Copper overload induces apoptosis and impaired proliferation of T cell in zebrafish

ATP7A Maintains Bactericidal Function of Neutrophils and Macrophages via Regulating the Formation and Activation of Phagolysosomes

Neutrophils and macrophages are indispensable phagocytic immune cells, critically responsible for fish's ability to combat pathogens. Studies unveil that ATP7A is essential for copper trafficking to the lysosome in the cells, a process that is fundamental for their antibacterial functions in vitro. However, its antibacterial role in vivo and the underlying mechanisms have been insufficiently explored. In this study, we have demonstrated that atp7a-/- mutant larvae are significantly more susceptible to Aeromonas hydrophila (AH) infection and possess fewer neutrophils and macrophages compared to their wild-type (WT) counterparts, and these mutants show a pronounced delay in the migration of the cells in response to infection. Atp7a deficiency leads to a marked downregulation of key phagosomal and lysosomal proteins, which impairs the formation of phagolysosomes and impairs lysosomal acidification and reactive oxygen species (ROS) elevation, then results in the ultimately impaired phagocytic activity and the attenuated release of phagolysosomal inflammatory and chemotactic signals such as il-1β/6/8, underscoring the impaired immune function of the mutants. Furthermore, Atp7a is shown to interact with proteins Lamp1 and Ctsb to facilitate copper trafficking and with Rabep1 and Rabgef1, to shield these proteins from degradation. Meanwhile, Atp7a-dependent copper trafficking is essential in Rabgef1 ubiquitination and the consequent activation of Rab5 and Rab7. These thereby enhance phagolysosomal activity and reinforce the immune response of neutrophils and macrophages against AH infection. In conclusion, this study compellingly establishes the pivotal role of Atp7a in sustaining the bactericidal capacities of immune cells in fish, while also illuminating the potential immune-related implications for individuals with ATP7A deficiency.

Curcumin's role in reshaping the redox dynamics of fish kidneys: NRF2 activation as a strategy against copper-induced nephropathy

From essential to harmful, excess copper compromises aquatic vitality. Curcumin, a potent antioxidant bioactive, counteracts heavy metal toxicity. This study examines its role in modulating the NRF2-KEAP1 pathway to boost antioxidant defenses and mitigate apoptosis in kidneys of Channa punctatus exposed to environmentally relevant Copper concentrations (ERCC). 180 fully habituated fish were categorized into six groups: Group 1 served as control, Group 2 was treated with 3 mg/L Curcumin, Group 3 was exposed to ERCC (0.85 mg/L Copper), while Group 4, Group 5 and Group 6 received co-exposure to ERCC along with the escalating Curcumin concentrations of 1 mg/L, 2 mg/L, and 3 mg/L, respectively, over periods of 15, 30, 45, 60, and 75 days. Biochemical assays were conducted to evaluate oxidative stress markers (Reactive oxygen species, reduced glutathione, glutathione peroxidase, and lipid peroxidation), kidney damage indicators (creatinine), and genotoxicity (micronuclei). Additionally, transcriptional profiling assessed mRNA levels of apoptosis-related factors (p53, bax, apaf1, cas9, cas3 and bcl2), while histopathological examinations revealed changes in renal architecture. Molecular docking analysis confirmed Curcumin's strong binding affinity to KEAP1, providing insights into its role in activating the NRF2-KEAP1 pathway. The results indicated that Curcumin significantly (p < 0.05) reduced Copper-induced oxidative stress, improved antioxidant defenses, suppressed genotoxicity, modulated apoptosis, and maintained renal tissue integrity. These findings validate curcumin's potential in effectively combating copper toxicity in aquaculture, paving the way for enhanced fish health and improved food safety.

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.

Spermidine alleviates copper-induced oxidative stress, inflammation and cuproptosis in the liver

Copper exposure poses potential detrimental effects on both public and ecosystem health. Spermidine, an antioxidant, has shown promise in reducing oxidative stress and inflammation within the liver. However, its specific role in mitigating copper-induced hepatic cuproptosis and disturbances in copper metabolism remains unexplored. Consequently, this research aims to investigate to examine the impact of spermidine on hepatic cuproptosis and the related disturbances in copper metabolism. In the study, we established a model of copper-induced liver toxicity by feeding C57BL/6 mice a high-copper diet for three months. Histopathological and biochemical analyses revealed that copper exposure induced hepatic inflammatory cell infiltration, hepatocyte degeneration, elevated levels of MDA, ROS, and Cu2+ accumulation in the liver, and increased ALT and AST activities in serum (p < .05). Regarding inflammation, copper exposure significantly increased serum levels of IL-1β, IL-6, and TNF-α (p < .05), upregulated TNF-α and IFN-γ expression, and downregulated IL-10 expression in the liver (p < .05). Meanwhile, copper exposure inhibited the expression of copper metabolism and Fe-S cluster-related proteins (p < .05). Exogenous spermidine administration effectively reduced ROS, MDA, and Cu2+ accumulation in the liver, while also decreasing ALT and AST activites, IL-1β, IL-6, and TNF-α levels in the serum (p < .05), and downregulated TNF-α and IFN-γ expression (p < .001). Additionally, spermidine combined with CuSO4 treatment significantly promotes the expression of copper metabolism and Fe-S cluster-related proteins, compared to the CuSO4 group (p < .05). In summary, spermidine reduces Cu2+ accumulation in the liver, alleviates hepatic cuproptosis, oxidative damage, and inflammation, and exerts a protective effect on the liver.

Biometallic ions and derivatives: a new direction for cancer immunotherapy

Biometallic ions play a crucial role in regulating the immune system. In recent years, cancer immunotherapy has become a breakthrough in cancer treatment, achieving good efficacy in a wide range of cancers with its specificity and durability advantages. However, existing therapies still face challenges, such as immune tolerance and immune escape. Biometallic ions (e.g. zinc, copper, magnesium, manganese, etc.) can assist in enhancing the efficacy of immunotherapy through the activation of immune cells, enhancement of tumor antigen presentation, and improvement of the tumor microenvironment. In addition, biometallic ions and derivatives can directly inhibit tumor cell progression and offer the possibility of effectively overcoming the limitations of current cancer immunotherapy by promoting immune responses and reducing immunosuppressive signals. This review explores the role and potential application prospects of biometallic ions in cancer immunotherapy, providing new ideas for future clinical application of metal ions as part of cancer immunotherapy and helping to guide the development of more effective and safe therapeutic regimens.

Alleviation of Copper-Induced Hepatotoxicity by Bergenin: Diminution of Oxidative Stress, Inflammation, and Apoptosis via Targeting SIRT1/FOXO3a/NF-κB Axes and p38 MAPK Signaling

Despite its biological importance, excess copper induces organ damage, especially to the liver. Disruption of critical signaling cascades that control redox status, inflammatory responses, and cellular apoptosis significantly contributes to the copper-induced hepatotoxicity. The present work explored the hepatoprotective ability of bergenin against the copper-induced hepatotoxicity using male Wistar rats as a mammalian model. The results revealed that bergenin suppressed the copper-evoked histopathological changes and hepatocellular necrosis as indicated by decreased activity of the liver enzymes ALT and AST in the sera of the copper-intoxicated rats. It decreased hepatic copper content and the copper-induced oxidative stress as revealed by reduced lipid peroxidation and improved activity of the antioxidant enzymes thioredoxin reductase, glutathione peroxidase, catalase, and superoxide dismutase. Bergenin downregulated the inflammatory cytokines TNF-α and IL-6, and the inflammatory cell infiltration to the liver tissues. Additionally, it inhibited the copper-induced apoptosis as indicated by significant reduction in caspase-3 activity. At the molecular level, bergenin activated the antioxidant transcription factor FOXO3a, inhibited the nuclear translocation of the inflammatory transcription factor NF-κB, and suppressed the inflammatory signaling molecules p38 MAPK and c-Fos. Interestingly, bergenin improved the expression of the anti-apoptotic protein Bcl2 and reduced the pro-apoptotic protein BAX. Bergenin markedly enhanced the expression of the histone deacetylase protein SIRT1 that regulates activity of NF-κB and FOXO3a. Collectively, these findings highlight the alleviating activity of bergenin against the copper-induced hepatotoxicity via controlling oxidative stress, inflammation, and apoptosis potentially through upregulation of SIRT1, activation of FOXO3a along with suppression of NF-κB and p38 MAPK signaling.

Prolonged Copper Supplementation Modified Minerals in the Kidney, Liver and Blood, and Potentiated Oxidative Stress and Vasodilation of Isolated Aortic Rings in Young Wistar Rats

BACKGROUND

Previous studies have highlighted that copper supplementation at 200% of the recommended daily dietary allowance modified vascular contraction and relaxation through increased reactive oxygen species (ROS) and prostaglandin formation, which modified the antioxidant status of middle-aged Wistar rats.

METHODS

In this study, young (1 month old) male Wistar rats (n/group = 10) received a diet supplemented with 6.45 mg copper/kg (100% of daily recommendation-Group A) for 8 weeks. The experimental group received 12.9 mg copper/kg of diet (200% of the daily recommendation-Group B).

RESULTS

Experimental supplementation with 200% copper modified the copper concentration in the blood (1.21-fold, p = 0.04), liver (1.15-fold, p = 0.032), and kidneys (1.23-fold, p = 0.045), potentiated the ROS formation in the aortic rings, and enhanced the sensitivity of the aortic rings to the vasodilator acetylcholine. We observed an increased participation of nitric oxide (NO) derived from inducible NO synthase (iNOS) in vascular contraction and a decreased net effect of vasodilator prostanoids derived from cyclooxygenase-2 in vascular relaxation. In rat kidneys, the concentrations of potassium (1.08-fold, p = 0.001) and iron (1.13-fold, p = 0.046) were higher, while, calcium (0.88-fold, p = 0.001) and chromium (0.77-fold, p = 0.005) concentrations were lower. In the rat liver, magnesium (1.06-fold, p = 0.012) was higher. No differences were observed in the concentrations of sodium, zinc, manganese, selenium, cobalt, molybdenum, and vanadium. The antioxidant activity of water- and lipid-soluble compounds; total antioxidant status in the blood; and superoxide dismutase, catalase, and malondialdehyde levels in the heart did not change.

CONCLUSIONS

In young rats, prolonged supplementation with 200% copper had a lesser effect than anticipated on oxidative stress and vascular reactivity. Detailed data on the status of trace elements and their interactions in patients of different age groups are strongly required for effective nutritional and therapeutic intervention.

Copper redox state in cells and aquatic organisms: Implication for toxicity

Copper (Cu) redox state has been an important issue in biology and toxicology research, but many research gaps remain to be explored due to the limitations in the detecting techniques. Herein, the regulation of Cu homeostasis, including absorption, translocation, utilization, storage, and elimination behavior is discussed. Cuproptosis, a newly identified type of cell death caused by excessive Cu accumulation, which results in the aggregation of DLAT protein or the loss of Fe-S cluster and finally proteotoxic stress, is reviewed. Several longstanding mysteries of diseases such as Wilson disease and toxic effects, may be attributed to cuproptosis. Furthermore, we review the advanced detection methods and application of Cu(I) and Cu(II), especially the in-situ imaging techniques such as XANES, and chemosensors. Most of the existing studies using these detection techniques focus on the bioaccumulation and toxicity of Cu(I) and Cu(II) in cells and aquatic organisms. Finally, it will be important to identify the roles of Cu(I) and Cu(II) in the growth, development, and diseases of organisms, as well as the relationship between bioaccumulation and toxicity of Cu(I) and Cu(II) in cellular and aquatic toxicology.