Copper Transport Protein Antioxidant-1 Promotes Inflammatory Neovascularization via Chaperone and Transcription Factor Function

The physiological role of copper: Dietary sources, metabolic regulation, and safety concerns

Copper plays an important physiological role in the body, with both deficiency and excess potentially impacting overall health. The body maintains a stringent copper metabolism mechanism to oversee absorption, utilization, storage, and elimination. Dietary consumption serves as the principal source of copper. The dietary factors may interfere with the absorption and metabolism of copper, leading to fluctuation of copper levels in the body. However, these dietary factors can also be strategically employed to facilitate the precise regulation of copper. This paper delved into the advancements in research concerning copper in food processing, including dietary sources of copper, the regulatory processes of copper metabolism and health implications of copper. The safety and its underlying mechanisms of excess copper were also highlighted. In particular, the paper examines the influence of dietary factors on the absorption and metabolism of copper, aiming to provide direction for accurate copper regulation and the creation of functional foods and pharmaceuticals.

DCBLD1 Modulates Angiogenesis by Regulation of the VEGFR-2 Endocytosis in Endothelial Cells

BACKGROUND

Unwanted angiogenesis is involved in the progression of various malignant tumors and cardiovascular diseases, and the factors that regulate angiogenesis are potential therapeutic targets. We tested the hypothesis that DCBLD1 (discoidin, CUB, and LCCL domain-containing protein 1) is a coreceptor of VEGFR-2 (vascular endothelial growth factor receptor-2) and modulates angiogenesis in endothelial cells.

METHODS

A carotid artery ligation model and retinal angiogenesis assay were used to study angiogenesis using globe knockout or endothelial cell-specific conditional Dcbld1 knockout mice in vivo. Immunoblotting, immunofluorescence staining, plasma membrane subfraction isolation, Coimmunoprecipitation, and mass spectrum assay were performed to clarify the molecular mechanisms.

RESULTS

Loss of Dcbld1 impaired VEGF (vascular endothelial growth factor) response and inhibited VEGF-induced endothelial cell proliferation and migration. Dcbld1 deletion interfered with adult and developmental angiogenesis. Mechanistically, DCBLD1 bound to VEGFR-2 and regulated the formation of VEGFR-2 complex with negative regulators: protein tyrosine phosphatases, E3 ubiquitin ligases (neuronal precursor cell-expressed developmentally downregulated gene 4, Nedd4 and c-Casitas B-lineage lymphoma, c-Cbl), and also Dcbld1 knockdown promoted lysosome-mediated VEGFR-2 degradation in endothelial cells.

CONCLUSION

These findings demonstrated the essential role of endothelial DCBLD1 in regulating VEGF signaling and provided evidence that DCBLD1 promotes VEGF-induced angiogenesis by limiting the dephosphorylation, ubiquitination, and lysosome degradation after VEGFR-2 endocytosis. We proposed that endothelial DCBLD1 is a potential therapeutic target for ischemic cardiovascular diseases by the modulation of angiogenesis through regulation of the VEGFR-2 endocytosis.

Endothelial Cu Uptake Transporter CTR1 Senses Disturbed Flow to Promote Atherosclerosis through Cuproptosis

Endothelial cells (ECs) lining blood vessels sense disturbed blood flow (D-flow), which drives mitochondrial dysfunction and atherosclerosis. Copper (Cu) is an essential micronutrient, and its disruption of homeostasis has been implicated in atherosclerosis. Cellular Cu levels are tightly controlled by Cu transport proteins including the Cu importer CTR1. Cuproptosis is a recently discovered form of regulated cell death triggered by mitochondrial Cu accumulation, but its endogenous stimulants and role in atherosclerosis remain unknown. Using EC-specific CTR1-deficient mice and cultured ECs, we show that endothelial CTR1 responds to D-flow by increasing mitochondrial Cu levels through its interaction with the mitochondrial Cu transporter SLC25A3 at caveolae/lipid rafts. This leads to the aggregation of lipoylated mitochondrial proteins, mitochondrial dysfunction, and cuproptosis, thereby exacerbating atherosclerosis. Importantly, mitochondria-targeted Cu-chelating nanoparticles effectively mitigate D-flow-induced cuproptosis and atherosclerosis, highlighting the endothelial CTR1-SLC25A3-mitochondrial Cu axis as a potential therapeutic target.

Copper in the colorectal cancer microenvironment: pioneering a new era of cuproptosis-based therapy

Copper, an essential trace element and biochemical cofactor in humans plays a critical role in maintaining health. Recent studies have identified a significant association between copper levels and the progression and metastasis of cancer. Copper is primarily absorbed in the intestinal tract, often leading to an imbalance of copper ions in the body. Colorectal cancer (CRC), the most common cancer originating in the intestines, thrives in an environment with elevated copper concentrations. Current research is focused on uncovering the relationship between copper and CRC which has introduced new concepts such as cuproplasia and cuproptosis, significantly deepening our understanding of copper's influence on cell proliferation and death. Cuproplasia is a kind of cell proliferation mediated by the co-regulatory activities of enzymes and non-enzymatic factors, while cuproptosis refers to cell death induced by excessive copper, which results in abnormal oligomerization of lipacylated proteins and the reduction of iron-sulfur cluster proteins. Exploring cuproplasia and cuproptosis opens new avenues for treating CRC. This review aims to summarize the critical role of copper in promoting colorectal cancer, the dual effects of copper in the tumor microenvironment (TME), and strategies for leveraging this unique microenvironment to induce cuproptosis in colorectal cancer. Understanding the relationship between copper and CRC holds promise for establishing a theoretical foundation for innovative therapeutic strategies in CRC.

Mammalian copper homeostasis: physiological roles and molecular mechanisms

In the past decade, evidence for the numerous roles of copper (Cu) in mammalian physiology has grown exponentially. The discoveries of Cu involvement in cell signaling, autophagy, cell motility, differentiation, and regulated cell death (cuproptosis) have markedly extended the list of already known functions of Cu, such as a cofactor of essential metabolic enzymes, a protein structural component, and a regulator of protein trafficking. Novel and unexpected functions of Cu transporting proteins and enzymes have been identified, and new disorders of Cu homeostasis have been described. Significant progress has been made in the mechanistic studies of two classic disorders of Cu metabolism, Menkes disease and Wilson's disease, which paved the way for novel approaches to their treatment. The discovery of cuproptosis and the role of Cu in cell metastatic growth have markedly increased interest in targeting Cu homeostatic pathways to treat cancer. In this review, we summarize the established concepts in the field of mammalian Cu physiology and discuss how new discoveries of the past decade expand and modify these concepts. The roles of Cu in brain metabolism and in cell functional speciation and a recently discovered regulated cell death have attracted significant attention and are highlighted in this review.

Reprogramming of epidermal keratinocytes by PITX1 transforms the cutaneous cellular landscape and promotes wound healing

Cutaneous wound healing is a slow process that often terminates with permanent scarring while oral wounds, in contrast, regenerate after damage faster. Unique molecular networks in epidermal and oral epithelial keratinocytes contribute to the tissue-specific response to wounding, but key factors that establish those networks and how the keratinocytes interact with their cellular environment remain to be elucidated. The transcription factor PITX1 is highly expressed in the oral epithelium but is undetectable in cutaneous keratinocytes. To delineate if PITX1 contributes to oral keratinocyte identity, cell-cell interactions, and the improved wound healing capabilities, we ectopically expressed PITX1 in the epidermis of murine skin. Using comparative analysis of murine skin and oral (buccal) mucosa with single-cell RNA-Seq and spatial transcriptomics, we found that PITX1 expression enhances epidermal keratinocyte migration and proliferation and alters differentiation to a quasi-oral keratinocyte state. PITX1+ keratinocytes reprogrammed intercellular communication between skin-resident cells to mirror buccal tissue while stimulating the influx of neutrophils that establish a pro-inflammatory environment. Furthermore, PITX1+ skin healed significantly faster than control skin via increased keratinocyte activation and migration and a tunable inflammatory environment. These results illustrate that PITX1 programs oral keratinocyte identity and cellular interactions while revealing critical downstream networks that promote wound closure.

The STAT1-SLC31A1 axis: Potential regulation of cuproptosis in diabetic retinopathy

BACKGROUND

By identifying molecular biological markers linked to cuproptosis in diabetic retinopathy (DR), new pathobiological pathways and more accessible diagnostic markers can be developed.

METHODS

The datasets related to DR were acquired from the Gene Expression Omnibus database, while genes associated with cuproptosis were sourced from previously published compilations. Consensus clustering was conducted to delineate distinct DR subclasses. Feature genes were identified utilizing weighted correlation network analysis (WGCNA). Additionally, two machine-learning algorithms were employed to refine the selection of feature genes. Finally, we conducted preliminary validation experiments to ascertain the involvement of cuproptosis in DR development and the transcriptional regulation of critical genes using both the streptozotocin-induced diabetic mouse model and the high glucose-induced BV2 model.

RESULTS

In the STZ-induced diabetic mouse retinas, a decrease in the expression of cuproptosis signature proteins (FDX1, DLAT, and NDUFS8) suggested the occurrence of cuproptosis in DR. Subsequently, the expression of eight cuproptosis differential genes was validated through the STZ-induced diabetes and oxygen-induced retinopathy (OIR) models, with the key gene SLC31A1 showing upregulation in both models and dataset species. Further analyses, including weighted gene co-expression network analysis, GSVA, and immune infiltration analysis, indicated a close correlation between cuproptosis and microglia function. Additionally, validation in an in vitro model of microglia indicated the occurrence of cuproptosis in microglia under high glucose conditions, alongside abnormal expression of STAT1 with SLC31A1.

CONCLUSION

Our findings suggest that STAT1/SLC31A1 may pave the way for a deeper comprehension of the mechanistic basis of DR and offer potential therapeutic avenues.

Chaperone-Derived Copper(I)-Binding Peptide Nanofibers Disrupt Copper Homeostasis in Cancer Cells

Copper (Cu) is a transition metal that plays crucial roles in cellular metabolism. Cu+ homeostasis is upregulated in many cancers and contributes to tumorigenesis. However, therapeutic strategies to target Cu+ homeostasis in cancer cells are rarely explored because small molecule Cu+ chelators have poor binding affinity in comparison to the intracellular Cu+ chaperones, enzymes, or ligands. To address this challenge, we introduce a Cu+ chaperone-inspired supramolecular approach to disrupt Cu+ homeostasis in cancer cells that induces programmed cell death. The Nap-FFMTCGGCR peptide self-assembles into nanofibers inside cancer cells with high binding affinity and selectivity for Cu+ due to the presence of the unique MTCGGC motif, which is conserved in intracellular Cu+ chaperones. Nap-FFMTCGGCR exhibits cytotoxicity towards triple negative breast cancer cells (MDA-MB-231), impairs the activity of Cu+ dependent co-chaperone super oxide dismutase1 (SOD1), and induces oxidative stress. In contrast, Nap-FFMTCGGCR has minimal impact on normal HEK 293T cells. Control peptides show that the self-assembly and Cu+ binding must work in synergy to successfully disrupt Cu+ homeostasis. We show that assembly-enhanced affinity for metal ions opens new therapeutic strategies to address disease-relevant metal ion homeostasis.

Roles of Copper Transport Systems Members in Breast Cancer

BACKGROUND

The occurrence and progression of breast cancer are closely linked to copper ion homeostasis. Both copper deficiency and excess can inhibit breast cancer growth, while copper transport systems may contribute to its progression by regulating copper ion transport and the activity of associated proteins. However, a comprehensive review of the roles and applications of copper transport systems in breast cancer remains limited. In this study, we summarize the workflow of copper transport systems and the dual role of copper in cancer, highlighting the contributions of specific members of the copper transport system to breast cancer.

METHODS

A comprehensive search of the PubMed database was conducted to identify articles published over the past 30 years that focus on the relationship between copper transport system members and breast cancer. The findings were synthesized to elucidate the roles and mechanisms of these transporters in the onset and progression of breast cancer.

RESULTS

We identified 13 members of the copper transport system associated with the occurrence, progression, and mortality of breast cancer, including SLC31A1, DMT1, ATP7A, ATP7B, MTs, GSH, ATOX1, CCS, COX17, SCO1, SCO2, and COX11. Our findings revealed that, apart from STEAP, the remaining 12 members were overexpressed in breast cancer. These members influence the onset, progression, and cell death of breast cancer by modulating biological pathways such as intracellular copper ion levels and ROS. Notably, we observed for the first time that depletion of the copper storage protein GSH leads to increased copper ion accumulation, resulting in cuproptosis in breast cancer cells.

CONCLUSION

By integrating the members of the copper transport system in breast cancer, we offer novel insights for the treatment of breast cancer and copper-related therapies.

Altered copper transport in oxidative stress-dependent brain endothelial barrier dysfunction associated with Alzheimer's disease

Oxidative stress and blood-brain barrier (BBB) disruption due to brain endothelial barrier dysfunction contribute to Alzheimer's Disease (AD), which is characterized by beta-amyloid (Aβ) accumulation in senile plaques. Copper (Cu) is implicated in AD pathology and its levels are tightly controlled by several Cu transport proteins. However, their expression and role in AD, particularly in relation to brain endothelial barrier function remains unclear. In this study, we examined the expression of Cu transport proteins in the brains of AD mouse models as well as their involvement in Aβ42-induced brain endothelial barrier dysfunction. We found that the Cu uptake transporter CTR1 was upregulated, while the Cu exporter ATP7A was downregulated in the hippocampus of AD mouse models and in Aβ42-treated human brain microvascular endothelial cells (hBMECs). In the 5xFAD AD mouse model, Cu levels (assessed by ICP-MS) were elevated in the hippocampus. Moreover, in cultured hBMECs, Aβ42-induced reactive oxygen species (ROS) production, ROS-dependent loss in barrier function (measured by transendothelial electrical resistance), and tyrosine phosphorylation of CDH5 were all inhibited by either a membrane permeable Cu chelator or by knocking down CTR1 expression. These findings suggest that dysregulated expression of Cu transport proteins may lead to intracellular Cu accumulation in the AD brain, and that Aβ42 promotes ROS-dependent brain endothelial barrier dysfunction and CDH5 phosphorylation in a CTR1-Cu-dependent manner. Our study uncovers the critical role of Cu transport proteins in oxidative stress-related loss of BBB integrity in AD.

Copper Dysmetabolism is Connected to Epithelial-Mesenchymal Transition: A Pilot Study in Colorectal Cancer Patients

Colorectal cancer (CRC) is among the most diagnosed cancers worldwide, whose risk of mortality is associated with the development of metastases to the liver, lungs, and peritoneum. Of note, CRC is highly dependent on copper to sustain its proliferation and aggressiveness. Copper acts not only as a pivotal cofactor for several cuproproteins but also as an allosteric modulator of kinases essential to fulfill the epithelial-to-mesenchymal-transition (EMT), the main mechanism driving cancer cell spreading. System biology identified the APP and SOD1 genes among the top 10 genes shared between CRC and copper metabolism, as confirmed by the upregulation of the protein/mRNA levels of APP observed in CRC tissues. The significant increase of copper found in the sera of CRC patients was paralleled by a strong reduction of copper in the CRC tissues, in agreement with the decreased level of the high-affinity copper transporter CTR1 mRNA (SLC31A1) and LOXL2. As expected, in CRC tissues the mesenchymal marker fibronectin was significantly increased, whereas vimentin and vinculin protein levels were decreased compared to adjacent healthy mucosa. Interestingly, correlation analysis showed an interconnection between vinculin and both CCS and APP. A positive correlation was also observed between APP mRNA and both CDH1 and SOD1 mRNAs. Overall, we demonstrate a correlation between cell copper imbalance and CRC progression via EMT. The results obtained lay the scientific basis for further investigation to describe the kinetics of copper dysregulation during CRC progression and to identify the main cuproproteins involved in the modulation of EMT.

Emerging perspectives of copper-mediated transcriptional regulation in mammalian cell development

Copper (Cu) is a vital micronutrient necessary for proper development and function of mammalian cells and tissues. Cu mediates the function of redox active enzymes that facilitate metabolic processes and signaling pathways. Cu levels are tightly regulated by a network of Cu-binding transporters, chaperones, and small molecule ligands. Extensive research has focused on the mammalian Cu homeostasis (cuprostasis) network and pathologies, which result from mutations and perturbations. There are roles for Cu-binding proteins as transcription factors (Cu-TFs) and regulators that mediate metal homeostasis through the activation or repression of genes associated with Cu handling. Emerging evidence suggests that Cu and some Cu-TFs may be involved in the regulation of targets related to development-expanding the biological roles of Cu-binding proteins. Cu and Cu-TFs are implicated in embryonic and tissue-specific development alongside the mediation of the cellular response to oxidative stress and hypoxia. Cu-TFs are also involved in the regulation of targets implicated in neurological disorders, providing new biomarkers and therapeutic targets for diseases such as Parkinson's disease, prion disease, and Friedreich's ataxia. This review provides a critical analysis of the current understanding of the role of Cu and cuproproteins in transcriptional regulation.

A spotlight on the role of copper in the epithelial to mesenchymal transition

The complex process known as epithelial to mesenchymal transition (EMT) plays a fundamental role in several biological settings, encompassing embryonic development, wound healing, and pathological conditions such as cancer and fibrosis. In recent years, a bulk of research has brought to light the key role of copper, a trace element with essential functions in cellular metabolism, cancer initiation and progression. Indeed, copper, besides functioning as cofactor of enzymes required for essential cellular processes, such as energy production and oxidation reactions, has emerged as an allosteric regulator of kinases whose activity is required to fulfill cancer dissemination through the EMT. In this comprehensive review, we try to describe the intricate relationship between the transition metal copper and EMT, spanning from the earliest foundational studies to the latest advancements. Our aim is to shed light on the multifaceted roles undertaken by copper in EMT in cancer and to unveil the diverse mechanisms by which copper homeostasis exerts its influence over EMT regulators, signaling pathways, cell metabolic reprogramming and transcription factors ultimately contributing to the spread of cancer. Therefore, this review not only may contribute to a deeper comprehension of copper-mediated mechanisms in EMT but also supports the hypothesis that targeting copper may contribute to counteract the progression of EMT-associated pathologies.

Copper homeostasis and cuproptosis in gynecological cancers

Copper (Cu) is an essential trace element involved in a variety of biological processes, such as antioxidant defense, mitochondrial respiration, and bio-compound synthesis. In recent years, a novel theory called cuproptosis has emerged to explain how Cu induces programmed cell death. Cu targets lipoylated enzymes in the tricarboxylic acid cycle and subsequently triggers the oligomerization of lipoylated dihydrolipoamide S-acetyltransferase, leading to the loss of Fe-S clusters and induction of heat shock protein 70. Gynecological malignancies including cervical cancer, ovarian cancer and uterine corpus endometrial carcinoma significantly impact women's quality of life and even pose a threat to their lives. Excessive Cu can promote cancer progression by enhancing tumor growth, proliferation, angiogenesis and metastasis through multiple signaling pathways. However, there are few studies investigating gynecological cancers in relation to cuproptosis. Therefore, this review discusses Cu homeostasis and cuproptosis while exploring the potential use of cuproptosis for prognosis prediction as well as its implications in the progression and treatment of gynecological cancers. Additionally, we explore the application of Cu ionophore therapy in treating gynecological malignancies.

The crosstalk between copper-induced oxidative stress and cuproptosis: a novel potential anticancer paradigm

Copper is a crucial trace element that plays a role in various pathophysiological processes in the human body. Copper also acts as a transition metal involved in redox reactions, contributing to the generation of reactive oxygen species (ROS). Under prolonged and increased ROS levels, oxidative stress occurs, which has been implicated in different types of regulated cell death. The recent discovery of cuproptosis, a copper-dependent regulated cell death pathway that is distinct from other known regulated cell death forms, has raised interest to researchers in the field of cancer therapy. Herein, the present work aims to outline the current understanding of cuproptosis, with an emphasis on its anticancer activities through the interplay with copper-induced oxidative stress, thereby providing new ideas for therapeutic approaches targeting modes of cell death in the future.

Atox1-cyclin D1 loop activity is critical for survival of tumor cells with inactivated TP53

The search for relevant molecular targets is one of the main tasks of modern tumor chemotherapy. To successfully achieve this, it is necessary to have the most complete understanding of the functioning of a transcriptional apparatus of the cell, particularly related to proliferation. The p53 protein plays an important role in regulating processes such as apoptosis, repair, and cell division, and the loss of its functionality often accompanies various types of tumors and contributes to the development of chemoresistance. Additionally, the proliferative activity of tumor cells is closely related to the metabolism of transition metals. For example, the metallochaperone Atox1 - a copper transporter protein - acts as a transcription activator for cyclin D1, promoting progression through the G1/S phase of the cell cycle. On the other hand, p53 suppresses cyclin D1 at the transcriptional level, thereby these proteins have divergent effects on cell cycle progression. However, the contribution of the interaction between these proteins to cell survival is poorly understood. This work demonstrates that not only exists a positive feedback loop between Atox1 and cyclin D1 but also that the activity of this loop depends on the status of the TP53 gene. Upon inactivation of TP53 in A549 and HepG2 cell lines, the expression of ATOX1 and CCND1 genes is enhanced, and their suppression in these cells leads to pronounced apoptosis. This fundamental observation may be useful in selecting more precise interventions for combined therapy of p53-negative tumors.

Cuproptosis in cancer: biological implications and therapeutic opportunities

Cuproptosis, a newly identified copper (Cu)-dependent form of cell death, stands out due to its distinct mechanism that sets it apart from other known cell death pathways. The molecular underpinnings of cuproptosis involve the binding of Cu to lipoylated enzymes in the tricarboxylic acid cycle. This interaction triggers enzyme aggregation and proteotoxic stress, culminating in cell death. The specific mechanism of cuproptosis has yet to be fully elucidated. This newly recognized form of cell death has sparked numerous investigations into its role in tumorigenesis and cancer therapy. In this review, we summarized the current knowledge on Cu metabolism and its link to cancer. Furthermore, we delineated the molecular mechanisms of cuproptosis and summarized the roles of cuproptosis-related genes in cancer. Finally, we offered a comprehensive discussion of the most recent advancements in Cu ionophores and nanoparticle delivery systems that utilize cuproptosis as a cutting-edge strategy for cancer treatment.

Endothelial Drp1 Couples VEGF-induced Redox Signaling with Glycolysis Through Cysteine Oxidation to Drive Angiogenesis

Angiogenesis plays a vital role for postnatal development and tissue repair following ischemia. Reactive oxygen species (ROS) generated by NADPH oxidases (NOXes) and mitochondria act as signaling molecules that promote angiogenesis in endothelial cells (ECs) which mainly relies on aerobic glycolysis for ATP production. However, the connections linking redox signaling with glycolysis are not well understood. The GTPase Drp1 is a member of the dynamin superfamily that moves from cytosol to mitochondria through posttranslational modifications to induce mitochondrial fission. The role of Drp1 in ROS-dependent VEGF signaling and angiogenesis in ECs has not been previously described. Here, we identify an unexpected function of endothelial Drp1 as a redox sensor, transmitting VEGF-induced H 2 O 2 signals to enhance glycolysis and angiogenesis. Loss of Drp1 expression in ECs inhibited VEGF-induced angiogenic responses. Mechanistically, VEGF rapidly induced the NOX4-dependent sulfenylation (CysOH) of Drp1 on Cys 644 , promoting disulfide bond formation with the metabolic kinase AMPK and subsequent sulfenylation of AMPK at Cys 299 / 304 via the mitochondrial fission-mitoROS axis. This cysteine oxidation of AMPK, in turn, enhanced glycolysis and angiogenesis. In vivo , mice with EC-specific Drp1 deficiency or CRISPR/Cas9-engineered "redox-dead" (Cys to Ala) Drp1 knock-in mutations exhibited impaired retinal angiogenesis and post-ischemic neovascularization. Our findings uncover a novel role for endothelial Drp1 in linking VEGF-induced mitochondrial redox signaling to glycolysis through a cysteine oxidation-mediated Drp1-AMPK redox relay, driving both developmental and reparative angiogenesis.

Copper homeostasis dysregulation in respiratory diseases: a review of current knowledge

Cu is an essential micronutrient for various physiological processes in almost all human cell types. Given the critical role of Cu in a wide range of cellular processes, the local concentrations of Cu and the cellular distribution of Cu transporter proteins in the lung are essential for maintaining a steady-state internal environment. Dysfunctional Cu metabolism or regulatory pathways can lead to an imbalance in Cu homeostasis in the lungs, affecting both acute and chronic pathological processes. Recent studies have identified a new form of Cu-dependent cell death called cuproptosis, which has generated renewed interest in the role of Cu homeostasis in diseases. Cuproptosis differs from other known cell death pathways. This occurs through the direct binding of Cu ions to lipoylated components of the tricarboxylic acid cycle during mitochondrial respiration, leading to the aggregation of lipoylated proteins and the subsequent downregulation of Fe-S cluster proteins, which causes toxic stress to the proteins and ultimately leads to cell death. Here, we discuss the impact of dysregulated Cu homeostasis on the pathogenesis of various respiratory diseases, including asthma, chronic obstructive pulmonary disease, idiopathic interstitial fibrosis, and lung cancer. We also discuss the therapeutic potential of targeting Cu. This study highlights the intricate interplay between copper, cellular processes, and respiratory health. Copper, while essential, must be carefully regulated to maintain the delicate balance between necessity and toxicity in living organisms. This review highlights the need to further investigate the precise mechanisms of copper interactions with infections and immune inflammation in the context of respiratory diseases and explore the potential of therapeutic strategies for copper, cuproptosis, and other related effects.

Atox1 regulates macrophage polarization in intestinal inflammation via ROS-NLRP3 inflammasome pathway

BACKGROUND

Inflammation and oxidative stress play an important role in the pathophysiology of inflammatory bowel disease (IBD). This study aimed to explore the effects of copper chaperone Antioxidant-1 (Atox1) on macrophages in a mouse model of intestinal inflammation.

METHODS

A mouse model of TNBS-induced colitis was established and verified using the disease activity index. Atox1 conditional knockout mice were applied. The proportion of macrophages in colonic lamina propria mononuclear cells and ROS production were analyzed using flow cytometry. Inflammatory cytokines were measured using ELISA. Expression of macrophage M1/M2 polarization markers, p47phox, NLRP3, and Caspase-1 p20 was measured using quantitative RT-PCR and Western blotting.

RESULTS

Atox1 expression was up-regulated in colon tissues of TNBS-induced colitis mice. Macrophages isolated from TNBS-induced colitis mice showed M1 polarization and nuclear translocation of Atox1. Inhibiting copper chaperone activity decreased p47phox, ROS production, and M1 polarization induced by CuCl2 in macrophages. TNBS induced up-regulation of inflammatory cytokines, M1 polarization markers, and p47phox expression in mice, an effect which was preempted by Atox1 knockout. Inflammatory cytokines and expression of M1 polarization markers, p47phox, NLRP3, Caspase-1 p20 were also increased in macrophages isolated from TNBS-induced colitis mice. These changes were alleviated in mice with Atox1 knockout. The effects of Atox1 on macrophage polarization were mediated via the ROS-NLRP3 inflammasome pathway.

CONCLUSION

Atox1 plays a pro-inflammatory role, promotes M1 polarization of macrophages, and increases the concentrations of pro-inflammatory cytokines in intestinal tissue by regulating the ROS-NLRP3 inflammasome pathway. Atox1 is a potential therapeutic target in IBD.

Comprehensive analysis of the effects of the cuprotosis-associated gene SLC31A1 on patient prognosis and tumor microenvironment in human cancer

BACKGROUND

Solute carrier family 31 (copper transporter), member 1 (SLC31A1) is a key factor in maintaining intracellular copper concentration and an important factor affecting cancer energy metabolism. Therefore, exploring the potential biological function and value of SLC31A1 could provide a new direction for the targeted therapy of tumors.

METHODS

This study assessed gene expression levels, survival, clinicopathology, gene mutations, methylation levels, the tumor mutational burden (TMB), microsatellite instability (MSI), and the immune cell infiltration of SLC31A1 in pan-cancer using the Tumor Immune Estimation Resource 2.0 (TIMER2.0), Gene Expression Profiling Interactive Analysis (GEPIA), University of Alabama at Birmingham CANcer (UALCAN) data analysis portal, and cBioPortal databases. To further understand the potential biological mechanisms of SLC31A1 in different cancers, single-cell level sequencing and a Gene Ontology/Kyoto Encyclopedia of Genes and Genomes (GO/KEGG) enrichment analysis of SLC31A1 were also performed. Finally, real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting (WB) were used to validate the expression of SLC31A1 in cancers, such as gastric cancer.

RESULTS

SLC31A1 was expressed in most cancer tissues. In kidney renal clear cell carcinoma (KIRC), the high expression of SLC31A1 was associated with good overall survival (OS), while in adrenocortical carcinoma (ACC), breast invasive carcinoma (BRCA), lower grade glioma (LGG), mesothelioma (MESO), and skin cutaneous melanoma (SKCM), the low expression of SLC31A1 was associated with good OS. The highest frequency of SLC31A1 amplification was observed in ACC. In addition, missense mutations accounted for a major portion of the mutation types. The truncation mutation S105Y may be a putative cancer driver. SLC31A1 affected methylation levels in cancer and was associated with the TMB, MSI, and the level of infiltration of various immune cells. Additionally, the single-cell sequencing results showed that SLC31A1 was associated with multiple biological functions in cancer. Finally, the SLC31A1 enrichment analysis revealed that the SLC31A1-related genes were mainly enriched in the mitochondrial matrix and envelope vesicles. The RT-qPCR and WB results were consistent with the predicted results.

CONCLUSIONS

SLC31A1 may be a potential target related to cancer energy metabolism and may have prognostic value.

Copper in Gynecological Diseases

Copper (Cu) is an essential micronutrient for the correct development of eukaryotic organisms. This metal plays a key role in many cellular and physiological activities, including enzymatic activity, oxygen transport, and cell signaling. Although the redox activity of Cu is crucial for enzymatic reactions, this property also makes it potentially toxic when found at high levels. Due to this dual action of Cu, highly regulated mechanisms are necessary to prevent both the deficiency and the accumulation of this metal since its dyshomeostasis may favor the development of multiple diseases, such as Menkes' and Wilson's diseases, neurodegenerative diseases, diabetes mellitus, and cancer. As the relationship between Cu and cancer has been the most studied, we analyze how this metal can affect three fundamental processes for tumor progression: cell proliferation, angiogenesis, and metastasis. Gynecological diseases are characterized by high prevalence, morbidity, and mortality, depending on the case, and mainly include benign and malignant tumors. The cellular processes that promote their progression are affected by Cu, and the mechanisms that occur may be similar. We analyze the crosstalk between Cu deregulation and gynecological diseases, focusing on therapeutic strategies derived from this metal.

Cardiomyocyte intercellular signalling increases oxidative stress and reprograms the global- and phospho-proteome of cardiac fibroblasts

Pathological reprogramming of cardiomyocyte and fibroblast proteome landscapes drive the initiation and progression of cardiac fibrosis. Although the secretome of dysfunctional cardiomyocytes is emerging as an important driver of pathological fibroblast reprogramming, our understanding of the downstream molecular players remains limited. Here, we show that cardiac fibroblast activation (αSMA+) and oxidative stress mediated by the secretome of TGFβ-stimulated cardiomyocytes is associated with a profound reprogramming of their proteome and phosphoproteome landscape. Within the fibroblast global proteome there was a striking dysregulation of proteins implicated in extracellular matrix, protein localisation/metabolism, KEAP1-NFE2L2 pathway, lysosomes, carbohydrate metabolism, and transcriptional regulation. Kinase substrate enrichment analysis of phosphopeptides revealed potential role of kinases (CK2, CDK2, PKC, GSK3B) during this remodelling. We verified upregulated activity of casein kinase 2 (CK2) in secretome-treated fibroblasts, and pharmacological CK2 inhibitor TBB (4,5,6,7-Tetrabromobenzotriazole) significantly abrogated fibroblast activation and oxidative stress. Our data provides molecular insights into cardiomyocyte to cardiac fibroblast crosstalk, and the potential role of CK2 in regulating cardiac fibroblast activation and oxidative stress.

The huge potential of targeting copper status in the treatment of colorectal cancer

Colorectal cancer (CRC) commonly leads to cancer deaths and is often diagnosed at advanced stages. It also faces difficulties due to the poor results of conventional treatments such as surgery, chemotherapy, and radiotherapy. Copper is a mineral nutrient whose intrinsic properties have a two-way effect on the production and treatment of cancer. Copper's redox properties allow it to be used in developing anti-cancer drugs, while its potential toxicity leads to oxidative stress and even cancer. Copper status is closely related to colorectal tumors' proliferation and metastasis. The study of the mechanisms of copper homeostasis, cuproplasia, and cuproptosis due to altered copper status plays a crucial role in developing anticancer drugs. Therefore, targeting alteration of copper status becomes a potential option for treating colorectal cancer. This review summarizes the mechanisms by which altered copper status causes CRC progression and emphasizes the potential of regulating copper status in treating CRC.

Multifactorial Distress, the Warburg Effect, and Respiratory and pH Imbalance in Cancer Development

Oncogenes are thought to play an important role in aberrant regulation of growth factors, which is believed to be an initiation event of carcinogenesis. However, recent genetic and pharmacological studies have shown that the Warburg effect (WE) is needed for tumour growth. It refers to extensively studied aerobic glycolysis over the past decade, although its impact on cancer remains unclear. Meanwhile, a large body of evidence has indicated that oxidative stress (OS) is connected with the occurrence and progression of various forms of cancer. Psychosocial factors (PSF), such as chronic depression, sadness, stressful life experiences, stress-prone personality, and emotional distress or poor quality of life affect the immune system and contribute to cancer outcomes. Here, we examine the relationship between WE, OS, PSF, metal ions, other carcinogens, and the development of different cancers from the viewpoint of physiological and biochemical mechanisms.

Protein disulfide isomerase A1 as a novel redox sensor in VEGFR2 signaling and angiogenesis

VEGFR2 signaling in endothelial cells (ECs) is regulated by reactive oxygen species (ROS) derived from NADPH oxidases (NOXs) and mitochondria, which plays an important role in postnatal angiogenesis. However, it remains unclear how highly diffusible ROS signal enhances VEGFR2 signaling and reparative angiogenesis. Protein disulfide isomerase A1 (PDIA1) functions as an oxidoreductase depending on the redox environment. We hypothesized that PDIA1 functions as a redox sensor to enhance angiogenesis. Here we showed that PDIA1 co-immunoprecipitated with VEGFR2 or colocalized with either VEGFR2 or an early endosome marker Rab5 at the perinuclear region upon stimulation of human ECs with VEGF. PDIA1 silencing significantly reduced VEGF-induced EC migration, proliferation and spheroid sprouting via inhibiting VEGFR2 signaling. Mechanistically, VEGF stimulation rapidly increased Cys-OH formation of PDIA1 via the NOX4-mitochondrial ROS axis. Overexpression of "redox-dead" mutant PDIA1 with replacement of the active four Cys residues with Ser significantly inhibited VEGF-induced PDIA1-CysOH formation and angiogenic responses via reducing VEGFR2 phosphorylation. Pdia1+/- mice showed impaired angiogenesis in developmental retina and Matrigel plug models as well as ex vivo aortic ring sprouting model. Study using hindlimb ischemia model revealed that PDIA1 expression was markedly increased in angiogenic ECs of ischemic muscles, and that ischemia-induced limb perfusion recovery and neovascularization were impaired in EC-specific Pdia1 conditional knockout mice. These results suggest that PDIA1 can sense VEGF-induced H2O2 signal via CysOH formation to promote VEGFR2 signaling and angiogenesis in ECs, thereby enhancing postnatal angiogenesis. The oxidized PDIA1 is a potential therapeutic target for treatment of ischemic vascular diseases.

Comparison of urine proteomes from tumor-bearing mice with those from tumor-resected mice

Objective

This study aimed to address on the most important concern of surgeons-whether to completely resect tumor. Urine can indicate early changes associated with physiological or pathophysiological processes. Based on these ideas, we conducted experiments to explore changes in the urine proteome between tumor-bearing mice and tumor-resected mice.

Method

The tumor-bearing mouse model was established with MC38 mouse colon cancer cells, and the mice were divided into the control group, tumor-resected group, and tumor-bearing group. Urine was collected 7 and 30 days after tumor resection. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used to identify the urine proteome, which was analyzed for differentially expressed proteins and functional annotation.

Results

(1) Seven days after tumor resection, 20 differentially expressed proteins distinguished the tumor-resected group and the tumor-bearing group. The identified biological processes included circadian rhythm, Notch signaling pathway, leukocyte cell-cell adhesion, and heterophilic cell-cell adhesion via plasma membrane cell adhesion molecules. (2) Thirty days after tumor resection, 33 differentially expressed proteins distinguished the tumor-resected group and the tumor-bearing group. The identified biological processes included cell adhesion; complement activation, the alternative pathway; the immune system process; and angiogenesis. (3) The difference in the urine proteome between the tumor-resected group and the healthy control group was smaller 30 days after tumor resection.

Conclusion

Changes in the urinary proteome can reflect the complete resection of MC38 tumors.

Disulfiram Enhances the Antineoplastic Activity and Sensitivity of Murine Hepatocellular Carcinoma to 5-FU via Redox Management

The efficacy of anticancer drug 5-FU is suppressed due to various factors, including severe side effects and decreased insensitivity during prolonged chemotherapy. Elevated endogenous copper (Cu) levels are one of the prominent hallmark features of cancer cells. In the present investigation, this feature was targeted in diethyl nitrosamine-phenobarbital-induced hepatocellular carcinoma (HCC) in a rat model system by an established anticancer drug, 5-FU, co-administered with copper and its chelating agent, disulfiram. After treatment with the test chemicals in HCC-induced rats, blood and liver samples were subjected to biochemical, molecular, and histopathological analyses. The analysis revealed that reactive oxygen species-mediated oxidative stress is the crucial etiological reason for the pathogenesis of HCC in rats, as evidenced by the significantly compromised activity of major antioxidant enzymes and elevated levels of oxidative damaged products with major histological alterations compared to the control. However, the combination of 5-FU with DSF demonstrated a significant improvement in most of the parameters, followed by 5-FU-Cu in the combination-treated groups. The combination treatment improved the histological details and triggered apoptosis in the cancer cells to a remarkable extent, as the levels of cleaved PARP and caspase-3 were significantly higher than those in the HCC rats treated with the drug alone. The present study envisages that manipulating the Cu-level greatly enhances the antineoplastic activity of 5-FU and sensitizes cancer cells to the increased efficacy of the drug.

AKT-driven epithelial-mesenchymal transition is affected by copper bioavailability in HER2 negative breast cancer cells via a LOXL2-independent mechanism

BACKGROUND

The main mechanism underlying cancer dissemination is the epithelial to mesenchymal transition (EMT). This process is orchestrated by cytokines like TGFβ, involving "non-canonical" AKT- or STAT3-driven pathways. Recently, the alteration of copper homeostasis seems involved in the onset and progression of cancer.

METHODS

We expose different breast cancer cell lines, including two triple negative (TNBC) ones, an HER2 enriched and one cell line representative of the Luminal A molecular subtype, to short- or long-term copper-chelation by triethylenetetramine (TRIEN). We analyse changes in the expression of EMT markers (E-cadherin, fibronectin, vimentin and αSMA), in the levels and activity of extracellular matrix components (LOXL2, fibronectin and MMP2/9) and of copper homeostasis markers by Western blot analyses, immunofluorescence, enzyme activity assays and RT-qPCR. Boyden Chamber and wound healing assays revealed the impact of copper chelation on cell migration. Additionally, we explored whether perturbation of copper homeostasis affects EMT prompted by TGFβ. Metabolomic and lipidomic analyses were applied to search the effects of copper chelation on the metabolism of breast cancer cells. Finally, bioinformatics analysis of data on breast cancer patients obtained from different databases was employed to correlate changes in kinases and copper markers with patients' survival.

RESULTS

Remarkably, only HER2 negative breast cancer cells differently responded to short- or long-term exposure to TRIEN, initially becoming more aggressive but, upon prolonged exposure, retrieving epithelial features, reducing their invasiveness. This phenomenon may be related to the different impact of the short and prolonged activation of the AKT kinase and to the repression of STAT3 signalling. Bioinformatics analyses confirmed the positive correlation of breast cancer patients' survival with AKT activation and up-regulation of CCS. Eventually, metabolomics studies demonstrate a prevalence of glycolysis over mitochondrial energetic metabolism and of lipidome changes in TNBC cells upon TRIEN treatment.

CONCLUSIONS

We provide evidence of a pivotal role of copper in AKT-driven EMT activation, acting independently of HER2 in TNBC cells and via a profound change in their metabolism. Our results support the use of copper-chelators as an adjuvant therapeutic strategy for TNBC.

Relationship between copper and immunity: The potential role of copper in tumor immunity

Copper is an essential trace element in an organism, and changes in copper levels in vivo often indicate a diseased state. Copper and immunity have been discussed since the last century, with copper deficiency significantly affecting the development and function of the immune system, such as increased host susceptibility to various pathogens, decreased number and impaired function of neutrophils, reduced antibacterial activity of macrophages, decreased proliferation of splenocytes, impaired B cell ability to produce antibodies and impaired function of cytotoxic T lymphocyte and helper T cells. In the past 20 years, some studies have shown that copper ions are related to the development of many tumors, including lung cancer, acute lymphoid leukaemia, multiple myeloma and other tumors, wherein copper ion levels were significantly elevated, and current studies reveal that copper ions are involved in the development, growth and metastasis of tumors through various pathways. Moreover, recent studies have shown that copper ions can regulate the expression of PD-L1, thus, attention should be paid to the important role of copper in tumor immunity. By exploring and studying copper ions and tumor immunity, new insights into tumor immunity could be generated and novel therapeutic approaches to improve the clinical prognosis of patients can be provided.

Regulation, genomics, and clinical characteristics of cuproptosis regulators in pan-cancer

Background

Cuproptosis, a copper-dependent controlled cell death, is a novel form of cell death that differs from known cell death mechanisms; however, its overall regulation in cancer remains elusive.

Methods

Multiple open-source bioinformatic platforms were used to comprehensively elucidate the expression levels, prognostic efficiency, potential biological functions, genomic and epigenetic characteristics, immune microenvironment, and drug sensitivity of cuproptosis regulators (ATP7A, ATP7B, DLAT, DLD, FDX1, GLS, LIAS, LIPT1, MTF1, NLRP3, PDHA1, PDHB, and SLC31A1) in pan-cancer.

Results

Cuproptosis-related genes (CRGs) were upregulated in most cancers tested. In KIRC, KIRP, LGG, MESO, and PCPG, most highly expressed CRGs predicted a better prognosis but poorer prognosis in patients with ACC, LIHC, and UCEC. Pathway analysis confirmed that cuproptosis regulators were associated with the metabolism-related pathways. The expression of MTF1, NLRP3, and SLC31A1 was positively related with ImmuneScore, StromalScore, and ESTIMATEScore in almost all types of tumor, whereas ATP7B, DLAT, DLD, LIAS, PDHA1, and PDHB were significantly negatively correlated with the scores. In addition, CRGs were significantly correlated with RNA stemness score, DNA stemness score, microsatellite instability, and tumor mutational burden. The expression of ATP7A, ATP7B, LIAS, and DLAT was significantly positively correlated with the drug sensitivity of Docetaxel. ATP7A, LIAS, and FDX1 were significantly negatively correlated with the drug sensitivity of UNC0638, XMD13−2, YM201636, and KIN001−260.

Conclusions

The altered genomic and clinical characteristics of cuproptosis regulators were comprehensively elucidated, providing a preliminary basis for understanding the functions of cuproptosis in pan-cancer.

Effect of Copper on the Function of Isolated Porcine Kidneys Stored Using Simple Hypothermia

Renal ischemia in the peri-transplant period causes a number of changes that adversely affect the initiation of normal vital functions in grafts after transplantation. To minimise the extent of ischemic damage, organs are stored in preservation fluid. The components of the fluid are supposed to ensure stabilisation of the cell cytoskeleton, protect against oxygen free radicals, reduce cell swelling, and ensure endothelial cell integrity. The aim of this study was to analyse the protective effect of Cu2+, as a component of Biolasol preservative fluid, in the prevention of nephron damage occurring during the graft storage period. Analyses of the effectiveness of copper in the presence of prolactin added to Biolasol fluid were also carried out. Forty isolated pig slaughter kidneys were used in the study, avoiding the use of laboratory animals. The kidneys were stored using simple hypothermia. After 2 h and 48 h of graft storage, selected biochemical indicators of renal function were determined in the collected perfusates. The addition of Cu2+ at a dose of 1 µg/L to the composition of Biolasol fluid was found to affect the generation of ischemic damage in the isolated pig kidney. The intensity of the occurrence of these processes is exacerbated by the presence of prolactin at a dose of 0.1 µg/L.

Copper-Dependent Kinases and Their Role in Cancer Inception, Progression and Metastasis

In recent years, copper function has been expanded beyond its consolidated role as a cofactor of enzyme catalysis. Recent papers have demonstrated a new dynamic role for copper in the regulation of cell signaling pathways through direct interaction with protein kinases, modulating their activity. The activation of these pathways is exacerbated in cancer cells to sustain the different steps of tumor growth and dissemination. This review will focus on a novel proposed role for the transition metal copper as a regulator of cell signaling pathways through direct interaction with known protein kinases, which exhibit binding domains for this metal. Activation of these pathways in cancer cells supports both tumor growth and dissemination. In addition to the description of the results recently reported in the literature on the subject, relevance will be given to the possibility of controlling the cellular levels of copper and its homeostatic regulators. Overall, these findings may be of central relevance in order to propose copper and its homeostatic regulators as possible targets for novel therapies, which may act synergistically to those already existing to control cancer growth and dissemination.

Whole-Transcriptome Sequencing Analyses of Nuclear Antixoxidant-1 in Endothelial Cells: Role in Inflammation and Atherosclerosis

Inflammation, oxidative stress, and copper (Cu) play an important role in cardiovascular disease, including atherosclerosis. We previously reported that cytosolic Cu chaperone antioxidant-1 (Atox1) translocates to the nucleus in response to inflammatory cytokines or exogenous Cu and that Atox1 is localized at the nucleus in the endothelium of inflamed atherosclerotic aorta. However, the roles of nuclear Atox1 and their function are poorly understood. Here we showed that Atox1 deficiency in ApoE-/- mice with a Western diet exhibited a significant reduction of atherosclerotic lesion formation. In vitro, adenovirus-mediated overexpression of nuclear-targeted Atox1 (Ad-Atox1-NLS) in cultured human endothelial cells (ECs) increased monocyte adhesion and reactive oxygen species (ROS) production compared to control cells (Ad-null). To address the underlying mechanisms, we performed genome-wide mapping of Atox1-regulated targets in ECs, using an unbiased systemic approach integrating sequencing data. Combination of ChIP-Seq and RNA-Seq analyses in ECs transfected with Ad-Atox1-NLS or Ad-null identified 1387 differentially expressed genes (DEG). Motif enrichment assay and KEGG pathway enrichment analysis revealed that 248 differentially expressed genes, including inflammatory and angiogenic genes, were regulated by Atox1-NLS, which was then confirmed by real-time qPCR. Among these genes, functional analysis of inflammatory responses identified CD137, CSF1, and IL5RA as new nuclear Atox1-targeted inflammatory genes, while CD137 is also a key regulator of Atox1-NLS-induced ROS production. These findings uncover new nuclear Atox1 downstream targets involved in inflammation and ROS production and provide insights into the nuclear Atox1 as a potential therapeutic target for the treatment of inflammatory diseases such as atherosclerosis.

New diagnostic and therapeutic strategies for myocardial infarction via nanomaterials

Myocardial infarction is lethal to patients because of insufficient blood perfusion to vital organs. Several attempts have been made to improve its prognosis, among which nanomaterial research offers an opportunity to address this problem at the molecular level and has the potential to improve disease prevention, diagnosis, and treatment significantly. Up to now, nanomaterial-based technology has played a crucial role in broad novel diagnostic and therapeutic strategies for cardiac repair. This review summarizes various nanomaterial applications in myocardial infarction from multiple aspects, including high precision detection, pro-angiogenesis, regulating immune homeostasis, and miRNA and stem cell delivery vehicles. We also propose promising research hotspots that have not been reported much yet, such as conjugating pro-angiogenetic elements with nanoparticles to construct drug carriers, developing nanodrugs targeting other immune cells except for macrophages in the infarcted myocardium or the remote region. Though most of those strategies are preclinical and lack clinical trials, there is tremendous potential for their further applications in the future.

Interleukin-22 Deficiency Reduces Angiotensin II-Induced Aortic Dissection and Abdominal Aortic Aneurysm in ApoE-/- Mice

Background

Our previous study showed that interleukin-22 (IL-22) levels were increased in patients with aortic dissection (AD). This study evaluated the effects of IL-22 on AD/abdominal aortic aneurysm (AAA) formation in angiotensin II (Ang II)-infused ApoE-/- mice.

Methods

ApoE-/- mice were treated with Ang II for 28 days, and IL-22 expression was examined. In addition, the effects of IL22 deficiency on AAA/AD formation induced by Ang II infusion in ApoE-/- mice were investigated. ApoE-/-IL-22-/- mice were transplanted with bone marrow cells isolated from ApoE-/- mice or ApoE-/-IL-22-/- mice, and AAA/AD formation was observed.

Results

IL-22 expression was increased in both the aortas and serum of ApoE-/- mice after Ang II infusion and was mainly derived from aortic CD4+ T lymphocytes (CD4+ TCs). IL-22 deficiency significantly reduced the AAA/AD formation as well as the maximal aortic diameter in Ang II-infused ApoE-/- mice. Decreased elastin fragmentation and reduced fibrosis were observed in the aortas of ApoE-/-IL-22-/- mice compared with ApoE-/- mice. The deletion of IL-22 also decreased aortic M1 macrophage differentiation, alleviated M1 macrophage-induced oxidative stress, and reduced aortic smooth muscle cell loss. Furthermore, M1 macrophage-induced oxidative stress was worsened and AAA/AD formation was promoted in ApoE-/-IL-22-/- mice that received transplanted bone marrow cells from ApoE-/- mice compared with those that were transplanted with bone marrow cells isolated from ApoE-/-IL-22-/- mice.

Conclusions

IL-22 deficiency inhibits AAA/AD formation by inhibiting M1 macrophage-induced oxidative stress. IL-22 potentially represents a promising new target for preventing the progression of AAA/AD.

Dichotomous Role of Tumor Necrosis Factor in Pulmonary Barrier Function and Alveolar Fluid Clearance

Alveolar-capillary leak is a hallmark of the acute respiratory distress syndrome (ARDS), a potentially lethal complication of severe sepsis, trauma and pneumonia, including COVID-19. Apart from barrier dysfunction, ARDS is characterized by hyper-inflammation and impaired alveolar fluid clearance (AFC), which foster the development of pulmonary permeability edema and hamper gas exchange. Tumor Necrosis Factor (TNF) is an evolutionarily conserved pleiotropic cytokine, involved in host immune defense against pathogens and cancer. TNF exists in both membrane-bound and soluble form and its mainly -but not exclusively- pro-inflammatory and cytolytic actions are mediated by partially overlapping TNFR1 and TNFR2 binding sites situated at the interface between neighboring subunits in the homo-trimer. Whereas TNFR1 signaling can mediate hyper-inflammation and impaired barrier function and AFC in the lungs, ligand stimulation of TNFR2 can protect from ventilation-induced lung injury. Spatially distinct from the TNFR binding sites, TNF harbors within its structure a lectin-like domain that rather protects lung function in ARDS. The lectin-like domain of TNF -mimicked by the 17 residue TIP peptide- represents a physiological mediator of alveolar-capillary barrier protection. and increases AFC in both hydrostatic and permeability pulmonary edema animal models. The TIP peptide directly activates the epithelial sodium channel (ENaC) -a key mediator of fluid and blood pressure control- upon binding to its α subunit, which is also a part of the non-selective cation channel (NSC). Activity of the lectin-like domain of TNF is preserved in complexes between TNF and its soluble TNFRs and can be physiologically relevant in pneumonia. Antibody- and soluble TNFR-based therapeutic strategies show considerable success in diseases such as rheumatoid arthritis, psoriasis and inflammatory bowel disease, but their chronic use can increase susceptibility to infection. Since the lectin-like domain of TNF does not interfere with TNF's anti-bacterial actions, while exerting protective actions in the alveolar-capillary compartments, it is currently evaluated in clinical trials in ARDS and COVID-19. A more comprehensive knowledge of the precise role of the TNFR binding sites versus the lectin-like domain of TNF in lung injury, tissue hypoxia, repair and remodeling may foster the development of novel therapeutics for ARDS.

FKBP52 in Neuronal Signaling and Neurodegenerative Diseases: A Microtubule Story

The FK506-binding protein 52 (FKBP52) belongs to a large family of ubiquitously expressed and highly conserved proteins (FKBPs) that share an FKBP domain and possess Peptidyl-Prolyl Isomerase (PPIase) activity. PPIase activity catalyzes the isomerization of Peptidyl-Prolyl bonds and therefore influences target protein folding and function. FKBP52 is particularly abundant in the nervous system and is partially associated with the microtubule network in different cell types suggesting its implication in microtubule function. Various studies have focused on FKBP52, highlighting its importance in several neuronal microtubule-dependent signaling pathways and its possible implication in neurodegenerative diseases such as tauopathies (i.e., Alzheimer disease) and alpha-synucleinopathies (i.e., Parkinson disease). This review summarizes our current understanding of FKBP52 actions in the microtubule environment, its implication in neuronal signaling and function, its interactions with other members of the FKBPs family and its involvement in neurodegenerative disease.

Role of copper nanoparticles in wound healing for chronic wounds: literature review

Chronic wounds are defined as wounds that fail to proceed through the normal phases of wound healing in an orderly and timely manner. The most common and inevitable impairment to wound healing is the installation of an infection, usually in the case of chronic wounds. Therefore, the objective of the present review was to identify the importance of copper nanoparticles in dressings for wound healing. Nanoparticles such as silver, gold and copper combat infectious processes through the inhibition of protein synthesis, peroxidation of the cell membrane and destroying the nucleic acids of bacteria and viruses. Among bioactive nanoparticles, copper plays a complex role in various cells, it modulates several cytokines and growth factor mechanisms of action and is essentially involved in all stages of the wound healing process. More importantly, copper plays a key role in skin regeneration and angiogenesis and accelerates the healing process through induction of vascular endothelial growth factor (VEGF) and angiogenesis by hypoxia-induced factor-1-alpha (HIF-1α) action where copper enhances HIF-1α expression and HIF-1α binding to the critical motifs in the promoter and putative enhancer regions of HIF-1-regulated genes.

Cysteine oxidation of copper transporter CTR1 drives VEGFR2 signalling and angiogenesis

VEGFR2 (KDR/Flk1) signaling in endothelial cells (ECs) is essential for developmental and reparative angiogenesis. Reactive oxygen species (ROS) and copper (Cu) are also involved.in these processes. However, their inter-relationship is poorly understood. The role of endothelial Cu importer CTR1 in VEGFR2 signaling and angiogenesis in vivo is hitherto unknown. Here we show that CTR1 functions as a previously unrecognized redox sensor to promote angiogenesis in ECs. CTR1-depleted ECs showed reduced VEGF-induced VEGFR2 signaling and angiogenic responses. Mechanistically, CTR1 was rapidly sulfenylated at Cys189 in cytosolic C-terminus upon VEGF stimulation, which induced CTR1-VEGFR2 disulfide bond formation and their co-internalization to early endosomes, driving sustained VEGFR2 signaling. In vivo, EC-specific Ctr1-deficient mice or CRISPR/Cas9-generated “redox-dead” Cys to Ala Ctr1 knock-in mutant mice had impaired developmental and reparative angiogenesis. Thus, oxidation of CTR1 at Cys189 promotes VEGFR2 internalization and signaling to enhance angiogenesis. Our study uncovers an important mechanism for ROS sensing through CTR1 to drive neovascularization.

Copper in the tumor microenvironment and tumor metastasis

Copper (Cu), an essential micronutrient, plays an essential role in several physiological processes, including cell proliferation and angiogenesis; however, its dysregulation induces oxidative stress and inflammatory responses. Significant Cu accumulation is observed in several tumor tissues. The bioavailability of intracellular Cu is tightly controlled by Cu transporters, including Cu transporter 1 (CTR1) and Cu-transporting P-type ATPase α and β (ATP7A and ATP7B), and Cu chaperones, including Cu chaperone for superoxide dismutase 1 (CCS) and antioxidant-1 (Atox-1). In several tumor tissues, these abnormalities that induce intra­cellular Cu accumulation are involved in tumor progression. In addition, functional disturbance in Cu-containing secretory enzymes, such as superoxide dismutase 3 (SOD3), and lysyl oxidase enzymes (LOX and LOXL1–4) with abnormal Cu dynamics plays a key role in tumor metastasis. For example, the loss of SOD3 in tumor tissues induces oxidative stress, which promotes neovascularization and epithelial-to-mesenchymal transition (EMT). LOX promotes collagen crosslinking, which functions in the metastatic niche formation. Accordingly, restricted Cu regulation may be a novel strategy for the inhibition of tumor metastasis. However, it is unclear how these Cu disturbances occur in tumor tissues and the exact molecular mechanisms underlying Cu secretory enzymes. In this review article, I discuss the role of Cu transporters, Cu chaperones, and Cu-containing secretory enzymes in tumor progression to better understand the role of Cu homeostasis in tumor tissues.

Role of Copper on Mitochondrial Function and Metabolism

Copper is essential for life processes like energy metabolism, reactive oxygen species detoxification, iron uptake, and signaling in eukaryotic organisms. Mitochondria gather copper for the assembly of cuproenzymes such as the respiratory complex IV, cytochrome c oxidase, and the antioxidant enzyme superoxide dismutase 1. In this regard, copper plays a role in mitochondrial function and signaling involving bioenergetics, dynamics, and mitophagy, which affect cell fate by means of metabolic reprogramming. In mammals, copper homeostasis is tightly regulated by the liver. However, cellular copper levels are tissue specific. Copper imbalances, either overload or deficiency, have been associated with many diseases, including anemia, neutropenia, and thrombocytopenia, as well as tumor development and cancer aggressivity. Consistently, new pharmacological developments have been addressed to reduce or exacerbate copper levels as potential cancer therapies. This review goes over the copper source, distribution, cellular uptake, and its role in mitochondrial function, metabolic reprograming, and cancer biology, linking copper metabolism with the field of regenerative medicine and cancer.

Targeting the Copper Transport System to Improve Treatment Efficacies of Platinum-Containing Drugs in Cancer Chemotherapy

The platinum (Pt)-containing antitumor drugs including cisplatin (cis-diamminedichloroplatinum II, cDDP), carboplatin, and oxaliplatin, have been the mainstay of cancer chemotherapy. These drugs are effective in treating many human malignancies. The major cell-killing target of Pt drugs is DNA. Recent findings underscored the important roles of Pt drug transport system in cancer therapy. While many mechanisms have been proposed for Pt-drug transport, the high-affinity copper transporter (hCtr1), Cu chaperone (Atox1), and Cu exporters (ATP7A and ATP7B) are also involved in cDDP transport, highlighting Cu homeostasis regulation in Pt-based cancer therapy. It was demonstrated that by reducing cellular Cu bioavailable levels by Cu chelators, hCtr1 is transcriptionally upregulated by transcription factor Sp1, which binds the promoters of Sp1 and hCtr1. In contrast, elevated Cu poisons Sp1, resulting in suppression of hCtr1 and Sp1, constituting the Cu-Sp1-hCtr1 mutually regulatory loop. Clinical investigations using copper chelator (trientine) in carboplatin treatment have been conducted for overcoming Pt drug resistance due in part to defective transport. While results are encouraging, future development may include targeting multiple steps in Cu transport system for improving the efficacies of Pt-based cancer chemotherapy. The focus of this review is to delineate the mechanistic interrelationships between Cu homeostasis regulation and antitumor efficacy of Pt drugs.

Interference between copper transport systems and platinum drugs

Cisplatin, or cis-diamminedichloridoplatinum(II) cis-[PtCl₂(NH₃)₂], is a platinum-based anticancer drug largely used for the treatment of various types of cancers, including testicular, ovarian and colorectal carcinomas, sarcomas, and lymphomas. Together with other platinum-based drugs, cisplatin triggers malignant cell death by binding to nuclear DNA, which appears to be the ultimate target. In addition to passive diffusion across the cell membrane, other transport systems, including endocytosis and some active or facilitated transport mechanisms, are currently proposed to play a pivotal role in the uptake of platinum-based drugs. In this review, an updated view of the current literature regarding the intracellular transport and processing of cisplatin will be presented, with special emphasis on the plasma membrane copper permease CTR1, the Cu-transporting ATPases, ATP7A and ATP7B, located in the trans-Golgi network, and the soluble copper chaperone ATOX1. Their role in eliciting cisplatin efficacy and their exploitation as pharmacological targets will be addressed.

The P-type ATPase transporter ATP7A promotes angiogenesis by limiting autophagic degradation of VEGFR2

VEGFR2 (KDR/Flk1) signaling in endothelial cells (ECs) plays a central role in angiogenesis. The P-type ATPase transporter ATP7A regulates copper homeostasis, and its role in VEGFR2 signaling and angiogenesis is entirely unknown. Here, we describe the unexpected crosstalk between the Copper transporter ATP7A, autophagy, and VEGFR2 degradation. The functional significance of this Copper transporter was demonstrated by the finding that inducible EC-specific ATP7A deficient mice or ATP7A-dysfunctional ATP7Amut mice showed impaired post-ischemic neovascularization. In ECs, loss of ATP7A inhibited VEGF-induced VEGFR2 signaling and angiogenic responses, in part by promoting ligand-induced VEGFR2 protein degradation. Mechanistically, VEGF stimulated ATP7A translocation from the trans-Golgi network to the plasma membrane where it bound to VEGFR2, which prevented autophagy-mediated lysosomal VEGFR2 degradation by inhibiting autophagic cargo/adapter p62/SQSTM1 binding to ubiquitinated VEGFR2. Enhanced autophagy flux due to ATP7A dysfunction in vivo was confirmed by autophagy reporter CAG-ATP7Amut -RFP-EGFP-LC3 transgenic mice. In summary, our study uncovers a novel function of ATP7A to limit autophagy-mediated degradation of VEGFR2, thereby promoting VEGFR2 signaling and angiogenesis, which restores perfusion recovery and neovascularization. Thus, endothelial ATP7A is identified as a potential therapeutic target for treatment of ischemic cardiovascular diseases.

The Multifaceted Roles of Copper in Cancer: A Trace Metal Element with Dysregulated Metabolism, but Also a Target or a Bullet for Therapy

In the human body, copper (Cu) is a major and essential player in a large number of cellular mechanisms and signaling pathways. The involvement of Cu in oxidation-reduction reactions requires close regulation of copper metabolism in order to avoid toxic effects. In many types of cancer, variations in copper protein levels have been demonstrated. These variations result in increased concentrations of intratumoral Cu and alterations in the systemic distribution of copper. Such alterations in Cu homeostasis may promote tumor growth or invasiveness or may even confer resistance to treatments. Once characterized, the dysregulated Cu metabolism is pinpointing several promising biomarkers for clinical use with prognostic or predictive capabilities. The altered Cu metabolism in cancer cells and the different responses of tumor cells to Cu are strongly supporting the development of treatments to disrupt, deplete, or increase Cu levels in tumors. The metallic nature of Cu as a chemical element is key for the development of anticancer agents via the synthesis of nanoparticles or copper-based complexes with antineoplastic properties for therapy. Finally, some of these new therapeutic strategies such as chelators or ionophores have shown promising results in a preclinical setting, and others are already in the clinic.

Cross-Talk between NADPH Oxidase and Mitochondria: Role in ROS Signaling and Angiogenesis

Angiogenesis, a new vessel formation from the pre-existing ones, is essential for embryonic development, wound repair and treatment of ischemic heart and limb diseases. However, dysregulated angiogenesis contributes to various pathologies such as diabetic retinopathy, atherosclerosis and cancer. Reactive oxygen species (ROS) derived from NADPH oxidase (NOX) as well as mitochondria play an important role in promoting the angiogenic switch from quiescent endothelial cells (ECs). However, how highly diffusible ROS produced from different sources and location can communicate with each other to regulate angiogenesis remains unclear. To detect a localized ROS signal in distinct subcellular compartments in real time in situ, compartment-specific genetically encoded redox-sensitive fluorescence biosensors have been developed. Recently, the intercellular communication, “cross-talk”, between ROS derived from NOX and mitochondria, termed “ROS-induced ROS release”, has been proposed as a mechanism for ROS amplification at distinct subcellular compartments, which are essential for activation of redox signaling. This “ROS-induced ROS release” may represent a feed-forward mechanism of localized ROS production to maintain sustained signaling, which can be targeted under pathological conditions with oxidative stress or enhanced to promote therapeutic angiogenesis. In this review, we summarize the recent knowledge regarding the role of the cross-talk between NOX and mitochondria organizing the sustained ROS signaling involved in VEGF signaling, neovascularization and tissue repair.

Lysyl Oxidase (LOX): Functional Contributions to Signaling Pathways

Cu-dependent lysyl oxidase (LOX) plays a catalytic activity-related, primary role in the assembly of the extracellular matrix (ECM), a dynamic structural and regulatory framework which is essential for cell fate, differentiation and communication during development, tissue maintenance and repair. LOX, additionally, plays both activity-dependent and independent extracellular, intracellular and nuclear roles that fulfill significant functions in normal tissues, and contribute to vascular, cardiac, pulmonary, dermal, placenta, diaphragm, kidney and pelvic floor disorders. LOX activities have also been recognized in glioblastoma, diabetic neovascularization, osteogenic differentiation, bone matrix formation, ligament remodeling, polycystic ovary syndrome, fetal membrane rupture and tumor progression and metastasis. In an inflammatory context, LOX plays a role in diminishing pluripotent mesenchymal cell pools which are relevant to the pathology of diabetes, osteoporosis and rheumatoid arthritis. Most of these conditions involve mechanisms with complex cell and tissue type-specific interactions of LOX with signaling pathways, not only as a regulatory target, but also as an active player, including LOX-mediated alterations of cell surface receptor functions and mutual regulatory activities within signaling loops. In this review, we aim to provide insight into the diverse ways in which LOX participates in signaling events, and explore the mechanistic details and functional significance of the regulatory and cross-regulatory interactions of LOX with the EGFR, PDGF, VEGF, TGF-β, mechano-transduction, inflammatory and steroid signaling pathways.

Rapid Evaluation of CRISPR Guides and Donors for Engineering Mice

Although the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/ CRISPR associated protein 9 (Cas9) technique has dramatically lowered the cost and increased the speed of generating genetically engineered mice, success depends on using guide RNAs and donor DNAs which direct efficient knock-out (KO) or knock-in (KI). By Sanger sequencing DNA from blastocysts previously injected with the same CRISPR components intended to produce the engineered mice, one can test the effectiveness of different guide RNAs and donor DNAs. We describe in detail here a simple, rapid (three days), inexpensive protocol, for amplifying DNA from blastocysts to determine the results of CRISPR point mutation KIs. Using it, we show that (1) the rate of KI seen in blastocysts is similar to that seen in mice for a given guide RNA/donor DNA pair, (2) a donor complementary to the variable portion of a guide integrated in a more all-or-none fashion, (3) donor DNAs can be used simultaneously to integrate two different mutations into the same locus, and (4) by placing silent mutations about every 6 to 10 bp between the Cas9 cut site and the desired mutation(s), the desired mutation(s) can be incorporated into genomic DNA over 30 bp away from the cut at the same high efficiency as close to the cut.

The molecular mechanisms of copper metabolism and its roles in human diseases

Copper is an essential element in cells; it can act as either a recipient or a donor of electrons, participating in various reactions. However, an excess of copper ions in cells is detrimental as these copper ions can generate free radicals and increase oxidative stress. In multicellular organisms, copper metabolism involves uptake, distribution, sequestration, and excretion, at both the cellular and systemic levels. Mammalian enterocytes take in bioavailable copper ions from the diet in a Ctr1-dependent manner. After incorporation, cuprous ions are delivered to ATP7A, which pumps Cu⁺ from enterocytes into the blood. Copper ions arrive at the liver through the portal vein and are incorporated into hepatocytes by Ctr1. Then, Cu⁺ can be secreted into the bile or the blood via the Atox1/ATP7B/ceruloplasmin route. In the bloodstream, this micronutrient can reach peripheral tissues and is again incorporated by Ctr1. In peripheral tissue cells, cuprous ions are either sequestrated by molecules such as metallothioneins or targeted to utilization pathways by chaperons such as Atox1, Cox17, and CCS. Copper metabolism must be tightly controlled in order to achieve homeostasis and avoid disorders. A hereditary or acquired copper unbalance, including deficiency, overload, or misdistribution, may cause or aggravate certain diseases such as Menkes disease, Wilson disease, neurodegenerative diseases, anemia, metabolic syndrome, cardiovascular diseases, and cancer. A full understanding of copper metabolism and its roles in diseases underlies the identification of novel effective therapies for such diseases.