxide dismutase (SOD), malondialdehyde (MDA) and total glutathione (GSH) in gingiva and alveolar bone were assayed. Furthermore, the mRNA expression levels of acsl4, slc7a11, gpx4 and tfr1 were measured using qPCR and the protein expression of ACSL4, SLC7A11, GPX4 and TfR1 were investigated by Western blot and immunocytochemistry (IHC). Curcumin reduced the level of MDA and increased the level of GSH. Additionally, curcumin was proven to significantly increase the expression levels of SLC7A11 and GPX4 and inhibit the expression of ACSL4 and TfR1. In conclusion, curcumin plays a protective role by inhibiting ferroptosis in ligature-induced periodontal-diseased mice.

The role of ferroptosis in metabolic diseases

The annual incidence of metabolic diseases such as diabetes, non-alcoholic fatty liver disease (NAFLD), osteoporosis, and atherosclerosis (AS) is increasing, resulting in a heavy burden on human health and the social economy. Ferroptosis is a novel form of programmed cell death driven by iron-dependent lipid peroxidation, which was discovered in recent years. Emerging evidence has suggested that ferroptosis contributes to the development of metabolic diseases. Here, we summarize the mechanisms and molecular signaling pathways involved in ferroptosis. Then we discuss the role of ferroptosis in metabolic diseases. Finally, we analyze the potential of targeting ferroptosis as a promising therapeutic approach for metabolic diseases.

PCSK9, a novel immune and ferroptosis related gene in abdominal aortic aneurysm neck

The gene expression profile of abdominal aortic aneurysm (AAA) neck is not fully understood. The etiology of AAA is considered to be related to atherosclerosis and the inflammatory response, involving congenital, genetic, metabolic, and other factors. The level of proprotein convertase subtilisin/kexin type 9 (PCSK9) is related to those of cholesterol, oxidized low-density lipoprotein, and triglycerides. PCSK9 inhibitors have significant effects on lowering LDL-cholesterol, reversing atherosclerotic plaques, and reducing the risk of cardiovascular events and have been approved by several lipid-lowering guidelines. This work was aimed to investigate the potential role of PCSK9 in the neck of AAA. We extracted the expression dataset (GSE47472) containing 14 AAA patients and 8 donors and single-cell RNAseq (scRNA-seq) data (GSE164678) of CaCl2-induced (AAA) samples from the Gene Expression Omnibus dataset. Through bioinformatics methods, we found that PCSK9 was up-regulated in the proximal neck of human AAA. In AAA, PCSK9 was mainly expressed in fibroblasts. Additionally, immune check-point PDCD1LG2 was also expressed higher in AAA neck than donor, while CTLA4, PDCD1, and SIGLEC15 were down-regulated in AAA neck. The expression of PCSK was correlated with PDCD1LG2, LAG3, and CTLA4 in AAA neck. Additionally, some ferroptosis-related genes were also down-regulated in AAA neck. PCSK9 was also correlated with ferroptosis-related genes in AAA neck. In conclusion, PCSK9 was highly expressed in AAA neck, and may exert its role through interacting with immune check-points and ferroptosis-related genes.

Ferrostatin-1 mitigates ionizing radiation-induced intestinal injuries by inhibiting apoptosis and ferroptosis: an in vitro and in vivo study

PURPOSE

Intestinal injuries caused by ionizing radiation (IR) are a major complication of radiotherapy. Ferrostatin-1 (Fer-1) exerts antioxidant and anti-inflammatory effects. We investigated the influence of Fer-1 on IR-induced intestinal damage and explored the possible mechanisms.

MATERIALS AND METHODS

IEC-6 cells were administrated with Fer-1 for 30 min and subsequently subjected to 9.0 Gy-irradiation. Flow cytometry, qPCR, and WB were used to detect changes. For in vivo experiments, Fer-1 was given intraperitoneally to mice at 1 h before and 24 h after 9.0 Gy total body irradiation (TBI) respectively. Three days after TBI, the small intestines were isolated for analysis. The diversity and composition of the gut microbiota were analyzed by 16S rRNA gene sequencing.

RESULTS

In vitro, Fer-1 protected IEC-6 cells from IR injury by reducing the production of ROS and inhibiting both ferroptosis and apoptosis. In vivo, Fer-1 enhanced the survival rates of mice subjected to lethal doses of IR and restored intestinal structure and physiological function. Further investigation showed that Fer-1 protected IEC-6 cells and mice by inhibiting the p53-mediated apoptosis signaling pathway and restoring the gut-microbe balance.

CONCLUSION

This study confirms that Fer-1 protects intestinal injuries through suppressing apoptosis and ferroptosis.

Chinese traditional formula Kaixin San suppressed ferroptosis of hippocampal neurons and cardiomyocytes in mice with paradoxical sleep deprivation

ETHNOPHARMACOLOGICAL RELEVANCE

Kaixin San (KXS) is one of the most famous traditional Chinese formulas prescribed by Sun Simiao in 652 Christian era. It is composed of Panax ginseng C.A.Mey, Polygala tenuifolia, Poria cocos and Acorus calamus var. angustatus Besser. KXS is widely used for the treatment of emotion-thought disease, such as settling fright, quieting the spirit and nourishing the heart. However, whether KXS benefits hippocampal neurons and myocardial cells of mice impaired by paradoxical sleep deprivation (PSD) and its mechanism remains unclear.

AIM OF THE STUDY

This study was aimed to investigate the effect of KXS on hippocampal neuron and cardiac ferroptosis in rapid-eye-movement (REM) sleep deprived mice and clarify its potential mechanism.

MATERIALS AND METHODS

PSD was induced by a modified multi-platform method. Morris water maze (MWM) was used to detect the ability of learning and memory. Cardiac morphological changes were assessed by hematoxylin and eosin (HE) staining. Heart rate was detected by a PowerLab multichannel physiological recorder. Serum levels of atrial natriuretic peptide (ANP) and lactate dehydrogenase (LDH) were measured with biochemical kits. Transmission electron microscopy (TEM), immunofluorescent, and Western blotting analysis were used to observe the process and pathway of ferrotosis in hippocampus tissue and heart tissue of PSD mice.

RESULTS

KXS administration improved the impaired learning and memory of PSD mice. It prevented the damage of mitochondria in the hippocampus and heart of PSD mice. KXS also alleviated the myocardial injury, such as morphological damage, abnormal heart rate, serum ANP, and serum LDH induced by PSD. Further study disclosed that KXS reversed the expressions of proteins involved in ferroptosis such as TFRC, SLC7A11/xCT, GPX-4, ACSL4, and FTH1 in hippocampus and heart tissues.

CONCLUSIONS

KXS improved learning and memory of mice with REM sleep deprivation, which was closely associated with suppressed ferroptosis in hippocampal neurons and myocardiocytes.

G-Quadruplex Structures as a "Switch" Regulate ATF4 Expression in Ferroptotic HepG2 Cells

G-quadruplex (G4) is a noncanonical structure folded in a widespread manner by guanine-rich tandem repeated sequences. As a key response factor, activating transcription factor 4 (ATF4) has dual functions in managing iron-dependent ferroptosis by regulating amino acid synthesis and antioxidant-related gene expression. In our study, the activity of ATF4 expression was elevated in HepG2 cells induced by erastin. Based on preliminary bioinformatics analyses, the G-tract region, named WT, had high potential to form G4, and it was found that PDS could markedly weaken the increase of ATF4 expression by reducing the sensitivity of HepG2 cells toward erastin. In circular dichroism spectra, WT oligonucleotides showed characteristic molar ellipticity at specific wavelengths of parallel G4 structures, while corresponding single-base mutants possessed a weaker ability to form G4, which were consistent with immunostaining results. In addition, endogenous G4 formed by the WT motif was significantly destroyed in HepG2 cells treated with erastin. After being transfected with WT oligonucleotides, the levels of ATF4 mRNA decreased significantly regardless of being treated with erastin or not. Meanwhile, mutations of G-tracts could advantageously impact the luciferase expression downstream of an ATF4 promoter in reporter assays, manifesting that the decrease of endogenous G4 in the ATF4 promoter was positively associated with the expression enhanced by erastin in HepG2 cells.

SiNPs induce ferroptosis in HUVECs through p38 inhibiting NrF2 pathway

Introduction

Despite of growing evidence linking silica nanoparticles (SiNPs), one of the global-top-three-produced and -used nanoparticle (NP), to human health risks, there remain many knowledge gaps over the adverse effects of SiNPs exposure on cardiovascular system and the underlying molecular mechanisms.

Methods

In this study, the ferroptotic effects of SiNPs (20 nm; 0, 25, 50, and 100 μg/mL) on human umbilical vein endothelial cells (HUVECs) and the possible molecular mechanism were studied with the corresponding biochemical and molecular biology assays.

Results and discussion

The results showed that at the tested concentrations, SiNPs could decrease HUVEC viability, but the deferoxamine mesylate (an iron ion chelator) might rescue this reduction of cell viability. Also, increased levels of intracellular reactive oxygen species and enhanced mRNA expression of lipid oxidation enzymes (ACSL4 and LPCAT3) with increase in lipid peroxidation (malondialdehyde), but decreased ratios of intracellular GSH/total-GSH and mitochondrial membrane potential as well as reduced enzymatic activities of anti-oxidative enzymes (CAT, SOD, and GSH-PX), were found in the SiNPs-treated HUVECs. Meanwhile, increase in p38 protein phosphorylation and decrease in NrF2 protein phosphorylation with reduced mRNA expressions of downstream anti-oxidative enzyme genes (CAT, SOD1, GSH-PX, and GPX4) was identified in the SiNPs-exposed HUVECs. These data indicated that SiNPs exposure might induce ferroptosis in HUVECs via p38 inhibiting NrF2 pathway. Ferroptosis of HUVECs will become a useful biomarker for assessing the cardiovascular health risks of environmental contaminants.

Ferroptosis: roles and molecular mechanisms in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a serious complication of type 1 and type 2 diabetes, which leads to the aggravation of myocardial fibrosis, disorders involving systolic and diastolic functions, and increased mortality of patients with diabetes through mechanisms such as glycolipid toxicity, inflammatory response, and oxidative stress. Ferroptosis is a form of iron-dependent regulatory cell death that is attributed to the accumulation of lipid peroxides and an imbalance in redox regulation. Increased production of lipid reactive oxygen species (ROS) during ferroptosis promotes oxidative stress and damages myocardial cells, leading to myocardial systolic and diastolic dysfunction. Overproduction of ROS is an important bridge between ferroptosis and DCM, and ferroptosis inhibitors may provide new targets for the treatment of patients with DCM.