Comparison of Copper Concentration Between Rejected Renal Grafts and Cancerous Kidneys

Direct and Indirect Linkages Between Trace Element Status and Health Indicators - a Multi-tissue Case-Study of Two Deer Species in Denmark

Measuring trace element concentrations in tissue can be a valuable approach to monitor animal health status. Temporal variation in the absorption, transport, and storage of elements between different tissues can, however, complicate the assessment of element-health relationships. Here, we measured concentrations of selected essential (copper (Cu), zinc (Zn), selenium (Se)) and non-essential (arsenic (As), cadmium (Cd), lead (Pb)) trace elements within blood, liver, kidney, and hair of fallow deer (Dama dama; N=20) and red deer (Cervus elaphus; N=21). Using multivariate regression and structural equation models, we estimated direct and indirect linkages between tissue-specific trace element profiles and long- (body condition) and short-term (serum protein biomarkers for acute inflammation, infection, and malnutrition) health indicators. Trace element concentrations varied markedly and were weakly correlated among tissues, with the exception of Se. After accounting for sex- and site-differences in trace element concentrations, body condition of red deer was directly, and positively, associated to trace element status in liver and hair, but not in kidney. For both deer species, trace element status in blood was directly linked to serum protein status with an indirect positive association to deer body condition. For fallow deer, no direct association between trace element status and body condition was detected in any of the tissues, possibly because of elemental homeostasis, and because all individuals were in good clinical health. This study shows that hair can serve as an effective, non-invasive, biomarker in deer health assessments, yet, to fully uncover trace element-health relationships a variety of sample matrices is preferred.

Cuproptosis: Mechanism, role, and advances in urological malignancies

Prostate, bladder, and kidney cancers are the most common malignancies of the urinary system. Chemotherapeutic drugs are generally used as adjuvant treatment in the middle, late, or recurrence stages after surgery for urologic cancers. However, traditional chemotherapy is plagued by problems such as poor efficacy, severe side effects, and complications. Copper-containing nanomedicines are promising novel cancer treatment modalities that can potentially overcome these disadvantages. Copper homeostasis and cuproptosis play crucial roles in the development, adaptability, and therapeutic sensitivity of urological malignancies. Cuproptosis refers to the direct binding of copper ions to lipoylated components of the tricarboxylic acid cycle, leading to protein oligomerization, loss of iron-sulfur proteins, proteotoxic stress, and cell death. This review focuses on copper homeostasis and cuproptosis as well as recent findings on copper and cuproptosis in urological malignancies. Furthermore, we highlight the potential therapeutic applications of copper- and cuproptosis-targeted therapies to better understand cuproptosis-based drugs for the treatment of urological tumors in the future.

Cope with copper: From molecular mechanisms of cuproptosis to copper-related kidney diseases

Cuproptosis has recently been identified as a novel regulatory mechanism of cell death. It is characterized by the accumulation of copper in mitochondria and its binding to acylated proteins. These characteristics lead to the downregulation of iron-sulfur cluster proteins and protein toxicity stress, ultimately resulting in cell death. Cuproptosis is distinct from other types of cell death, including necrosis, apoptosis, ferroptosis, and pyroptosis. Cu induces oxidative stress damage, protein acylation, and the oligomerization of acylated TCA cycle proteins. These processes lead to the downregulation of iron-sulfur cluster proteins and protein toxicity stress, disrupting cellular Cu homeostasis, and causing cell death. Cuproptosis plays a significant role in the development and progression of various kidney diseases such as acute kidney injury, chronic kidney disease, diabetic nephropathy, kidney transplantation, and kidney stones. On the one hand, inducers of cuproptosis, such as disulfiram (DSF), chloroquinolone, and elesclomol facilitate cuproptosis by promoting cell oxidative stress. In contrast, inhibitors of Cu chelators, such as tetraethylenepentamine and tetrathiomolybdate, relieve these diseases by inhibiting apoptosis. To summarize, cuproptosis plays a significant role in the pathogenesis of kidney disease. This review comprehensively discusses the molecular mechanisms underlying cuproptosis and its significance in kidney diseases.

Interaction mechanism of Cu+/Cu2+ on bovine serum albumin: Vitro simulation experiments by spectroscopic methods

Copper (Cu) is an essential trace element for organisms, while excessive concentration of Cu is toxic. In order to assess the toxicity risk of copper in different valences, FTIR, fluorescence, and UV-vis absorption techniques were conducted to study the interactions between either Cu⁺ or Cu²⁺ and bovine serum albumin (BSA) under vitro simulated physiological condition. The spectroscopic analysis demonstrated that the intrinsic fluorescence emitted by BSA could be quenched by Cu⁺/Cu²⁺ via static quenching with binding sites 0.88 and 1.12 for Cu⁺ and Cu²⁺, respectively. On the other hand, the constants of Cu⁺ and Cu²⁺ are 1.14 × 10³ L/mol and 2.08 × 10⁴ L/mol respectively. ΔH is negative whereas ΔS is positive, showing that the interaction between BSA and Cu⁺/Cu²⁺ was mainly driven by electrostatic force. In accordance with Föster's energy transfer theory, the binding distance r showed that the transition of energy from BSA to Cu⁺/Cu²⁺ is highly likely to happen. BSA conformation analyses indicated that the interactions between Cu⁺/Cu²⁺ and BSA could alter the secondary structure of proteins. Current study provides more information of the interaction between Cu⁺/Cu²⁺ and BSA, and reveals the potential toxicological effect of different speciation of copper at molecular level.

Benefits and risks of essential trace elements in chronic kidney disease: a narrative review

Background and Objective

Chronic kidney disease (CKD) is an important public health concern. With the decline of renal function, CKD patients gradually progress to end-stage kidney disease and need to undergo dialysis or kidney transplantation to maintain life, bringing a heavy economic burden to the family and society. Therefore, it is necessary to effectively prevent and delay the progression of CKD. Essential trace elements play an indispensable role in CKD, and the objective of this study is to systematically review their benefits in the disease and summarize the risks of their excess.

Methods

The keywords "trace elements", "chronic kidney disease", "dialysis", "inflammation", and "fibrosis" and their combinations were used to search for relevant literature published in the PubMed database and Web of Science. We then summarized the role of trace element abnormalities in CKD patients in anemia, oxidative stress, inflammation, and chronic fibrosis, and the risk of their excess.

Key Content and Findings

Imbalance of essential trace elements is a common complication of CKD and a risk factor for CKD progression, cardiovascular events, and death. This article reviews the effects of essential trace elements (iron, zinc, selenium, copper, iodine, and manganese) on CKD. We analyze literature and discuss the advantages and disadvantages of various essential trace elements.

Conclusions

Research shows CKD patients have an imbalance of essential trace elements, and treatment based on these is an important direction for future exploration. A knowledge of the homeostasis of trace elements is important to improving the prognosis of CKD patients and delaying the progression of the disease.

Serum Selenium, Iron, Zinc, and Copper Concentrations in Renal Transplant Recipients Treated with Mycophenolate Mofetil

There are data available in the literature on bioelement concentrations in the serum of various groups of patients; however, very little is known about the serum concentration of selenium (Se), iron (Fe), zinc (Zn), and copper (Cu) in renal transplant patients treated with immunosuppressive drugs, including mycophenolate mofetil (MMF). Monitoring of serum bioelement concentrations in renal transplant recipients is of profound importance, as the proper bioelement levels seem to prolong the normal function of the transplanted organ. Thus, the aim of this current study was to examine and carry out comparative analysis involving serum concentrations of Se, Fe, Cu, and Zn of renal transplant recipients treated with MMF and without MMF. The material consisted of blood samples from 115 patients of the Department of Nephrology, Transplantology, and Internal Medicine of Independent Public Clinical Hospital No. 2, Pomeranian Medical University, in the city of Szczecin in the northwestern Poland. Serum Se, Fe, Cu, and Zn levels were quantified by inductively coupled mass spectroscopy (ICP-MS). Taking into account all patients, MMF increases Cu level. Cu and Fe concentrations were significantly higher in women treated with MMF; in group of younger patients treated with MMF, Se level was significantly lower comparing with those whose regimen did not include MMF. Additionally, MMF in combination with prednisone increased Se concentration in blood of transplant recipients. Our study highlights that trace elements should be monitored to allow for an early detection of trace elements deficits, which can easily be corrected for by an adjusted diet or supplemental intake.

Arsenic and Selenium Profile in Erythrocytes of Renal Transplant Recipients

Arsenic and selenium elements play extremely important roles in organisms. Too high As concentration in blood may lead to functional disorders within organs, including cancer. Arsenic is designated as a Group 1 human carcinogen by the International Agency for Research on Cancer that has established causal role of arsenic in cancers of the urinary bladder, lung, and skin in humans. In contrast, Se is believed to be the antioxidant trace element that is important in the biological defense against oxidative damage. We tested the hypothesis that immunosuppressive treatment based on mycophenolate mofetil (MMF), that is one of the most commonly used drug by renal transplant recipients, affects arsenic and selenium concentration in erythrocytes of renal transplant recipients. Current research was undertaken due to the fact that there are few studies on the concentration of chemical elements in the erythrocytes in kidney patients receiving immunosuppressive drugs. Monitoring of the concentration of chemical elements in the blood in patients who underwent kidney transplantation could be helpful, since chemical elements play an important role in many biological processes and it seems to be crucial in the prevention of cancer to which renal transplant recipients are more often exposed.The material consisted of blood from 115 renal transplant recipients of the Department of Nephrology, Transplantology, and Internal Medicine of Independent Public Clinical Hospital No. 2, Pomeranian Medical University, in the city of Szczecin in northwestern Poland. Arsenic and selenium levels in erythrocytes were quantified by inductively coupled mass spectroscopy.Men MMF+ had significantly higher As concentration than men MMF-. Se concentration was significantly higher in younger patients compared with older patients. The patients with lower creatinine level who used MMF had significantly higher As than MMF- patients. Patients whose therapy was based on MMF, cyclosporine A and glucocorticosteroids exhibited significantly higher concentration of As compared with patients whose regimen was based on MMF, tacrolimus, and glucocorticosteroids.This is the first study that demonstrates that regimen based on mycophenolate mofetil affects As and Se concentrations in erythrocytes in renal transplant recipients.