Elevated Copper Concentrations Research Articles

Ichthyobodo necator infection as a first record in cultured Dicentrarchus labrax: morphomolecular characterization and infestation patterns in correlation to water quality parameters

Abstract Ichthyobodo necator is a damaging and economically important protozoan parasite; however, its clinical patterns and incidence, correlated to environmental factors, are still poorly understood. This study provides the first report of Ichthyobodo necator infestation among Dicentrarchus labrax. We recorded significant mortalities in the cultured D. labrax of average size (5.92 g weight, and 11.55 cm length) in El-Max Station, National Institute of Oceanography and Fisheries, NIOF, Egypt, during the period extending from early summer to early fall (June to October) 2023. Behavioral and gross lesions of the infested fish were recorded; besides, dead and moribund fish were collected. Wet smears of the skin and gill of the affected fish were examined by compound light microscopy. Moreover, water samples from the affected ponds were collected and examined for their physicochemical parameters. The bodonid biflagellated Ichthyobodo necator (Henneguy) C. Pinto, 1928 was isolated from the skin and gills and identified based on specific morphological characteristics. DNA sequencing of PCR products and phylogenetic analysis confirmed identification, with clustering of the current isolates with I. necator isolates from different fish species. The multivariate analysis revealed a positive correlation between the prevalence and infestation intensity of Ichthyobodo, increased temperature levels, decreased dissolved oxygen DO, and also correlated with higher ammonia, and pH values. Additionally, the elevated concentrations of iron, calcium, magnesium, zinc, and copper in pond water were positively correlated with infestation and mortalities. These water parameter levels promote respiratory distress, accelerated prevalence, and infestation intensities of I. necator, particularly during the infestation peak in August and September. This study bridges the knowledge gap regarding I. necator parasite infestations and their correlation with water quality parameters.

Dysfunction of ATP7B Splicing Variant Caused by Enhanced Interaction With COMMD1 in Wilson Disease

Background & AimsThe association between Wilson disease and various ATP7B mutations is well-established; however, the molecular mechanism underlying the functional consequence of these mutations, particularly the splicing mutations, remains unclear. This study focused on the ATP7B c.1543+1G>C variant, to reveal a universal pathogenic mechanism of the ATP7B mutants with altered N-terminus. MethodsThe splicing assay and RNA pull-down were performed to explore the mechanism of the aberrant splicing. The ATP7B knockout HuH-7 cell line and Atp7b-/- mice were created, and the functional consequence of the mutant ATP7B were evaluated in-vitro and in-vivo. ResultsThe c.1543+1G>C mutation resulted in the skipping of ATP7B exon 3, and the mutant ATP7B showed a loss of trans-Golgi network (TGN) localization and was degraded via the ubiquitin-proteasome pathway, facilitated by enhanced interactions with COMMD1. Elevated intercellular copper concentration and reduced survival rate were observed in HuH-7 cells expressing mutant ATP7B. Restoration of wild-type ATP7B in Atp7b-/- mice resulted in a substantial improvement in phenotype, while mice treated with mutant ATP7B did not demonstrate equivalent benefits. ConclusionsOur research investigated the pathogenicity and mechanism of ATP7B c.1543+1G>C variant, with particular focus on its enhanced interaction with COMMD1 as a potential universal mechanism contributing to the dysfunction of various ATP7B variants. These findings provide a foundation for the development of innovative therapeutic strategies that target abnormal splicing events in a range of hereditary diseases, including Wilson disease.

Assessment of Essential Trace Elements Cu, Zn, Mn, and Ni in Mediterranean Mussels (Mytilus galloprovincialis) from the Algerian Coast.

The aim of this study was to determine the levels of essential trace elements copper, zinc, manganese, and nickel in two size groups of mussels, Mytilus galloprovincialis, sampled from three sites along the Algerian coast with different levels of pollution. The results of this work are very interesting for determining the effect of mussel size on the variation of contaminant levels in environmental monitoring studies. Thirty individuals from 2 size groups, less than 4-cm and more than 4-cm shell length, were collected over 4 seasons at each site studied. The samples were dissected, and copper, zinc, manganese, and nickel were measured in the whole soft tissues by inductively coupled plasma mass spectrometry (ICP-MS). The maximum concentrations of copper, zinc, manganese, and nickel expressed in mg/kg dry weight at the three sites were 54.01, 146.25, 20.69, and 8.85, respectively. A clear distribution pattern of the studied elements was observed in the two size classes. In fact, significantly higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm. Significantly, higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm due to their high filtration and low excretion activities compared to long individuals. In addition, metal pollution index (MPI) values were higher in small bivalve individuals. The trace element contents found in the mussel samples of the present study showed large spatial and temporal variations among the different sites studied, highlighting the typical exposure of marine sites to different marine pollutants. Notably, elevated concentrations of copper were observed in the port of Zemmouri, likely due to port activities. Conversely, the highest levels of manganese and nickel were recorded at Boudouaou El Bahri, potentially attributable to the use of fertilisers by agricultural activities. Some shellfish samples had exceeded the permissible concentration levels of copper and manganese, thereby posing a danger to bivalve consumers.

Mycobacterium marinum MMAR_0267-regulated copper utilization facilitates bacterial escape from phagolysosome

The host limits Mycobacterium tuberculosis (Mtb) by enriching copper in high concentrations. This research investigates how Mtb escapes copper stress. The membrane protein encoded by Mtb Rv0102, when its homolog in M. smegmatis (MSMEG_4702) was knocked out, resulted in a fourfold decrease in intracellular copper levels and enhanced tolerance to elevated extracellular copper concentrations. Similarly, knockout mutants of its homolog in M. marinum (MMAR_0267) showed increased virulence in zebrafish and higher bacterial load within macrophages. In THP-1 cells infected with MMAR_0267 deletion mutants, the intracellular survival of these mutants increased, along with reduced THP-1 cell apoptosis. Deficiency in copper down-regulated the transcriptional level of the virulence factor CFP-10 in M. marinum, suppressed cytosolic signaling via the macrophage STING pathway, leading to decreased production of IFN-β and reduced cell apoptosis. In conclusion, these findings highlight the significant impact of copper on the survival and reproduction of mycobacteria, underscoring the importance of studying mycobacterial adaptation mechanisms in copper-rich environments.

As-deposited and dewetted Cu layers on plasma treated glass: Adhesion study and its effect on biological response

Improving the adhesion of nanosized copper films to a glass substrate is vital for their application in electronics and medicine, as it enhances their overall reliability. For this purpose, we employed Ar plasma etching (240 s) and magnetron sputtering to create copper layers on a glass substrate. Furthermore, we investigated the effect of subsequent solid state dewetting (at 300 °C) of Cu nanolayers on the interface stability. Increasing the sputtering time resulted in elevated copper concentration, UV-Vis absorption, conductivity, and surface roughness. The as-deposited and dewetted samples exhibited very good wettability with water contact angles below 60°. Importantly, plasma treatment improved the adhesion of the Cu layers to the glass. Subsequent dewetting accelerated surface diffusion and the oxidation of Cu atoms, causing structural and morphological changes. The presence of CuO after dewetting caused loss of the surface plasmon resonance (SPR) band in the UV-Vis spectrum and a decrease in sample conductivity due to the transformation of the copper layer from a metal to an oxide. Biological testing revealed a more pronounced bactericidal effect for the as-deposited Cu layer against E. coli and S. epidermidis on contrary to dewetted samples. The similar cytotoxic trend was observed for human dermal fibroblasts and hepatocytes. Nonetheless, biological testing confirmed better cell adhesion on dewetted Cu layers compared to the as-deposited ones. Therefore, our copper nanostructured samples could find application as antibacterial coatings of biomedical devices.

Impaired cellular copper regulation in the presence of ApoE4.

The strongest genetic risk factor for late-onset Alzheimer's disease (AD) is allelic variation of the APOE gene, with the following risk structure: ε4 > ε3 > ε2. The biochemical basis for this risk profile is unclear. Here, we reveal a new role for the APOE gene product, apolipoprotein E (ApoE) in regulating cellular copper homeostasis, which is perturbed in the AD brain. Exposure of ApoE target replacement (TR) astrocytes (immortalised astrocytes from APOE knock-in mice) to elevated copper concentrations resulted in exacerbated copper accumulation in ApoE4- compared to ApoE2- and ApoE3-TR astrocytes. This effect was also observed in SH-SY5Y neuroblastoma cells treated with conditioned medium from ApoE4-TR astrocytes. Increased intracellular copper levels in the presence of ApoE4 may be explained by reduced levels and delayed trafficking of the copper transport protein, copper-transporting ATPase 1 (ATP7A/Atp7a), potentially leading to impaired cellular copper export. This new role for ApoE in copper regulation lends further biochemical insight into how APOE genotype confers risk for AD and reveals a potential contribution of ApoE4 to the copper dysregulation that is a characteristic pathological feature of the AD brain.

Prevailing parasitic diseases affecting Oreochromis aureus in Lake Burullus.

Lake Burullus is an important source of fish production in Egypt; it produces 20.5% of the Egyptian fisheries' production. There is intense controversy about the heavy metal pollution in Burullus water and its effects on fish health and safety for human consumption. Heavy metals represent a major concern for aquatic life and could negatively affect fish health. Agricultural and industrial water drainage represents a considerable part of the lake water supply. The present work was conducted to determine heavy metal concentrations in lake water and blue tilapia Oreochromis aureus musculature. Water samples were collected from six locations to determine cadmium, copper, lead, zinc and iron. Sixty O. aureus fish samples were also collected from the same sampling points to assess the prevalent parasites infesting fish and to determine the heavy metal (Cd, Cu, Pb, Zn and Fe) concentrations in fish musculature then study the relationship between heavy metals concentration and prevailing fish parasites. Results indicated that 53.34% of the examined fish were infested with encysted metacercaria. Centrocestus formosanus, Prohemistomum vivax, and Euclinostomum heterostomum were retrieved from gills, musculature, hepatopancreas and the posterior kidney. The parasitic intensity in fish tissues was between 1 and 9 cystg-1. Centrocestus formosanus was identified using the polymerase chain reaction in the gill tissues of 16 fish. The gill parasitic copepod Lamproglena monodi was identified in one fish. Degenerative changes such as thickening, corrugation, and destruction of gill filament are the most dominant pathological changes in infested fish gills. Heavy metal concentrations in water samples were at normal levels, except for copper and iron in the southern part of the lake. All heavy metals in fish musculature were below the permissible limits. The parasitic infestation was more dominant in the northern part of the lake than in the southern region; this could be due to elevated copper concentration in the southern part of the lake that could negatively affect the survival of the first intermediate host and parasite cercaria. In conclusion, captured fish from Lake Burullus were safe for human consumption, and heavy metal pollution in lake water does not represent a severe risk.

Ecotoxicological impact of heavy metals on wild mud crabs (Scylla olivacea) in Malaysia: An integrative approach of omics, molecular docking and human risk assessment

Mud crab, one of the aquatic organisms found in estuary areas, has become a significant economic source of seafood for communities due to its delectable taste. However, they face the threat of heavy metal contamination, which may adversely affect their biological traits. This study explored the comparison of the mud crabs collected from Setiu Wetland as a reference site, while Kuala Sepetang is an area that contains a higher concentration of heavy metals than Setiu Wetlands. Heavy metal levels were quantified using inductively coupled plasma mass spectrometry (ICP-MS), while proteomes were assessed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and 1H nuclear magnetic resonance (NMR)-based metabolomics, respectively. Heavy metal contamination affects the proteome, metabolome, and putative molecular targets in mud crabs (Scylla olivacea), leading to oxidative stress. Mud crabs collected from the metal-polluted area of Kuala Sepetang in Perak had considerably elevated concentrations of nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), chromium (Cr), and cadmium (Cd) in comparison to the reference site of Setiu Wetlands in Terengganu. The proteome analysis revealed an upregulation of the stress-response protein Hsp70, which triggered superoxide dismutase (SOD) and increased arginine kinase expression (5.47 fold) in the muscle tissue, results in the alteration of metabolite regulation in the mud crab from Kuala Sepetang. Additionally, in the muscle tissues of mud crabs obtained from Kuala Sepetang, uncharacterized myosin-tail 1 domain proteins and sarcoplasmic calcium-binding proteins were downregulated. The metabolomic investigation identified changes in metabolites associated with energy metabolism and osmoregulation. Exploration of docking analysis suggests potential connections between methylarsonic acid and essential proteins in mud crabs. These findings suggest that the presence of heavy metals disrupts physiological processes and highlights potential molecular targets that warrant further investigation.

Serum copper assessment in patients with polycystic ovary syndrome and tubal infertility: A retrospective 5-year study.

The association between serum copper and polycystic ovary syndrome (PCOS) lacks definitive conclusions, and the intricate interactions with invitro fertilization (IVF) cycle characteristics in infertility remain insufficiently explored. This retrospective study included 560 patients with tubal infertility (no-PCOS) and 266 patients with PCOS undergoing IVF at the Affiliated Suzhou Hospital of Nanjing Medical University from January 2018 to December 2022. Patients' basic characteristics, hormonal and metabolic parameters, essential trace elements, and IVF cycle characteristics were measured and analyzed. The results revealed a significantly elevated serum copper level in the PCOS group compared to the control group [17.27 (15.54, 19.67) vs 15.4 (13.87, 17.35), μmol/L; p < .001]. Spearman correlation analyses revealed a significant positive correlation between serum copper concentration and body mass index (BMI), fasting glucose (FG), triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL) in the no-PCOS group. Additionally, a notable negative correlation with high-density lipoprotein (HDL) was observed (r = -.184, p < .001). Within the PCOS group, serum copper concentration correlated significantly with BMI (r = .198, p = .004) and TG (r = .214, p = .002). The linear trend analysis indicated no significant relationship between serum copper concentration and ovarian response as well as preimplantation outcomes in both groups after adjusting for confounding factors. Our study provided evidence of elevated serum copper concentration in PCOS patients, closely associated with lipid metabolism but showing no correlation with IVF outcomes. These findings provide valuable real-world data, enriching our nuanced understanding of the role of copper in female fertility.

Seeing is believing: The colour of silver alloys and the global silver circulation in the Chinese Ming and Qing dynasties

AbstractThis research investigates the correlation between colour perception and the circulation of silver in China during the Ming (1368–1644 CE) and Qing (1644–1911 CE) dynasties. The primary aim is to deepen our understanding of how silver alloys were perceived and experienced in this historical context while also situating our study within the broader context of the global silver trade. During the Ming and Qing dynasties, silver possessed immense historical significance as a precious commodity. We argue that copper had a more substantial influence on the final colour of silver alloys compared to lead. Furthermore, employing a colourimetric model, our Monte‐Carlo simulation demonstrates that over 70% of silver from Mesoamerica to China could be discerned by nonexperts using only their unaided vision, largely due to the elevated copper content. Crucially, our simulation experiment reveals differing effects of copper and lead on the colour of silver alloys. The latter demonstrates minimal change until reaching a threshold of 15%, signifying that lead is a suitable and cost‐effective substitute for silver. These findings suggest that the detection of silver purity was less demanding than previously assumed, opening up opportunities for arbitrage.

Interplay between diphenyl diselenide and copper: Impact on D. melanogaster survival, behavior, and biochemical parameters

Copper (Cu2+) is a biologically essential element that participates in numerous physiological processes. However, elevated concentrations of copper have been associated with cellular oxidative stress and neurodegenerative diseases. Organo‑selenium compounds such as diphenyl diselenide (DPDS) have in vitro and in vivo antioxidant properties. Hence, we hypothesized that DPDS may modulate the toxicity of Cu2+ in Drosophila melanogaster. The acute effects (4 days of exposure) caused by a high concentration of Cu2+ (3 mM) were studied using endpoints of toxicity such as survival and behavior in D. melanogaster. The potential protective effect of low concentration of DPDS (20 μM) against Cu2+ was also investigated. Adult flies aged 1–5 days post-eclosion (both sexes) were divided into four groups: Control, DPDS (20 μM), CuSO4 (3 mM), and the combined exposure of DPDS (20 μM) and CuSO4 (3 mM). Survival, biochemical, and behavioral parameters were determined. Co-exposure of DPDS and CuSO4 increased acetylcholinesterase (AChE) activity and the generation of reactive oxygen species (ROS as determined by DFCH oxidation). Contrary to our expectation, the co-exposure reduced survival, body weight, locomotion, catalase activity, and cell viability in relation to control group. Taken together, DPDS potentiated the Cu2+ toxicity.

Hull-cleaning wastewater poses serious acute and chronic toxicity to a marine mysid—A multigenerational study

We conducted a comprehensive assessment involving acute effects on 96-hour survival and biochemical parameters, as well as chronic effects on growth and reproduction spanning three generations of the marine mysid Neomysis awatschensis exposed to filtered wastewater to evaluate the potential impact of ship hull-cleaning wastewater on crustaceans. The analyzed wastewater exhibited elevated concentrations of metals, specifically zinc (Zn) and copper (Cu) and metal-based antifoulants, i.e., Cu pyrithoine (CuPT) and Zn pyrithoine (ZnPT). The results revealed dose-dependent reductions in survival rates, accompanied by a notable increase in oxidative stress, in response to the sublethal values of two wastewater samples: 1) mechanically filtered using the cleaning system (MF) and 2) additionally filtered in the laboratory (LF) for 96 h. Mysids exposed to MF displayed higher mortality than those exposed to LF. Furthermore, mysids subjected to continuous exposure of 0.001% LF across three generations exhibited significant inhibition of the feeding rate, more pronounced growth retardation along with an extended intermolt duration, and a diminished rate of reproduction compared to the control. A noteworthy inhibition of the feeding rate and growth was observed in the first generation exposed only to the LF sample. However, although the reproduction rate was not significantly affected. Collectively, these findings underscore the potential harm posed by sublethal concentrations of wastewater to the health of mysid populations under consistent exposure.

Copper Promotes LPS-Induced Inflammation via the NF-кB Pathway in Bovine Macrophages.

Inflammation is a complex physiological process that enables the clearance of pathogens and repairing damaged tissues. Elevated serum copper concentration has been reported in cases of inflammation, but the role of copper in inflammatory responses remains unclear. This study used bovine macrophages to establish lipopolysaccharide (LPS)-induced inflammation model. There were five groups in the study: a group treated with LPS (100ng/ml), a group treated with either copper chelator (tetrathiomolybdate, TTM) (20μmol) or CuSO4 (25μmol or 50μmol) after LPS stimulation, and a control group. Copper concentrations increased in macrophages after the LPS treatment. TTM decreased mRNA expression of pro-inflammatory factors (IL-1β, TNF-α, IL-6, iNOS, and COX-2), whereas copper supplement increased them. Compared to the control group, TLP4 and MyD88 protein levels were increased in the TTM and copper groups. However, TTM treatment decreased p-p65 and increased IкB-α while the copper supplement showed reversed results. In addition, the phagocytosis and migration of bovine macrophages decreased in the TTM treatment group while increased in the copper treatment groups. Results mentioned above indicated that copper could promote the LPS-induced inflammatory response in bovine macrophages, promote pro-inflammatory factors by activating the NF-кB pathway, and increase phagocytosis capacity and migration. Our study provides a possible targeted therapy for bovine inflammation.

Evaluating the ecological consequences of heavy metal contamination in soil induced by spent engine oil and palm oil mill effluents for sustainable development

&lt;p&gt;This study assessed the ecological consequences of heavy metal contamination in soil induced by spent engine oil (SEO) and palm oil mill effluents (POME) in Ebonyi State, Nigeria. Concentrations of zinc, nickel, mercury, manganese, lead, iron, copper, chromium, and cadmium were analyzed across contaminated and uncontaminated sites. The research, conducted at Ebonyi State University’s Presco Campus, employed rigorous sampling and analytical methods. Results revealed that soil contaminated with spent engine oil effluent exhibited elevated mean concentrations of zinc, nickel, manganese, lead, iron, copper, chromium, and cadmium compared to the palm oil mill effluent and control sites. Conversely, mercury concentrations were higher in soil contaminated with palm oil mill effluent. Comparative analyses highlighted unique dynamics, such as lead concentrations being highest at the control site, challenging general trends observed for other metals. Importantly, none of the mean concentrations exceeded the WHO acceptable limits at the time of the study, indicating compliance with internationally recognized safety thresholds. The findings underscore the need for tailored environmental management strategies, considering specific contaminants associated with each effluent type. Continuous monitoring is crucial to ensure sustained adherence to safety standards and prevent potential future exceedances. This study contributes a valuable understanding of the nuanced ecological impact of industrial effluents on soil quality in Nigeria, emphasizing the importance of sustainable practices for environmental protection.&lt;/p&gt;

Copper stress shapes the dynamic behavior of amoebae and their associated bacteria.

Amoeba-bacteria interactions are prevalent in both natural ecosystems and engineered environments. Amoebae, as essential consumers, hold significant ecological importance within ecosystems. Besides, they can establish stable symbiotic associations with bacteria. Copper plays a critical role in amoeba predation by either killing or restricting the growth of ingested bacteria in phagosomes. However, certain symbiotic bacteria have evolved mechanisms to persist within the phagosomal vacuole, evading antimicrobial defenses. Despite these insights, the impact of copper on the symbiotic relationships between amoebae and bacteria remains poorly understood. In this study, we investigated the effects of copper stress on amoebae and their symbiotic relationships with bacteria. Our findings revealed that elevated copper concentration adversely affected amoeba growth and altered cellular fate. Symbiont type significantly influenced the responses of the symbiotic relationships to copper stress. Beneficial symbionts maintained stability under copper stress, but parasitic symbionts exhibited enhanced colonization of amoebae. Furthermore, copper stress favored the transition of symbiotic relationships between amoebae and beneficial symbionts toward the host's benefit. Conversely, the pathogenic effects of parasitic symbionts on hosts were exacerbated under copper stress. This study sheds light on the intricate response mechanisms of soil amoebae and amoeba-bacteria symbiotic systems to copper stress, providing new insights into symbiotic dynamics under abiotic factors. Additionally, the results underscore the potential risks of copper accumulation in the environment for pathogen transmission and biosafety.

Enhanced biodegradation kinetics in the copper-polluted sediment through bioaugmentation with water spinach and peanut husk-derived biochar

Stenotrophomonas maltophilia is a copper-tolerant bacterium that is used for improving the resilience and efficacy of microorganisms engaged in degrading substrate under high copper contamination. Examination of reaction kinetics indicates that the original consortia, Stenotrophomonas maltophilia and the mixed culture, follow a first-order reaction. The Michaelis-Menten model suggests that elevated copper concentrations exert stress on the original bacterial population and Stenotrophomonas maltophilia. However, when a mixed culture is employed during the bioaugmentation process, it brings about an enhancement in microbial resistance and performance. This study demonstrates that the poor performance of indigenous bacteria in media that are highly contaminated with copper can be improved by adding exogenous copper-tolerant bacteria. Furthermore, poor mass transfer in sediments can be improved by adding plants and biochar. This strategic addition serves a dual purpose: it increases the affinity of the substrate for sediments characterized by poor mass transfer and alleviates the inhibitory effects induced by copper. In addition, high percentages of Firmicutes, Bacteroidetes, and Euryarchaeota within the biochar matrix were verified to expedite the substrate biodegradation process even at high copper concentrations. The findings in this work provide an important basis for the future design of in situ bioremediation systems for heavy metal-contaminated sites.

California condor poisoned by lead, not copper, when both are ingested: A case study

AbstractLead poisoning from feeding on carcasses shot with lead‐based ammunition is a well‐known threat to wildlife. Thus, nonlead (e.g., copper‐based) ammunition is promoted as a safe alternative. We present a unique situation of a male California condor (Gymnogyps californianus) discovered with both a lead fragment and a copper bullet in his digestive tract simultaneously. We show that ingestion of a copper bullet did not result in elevated blood copper concentrations, while ingestion of a lead fragment contributed to lead toxicity. Our findings can inform nonlead ammunition outreach efforts by demonstrating that ingestion of a copper‐based bullet did not result in the poisoning of a California condor.

The copper chelator ammonium tetrathiomolybdate inhibits the progression of experimental endometriosis in TNFR1-deficient mice

The TNF-α/TNFR system is involved in endometriosis (EDT), a gynecologic estrogen-dependent disease. Elevated copper concentrations have also been associated with EDT, even in TNFR1-deficient mice where disease worsening occurs. We aimed to evaluate whether treatment with ammonium tetrathiomolybdate (TM, copper chelator) is beneficial in TNFR1-deficient mice presenting with worsened EDT status. Female C57BL/6 mice were divided into three groups: KO Sham, KO EDT, and KO EDT+TM. TM was administered from the 15th postoperative day, and samples were collected one month after inducing pathology. In peritoneal fluid, copper and estradiol levels were determined by electrothermal atomic absorption spectrometry and electrochemiluminescence, respectively. Lesions were processed for the analysis of cell proliferation (PCNA immunohistochemistry), expression of angiogenic markers (RT-qPCR), and oxidative stress (spectrophotometric methods). We found that EDT increased copper and estradiol levels compared to the KO Sham group, while the TM administration restored the levels of both factors. TM also reduced the volume and weight of the lesions and cell proliferation rate. Besides, TM treatment decreased the number of blood vessels and the Vegfa, Fgf2, and Pdgfb expression. Furthermore, superoxide dismutase and catalase activity decreased, and lipid peroxidation increased. TM administration inhibits EDT progression in TNFR1-deficient mice where the pathology is exacerbated.

Chronic Engineered Nanoparticle Additions Alter Insect Emergence and Result in Metal Flux from Aquatic Ecosystems into Riparian Food Webs.

Freshwater ecosystems are exposed to engineered nanoparticles (NPs) through discharge from wastewater and agricultural runoff. We conducted a 9-month mesocosm experiment to examine the combined effects of chronic NP additions on insect emergence and insect-mediated contaminant flux to riparian spiders. Two NPs (copper, gold, plus controls) were crossed by two levels of nutrients in 18 outdoor mesocosms open to natural insect and spider colonization. We collected adult insects and two riparian spider genera, Tetragnatha and Dolomedes, for 1 week on a monthly basis. We estimated a significant decrease in cumulative insect emergence of 19% and 24% after exposure to copper and gold NPs, irrespective of nutrient level. NP treatments led to elevated copper and gold tissue concentrations in adult insects, which resulted in terrestrial fluxes of metals. These metal fluxes were associated with increased gold and copper tissue concentrations for both spider genera. We also observed about 25% fewer spiders in the NP mesocosms, likely due to reduced insect emergence and/or NP toxicity. These results demonstrate the transfer of NPs from aquatic to terrestrial ecosystems via emergence of aquatic insects and predation by riparian spiders, as well as significant reductions in insect and spider abundance in response to NP additions.

The role of antioxidant response and nonphotochemical quenching of chlorophyll fluorescence in long-term adaptation to Cu-induced stress in Chlamydomonas reinhardtii

Copper is an essential micronutrient, but at supraoptimal concentrations it is also highly toxic, inducing oxidative stress and disrupting photosynthesis. The aim of the present study was to analyze selected protective mechanisms in strains of Chlamydomonas reinhardtii adapted and not adapted for growth in the presence of elevated copper concentrations. Two algal lines (tolerant and non-tolerant to high Cu2+ concentrations) were used in experiments to study photosynthetic pigment content, peroxidase activity, and non-photochemical quenching. The content of prenyllipids was studied in four different algal lines (two of the same as above and two new ones). The copper-adapted strains contained about 2.6 times more α-tocopherol and plastoquinol and about 1.7 times more total plastoquinone than non-tolerant strains. Exposure to excess copper led to oxidation of the plastoquinone pool in non-tolerant strains, whereas this effect was less pronounced or did not occur in copper-tolerant strains. Peroxidase activity was approximately 1.75 times higher in the tolerant strain than in the non-tolerant one. The increase in peroxidase activity in the tolerant strain was less pronounced when the algae were grown in dim light. In the tolerant line nonphotochemical quenching was induced faster and was usually about 20–30% more efficient than in the non-tolerant line. The improvement of antioxidant defense and photoprotection may be important factors in the evolutionary processes leading to tolerance to heavy metals.