-
1.
Plasma copper and the risk of first stroke in hypertensive patients: a nested case-control study.
Zhang, J, Cao, J, Zhang, H, Jiang, C, Lin, T, Zhou, Z, Song, Y, Li, Y, Liu, C, Liu, L, et al
The American journal of clinical nutrition. 2019;(1):212-220
-
-
Free full text
-
Abstract
BACKGROUND Previous studies indicated that trace elements may play an important role in cardiovascular diseases. However, data concerning the association between blood copper and the risk of stroke are limited. OBJECTIVE The aim of this study was to evaluate the association between plasma copper and the risk of first stroke, and examine any possible effect modifiers in hypertensive patients. METHODS We conducted a nested case-control study, using data from the China Stroke Primary Prevention Trial. Hypertension is defined as systolic blood pressure ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg, or taking antihypertensive medication. A total of 618 first stroke cases and 618 controls matched for age, sex, treatment group, and study site were included in this study. The crude and adjusted risks of first stroke were estimated by ORs and 95% CIs using conditional logistic regression, without or with adjusting for pertinent covariates, respectively. RESULTS There were significant positive associations of plasma copper with risk of first stroke (per SD increment-OR: 1.20; 95% CI: 1.03, 1.39) and first ischemic stroke (OR: 1.26; 95% CI: 1.07, 1.50). When plasma copper was categorized in quartiles, significantly higher risks of first stroke (OR: 1.72; 95% CI: 1.12, 2.65) and first ischemic stroke (OR: 1.91; 95% CI: 1.18, 3.11) were found in participants in quartile 4 (≥ 117.0 μg/dL) than in those in quartile 1 (< 91.2 μg/dL). Furthermore, the plasma copper-first stroke association was significantly stronger in participants with higher BMI (< 25.0 compared with ≥ 25.0 kg/m2, P-interaction = 0.024). However, there was no significant association between plasma copper and first hemorrhagic stroke. CONCLUSIONS In Chinese hypertensive patients, there was a significant positive association between baseline plasma copper and the risk of first stroke, especially among those with higher BMI.This trial was registered at clinicaltrials.gov as NCT00794885.
-
2.
DNA-templated copper nanoparticles as signalling probe for electrochemical determination of microRNA-222.
Wang, Y, Meng, W, Chen, X, Zhang, Y
Mikrochimica acta. 2019;(1):4
Abstract
An ultrasensitive electrochemical biosensor is described for the determination of microRNAs. It is based on the use of DNA-templated copper nanoparticles (Cu NPs) as signalling probe. MicroRNA-222 was selected as the model analyte. The probe was obtained from two different oligonucleotides (containing complementary bases) via hybridization chain reaction to form long DNA concatemers as template. The Cu NPs were formed by reaction of ascorbate with copper sulfate. The biosensor was fabricated as follows: (a) Capture probe (cDNA) with a thiolated group was immobilized on reduced graphene oxide modified with gold nanoparticles (rGO/Au NPs), (b) materials was placed on a glassy carbon electrode (GCE); (c) the modified electrode (cDNA/rGO/Au NPs/GCE) was sequentially hybridized with microRNA-222 and signal probe; this results in the formation of a sandwich structure of cDNA-microRNA-signal probe on surface of the modified electrode. Differential pulse voltammetry was employed to record the electrochemical response of biosensor in pH 6.0 solution. As a result, a sensitive oxidation current with a peak potential at 0.10 V (vs. SCE) was obtained corresponding to Cu NPs. The experimental conditions were optimized. Under optimal conditions, the biosensor exhibited wide linear response range (0.5 fM to 70 nM) and low limit of detection (0.03 fM; at S/N = 3). The assay possesses high selectivity and can discriminate analyte microRNA from single-base mismatched microRNA. Graphical abstractA sensitive electrochemical biosensor is described for the determination of microRNA-222 by using a dsDNA-templated Cu NPs as signalling probe. (A) represents the preparation of signal probe, and (B) represents the fabrication of electrochemical microRNA sensor.
-
3.
Pre-aeration of the rhizosphere offers potential for phytoremediation of heavy metal-contaminated wetlands.
Xin, J, Tang, J, Liu, Y, Zhang, Y, Tian, R
Journal of hazardous materials. 2019;:437-446
Abstract
Two solution cultures with different oxygen pretreatments were used to investigate (ⅰ) the variation in the radial oxygen loss in the roots and root morphology of Triarrhena sacchariflora seedlings and (ii) their tolerance to Cu2+ and Cd2+, as well as both the metal uptake and accumulation by pretreated seedlings. Developed aerenchyma in the roots was induced by the hypoxia pretreatment (HP) and aeration pretreatment (AP), for which root porosity, respectively, increased by 45.76%-53.39% and 84.07%-88.66%. AP altered the natural radial oxygen loss coupled to an enhanced secretion of oxygen in the root tips. AP was found to effectively improve the seedlings' tolerance to Cu2+ and Cd2+, facilitating their growth, thereby increasing their root diameter, dry weight, and number of root tips, as well as promoting shoot growth. AP was capable of promoting the uptake and bioaccumulation in seedlings of Cu2+ and Cd2+; it also induced more Cu2+ and Cd2+ immobilized in roots so that less of either metal was transported from roots to shoots, which may well be a key mechanism for strengthening seedlings' tolerance to metal ions. Our experimental results suggest that AP offers great potential for the remediation of heavy metal-contaminated wetlands.
-
4.
A "turn-on" fluorescent probe for glutathione detection based on the polyethylenimine-carbon dots-Cu2+ system.
Zhang, B, Duan, Q, Li, Y, Zhang, Y, Che, M, Zhang, W, Sang, S
Journal of photochemistry and photobiology. B, Biology. 2019;:111532
Abstract
Glutathione (GSH) plays critical roles in many physiological processes usually present in live cells, and altered levels have been linked to some clinical pathological conditions. However, current techniques of GSH detection with fluorescence assay strategies remain poorly researched. In this work, branched polyethylenimine-functionalized carbon dots (PEI-CDs) are synthesized by simple hydrothermal treatment of glucose and PEI. The fluorescence of the PEI-CDs could be efficiently quenched by Cu2+ and then recovered by some biothiols. Basing on this, a "turn-on" fluorescent probe for detecting GSH has been developed using PEI-CDs-Cu2+ system. Compared with traditional probes for GSH detection, a significant advantage of the PEI-CDs-Cu2+ system is that it can be used for GSH detection at both low and high concentrations with different concentration combinations of PEI-CDs and Cu2+. More specifically, two good linear relationships are achieved in the ranges of 0-80 μM and 0-1400 μM for GSH, respectively. Correspondingly, the detection limits of GSH are 0.33 μM and 9.49 μM, respectively. The quantum yields (QYs) of PEI-CDs and PEI-CDs-Cu2++GSH was 9.6% and 4.2%, respectively. Moreover, the PEI-CDs-Cu2+ has excellent optical stability and good biocompatibility. Additionally, it is worth noting that the developed probe has successfully realized the visualization of GSH detection in MGC-803 cells.
-
5.
Structurally Well-Defined Au@Cu2- x S Core-Shell Nanocrystals for Improved Cancer Treatment Based on Enhanced Photothermal Efficiency.
Ji, M, Xu, M, Zhang, W, Yang, Z, Huang, L, Liu, J, Zhang, Y, Gu, L, Yu, Y, Hao, W, et al
Advanced materials (Deerfield Beach, Fla.). 2016;(16):3094-101
Abstract
Au@Cu2- x S core-shell nanocrystals (NCs) have been synthesized under large lattice mismatch with high crystallinity, controllable shape, and nonstoichiometric composition. Both experimental observations and simulations are used to verify the flexible dual-mode plasmon coupling. The enhanced photothermal effect is harnessed for diverse HeLa cancer cell ablation applications in the NIR-I window (750-900 nm) and the NIR-II window (1000-1400 nm).
-
6.
Detention of copper by sulfur nanoparticles inhibits the proliferation of A375 malignant melanoma and MCF-7 breast cancer cells.
Liu, H, Zhang, Y, Zheng, S, Weng, Z, Ma, J, Li, Y, Xie, X, Zheng, W
Biochemical and biophysical research communications. 2016;(4):1031-1037
Abstract
Selective induction of cell death or growth inhibition of cancer cells is the future of chemotherapy. Clinical trials have found that cancer tissues are enriched with copper. Based on this finding, many copper-containing compounds and complexes have been designed to "copper" cancer cells using copper as bait. However, recent studies have demonstrated that copper boosts tumor development, and copper deprivation from serum was shown to effectively inhibit the promotion of cancer. Mechanistically, copper is an essential cofactor for mitogen-activated protein kinase (MAPK)/extracellular activating kinase (ERK) kinase (MEK), a central molecule in the BRAF/MEK/ERK pathway. Therefore, depleting copper from cancer cells by directly sequestering copper has a wider field for research and potential for combination therapy. Based on the affinity between sulfur and copper, we therefore designed sulfur nanoparticles (Nano-S) that detain copper, achieving tumor growth restriction. We found that spherical Nano-S could effectively bind copper and form a tighter surficial structure. Moreover, this Nano-S detention of copper effectively inhibited the proliferation of A375 melanoma and MCF-7 breast cancer cells with minimum toxicity to normal cells. Mechanistic studies revealed that Nano-S triggered inactivation of the MEK-ERK pathway followed by inhibition of the proliferation of the A375 and MCF-7 cells. In addition, lower Nano-S concentrations and shorter exposure stimulated the expression of a copper transporter as compensation, which further increased the cellular uptake and anticancer activities of cisplatin. Collectively, our results highlight the potential of Nano-S as an anticancer agent or adjuvant through its detention of copper.
-
7.
Alkali and alkaline earth metallic (AAEM) species leaching and Cu(II) sorption by biochar.
Li, M, Lou, Z, Wang, Y, Liu, Q, Zhang, Y, Zhou, J, Qian, G
Chemosphere. 2015;:778-785
Abstract
Alkali and alkaline earth metallic (AAEM) species water leaching and Cu(II) sorption by biochar prepared from two invasive plants, Spartina alterniflora (SA) and water hyacinth (WH), were explored in this work. Significant amounts of Na and K can be released (maximum leaching for Na 59.0 mg g(-1) and K 79.9 mg g(-1)) from SA and WH biochar when they are exposed to contact with water. Cu(II) removal by biochar is highly related with pyrolysis temperature and environmental pH with 600-700 °C and pH of 6 showing best performance (29.4 and 28.2 mg g(-1) for SA and WH biochar). Cu(II) sorption exerts negligible influence on Na/K/Mg leaching but clearly promotes the release of Ca. Biochars from these two plant species provide multiple benefits, including nutrient release (K), heavy metal immobilization as well as promoting the aggregation of soil particles (Ca) for soil amelioration. AAEM and Cu(II) equilibrium concentrations in sorption were analyzed by positive matrix factorization (PMF) to examine the factors underlying the leaching and sorption behavior of biochar. The identified factors can provide insightful understanding on experimental phenomena.
-
8.
Ultrasonic oscillation dialysis-graphite furnace atomic absorption spectrometer method for determination of "free" copper and exchangeable copper in serum.
Zhang, Y, Chen, Y, Lin, Z, Li, Q, Chen, Y, Peng, L, Han, M
Clinical laboratory. 2014;(4):543-51
Abstract
BACKGROUND The determination of copper (Cu) in human blood is important in medical diagnosis. However, its biological activities strongly depend on the chemical forms, and thus data for total Cu concentration is not sufficient for medical diagnosis or mechanism study. Therefore, analyses of copper species in serum have much more physiologically meaningful. METHODS Ultrasonic oscillation dialysis procedure was introduced in the determination of "free" Cu, more precisely PBS dialysis Cu (DiaCu), and exchangeable Cu (EXCu) by graphite furnace atomic absorption spectrometry (GFAAS). Then the levels of serum "free" Cu and EXCu from hepatitis, liver cancer, and cervical cancer patients were determined. RESULTS The accuracy of the method ranged from 92% - 97% for PBS DiaCu and 90% - 107% for EXCu when using a dialysis membrane pore size of 25 kDa. The regression equation of the calibration curve was expressed as y = bChi + a, with linear regression coefficients (r2) of 0.9999 for ultrapure water and 0.9998 for PBS buffer and EDTA buffer. The limit of detection is 0.76 microg/L. Application of this method to serum samples showed that the levels of"free" Cu and EXCu in serum changed in various pathophysiological conditions. CONCLUSIONS Ultrasonic oscillation dialysis-GFAAS method described here for the speciation of "free" Cu and EXCu in serum is simple with good reproducibility and small sample volume.
-
9.
Effects of copper ions on DNA binding and cytotoxic activity of a chiral salicylidene Schiff base.
Fei, BL, Xu, WS, Tao, HW, Li, W, Zhang, Y, Long, JY, Liu, QB, Xia, B, Sun, WY
Journal of photochemistry and photobiology. B, Biology. 2014;:36-44
Abstract
A chiral Schiff base HL N-(5-bromo-salicylaldehyde)dehydroabietylamine (1) and its chiral dinuclear copper complex [Cu2L4]·4DMF (2) have been synthesized and fully characterized. The interactions of 1 and 2 with salmon sperm DNA have been investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral (Kb=3.30 × 10(5)M(-)(1) (1), 6.63 × 10(5)M(-)(1)(2)), emission spectral (Ksv=7.58 × 10(3)M(-)(1) (1), 1.52 × 10(4)M(-)(1) (2)), and viscosity measurements reveal that 1 and 2 interact with DNA through intercalation and 2 exhibits a higher DNA binding ability. In addition, CD study indicates 2 cause a more evident perturbation on the base stacking and helicity of B-DNA upon binding to it. In fluorimetric studies, the enthalpy (ΔH>0) and entropy (ΔS>0) changes of the reactions between the compounds with DNA demonstrate hydrophobic interactions. 1 and 2 were also screened for their cytotoxic ability and 2 demonstrates higher growth inhibition of the selected cancer cells at concentration of 50 μM, this result is identical with their DNA binding ability order. All the experimental results show that the involvement of Cu (II) centers has some interesting effect on DNA binding ability and cytotoxicity of the chiral Schiff base.
-
10.
Roles and mechanisms of copper transporting ATPases in cancer pathogenesis.
Zhang, Y, Li, M, Yao, Q, Chen, C
Medical science monitor : international medical journal of experimental and clinical research. 2009;(1):RA1-5
Abstract
Copper (Cu) is an essential trace element for cell metabolism as a cofactor to many key metabolic enzymes. Numerous physiological processes rely on the adequate and timely transport of copper ions mediated by copper-transporting ATPases (Cu-ATPases), which are essential for human cell growth and development. Inherited gene mutations of ATP7A and ATP7B result in clinical diseases related to damage in the multiple organ systems. Increased expression of these genes has been recently observed in some human cancer specimens, and may be associated with tumorigenesis and chemotherapy resistance. However, underlying mechanisms of Cu-ATPases in human cancer progression and treatment are largely unknown. In this review, we summarize current progress on the copper transport system, the structural and functional properties of the Cu-ATPases, ATP7A and ATP7B, in copper homeostasis, and their roles in anti-tumor drug resistance and cancer metastasis. This review provides valuable information for clinicians and researchers who want to recognize the newest advances in this new field and identify possible lines of investigation in copper transport as important mediators in human physiology and cancer.