Copper homeostasis and cuproptosis in health and disease

Copper homeostasis and neurodegenerative diseases

Copper, one of the most prolific transition metals in the body, is required for normal brain physiological activity and allows various functions to work normally through its range of concentrations. Copper homeostasis is meticulously maintained through a complex network of copper-dependent proteins, including copper transporters (CTR1 and CTR2), the two copper ion transporters the Cu -transporting ATPase 1 (ATP7A) and Cu-transporting beta (ATP7B), and the three copper chaperones ATOX1, CCS, and COX17. Disruptions in copper homeostasis can lead to either the deficiency or accumulation of copper in brain tissue. Emerging evidence suggests that abnormal copper metabolism or copper binding to various proteins, including ceruloplasmin and metallothionein, is involved in the pathogenesis of neurodegenerative disorders. However, the exact mechanisms underlying these processes are not known. Copper is a potent oxidant that increases reactive oxygen species production and promotes oxidative stress. Elevated reactive oxygen species levels may further compromise mitochondrial integrity and cause mitochondrial dysfunction. Reactive oxygen species serve as key signaling molecules in copper-induced neuroinflammation, with elevated levels activating several critical inflammatory pathways. Additionally, copper can bind aberrantly to several neuronal proteins, including alpha-synuclein, tau, superoxide dismutase 1, and huntingtin, thereby inducing neurotoxicity and ultimately cell death. This study focuses on the latest literature evaluating the role of copper in neurodegenerative diseases, with a particular focus on copper-containing metalloenzymes and copper-binding proteins in the regulation of copper homeostasis and their involvement in neurodegenerative disease pathogenesis. By synthesizing the current findings on the functions of copper in oxidative stress, neuroinflammation, mitochondrial dysfunction, and protein misfolding, we aim to elucidate the mechanisms by which copper contributes to a wide range of hereditary and neuronal disorders, such as Wilson's disease, Menkes' disease, Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis. Potential clinically significant therapeutic targets, including superoxide dismutase 1, D-penicillamine, and 5,7-dichloro-2-[(dimethylamino)methyl]-8-hydroxyquinoline, along with their associated therapeutic agents, are further discussed. Ultimately, we collate evidence that copper homeostasis may function in the underlying etiology of several neurodegenerative diseases and offer novel insights into the potential prevention and treatment of these diseases based on copper homeostasis.

Responsive plasmonic hybrid nanorods enables metabolism reprogramming via cuproptosis-photothermal combined cancer therapy

Abnormal tumor metabolism leads to tumor growth, metastasis, and recurrence, reprogramming tumor metabolism and activating potent anti-tumor immune response have been demonstrated to have good therapeutic effects on tumor elimination. Copper-based nanomaterials involved in cuproptosis show great prospects in these two aspects, but their efficiency is restricted by Cu homeostasis and the toxicity of the chelator. Here, the pH-responsive AuNRs@Cu2O core-shell plasmonic hybrid nanorods (ACNRs) have been successfully fabricated to realize microenvironment-controlled release at the tumor site for the combined therapy of cuproptosis and photothermal treatment. The AuNRs core exhibited excellent NIR-II photothermal property, which boost the intracellular concentration of copper to trigger severe cuproptosis and induce immunogenic cell death of tumor cells. In vivo studies demonstrated the ACNR exhibited efficient tumor therapy for primary, metastatic, and recurrent tumors. ACNRs-induced cuproptosis and PTT were capable of reprogramming energy metabolism, leading to a decreased production of lactic acid. This potential of metabolic reprogramming assisted in reshaping the immunosuppressive tumor microenvironment to facilitate the infiltration of immune cells and boost the immune responses triggered by PTT. The therapeutic mechanism was further verified by metabolomics analysis, which indicated that ACNRs + PTT treatment led to the inhibition of the Pentose Phosphate Pathway and Glycolysis pathways in tumor cells. The suppression of glycolytic reduced ATP synthesis, thereby hindering energy-dependent copper efflux, which in turn promoted cuproptosis. Taken together, this study offers promising insights for cuproptosis-based cancer treatment and sheds new light on nanomedicine-mediated metabolic modulation for future tumor therapy.

Engineering M2 macrophage-derived exosomes modulate activated T cell cuproptosis to promote immune tolerance in rheumatoid arthritis

Nanomedicines for immune modulation have made advancements in the treatment of rheumatoid arthritis (RA). However, due to aberrations in patients' immune systems, inducing antigen-specific immune tolerance while halting disease progression remains a significant challenge. Here, we develop a highly targeted multifunctional nanocomplex, termed M2Exo@CuS-CitP-Rapa (M2CPR), with the aim of selectively inhibiting inflammatory immune reactions while promoting immune tolerance towards specific antigens. M2CPR specifically targets inflammatory tissues in RA, delivering CuS NPs, CitP, Rapa, and endogenous anti-inflammatory factors, thereby ameliorating the inflammatory joint microenvironment. CuS NPs induce Cuproptosis of activated T cells, whose fragments are engulfed by resident or recruited macrophages, resulting in abundant production of TGF-β. TGF-β acts synergistically with Rapa to induce the iDCs into tDCs. tDCs present CitP to Naive T cells, promoting Tregs differentiation. Tregs, in turn, produce more TGF-β, inducing tDCs differentiation, thereby establishing a cycle of immune tolerance. Through in vitro and in vivo experiments, we validate that M2CPR can induce robust and durable antigen-specific immune tolerance, offering a new paradigm for RA therapy.

pH-responsive and nanoenzyme-loaded artificial nanocells relieved osteomyelitis efficiently by synergistic chemodynamic and cuproptosis therapy

Osteomyelitis is an osseous infectious disease that primarily affects children and the elderly with high morbidity and recurrence. The conventional treatments of osteomyelitis contain long-term and high-dose systemic antibiotics with debridements, which are not effective and lead to antibiotic resistance with serious side/adverse effects in many cases. Hence, developing novel antibiotic-free interventions against osteomyelitis (especially antibiotic-resistant bacterial infection) is urgent and anticipated. Here, a bone mesenchymal stem cell membrane-constructed nanocell (CFE@CM) was fabricated against osteomyelitis with the characteristics of acid-responsiveness, hydrogen peroxide self-supplying, enhanced chemodynamic therapeutic efficacy, bone marrow targeting and cuproptosis induction. Notably, mRNA sequencing was applied to unveil the underlying biological mechanisms and found that the biological processes related to copper ion binding, oxidative phosphorylation, peptide biosynthesis and metabolism, etc., were disturbed by CFE@CM in bacteria. This work provided an innovative antibiotic-free strategy against osteomyelitis through copper-enhanced Fenton reaction and distinct cuproptosis, promising to complement the current insufficient therapeutic regimen in clinic.

Interactions between ferroptosis and tumour development mechanisms: Implications for gynaecological cancer therapy (Review)

Ferroptosis is a form of programmed cell death that is distinct from apoptosis. The mechanism involves redox‑active metallic iron and is characterized by an abnormal increase in iron‑dependent lipid reactive oxygen species, which results in high levels of membrane lipid peroxides. The relationship between ferroptosis and gynaecological tumours is complex. Ferroptosis can regulate tumour proliferation, metastasis and chemotherapy resistance, and targeting ferroptosis is a promising antitumour approach. Ferroptosis interacts with mechanisms related to tumorigenesis and development, such as macrophage polarization, the neutrophil trap network, mitochondrial autophagy and cuproptosis. The present review examines recent information on the interaction between the molecular mechanism of ferroptosis and other tumour‑related mechanisms, as well as the involvement of ferroptosis in gynaecological tumours, to identify implications for gynaecological cancer therapy.

Unc5b prevents macrophage-derived foam cell migration and promotes atherosclerotic development via the P53-cuproptosis signaling pathway

BACKGROUND

Atherosclerosis involves the buildup of macrophage-derived foam cells in the arterial intima. Facilitating the egress of these cells from plaques can significantly slow disease progression. The transmembrane receptor Unc5b, a vascular-specific axon guidance receptor, is upregulated in foam cells, and inhibits their migration from the plaques. However, the mechanisms underlying Unc5b's regulation of foam cell production and retention within plaques, along with its downstream signaling pathways, remain insufficiently understood.

METHODS

We employed both a foam cell model and an ApoE-deficient mouse model of atherosclerosis to evaluate these effects. Western blotting, RT-PCR, wound healing assays, and immunofluorescence staining were performed to explore the role of Unc5b in foam cell migration.

RESULTS

Unc5b played a role in advancing atherosclerosis by regulating the P53-cuproptosis pathway, thereby inhibiting the migration of foam cells. Stimulation of Raw264.7 cells with oxidized low-density lipoprotein (ox-LDL) resulted in increased cuproptosis and inflammation, impacting migration regulation. Macrophage-derived foam cell migration was prevented by Unc5b via the P53-cuproptosis signaling pathway. Notably, PFT-α (a P53 inhibitor) and VI (a Cu2+ chelator) counteracted the inhibitory effect of ox-LDL on migration. Similarly, upregulation of cuproptosis-related proteins was observed within the aortic sinus plaques of ApoE-/- mice fed a hyperlipidemic diet. Importantly, the progression of atherosclerosis induced by a hyperlipidemic diet can be effectively reversed by PFT-α and VI.

CONCLUSION

These findings underscore Unc5b's role in promoting inflammation, inhibiting macrophage migration, and promoting atherosclerotic development via the P53-cuproptosis signaling pathway.

Taxifolin regulates SLC31A1-mediated cuproptosis and tumor progression in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary malignant neoplasm exhibiting a high mortality rate. Taxifolin is a naturally occurring flavonoid compound that exhibits a range of pharmacological properties. The effects of taxifolin on HCC remain largely unexplored. Therefore, the aim of this study was to examine the potential roles of taxifolin in the development and progression of HCC. In this study, CCK-8 assay was utilized to examine the impact of taxifolin on the cell viability. The copper ions level and the activity of mitochondrial respiratory chain were determined by the correspondent kits. The biological properties of HCC cells were evaluated using colony formation, transwell, flow cytometry, and TUNEL assays, respectively. Transcriptome sequencing was carried out either with or without taxifolin treatment. The expression of cuproptosis-related proteins was determined by Western blot. We observed significant decrease of cell viability, Glutathione (GSH), and mitochondrial respiratory chain under the treatment of taxifolin, while an increase of copper ions level. Taxifolin was observed to suppress HCC progression both in vitro and in vivo. The intersection analysis was performed between upregulated genes and cuproptosis-related genes to obtain one intersection gene-SLC31A1. The knockdown of SLC31A1 reversed the tumor-suppressive effects induced by taxifolin. Taxifolin inhibited HCC progression through inducing cuproptosis in an SLC31A1-mediated manner.

Copper homeostasis and Cuprotosis: Exploring novel therapeutic strategies for connective tissue diseases

Copper is an indispensable element for human health, with its balance being critical to prevent the onset of diseases, particularly those affecting connective tissues. Imbalances in copper levels can lead to pathological alterations. Research indicates that copper supplements and chelators hold promise for the treatment of certain conditions, yet the precise mechanisms by which copper imbalances and the cell death mechanism known as cuprotosis contribute to connective tissue diseases remain elusive. This paper delves into the potential role of copper imbalance and cuprotosis in connective tissue diseases and evaluates the underlying cellular mechanisms. The goal is to offer practical insights into targeted therapies for dysregulated copper metabolism, with the aim of devising novel strategies for the treatment of connective tissue diseases.

Metal Ion Signaling in Biomedicine

Complex multicellular organisms are composed of distinct tissues involving specialized cells that can perform specific functions, making such life forms possible. Species are defined by their genomes, and differences between individuals within a given species directly result from variations in their genetic codes. While genetic alterations can give rise to disease-causing acquisitions of distinct cell identities, it is now well-established that biochemical imbalances within a cell can also lead to cellular dysfunction and diseases. Specifically, nongenetic chemical events orchestrate cell metabolism and transcriptional programs that govern functional cell identity. Thus, imbalances in cell signaling, which broadly defines the conversion of extracellular signals into intracellular biochemical changes, can also contribute to the acquisition of diseased cell states. Metal ions exhibit unique chemical properties that can be exploited by the cell. For instance, metal ions maintain the ionic balance within the cell, coordinate amino acid residues or nucleobases altering folding and function of biomolecules, or directly catalyze specific chemical reactions. Thus, metals are essential cell signaling effectors in normal physiology and disease. Deciphering metal ion signaling is a challenging endeavor that can illuminate pathways to be targeted for therapeutic intervention. Here, we review key cellular processes where metal ions play essential roles and describe how targeting metal ion signaling pathways has been instrumental to dissecting the biochemistry of the cell and how this has led to the development of effective therapeutic strategies.

Post-Functionalization of Fluorinated Dibenzosulfone-Based Conjugated Polymer for Smart 'Turn-off' Sensing of Cu2+ Ions

Post-functionalization of conjugated polymeric backbone with various N-containing heterocycles through nucleophilic aromatic substitution reaction (SNAr) demonstrates crucial tailoring of their photophysical properties. This study explores an approach of post-polymerization modification of a fluorinated dibenzosulfone-based conjugated polymer aiming to incorporate functional groups having coordinating sites to bind metal ions. The resulting polymers, namely BDT-DBTS-IM, BDT-DBTS-TR, and BDT-DBTS-PY revealed successful substitution reactions with imidazole, triazole, and pyridine respectively, and showed significant changes in their absorption and emission properties. Notably, BDT-DBTS-IM demonstrated exceptional performance as a chemosensor, exhibiting a dramatic fluorescence turn-off response specifically to copper ions (Cu2+) with the limit of detection of 26 nM and Stern-Volmer quenching constant (KSV) of 8.2×105 Lmol-1. This high selectivity and sensitivity are attributed to the ability of the imidazole group to form a stable complex with Cu2+, resulting in both static and dynamic quenching efficiently. Our findings underscore the potential of post-polymerization modifications to significantly enhance the functionality of conjugated polymers. The ability of BDT-DBTS-IM to detect trace levels of copper ions with high precision highlights its practical utility in environmental and biological monitoring. This research not only demonstrates an approach for post-polymeric modification through SNAr reaction but also opens new avenues for developing sensors.

Recent Advances in Nanomaterial-Mediated Cell Death for Cancer Therapy

Nanomedicine has shown great anticancer potential by disrupting redox homeostasis and increasing the levels of oxidative stress, but the therapeutic effect is limited by factors including the intrinsic self-protection mechanism of tumors. Cancer cell death can be induced by the exploration of different cell death mechanisms, such as apoptosis, pyroptosis, necroptosis, cuproptosis, and ferroptosis. The merging of nanotechnology with biomedicine has provided tremendous opportunities to construct cell death-based nanomedicine for innovative cancer therapy. Nanocarriers are not only used for the targeted delivery of cell death inducers, but also as therapeutic components to induce cell death to achieve efficient tumor treatment. This review focuses on seven cell death modalities mediated by nanomaterials, such as apoptosis, pyroptosis, necroptosis, ferroptosis, cuprotosis, immunogenic cell death, and autophagy. The mechanisms of these seven cell death modalities are described in detail, as well as the preparation of nanomaterials that induce them and the mechanisms, they used to exert their effects. Finally, this work describes the potential future development based on the current knowledge related to cell death induced by nanomaterials.

Abnormalities in copper status associated with diminished ovarian reserve: A case-control and cross-sectional study

OBJECTIVE

This study aimed to illustrate the copper status of diminished ovarian reserve in Chinese women, especially the effects of copper, ceruloplasmin, non-ceruloplasmin-bound copper (NCC) and CuZn superoxide dismutase (SOD1).

METHODS

This case-control, cross-sectional investigation included women with diminished ovarian reserve (DOR group, n = 35) and matched normal ovarian reserve (NOR group, n = 35). The serum levels of copper, ceruloplasmin, NCC, SOD1, follicle-stimulating hormone, luteinizing hormone, estradiol, testosterone, and anti-Müllerian hormone were tested and analyzed.

RESULTS

The serum copper concentrations (60.88%), NCC (54.75%) and SOD1 (54.75%) in the DOR group were significantly higher than those in the NOR group (all P < 0.001), and the concentrations of the three markers were higher in most subgroups (P < 0.001). The correlation analysis verified the correlation between copper status and impaired ovarian function. Additionally, linear regression analysis showed that NCC and SOD1 levels were negatively correlated with anti-Müllerian hormone (P < 0.05 or 0.001).

CONCLUSION

Our exploration found significant increases in copper, NCC and SOD1 levels in DOR and suggests a possible link. Copper status is expected to serve as the predictive marker for DOR.

Identification and validation of cuproptosis-related genes for diagnosis and therapy in nonalcoholic fatty liver disease

In recent years, nonalcoholic fatty liver disease (NAFLD) has become a more serious public health issue worldwide. This study strived to investigate the molecular mechanism of pathogenesis of NAFLD and explore promising diagnostic and therapeutic targets for NAFLD. Raw data from GSE130970 were downloaded from the Gene Expression Omnibus database. We used the dataset to analyze the expression levels of cuproptosis-related genes in NAFLD patients and healthy controls to identify the differentially expressed cuproptosis-related genes (DECRGs). The relationship and potential mechanism between DECRGs and clinicopathological factors were examined by enrichment analysis and two consensus clustering methods. We screened key DECRGs based on Random Forest (RF), and then verified the key DECRGs in NAFLD patients, high-fat diet (HFD)-fed mice, and palmitic acid-induced AML12 cells. ROC analysis showed good diagnostic function of DECRGs in normal and NAFLD liver tissue. Two consensus clusters indicated the important role of cuproptosis in the development of NAFLD. We screened for key DECRGs (DLD, DLAT) based on RF and found a close relationship between the DECRGs and clinicopathological factors. We collected clinical blood samples to verify the differences in gene expression levels by qPCR. In addition, we further verified the expression levels of DLD and DLAT in HFD mice and AML12 cells, which showed the same results. This study provides a novel perspective on the pathogenesis of NAFLD. We identified two cuproptosis-related genes that are closely related to NAFLD. These genes may play a significant role in the molecular pathogenesis of NAFLD, which may be useful to make progress in the diagnosis and treatment of NAFLD.

Assessing antioxidant responses in C6 and U-87 MG cell lines exposed to high copper levels

Copper excess has been tested as an anticancer therapy, due to its properties to generate oxidative stress resulting in tumoral cell death. Thus, this study aimed to evaluate the impact of copper excess on oxidative stress and antioxidant responses in glioma cells, establishing the antioxidant system as a target of copper toxicity in tumoral cells. C6 and U-87 MG cells were exposed to CuSO4 (0-600 μM) for 24-48 h. SOD, CAT, GPx, GR, and CK activities, protein and non-protein thiol levels (PSH and NPSH), and O2- production were assessed, alongside SOD1, GPx1, and GR gene expression. Results revealed a decrease in GPx, GR, and CAT activity after CuSO4 exposure in both cell lines over 24-48 h, while SOD activity initially increased, then declined after 48 h. CK activity was also decreased in C6 cells. NPSH and PSH levels dropped after 24 h, and O2- production was observed in all CuSO4 concentrations. GR mRNA was reduced in both cell lines, contrasting with increased GPx1 mRNA in C6. U-87 MG cells exhibited higher levels of SOD1 mRNA, while C6 cells displayed lower expression. Our findings suggest that copper excess limits antioxidant enzyme activity and thiol levels, particularly in the C6 cells, likely attributable to oxidative stress or direct copper-enzyme interactions. Moreover, our results imply differences in copper toxicity regarding the cell lineage used, highlighting the importance of analyzing high copper levels effects in different models. Moreover, it could be proposed that the antioxidant system is a target of copper toxicity, contributing to glioma cell death.

Understanding Cu+2 binding with DNA: A molecular dynamics study comparing Cu2+ and Mg2+ binding to the Dickerson DNA

Cu2+ ions led DNA damage by reactive oxygen species (ROS) is widely known biological phenomena. The ionic radii of Cu2+ and Mg2+ being similar, the binding of Cu2+ ions to DNA is expected to be similar to that of the Mg2+ ions. However, little is known how Cu2+ ions bind in different parts (phosphate, major and minor grooves) of a double-strand (ds) DNA, especially at atomic level. In the present study, we employ molecular dynamic (MD) simulations to investigate the binding of Cu2+ ions with the Dickerson DNA, a B-type dodecamer double stranded (ds) DNA. The binding characteristics of Cu2+ and Mg2+ ions with this dsDNA are compared to get an insight into the differences and similarities in binding behavior of both ions. Unlike Mg2+ ions, the first hydration shell of Cu2+ is found to be labile, thus it shows both direct and indirect binding with the dsDNA, i.e., binding through displacement of water from the hydration shell or through the hydration shell. Though the binding propensity of Cu2+ ions with dsDNA is observed relatively stronger, the binding order to phosphates, major groove, and minor groove is found qualitatively similar (phosphates > major groove > minor groove) for both ions. The study gives a deep understanding of Cu2+ binding to DNA, which could be helpful in rationalizing the Cu2+ led ROS-mediated DNA damage.

Endoplasmic reticulum stress induced autophagy in cancer and its potential interactions with apoptosis and ferroptosis

The endoplasmic reticulum (ER) is a dynamic organelle that is a site of the synthesis of proteins and lipids, contributing to the regulation of proteostasis, lipid metabolism, redox balance, and calcium storage/-dependent signaling events. The disruption of ER homeostasis due to the accumulation of misfolded proteins in the ER causes ER stress which activates the unfolded protein response (UPR) system through the activation of IRE1, PERK, and ATF6. Activation of UPR is observed in various cancers and therefore, its association with process of carcinogenesis has been of importance. Tumor cells effectively utilize the UPR system to overcome ER stress. Moreover, ER stress and autophagy are the stress response mechanisms operating together to maintain cellular homeostasis. In human cancers, ER stress-driven autophagy can function as either pro-survival or pro-death in a context-dependent manner. ER stress-mediated autophagy can have crosstalk with other types of cell death pathways including apoptosis and ferroptosis. In this connection, the present review has evaluated the role of ER stress in the regulation of autophagy-mediated tumorigenesis and its interactions with other cell death mechanisms such as apoptosis and ferroptosis. We have also comprehensively discussed the effect of ER stress-mediated autophagy on cancer progression and chemotherapeutic resistance.

Effect of Cu- and Fe- Isolated from Environmental Particulate Matter on Mitochondrial Dynamics in Human Colon CaCo-2 Cells

Atmospheric particulate matter (PM) is one of the most dangerous air pollutants of anthropogenic origin; it consists of a heterogeneous mixture of inorganic and organic components, including transition metals and polycyclic aromatic hydrocarbons. Although previous studies have focused on the effects of exposure to highly concentrated PM on the respiratory and cardiovascular systems, emerging evidence supports a significant impact of air pollution on the gastrointestinal (GI) tract by linking exposure to external stressors with conditions such as appendicitis, colorectal cancer, and inflammatory bowel disease. In general, it has been hypothesized that the main mechanism involved in PM toxicity consists of an inflammatory response and this has also been suggested for the GI tract. In the present study, we analyzed the effect of specific redox-active PM components, such as copper (Cu) and iron (Fe), in human intestinal cells focusing on ultrastructural integrity, redox homeostasis, and modulation of some mitochondrial-related markers. According to our results, exposure to Cu- and Fe-PM components and their combination induced ultrastructural alterations in the endoplasmic reticulum and in the mitochondria with an additive effect when combined. The increase in ROS and the loss of the mitochondrial mass in the cells exposed to PM indicates that mitochondria are a target of acute metal exposure. Furthermore, the gene expression and the protein levels of mitochondria dynamics markers were affected by the PM exposure. In particular, OPA1 increases at both gene and protein levels in all conditions while Mitofusin1 decreases significantly only in the presence of Fe. The increase in PINK expression is modulated by Fe, while Cu seems to affect mainly Parkin. Finally, a significant decrease in trans-epithelial resistance was also observed. In general, our study can confirm the correlation observed between pollution exposure areas and increased incidence of GI tract conditions.

Identifying the NEAT1/miR-26b-5p/S100A2 axis as a regulator in Parkinson's disease based on the ferroptosis-related genes

OBJECTIVES

Parkinson's disease (PD) is a complex neurodegenerative disease with unclear pathogenesis. Some recent studies have shown that there is a close relationship between PD and ferroptosis. We aimed to identify the ferroptosis-related genes (FRGs) and construct competing endogenous RNA (ceRNA) networks to further assess the pathogenesis of PD.

METHODS

Expression of 97 substantia nigra (SN) samples were obtained and intersected with FRGs. Bioinformatics analysis, including the gene set enrichment analysis (GSEA), consensus cluster analysis, weight gene co-expression network analysis (WGCNA), and machine learning algorithms, were employed to assess the feasible differentially expressed genes (DEGs). Characteristic signature genes were used to create novel diagnostic models and construct competing endogenous RNA (ceRNA) regulatory network for PD, which were further verified by in vitro experiments and single-cell RNA sequencing (scRNA-seq).

RESULTS

A total of 453 DEGs were identified and 11 FRGs were selected. We sorted the entire PD cohort into two subtypes based on the FRGs and obtained 67 hub genes. According to the five machine algorithms, 4 features (S100A2, GNGT1, NEUROD4, FCN2) were screened and used to create a PD diagnostic model. Corresponding miRNAs and lncRNAs were predicted to construct a ceRNA network. The scRNA-seq and experimental results showed that the signature model had a certain diagnostic effect and lncRNA NEAT1 might regulate the progression of ferroptosis in PD via the NEAT1/miR-26b-5p/S100A2 axis.

CONCLUSION

The diagnostic signatures based on the four FRGs had certain diagnostic and individual effects. NEAT1/miR-26b-5p/S100A2 axis is associated with ferroptosis in the pathogenesis of PD. Our findings provide new solutions for treating PD.

Development of a prognostic gene signature and exploration of P4HA1 in the modulation of cuproptosis in colorectal cancer

Cuproptosis, a newly identified form of cell death, has drawn increasing attention for its association with various cancers, though its specific role in colorectal cancer (CRC) remains unclear. In this study, transcriptomic and clinical data from CRC patients available in the TCGA database were analyzed to investigate the impact of cuproptosis. Differentially expressed genes linked to cuproptosis were identified using Weighted Gene Co-Expression Network Analysis (WGCNA). Key genes were further refined through LASSO regression and random forest approaches, culminating in the development of a prognostic model comprising six critical genes. The predictive accuracy of the model was validated using two independent external datasets. This model effectively stratified patients into high- and low-risk groups, which exhibited significant differences in disease stage, immune landscape, tumor mutational burden, and therapeutic response, underscoring the robustness of the model. P4HA1 was identified as a key gene of interest, where downregulation was found to inhibit tumor progression in single-cell sequencing analyses and in vitro experiments. Additionally, suppression of P4HA1 enhanced the sensitivity of CRC cells to the cuproptosis inducer elesclomol (ES), potentially through oxidative stress mechanisms. In conclusion, this study proposes a prognostic model based on six cuproptosis-related genes that could aid in personalizing CRC treatment. Furthermore, P4HA1 emerges as a promising therapeutic target.

Application of autophagy in mesenchymal stem cells

In this editorial, we have taken an in-depth look at the article published by Wan et al. The study showed that preconditioning mesenchymal stem cells (MSCs) protected them against programmed cell death, and increased their survival rate and therapeutic potential. Autophagy, a type of programmed cell death, is a major intracellular degradation and recycling pathway that is crucial for maintaining cellular homeostasis, self-renewal, and pluripotency. We have explored the relationship between autophagy and MSCs to determine the role of autophagy in the therapeutic applications of MSCs.

Targeting CDK1 and copper homeostasis in breast cancer via a nanopolymer drug delivery system

The prevalence of breast cancer (BRCA) is notable in the female population, being a commonly diagnosed malignancy, where the management of copper levels is crucial for treatment success. This research aims to explore the influence of copper homeostasis on BRCA therapy, with a specific focus on the role of Cyclin-Dependent Kinase 1 (CDK1) and its relationship to copper regulation. A novel thermosensitive hydrogel incorporating nanoparticles (NPs) was engineered to synergize with the chemotherapy drug vincristine (VCR) in inhibiting tumor growth and metastasis. Through a comprehensive approach involving bioinformatics analyses, in vitro experiments, and in vivo models, the study identified CDK1 as a significant factor in BRCA progression under copper homeostasis. MBVP-Gel, a novel thermosensitive hydrogel incorporating NPs, was developed to enhance the delivery of chemotherapy drugs and regulate copper homeostasis in breast cancer treatment. The MBVP-Gel, formulated with copper chelation and VCR NPs, effectively suppressed CDK1 expression, thereby restraining BRCA cell growth and metastasis while enhancing the therapeutic impact of VCR. This investigation offers fresh insights and experimental validation on the interaction between copper homeostasis and BRCA, providing a valuable foundation for refining future treatment strategies. These findings underscore the potential advantages of targeting copper homeostasis and CDK1 in enhancing BRCA therapy, setting the stage for individualized interventions and improved patient consequences.

Janus PEGylated CuS-engineered Lactobacillus casei combats biofilm infections via metabolic interference and innate immunomodulation

Bacterial implant-associated infections predominantly contribute to the failure of prosthesis implantation. The local biofilm microenvironment (BME), characterized by its hyperacidic condition and high hydrogen peroxide (H2O2) level, inhibits the host's immune response, thereby facilitating recurrent infections. Here, a Janus PEGylated CuS nanoparticle (CuPen) armed engineered Lactobacillus casei (L. casei) denoted as LC@CuPen, is proposed to interfere with bacterial metabolism and arouse macrophage antibiofilm function. Once LC@CuPen reached the BME, NIR irradiation-activated mild heat damages L. casei and biofilm structure. Meanwhile, the BME-responsive LC@CuPen can catalyze local H2O2 to produce toxic •OH, whereas in normal tissues, the effect of •OH production is greatly reduced due to the higher pH and lower H2O2 concentration. The released bacteriocin from damaged L. casei can destroy the bacterial membrane to enhance the penetration of •OH into damaged biofilm. Excessive •OH interferes with normal bacterial metabolism, resulting in reduced resistance of bacteria to heat stress. Finally, under the action of mild heat treatment, the bacterial biofilm lysed and died. Furthermore, the pathogen-associated molecular patterns (PAMPs) in LC@CuPen can induce M1 polarization of macrophages through NF-κB pathway and promote the release of inflammatory factors. Inflammatory factors enhance the migration of macrophages to the site of infection and phagocytose bacteria, thereby inhibiting the recurrence of infection. Generally, this engineered L. casei program presents a novel perspective for the treatment of bacterial implant-associated infections and serves as a valuable reference for future clinical applications of engineered probiotics.

Cuproptosis: A new mechanism for anti-tumour therapy

As an indispensable trace metal element in the organism, copper acts as a key catalytic cofactor in a wide range of biological processes. Copper homeostasis disorders can be caused by either copper excess or deficiency, and copper homeostasis disorders will affect the normal physiological functions of cells and induce cell death through a variety of mechanisms, such as the emerging cuproptosis model. The imbalance of copper homeostasis will lead to the occurrence of cancer, and copper is a key factor in cell signalling, so copper is involved in the development of cancer by promoting cell proliferation, angiogenesis and metastasis, etc. The therapeutic role of Cuproptosis as a hotspot of research in cancer has also attracted much attention. Therefore, this paper comprehensively searches the literature to review the roles and mechanisms of Cuproptosis in the treatment of malignant tumours, aiming to provide new insights into the role and mechanism of Cuproptosis in anti-malignant tumour therapy and present novel ideas and methods.

Novel insights into cuproptosis in alcoholic liver disease using bioinformatics analysis and experimental validation

Cuproptosis is crucial in the development of various liver diseases, yet its involvement in alcoholic liver disease (ALD) remains poorly understood. In this study, we screened cuproptosis-related genes (CRGs) regulating ALD and explored their potential molecular mechanisms. Bioinformatic methods were employed to screen CRGs in ALD, analyze their functional enrichment, signaling pathways, transcriptional regulation, relationship with the immune microenvironment and pathogenic genes, and corresponding single nucleotide polymorphism pathogenic regions, and construct transcription factor-miRNA-mRNA networks. Liver tissues from patients with ALD and NIAAA model mice were collected and assessed for copper deposition. CRG expression in the livers of patients was analyzed using RNA sequencing. CRG expression in liver tissues was also analyzed using RNA sequencing and verified using quantitative polymerase chain reaction (RT-qPCR), western blotting, and immunofluorescence. Dihydrolipoamide S-acetyltransferase (DLAT), glutaminase (GLS), and cyclin-dependent protein kinase inhibitor 2A (CDKN2A) were identified as potential ALD-associated CRGs with significant diagnostic value. Consistent with the results of bioinformatics analysis, these genes were notably upregulated in liver tissues from both patients with ALD and NIAAA model mice. All three ALD-associated CRGs were regulated by E2F transcription factor 1 (E2F1) and showed a significant negative correlation with the expression of ADH1B and ALDH2, key enzymes in alcohol metabolism. They were positively correlated with PI3K/AKT/mTOR, IFN-γ response, and complement signaling pathways but negatively correlated with bile acid and xenobiotic metabolism. This study identified DLAT, GLS, and CDKN2A as the ALD-associated CRGs, providing valuable insights into their molecular mechanisms in ALD pathogenesis, which may inform diagnosis and treatment.

Assembly of a biomimetic copper-based nanocomplex for alleviating hypoxia to enhance cuproptosis against osteosarcoma and lung metastasis

Osteosarcoma tissues demonstrated elevated expression of proteins (FDX1 and DLAT) integral to cuproptosis in our preliminary study, indicating the potential effectiveness of anti-tumor strategies predicated on this process. Nevertheless, the overexpression of copper export proteins and the challenge of copper ion penetration may contribute to insufficient local copper ion concentration for inducing cuproptosis. Herein, we engineered a biomimetic copper-elesclomol-polyphenol network for the efficient delivery of copper ions and the copper ionophore elesclomol. Simultaneously, we integrated catalase (CAT) to alleviate tumor hypoxia, thereby inducing a greater reliance of tumor cells on aerobic respiration and enhancing cuproptosis sensitivity. In vitro analyses revealed that the nanocomplex exhibited potent cytotoxicity and displayed hallmark characteristics of cuproptosis. In vivo trials further validated targeted tumor accumulation, resulting in the suppression of tumor growth and lung metastasis. An augmentation in the proportion of activated immune cells in both tumor and draining lymph nodes was observed. The improvement of immunosuppressive microenvironment facilitated a synergistic antitumor effect with cuproptosis. The therapeutic efficacy was further evidenced in two osteosarcoma models, highlighting the potential as a safe and effective strategy against osteosarcoma and lung metastasis. STATEMENT OF SIGNIFICANCE: Osteosarcoma tissues exhibit a marked increase in the expression of proteins FDX1 and DLAT, which are crucial for cuproptosis. Moreover, cells that depend on mitochondrial respiration are more susceptible to cuproptosis. Here we developed a biomimetic copper-based nanocomplex to trigger cuproptosis against osteosarcoma and lung metastases. The nanocomplex demonstrated excellent biocompatibility and tumor targeting. Catalase incorporating facilitated oxygen generation within tumor microenvironment and alleviated hypoxia, thereby inducing a greater reliance of tumor cells on aerobic respiration and enhancing cuproptosis sensitivity. Simultaneously, the released Cu-elesclomol complexes induced proteotoxic stress responses and efficiently elicited cuproptosis, leading to increased release of proinflammatory factors and triggering anti-tumor immune activation. Our strategy holds promise for osteosarcoma treatment by inducing cuproptosis and achieving potent tumor suppression.

Cuproptosis: a promising new target for breast cancer therapy

Breast cancer (BC) is the leading cause of cancer-related mortality among women globally, affecting approximately one-quarter of all female cancer patients and accounting for one-sixth of cancer-related deaths in women. Despite significant advancements in diagnostic and therapeutic approaches, breast cancer treatment remains challenging due to issues such as recurrence and metastasis. Recently, a novel form of regulated cell death, termed cuproptosis, has been identified. This process disrupts mitochondrial respiration by targeting the copper-dependent cellular pathways. The role of cuproptosis has been extensively investigated in various therapeutic contexts, including chemotherapy, immunotherapy, radiotherapy, and nanotherapy, with the development of novel drugs significantly improving clinical outcomes. This article aims to further elucidate the connection between cuproptosis and breast cancer, focusing on its therapeutic targets, signaling pathways, and potential biomarkers that could enhance treatment strategies. These insights may offer new opportunities for improved patient care and outcomes in breast cancer therapy.

Cross-talk between cuproptosis and ferroptosis to identify immune landscape in cervical cancer for mRNA vaccines development

Messenger RNA (mRNA)-based vaccines present a promising avenue for cancer immunotherapy; however, their application in cervical cancer remains unexplored. This study investigated the interplay between the regulated cell death pathways of cuproptosis and ferroptosis to advance the development of mRNA vaccines for cervical cancer. We identified key cuproptosis-related and ferroptosis-related genes (CFRGs) from public mRNA profiles and determined their prognostic significance, mutation frequencies, and effect on the immune landscape. Our analysis revealed two distinct subtypes of cervical cancer associated with CFRGs, with differences in prognosis and immune characteristics. Using LASSO, XGBoost, and SVM-RFE methods, we established a 4-gene prognostic signature (TSC22D3, SQLE, ZNF419, and TFRC) to stratify patients based on their risk and determine its correlation with immune microenvironment, mutation profiles, and treatment responses. RT-qPCR validation confirmed the differential expression of these genes in clinical samples. Our findings identify TSC22D3, SQLE, ZNF419, and TFRC as candidate targets for mRNA vaccine development and offer a potential prognostic tool for personalized cervical cancer treatment.

Heterojunction Nanozyme Hydrogels Containing Cu-O-Zn Bonds with Strong Charge Transfer for Accelerated Diabetic Wound Healing

The complex microenvironment of persistent inflammation and bacterial infection is a major challenge in chronic diabetic wounds. The development of nanozymes capable of efficiently scavenging reactive oxygen species (ROS) is a promising method to promote diabetic wound healing. However, many nanozymes show rather limited antioxidant activity and ROS-dependent antibacterial effects under certain circumstances, further weakening their ability to scavenge ROS. To meet these challenges, electronically regulated bioheterojunction (E-bio-HJ) nanozyme hydrogels derived from metal-organic frameworks (MOFs) were designed and prepared via an interface engineering strategy. Owing to the electron transfer and redistribution effects of the abundant and highly dispersed Cu-O-Zn sites at the heterogeneous interface, the E-bio-HJ nanozymes exhibited catalase (CAT)-like activity with ultrahigh hydrogen peroxide affinity (Km = 25.76 mM) and sustained ROS consumption. In addition, owing to the enhanced interfacial effect of E-bio-HJ and the good biocompatibility and cell adhesion of the methacryloylated gelatin (Gel) hydrogel, the E-bio-HJ gelatin hydrogel (E-bio-HJ/Gel) further reduced inflammation by inducing macrophage transformation to the M2 phenotype, accompanied by excellent antimicrobial properties and enhanced cell migration, angiogenesis, and collagen deposition, which synergistically promoted diabetic wound healing. This highly effective and comprehensive strategy offers a new approach for the rapid healing of diabetic wounds.

Synergistic SDT/cuproptosis therapy for liver hepatocellular carcinoma: enhanced antitumor efficacy and specific mechanisms

The efficacy of sonodynamic therapy (SDT), an emerging approach for tumor treatment, is hindered by the high levels of the antioxidant glutathione (GSH) in the tumor microenvironment (TME). In this study, we constructed nanobubbles loaded with the sonosensitizer HMME and the tumor-targeting peptide RGD (HMME-RGD@C3F8 NBs) for synergistic SDT/cuproptosis therapy of liver hepatocellular carcinoma (LIHC) in combination with Elesclomol-Cu as cuproptosis inducers. Endogenous GSH is consumed by Cu2+ to modulate the complex TME, thereby amplifying oxidative stress and further improving SDT performance. Additionally, intracellular Cu2+ overload can induce cuproptosis, which is further amplified by SDT, to initiate irreversible protein toxicity. The specific mechanism of synergistic SDT/cuproptosis therapy in LIHC was investigated by RNA sequencing analysis. The synergistic SDT/cuproptosis therapy reprogrammed the TME to improve the efficacy of immune checkpoint inhibitor-based immunotherapy. Furthermore, a risk-scoring model was created and displayed significant promise in the prognosis of LIHC.

Hippo-YAP signaling alleviates copper-induced mitochondrial dysfunction and oxidative damage via the ATOX1-PPA2 pathway

Hippo signaling plays a crucial role in the cellular response to various stressors, such as mechanical stress, metabolic stress, and hypoxic stress. However, its physiological significance in copper (Cu) stress remains poorly understood. Here, we demonstrated aberrant activation of Hippo-YAP signaling in sheep pancreas and pancreatic organoids exposed to excessive Cu, accompanied by significant pathological changes, elevated levels of oxidative stress, and impaired mitochondrial structure and function. The inhibition of Hippo signaling or overexpression of YAP protected against Cu-induced damage by improving mitochondrial function and maintaining cellular Cu homeostasis. YAP interacted with TEAD and upregulated the expression of Cu chaperone ATOX1, a key regulator of intracellular Cu homeostasis. ATOX1 restored mitochondrial function under Cu stress by reducing mitochondrial superoxide levels, increasing ATP production and mitochondrial membrane potential. Additionally, our findings confirmed that ATOX1 indirectly bound to the PPA2 promoter and increased its transcription. Notably, the restoration of ATP production in mitochondria mediated by PPA2 overexpression facilitated efficient intracellular Cu efflux, allowing rapid and precise reestablishment of intracellular Cu homeostasis under Cu stress. Collectively, Hippo-YAP signaling alleviates Cu-induced oxidative damage by restoring mitochondrial function through activation of PPA2 transcription depending on ATOX1, thereby ensuring cellular Cu efflux and enhancing antioxidant capacity.

A highly-sensitive fluorescent probe for the detection of copper ions and its applications in water quality monitoring, neural cell imaging and plant imaging

High copper levels pose a risk to environmental and human health due to their toxicity and widespread industrial application, in which abnormal copper levels are associated with various diseases both in neurodegenerative diseases and plant growth. Thus, a turn-on fluorescent probe BBYD-Cu, based on donor-acceptor type structure, was designed and synthesized with easy preparations. BBYD-Cu can specifically recognized Cu2+ by 2-picolinic ester group, then released the fluorophore to enhance the fluorescent signals. With a detection limit of 31 nM, it displays extremely sensitive and precise Cu2+ detection. In addition, BBYD-Cu has the advantages of fast response speed (within 3 min), excellent selectivity and strong anti-interference ability for Cu2+. Significantly, the BBYD-Cu demonstrates superior detection and imaging performance even in intricate real-world environmental samples, biological nerve cells and plant soybean sprout root tissue.

Large Language Model-Assisted Genotoxic Metal-Phenolic Nanoplatform for Osteosarcoma Therapy

Osteosarcoma, a leading primary bone malignancy in children and adolescents, is associated with a poor prognosis and a low global fertility rate. A large language model-assisted phenolic network (LLMPN) platform is demonstrated that integrates the large language model (LLM) GPT-4 into the design of multifunctional metal-phenolic network materials. Fine-tuned GPT-4 identified gossypol as a phenolic compound with superior efficacy against osteosarcoma after evaluating across a library of 60 polyphenols based on the correlation between experimental anti-osteosarcoma activity and multiplexed chemical properties of polyphenols. Subsequently, gossypol is then self-assembled into Cu2+-gossypol nanocomplexes with a hyaluronic acid surface modification (CuGOS NPs). CuGOS NPs has demonstrated the ability to induce genetic alterations and cell death in osteosarcoma cells, offering significant therapeutic benefits for primary osteosarcoma tumors and reducing metastasis without adverse effects on major organs or the genital system. This work presents an LLM-driven approach for engineering metal-organic nanoplatform and broadening applications by harnessing the capabilities of LLMs, thereby improving the feasibility and efficiency of research activities.

Cuproptosis-related gene ATOX1 promotes MAPK signaling and diffuse large B-cell lymphoma proliferation via modulating copper transport

Diffuse Large B-cell lymphoma (DLBCL) is a common subtype of non-Hodgkin lymphoma, highlighting the importance of studying susceptibility genes to develop personalized treatment strategies. While cuproptosis, caused by high levels of copper ions induced by ionophores, has been shown to affect cancer survival, its specific role in lymphoma is not yet clear. To investigate the involvement of upregulation-related genes in DLBCL, we employed bioinformatics techniques. Specifically, we analyzed the differentially expressed genes (DEGs) in the GSE25638 dataset using Weighted Gene Co-expression Network Analysis (WGCNA) and performed functional enrichment analysis. By building a Protein-Protein Interaction (PPI) network, candidate genes were identified. Gene Set Enrichment Analysis (GSEA) and Receiver Operating Characteristic (ROC) curve analysis were used to confirm the clinical diagnostic use of these genes. The effects of Antioxidant 1 (ATOX1) knockdown, CuCl2, and DCAC50 treatments on DLBCL cells and the activation of the Mitogen-Activated Protein Kinase (MAPK) pathway were investigated by conducting in vitro experiments. Bioinformatics and in vitro experiments confirmed elevated expression of ATOX1 in DLBCL cells and tumor samples. ATOX1 knockdown led to decreased cell proliferation and G2 cell cycle arrest in vitro. Additionally, Phosphorylated Extracellular Signal-Regulated Kinases 1 and 2 (P-ERK1/2) protein levels within the MAPK pathway were reduced as a result of ATOX1 knockdown, but these levels were recovered by CuCl2. Treatment with DCAC50 showed a dose-dependent antiproliferative effect in DLBCL cells, which was strengthened by ATOX1 knockdown. Our study demonstrated that ATOX1 may be important in DLBCL via controlling the MAPK pathway through copper transport, providing new insights into potential therapeutic strategies for DLBCL.

Exploration and breakthrough in the mode of intervertebral disc cell death may lead to significant advances in treatments for intervertebral disc degeneration

Low back pain caused by intervertebral disc degeneration (IDD) has emerged as a significant global public health concern, with far-reaching consequences for patients' quality of life and healthcare systems. Although previous research have revealed that the mechanisms of intervertebral disc cell apoptosis, pyroptosis and necroptosis can aggravate IDD damage by mediating inflammation and promoting extracellular matrix degradation, but they cannot explain the connection between different cell death mechanisms and ion metabolism disorders. The latest study shows that cell death mechanisms such as cellular senescence, ferroptosis, and cuproptosis, and PANopotosis have similar roles in the progression of intervertebral disc degeneration, but not exactly the same damage mechanism. This paper summarizes the effects of various cell death patterns on the disease progression of IDD, related molecular mechanisms and signaling pathways, providing new perspectives and potential clinical intervention strategies for the prevention and treatment of IDD.

Biological and pharmacological roles of pyroptosis in pulmonary inflammation and fibrosis: recent advances and future directions

Pyroptosis, an inflammatory regulated cell death (RCD) mechanism, is characterized by cellular swelling, membrane rupture, and subsequent discharge of cellular contents, exerting robust proinflammatory effects. Recent studies have significantly advanced our understanding of pyroptosis, revealing that it can be triggered through inflammasome- and caspase-independent pathways, and interacts intricately with other RCD pathways (e.g., pyroptosis, necroptosis, ferroptosis, and cuproptosis). The pathogenesis of pulmonary fibrosis (PF), including idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases, involves a multifaceted interplay of factors such as pathogen infections, environmental pollutants, genetic variations, and immune dysfunction. This chronic and progressive interstitial lung disease is characterized by persistent inflammation, extracellular matrix (ECM) accumulation, and fibrotic alveolar wall thickening, which potentially contribute to deteriorated lung function. Despite recent advances in understanding pyroptosis, the mechanisms by which it regulates PF are not entirely elucidated, and effective strategies to improve clinical outcomes remain unclear. This review strives to deliver a comprehensive overview of the biological functions and molecular mechanisms of pyroptosis, exploring its roles in the pathogenesis of PF. Furthermore, it examines potential biomarkers and therapeutic agents for anti-fibrotic treatments.

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.

Cu(II) Stability and UV-Induced Electron Transfer in a Metal-Organic Hybrid: An EPR, DFT, and Crystallographic Characterization of Copper-Doped Zinc Creatininium Sulfate

Single-crystal X-ray diffraction and electron paramagnetic resonance (EPR) spectroscopic experiments, complemented by quantum chemical DFT calculations, were carried out on the copper-doped metal-organic hybrid and Tutton salt analogue zinc creatininium sulfate to determine its crystal structure, to characterize the electronic structure of the doped Cu(II) binding site, and to propose a pathway for an excited-state, proton-coupled electron transfer (PCET) process in UV-exposed crystals. The crystal structure is isomorphous to that of cadmium creatininium sulfate, which has the transition ion, not in direct coordination with the creatinine, but forming a hexahydrate complex, which is bridged to a creatininium through an intervening sulfate ion. The EPR g (2.446, 2.112, 2.082) and copper hyperfine (ACu: -327, -59.6, 10.8 MHz) tensor parameters are consistent with doped copper replacing host zinc in the metal-hexahydrate complex. These parameters are similar to those observed for copper hexahydrate in doped Tutton salt systems at low temperature, where the unpaired electron occupies mainly the copper 3dx2-y2 orbital. At room temperature in the Tutton systems, vibration couplings stemming from a dynamic Jahn-Teller effect cause tensor averaging which results in a reduction in their maximum g-tensor and hyperfine tensor values. However, like for the doped isomorphous Cd creatinine crystal, the Cu(II) EPR exhibits little, or no room temperature averaging compared to its low temperature pattern. Samples exposed to 254 nm UV light generate a carbon-centered free radical species, characterized by an isotropic g-tensor (g = 2.0029) and an alpha-proton hyperfine coupling (-24 -14 +4 G). These parameters identify it as a creatinine radical cation formed by the oxidative release of one of its C2 methylene hydrogens. DFT calculations confirm the unpaired electronic structures of both the Cu(II) site and free radical. The growth in radical concentration with an increase in the UV exposure time coincides with a decrease in the copper EPR signal, indicating a coupled light-induced oxidation reduction process. A comparison of the crystal structure with the EPR parameters and DFT results provides evidence for a UV-induced PCET.

A Smart Nanomedicine Unleashes a Dual Assault of Glucose Starvation and Cuproptosis to Supercharge αPD-L1 Therapy

Combination therapy has become a promising strategy for promoting the outcomes of anti-programmed death ligand-1 (αPD-L1) therapy in lung cancer. Among all, emerging strategies targeting cancer metabolism have shown great potency in treating cancers with immunotherapy. Here, alteration in glucose and copper metabolisms is found to synergistically regulate PD-L1 expression in lung cancer cells. Thus, an intelligent biomimetic nano-delivery system is synthesized by camouflaging lung cancer cell membranes onto glucose oxidase-loaded Cu-LDHs (CMGCL) for cancer metabolism targeted interference. Such novel nanomedicine is able to induce lung cancer cell cuproptosis and PD-L1 upregulation significantly via self-amplified cascade reactions. Meanwhile, with a decent cancer cell membrane coating, CMGCL exhibited great biosafety, tumor-targeted efficiency and anti-tumor effects in LLC lung tumor-bearing mice models. Additionally, a combination of CMGCL can sensitize the therapeutic effects of αPD-L1, substantially promoting tumor inhibition in both subcutaneous and lung metastasis LLC-bearing mice models. Overall, these findings highlight the potential connections between glucose metabolism and cell cuproptosis, offering a promising approach for treating lung cancer by integrating starvation, cuproptosis, and immunotherapy.

Cuproptosis in cancer therapy: mechanisms, therapeutic application and future prospects

Cuproptosis is a regulated form of cell death induced by the accumulation of metal ions and is closely linked to aspects of cellular drug resistance, cellular metabolism, and signalling pathways. Due to its crucial role in regulating physiological and pathological processes, cuproptosis has gained increasing significance as a potential target for anticancer drug development. In this review, we introduce the definition of cuproptosis and provide a comprehensive discussion of the mechanisms of cuproptosis. In addition, the methods for the detection of cuproptosis are summarized, and recent advances in cuproptosis in cancer therapy are reviewed, mainly in terms of elesclomol (ES)-mediated cuproptosis and disulfiram (DSF)-mediated cuproptosis, which provided practical value for applications. Finally, the current challenges and future development of cuproptosis-mediated cancer therapy are discussed. In summary, this review highlights recent progress on cuproptosis in cancer therapy, offering novel ideas and strategies for future research and applications.

Targeting cuproptosis with nano material: new way to enhancing the efficacy of immunotherapy in colorectal cancer

Colorectal cancer has emerged as one of the predominant malignant tumors globally. Immunotherapy, as a novel therapeutic methodology, has opened up new possibilities for colorectal cancer patients. However, its actual clinical efficacy requires further enhancement. Copper, as an exceptionally crucial trace element, can influence various signaling pathways, gene expression, and biological metabolic processes in cells, thus playing a critical role in the pathogenesis of colorectal cancer. Recent studies have revealed that cuproptosis, a novel mode of cell death, holds promise to become a potential target to overcome resistance to colorectal cancer immunotherapy. This shows substantial potential in the combination treatment of colorectal cancer. Conveying copper into tumor cells via a nano-drug delivery system to induce cuproptosis of colorectal cancer cells could offer a potential strategy for eliminating drug-resistant colorectal cancer cells and vastly improving the efficacy of immunotherapy while ultimately destroy colorectal tumors. Moreover, combining the cuproptosis induction strategy with other anti-tumor approaches such as photothermal therapy, photodynamic therapy, and chemodynamic therapy could further enhance its therapeutic effect. This review aims to illuminate the practical significance of cuproptosis and cuproptosis-inducing nano-drugs in colorectal cancer immunotherapy, and scrutinize the current challenges and limitations of this methodology, thereby providing innovative thoughts and references for the advancement of cuproptosis-based colorectal cancer immunotherapy strategies.

Iridium(III) Photosensitizers Induce Simultaneous Pyroptosis and Ferroptosis for Multi-Network Synergistic Tumor Immunotherapy

The integration of pyroptosis and ferroptosis hybrid cell death induction to augment immune activation represents a promising avenue for anti-tumor treatment, but there is a lack of research. Herein, we developed two iridium (III)-triphenylamine photosensitizers, IrC and IrF, with the capacity to disrupt redox balance and induce photo-driven cascade damage to DNA and Kelch-like ECH-associated protein 1 (KEAP1). The activation of the absent in melanoma 2 (AIM2)-related cytoplasmic nucleic acid-sensing pathway, triggered by damaged DNA, leads to the induction of gasdermin D (GSDMD)-mediated pyroptosis. Simultaneously, iron homeostasis, regulated by the KEAP1/nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase 1 (HO-1) pathway, serves as a pivotal bridge, facilitating not only the induction of gasdermin E (GSDME)-mediated non-canonical pyroptosis, but also ferroptosis in synergy with glutathione peroxidase 4 (GPX4) depletion. The collaborative action of pyroptosis and ferroptosis generates a synergistic effect that elicits immunogenic cell death, stimulates a robust immune response and effectively inhibits tumor growth in vivo. Our work introduces the first metal-based small molecule dual-inducers of pyroptosis and ferroptosis for potent cancer immunotherapy, and highlights the significance of iron homeostasis as a vital hub connecting synergistic effects of pyroptosis and ferroptosis.

Copper and its isotopes: a brief overview of its implications in geology, environmental system, and human health

Copper, a malleable and ductile transition metal, possesses two stable isotopes. These copper isotopic composition data have recently found diverse applications in various fields and disciplines. In geology, copper isotopes serve as tracers that aid in investigating ore formation processes and the mechanisms of copper deposits Likewise, it has emerged as a valuable tracer in polluted environments. In plant biology, copper acts as an essential micronutrient crucial for photosynthesis, respiration, and growth. Copper isotopes contribute to understanding how plants uptake and dispense copper from the soil within their tissues. Similarly, in animals, copper serves as an essential trace element, playing a vital role in growth, white blood cell function, and enzyme activity. In humans, copper acts as an antioxidant, neutralising harmful free radicals within the body. It also helps in maintaining the nervous and immune system. Furthermore, copper isotopes find medical applications, particularly in cancer diagnostics, neurodegenerative diseases, and targeted radiotherapy. However, excessive copper can have detrimental effects in humans such as it can cause liver damage, nausea, and abdominal pain, whilst in plants it can affect the growth of plants, photosynthesis, and membrane permeability. This review emphasises the significance of copper and its isotopes in geology, the environment, and human health.

Imbalanced and Unchecked: The Role of Metal Dyshomeostasis in Driving COPD Progression

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition characterized by persistent inflammation and oxidative stress, which ultimately leads to progressive restriction of airflow. Extensive research findings have cogently suggested that the dysregulation of essential transition metal ions, notably iron, copper, and zinc, stands as a critical nexus in the perpetuation of inflammatory processes and oxidative damage within the lungs of COPD patients. Unraveling the intricate interplay between metal homeostasis, oxidative stress, and inflammatory signaling is of paramount importance in unraveling the intricacies of COPD pathogenesis. This comprehensive review aims to examine the current literature on the sources, regulation, and mechanisms by which metal dyshomeostasis contributes to COPD progression. We specifically focus on iron, copper, and zinc, given their well-characterized roles in orchestrating cytokine production, immune cell function, antioxidant depletion, and matrix remodeling. Despite the limited number of clinical trials investigating metal modulation in COPD, the advent of emerging methodologies tailored to monitor metal fluxes and gauge responses to chelation and supplementation hold great promise in unlocking the potential of metal-based interventions. We conclude that targeted restoration of metal homeostasis represents a promising frontier for ameliorating pathological processes driving COPD progression.

Crosstalk Between Cell Death and Spinal Cord Injury: Neurology and Therapy

Spinal cord injury (SCI) often leads to neurological dysfunction, and neuronal cell death is one of the main causes of neurological dysfunction. After SCI, in addition to necrosis, programmed cell death (PCD) occurs in nerve cells. At first, studies recognized only necrosis, apoptosis, and autophagy. In recent years, researchers have identified new forms of PCD, including pyroptosis, necroptosis, ferroptosis, and cuproptosis. Related studies have confirmed that all of these cell death modes are involved in various phases of SCI and affect the direction of the disease through different mechanisms and pathways. Furthermore, regulating neuronal cell death after SCI through various means has been proven to be beneficial for the recovery of neural function. In recent years, emerging therapies for SCI have also provided new potential methods to restore neural function. Thus, the relationship between SCI and cell death plays an important role in the occurrence and development of SCI. This review summarizes and generalizes the relevant research results on neuronal necrosis, apoptosis, autophagy, pyroptosis, necroptosis, ferroptosis, and cuproptosis after SCI to provide a new understanding of neuronal cell death after SCI and to aid in the treatment of SCI.

In situ hydrogel based on Cu-Fe3O4 nanoclusters exploits oxidative stress and the ferroptosis/cuproptosis pathway for chemodynamic therapy

Chemodynamic therapy (CDT) involving the use of metal nanozymes presents new opportunities for the treatment of deep-seated tumors. However, the lower ROS catalytic rate and dependence on high H2O2 concentrations affect therapeutic efficacy. To address this issue, a hydrogel was constructed for the treatment of osteosarcoma by combining Cu-Fe3O4 nanozymes (NCs) and artemisinin (AS) coencapsulated in situ with sodium alginate (ALG) and calcium ions. This hydrogel can release nanoparticles and AS within tumor tissue for an extended period of time, utilizing the multienzyme activity of NCs to achieve ROS accumulation. The carbon radicals (•C) generated from the interaction of Fe2+/Cu2+ with AS amplify oxidative stress, leading to tumor cell damage. Simultaneously, the NCs activate ferroptosis via the GPX4 pathway by depleting GSH and activate cuproptosis via the DLAT pathway by causing intracellular copper overload, enhancing therapeutic efficacy. In vitro experiments confirmed that the NCs-AS-ALG hydrogel has an excellent tumor cell killing effect, while in vivo experimental results demonstrated that it can effectively eliminate tumors with excellent biocompatibility, providing a new approach for osteosarcoma treatment.

A cuproptosis nanocapsule for cancer radiotherapy

Residual tumours that persist after radiotherapy often develop acquired radiation resistance, increasing the risk of recurrence and metastasis while providing obstacles to re-irradiation. Using samples from patients and experimental mice, we discovered that FDX1 and LIAS, key regulators of cuproptosis, were up-regulated in residual tumours following radiotherapy, conferring the increased sensitivity to cuproptosis. Therefore, we proposed a novel radiosensitization strategy focused on cuproptosis, using a copper-containing nanocapsule-like polyoxometalate as a paradigm. In an initial demonstration, we showed that the nanocapsule released copper ions in a controlled manner upon exposure to ionizing radiation. Furthermore, radiation-triggered cuproptosis overcame acquired radiation resistance even at clinically relevant radiation doses and activated a robust abscopal effect, with a 40% cure rate in both radioresistant and re-irradiation tumour models. Collectively, targeting cuproptosis is a compelling strategy for addressing acquired radiation resistance, optimizing the local antitumour effects of radiotherapy while simultaneously activating systemic antitumour immunity.

Pitaya-Inspired Metal-Organic Framework Nanozyme for Multimodal Imaging-Guided Synergistic Cuproptosis, Nanocatalytic Therapy, and Photothermal Therapy

Nature often provides invaluable insights into technological innovation and the construction of nanomaterials. Inspired by the pitaya fruit's strategy of wrapping seeds within its pulp to enhance seed survival, a unique nanocomposite based on metal-organic framework (MOF)-encapsulated CuS nanoparticles (NPs) is developed. This design effectively addresses the challenge of short retention time afforded by CuS NPs for therapeutic and imaging purposes. The MOF acts as the "pitaya pulp" protecting the internal CuS NPs ("pitaya seeds"), thereby increasing their retention time in vivo. This system exhibits triple-enzyme-mimicking activities and is proposed for application in photoacoustic and magnetic resonance imaging-guided therapies, including chemodynamic therapy, photothermal therapy, and cuproptosis-related therapy. The exceptional enzyme-mimicking activities of superoxide dismutase, catalase, and peroxidase not only produce oxygen to alleviate hypoxia but also generate a reactive oxygen species (ROS) storm for effective tumor destruction. By combining these multienzymatic properties, superior photothermal performance, and Cu-induced cuproptosis, nanozyme-treated mice exhibited an 84% inhibition of tumor growth-approximately double the effect observed in mice treated with CuS NPs alone. This study presents a smart strategy for integrating imaging with therapeutic modalities, achieving exceptional outcomes for precise imaging-guided tumor therapy.

Sirtuin 7 ameliorates cuproptosis, myocardial remodeling and heart dysfunction in hypertension through the modulation of YAP/ATP7A signaling

Myocardial fibrosis is a typical pathological manifestation of hypertension. However, the exact role of sirtuin 7 (SIRT7) in myocardial remodeling remains largely unclear. Here, spontaneously hypertensive rats (SHRs) and angiotensin (Ang) II-induced hypertensive mice were pretreated with recombinant adeno-associated virus (rAAV)-SIRT7, copper chelator tetrathiomolybdate (TTM) or copper ionophore elesclomol, respectively. Compared with normotensive controls, reduced SIRT7 expression and augmented cuproptosis were observed in hearts of hypertensive rats and mice with decreased FDX1 levels and increased HSP70 levels. Notably, intervention with rAAV-SIRT7 and TTM strikingly prevented DLAT oligomers aggregation, and elevated ATP7A and TOM20 expressions, contributing to the alleviation of cuproptosis, mitochondrial injury, myocardial remodeling and heart dysfunction in spontaneously hypertensive rats and Ang II-induced hypertensive mice. In cultured rat primary cardiac fibroblasts (CFs), rhSIRT7 alleviated CuCl2, Ang II or elesclomol-induced cuproptosis and fibroblast activation by blunting DLAT oligomers accumulation and downregulating α-SMA expression. Additionally, conditioned medium from rhSIRT7-pretreated CFs remarkably mitigated cellular hypertrophy and mitochondrial impairments of neonatal rat cardiomyocytes, as well as cell migration and polarization of RAW 264.7 macrophages. Importantly, verteporfin reduced CuCl2-induced cuproptosis, mitochondrial injury and fibrotic activation in CFs. Knockdown of ATP7A with si-ATP7A blocked cellular protective effects of rhSIRT7 and verteporfin in CFs. In conclusion, SIRT7 attenuates cuproptosis, myocardial fibrosis and heart dysfunction in hypertension through the modulation of YAP/ATP7A signaling. Targeting SIRT7 is of vital importance for developing therapeutic strategies in hypertension and hypertensive heart disorders.

Copper supplementation alleviates hypoxia‑induced ferroptosis and oxidative stress in neuronal cells

Hypoxic ischemia is the primary cause of brain damage in newborns. Notably, copper supplementation has potential benefits in ischemic brain damage; however, the precise mechanisms underlying this protective effect remain unclear. In the present study, a hypoxic HT22 cell model was developed to examine the mechanism by which copper mitigates hypoxia‑induced oxidative stress. Cell viability was assessed using the Cell Counting Kit‑8 assay, mitochondrial structure was examined with a transmission electron microscope, intracellular ferrous ions and lipid reactive oxygen species levels in HT22 cells were measured using FerroOrange and BODIPY 581/591 C11 staining, copper content was determined using graphite furnace atomic absorption spectroscopy, and gene and protein expression were analyzed by reverse transcription‑quantitative PCR and western blotting. The present findings indicated that hypoxic exposure may lead to reduced cell viability, along with the upregulation of various markers associated with ferroptosis. Furthermore, hypoxia elevated the levels of reactive oxygen species, hydrogen peroxide and malondialdehyde, and decreased the activity of superoxide dismutase 1 (SOD1) in HT22 cells. In addition, the intracellular copper concentration exhibited a notable decrease, while supplementation with an appropriate dose of copper effectively shielded neurons from hypoxia‑induced oxidative stress and ferroptosis, and elevated cell viability in hypoxia‑exposed HT22 cells through the copper chaperone for superoxide dismutase/SOD1/glutathione peroxidase 4 axis. In conclusion, the present study identified a novel function of copper in protecting neurons from oxidative stress and ferroptosis under hypoxic conditions, providing fresh insights into the therapeutic potential of copper in mitigating hypoxia‑induced neuronal injury.