An Emerging Role of Defective Copper Metabolism in Heart Disease

Copper is an essential trace metal element that significantly affects human physiology and pathology by regulating various important biological processes, including mitochondrial oxidative phosphorylation, iron mobilization, connective tissue crosslinking, antioxidant defense, melanin synthesis, blood clotting, and neuron peptide maturation. Increasing lines of evidence obtained from studies of cell culture, animals, and human genetics have demonstrated that dysregulation of copper metabolism causes heart disease, which is the leading cause of mortality in the US. Defects of copper homeostasis caused by perturbed regulation of copper chaperones or copper transporters or by copper deficiency resulted in various types of heart disease, including cardiac hypertrophy, heart failure, ischemic heart disease, and diabetes mellitus cardiomyopathy. This review aims to provide a timely summary of the effects of defective copper homeostasis on heart disease and discuss potential underlying molecular mechanisms.     

Assessment of Serum CoQ10 Levels and other Antioxidant Markers in Breast Cancer

Background: The balance of the oxidative state in the body is fundamental for the maintenance of homeostasis. It has been implicated in the onset and progression of several diseases including breast cancer. The way in which the Reactive Oxygen Species (ROS) / antioxidants balance leads to or responds to disease is still controversial. In this study, TAC is used as a reference for the total antioxidant power of the body and Coenzyme Q10 (CoQ10) for its vital importance in cellular antioxidant action and being the only lipid soluble antioxidant synthesized endogenously. Copper and zinc were measured as trace elements reflecting the antioxidant micronutrient profile of the body. Methods: After approval of the ethical committee, 60 recently diagnosed non-intervened breast cancer patients were recruited from the Medical Research Institute hospital, Alexandria University along with 20 apparently healthy volunteers as control group. Full patient history was taken including breastfeeding history, parity, hormone replacement therapy use, body mass index, pathological examination, metastatic work up results, past medical history and drug use. CA 15-3 and laboratory investigations evaluating blood glucose, kidney and liver functions were performed. Q10 levels were measured by HPLC using a kit from Recipe®. TAC was assayed spectrophotometrically (Biodiagnostics®). Copper and Zinc levels were determined by inductively coupled plasma-optical emission spectrometry. Results: There was a statistically significant increase in the CoQ10, TAC and copper levels in the breast cancer group when compared to the control group. Zinc showed no statistically significant difference between the studied groups. Conclusion: Inspite of the fact that a high antioxidant level is usually considered as a favourable state, TAC, CoQ10 and copper levels showed significantly higher levels in the breast cancer group when compared to the control group. It is worth mentioning that the cancer group were all recently diagnosed, non-intervened and showed no signs of metastasis. It is still unclear whether the increased antioxidant levels offer a selective growth advantage to tumor cells over their surrounding normal cells or serve as a protective measure by the body in an attempt to correct the assault triggered by the ROS.     

Copper and Zinc Levels in Myelodysplastic Syndrome Patients versus Healthy Subjects

Background: Myelodysplastic syndrome (MDS) is a heterogeneous hematological disease and certain serum factors are assumed to be involved in its pathogenesis and progression. Given this, our aim was to comparatively investigate the copper, zinc, and iron levels in MDS patients and healthy individuals. Methods: This case-control study was conducted on 31 patients with MDS (according to the WHO criteria after investigating laboratory tests such as peripheral blood smear and bone marrow aspiration) attending Bahonar Hospital, Kerman, Iran, and 31 healthy subjects from 2016 to 2018. The levels of copper, ceruloplasmin, zinc, ferritin, and iron were compared between the two groups. Results: Among the MDS patients, five individuals (16.13%) had low serum copper level (mean: 67.8 ± 4.35 µg/dl). Serum copper level was 111.3 ± 27.7 and 138.3 ± 26.6 in case and control groups, respectively (P = 0.0001). The serum zinc level and bone marrow iron level were also significantly different between the two groups (P < 0.05). Conclusion: Overall, it can be concluded that because only a small proportion of the MDS patients enrolled in this study were found to have lower copper levels compared with the MDS patients population, further studies with a larger sample size and also clinical trials in MDS patients with serum zinc, and copper deficiency are recommended, and post-treatment hematological reassessment would also be beneficial to achieving more definitive results.     

铜绿微囊藻抗性株与野生株对铜离子的富积效应

目的：分离筛选高铜离子抗性的铜绿微囊藻(Microcystis aeruginosa),并研究其抗性机制及对铜离子的富积效果。方法：将抗性株与野生株分别加入不同浓度铜离子的BG11培养基中,在不同时间段取样过滤,分析过滤液中铜离子的残留量。结果：在相同时间内,抗性株比野生株产生类金属硫蛋白(MTL)的量要大,培养基中Cu^2 减少主要发生在培养后24h以前。抗性株在24h之前对Cu^2 富积较快,24h的去除率为48．87％,96h的去除率为80．77％;而野生株在24h之前对Cu^2 富积相对较慢,24h去除率为20．88％,96h的去除率为34．29％。结论：利用抗性株铜绿微囊藻治理高铜离子污染源具有较大的应用前景。     

益气化瘀法对置铜宫内避孕器家兔子宫内膜血管内皮细胞及平滑肌细胞超微结构的影响

目的:探讨益气化瘀法治疗置铜宫内避孕器(intrauterine device,IUD)所致家兔子宫不规则出血的作用机制。方法:56只家兔,随机分为宫环止血灵大、中、小剂量组,吲哚美辛对照组,模型组,假手术组(手术后不放置宫内避孕器)和空白对照组(不造模),每组8只。前5组建立家兔置铜宫内避孕器模型。宫环止血灵大、中、小剂量组及吲哚美辛对照组分别予以宫环止血灵大、中、小剂量及吲哚美辛灌胃。模型组、假手术组及空白对照组则予以蒸馏水灌胃。透射电镜观察家兔子宫内膜血管内皮细胞(vascular endothelial cells,VECs)及血管平滑肌细胞(vascular smooth muscle cells,VSMCs)超微结构的变化。结果:模型组子宫螺旋动脉VSMCs胞浆内水肿,细胞器部分崩解、数量减少,或细胞萎缩,线粒体空泡样变性,其外周胶原纤维增多,血管内皮下间质局部水肿。VECs内线粒体空泡样变性。益气化瘀法治疗组,子宫内膜螺旋动脉VECs及VSMCs的线粒体、肌丝、高尔基体、间质等超微结构损伤较模型组均有明显减轻,与吲哚美辛对照组相似。结论:益气化瘀法对置铜IUD家兔子宫内膜的血管内皮有一定的保护作用,可较好地防治因置铜IUD引起的子宫不规则出血。     

肾小球疾病患儿24小时尿锌铜含量变化研究

目的探讨肾小球疾病患儿尿中24小时尿锌、铜的含量变化以及肾小球疾病损伤程度与尿锌、铜变化的关系。方法采用电感耦合等离子体原子发射光谱ICP-AES法测定42例肾小球损伤患儿以及65例正常对照组24小时尿锌、铜含量。结果肾小球损伤患儿尿锌、铜含量与对照组之间有显著差异（P〈0.05）,肾小球疾病尿蛋白电泳两条带以上组较两条带组之间尿锌、铜有显著差异（P〈0.05）。结论 24小时尿铜、锌在肾小球疾病时排除量明显增加,尿锌、铜的含量可作为肾小球损伤的辅助诊断标准,同时提示补充和调整微量元素对肾小球损伤患儿有一定意义。     

Copper ions stimulate the proliferation of hepatic stellate cells via oxygen stress in vitro

This study examined the effect of copper ions on the proliferation of hepatic stellate cells (HSCs) and the role of oxidative stress in this process in order to gain insight into the mechanism of hepatic fibrosis in Wilson’s disease. LX-2 cells, a cell line of human HSCs, were cultured in vitro and treated with different agents including copper sulfate, N-acetyl cysteine (NAC) and buthionine sulfoximine (BSO) for different time. The proliferation of LX-2 cells was measured by non-radioactive cell proliferation assay. Real-time PCR and Western blotting were used to detect the mRNA and protein expression of platelet-derived growth factor receptor β subunit (PDGFβR), ELISA to determine the level of glutathione (GSH) and oxidized glutathione (GSSG), dichlorofluorescein assay to measure the level of reactive oxygen species (ROS), and lipid hydroperoxide assay to quantify the level of lipid peroxide (LPO). The results showed that copper sulfate over a certain concentration range could promote the pro- liferation of LX-2 cells in a time- and dose-dependent manner. The effect was most manifest when LX-2 cells were treated with copper sulfate at a concentration of 100 μmol/L for 24h. Additionally, copper sulfate could dose-dependently increase the levels of ROS and LPO, and decrease the ratio of GSH/GSSG in LX-2 cells. The copper-induced increase in mRNA and protein expression of PDGFβR was significantly inhibited in LX-2 cells pre-treated with NAC, a precursor of GSH, and this phenome- non could be reversed by the intervention of BSO, an inhibitor of NAC. It was concluded that copper ions may directly stimulate the proliferation of HSCs via oxidative stress. Anti-oxidative stress therapies may help suppress the copper-induced activation and proliferation of HSCs.     

肺癌病人血清铜、锌水平的研究

本研究应用原子吸收分光光度法，检测186例肺癌病人血清铜，锌水平，并以150例正常人和64例良性胸部疾患病人作对照，结果显示：肺癌病人血清铜水平明显高于良性胸部疾患病人和正常人，血清锌水平明显低于良性胸部疾患病人和正常人，铜，锌水平的改变与肺癌的病期有明显的关系（P＜0．04），而与组织学类型无关，本研究结果表明：检测肺癌病人血清铜，锌水平可用于肺癌的辅助诊断和判别肺癌的 病期。     

Novel ATP7B gene mutations in Chinese Han patients with hepatolenticular degeneration

BACKGROUND: ATP7B gene exon 8 Arg778Leu and exon 12 Arg952Lys are gene mutation hot spots in Chinese Han patients with hepatolenticular degeneration, or Wilson's disease (WD). However, the gene fragments are too short for detection and the mutation detection rate remains low.OBJECTIVE: To analyze DNA sequences of ATP7B gene exon 8-exon 9 and exon 10-exon 12 sections. DESIGN, TIME AND SETTING: A concurrent, non-randomized, controlled, genetic polymorphism study was performed at the Anhui Medical Genetics Center, Anhui, China from March to July in 2009.PARTICIPANTS: Fifty patients, who were admitted to the Department of Neurology at the First Affiliated Hospital of Anhui Traditional Chinese Medical College between March and July in 2009, were diagnosed with WD. The WD group comprised 32 males and 18 females, with an average age of (18.8 ± 8.3) years. WD was confirmed by clinical observation, as well as physical, imaging, and biochemical examinations, including testing for serum copper, ceruloplasmin, and copper oxidase. The control group comprised 20 normal subjects, who underwent physical examination at the First Affiliated Hospital of Anhui Traditional Chinese Medical College, and included 13 males and 7 females, with an average age of (27.9 ± 2.4) years. All subjects were Chinese Han population.METHODS: Genomic DNA was extracted from 50 WD patients and 20 normal controls. Polymerase chain reaction amplification of ATP7B gene exon 8-exon 9 (about 1 100 bp) and exon 10-exon 12 (about 850 bp) segments was performed. DNA exon-intron amplification products from all subjects were processed through direct bidirectional sequencing, and sequencing results were analyzed. MAIN OUTCOME MEASURES: Sequence changes of ATP7B gene exon 8-exon 9 and exon 10-exon 12 segments.RESULTS: In the 50 included WD patients, ATP7B gene intron 8 nt53592A → G with nt53671G → A homozygous mutation was detected between exon 8-exon 9 in seven cases; exon 8 Arg778Leu mutations with Leu770Leu synonymous mutation was detected in four cases; exon 11 Gly790Arg heterozygous missense mutation between exon 10-exon 12 was found in four cases; exon 12 Arg952Lys heterozygous missense mutation was seen in 11 cases; and two additional cases were associated with exon 12IIe929Val polymorphism.CONCLUSION: ATP7B gene intron 8 mutation is a possible pathogenic mutation that is associated with WD pathogenesis. The exon 11 mutation rate accounts for 8% of all WD patients, and the very few previously reported cases deserve further study.     

Surface residues dynamically organize water bridges to enhance electron transfer between proteins

Cellular energy production depends on electron transfer (ET) between proteins. In this theoretical study, we investigate the impact of structural and conformational variations on the electronic coupling between the redox proteins methylamine dehydrogenase and amicyanin from Paracoccus denitrificans. We used molecular dynamics simulations to generate configurations over a duration of 40 ns (sampled at 100-fs intervals) in conjunction with an ET pathway analysis to estimate the ET coupling strength of each configuration. In the wild-type complex, we find that the most frequently occurring molecular configurations afford superior electronic coupling due to the consistent presence of a water molecule hydrogen-bonded between the donor and acceptor sites. We attribute the persistence of this water bridge to a “molecular breakwater” composed of several hydrophobic residues surrounding the acceptor site. The breakwater supports the function of nearby solvent-organizing residues by limiting the exchange of water molecules between the sterically constrained ET region and the more turbulent surrounding bulk. When the breakwater is affected by a mutation, bulk solvent molecules disrupt the water bridge, resulting in reduced electronic coupling that is consistent with recent experimental findings. Our analysis suggests that, in addition to enabling the association and docking of the proteins, surface residues stabilize and control interprotein solvent dynamics in a concerted way.