Effects of copper on oxidative stress and autophagy in hypothalamus of broilers

Luteolin alleviates cadmium-induced metabolism disorder through antioxidant and anti-inflammatory mechanisms in chicken kidney

Cadmium (Cd) is a common environmental pollutant associated with an increased incidence of renal metabolic diseases. Luteolin (Lut), a natural flavonoid, is widely used for its multifaceted therapeutic properties in inflammatory diseases. However, whether Lut protects against Cd-induced nephrotoxicity is still equivocal. The present study investigated the effects of Lut supplementation on renal oxidative stress, inflammation and metabolism and their related mechanisms. Therefore, 40 chickens were treated with Cd and/or Lut with automatic water and free food intake for 1 mo and then the kidney tissues were collected to explore this issue. In this study, Cd exposure induced renal glycolipid metabolism disorders and resultant kidney damage by periodic acid Schiff (PAS) staining, Oil Red O staining, total cholesterol (TC), triglyceride (TG), and glucose (Glu) levels in kidney, which were significantly ameliorated by Lut. Moreover, Lut also normalized the expression levels of factors related to Cd-disturbed glycolipid metabolism, improving metabolic homeostasis, and contributing to alleviating kidney damage. Furthermore, Lut demonstrated therapeutic potential against Cd-induced renal oxidative stress and inflammation by enhancing antioxidant capacity and inhibiting cytokine production in the kidney tissues. Mechanistically, Lut activated the AMPK/SIRT1/FOXO1 signaling pathway, attenuating oxidative stress and inflammatory responses, ameliorating the metabolic disturbance. In conclusion, these observations demonstrate that Lut treatment activates AMPK/SIRT1/FOXO1 signaling pathway, decreases oxidative stress and inflammation response, which may contribute to prevent Cd-induced metabolism disorder and consequent kidney damage.

Cu exposure induces liver inflammation via regulating gut microbiota/LPS/liver TLR4 signaling axis

Copper (Cu) serves as an essential cofactor in all organisms, yet excessive Cu exposure is widely recognized for its role in inducing liver inflammation. However, the precise mechanism by which Cu triggers liver inflammation in ducks, particularly in relation to the interplay in gut microbiota regulation, has remained elusive. In this investigation, we sought to elucidate the impact of Cu exposure on liver inflammation through gut-liver axis in ducks. Our findings revealed that Cu exposure markedly elevated liver AST and ALT levels and induced liver inflammation through upregulating pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) and triggering the LPS/TLR4/NF-κB signaling pathway. Simultaneously, Cu exposure induced alterations in the composition of intestinal flora communities, notably increasing the relative abundance of Sphingobacterium, Campylobacter, Acinetobacter and reducing the relative abundance of Lactobacillus. Cu exposure significantly decreased the protein expression related to intestinal barrier (Occludin, Claudin-1 and ZO-1) and promoted the secretion of intestinal pro-inflammatory cytokines. Furthermore, correlation analysis was observed that intestinal microbiome and gut barrier induced by Cu were closely related to liver inflammation. Fecal microbiota transplantation (FMT) experiments further demonstrated the microbiota-depleted ducks transplanting fecal samples from Cu-exposed ducks disturbed the intestinal dysfunction, which lead to impaire liver function and activate the liver inflammation. Our study provided insights into the mechanism by which Cu exposure induced liver inflammation in ducks through the regulation of gut-liver axis. These results enhanced our comprehension of the potential mechanisms driving Cu-induced hepatotoxicity in avian species.

Arsenic and chromium induced hepatotoxicity in zebrafish (Danio rerio) at environmentally relevant concentrations: Mixture effects and involvement of Nrf2-Keap1-ARE pathway

Arsenic (As) and chromium (Cr), two well-known cytotoxic and carcinogenic metals are reported to coexist in industrial effluents and groundwater. Their individual toxicities have been thoroughly studied but the combined effects, especially the mechanism of toxicity and cellular stress response remain unclear. Considering co-exposure as a more realistic scenario, current study compared the individual and mixture effects of As and Cr in the liver of zebrafish (Danio rerio). Fish were exposed to environmentally relevant concentrations of As and Cr for 15, 30 and 60 days. ROS generation, biochemical stress parameters like lipid peroxidation, reduced glutathione content, catalase activity and histological alterations were studied. Results showed increase in ROS production, MDA content and GSH level; and vicissitude in catalase activity as well as altered histoarchitecture, indicating oxidative stress conditions after individual and combined exposure of As and Cr which were additive in nature. This study also included the expression of Nrf2, the key regulator of antioxidant stress responses and its nuclear translocation. Related antioxidant and xenobiotic metabolizing enzyme genes like keap1, nqo1, ho1, mnsod and cyp1a were also studied. Overall results indicated increased nrf2, nqo1, ho1, mnsod expression at all time points and increased cyp1a expression after 60 days exposure. Emphasizing on the Nrf2-Keap1 pathway, this study exhibited additive or sometimes synergistic effects of As and Cr in zebrafish liver.

Mitochondrial derived vesicle-carrying protein MIGA2 promotes copper-induced autophagosomes-lysosomes fusion by regulating ATG14

As an environmental pollution metal, copper (Cu) exposure-induced toxicity is closely related to mitochondrial damage. Mitochondrial-derived vesicles (MDVs) plays an essential role in mitochondrial quality control and cellular metabolism. However, the mechanism by which MDVs are involved in cellular metabolism under Cu exposure remains unclear. Here, the MDV-carrying protein MIGA2 was identified as a crucial molecule involved in the Cu-induced autophagosomes-lysosomes fusion. Furthermore, Cu exposure significantly promoted MDVs secretion, accompanied by a markedly increased MIGA2 expression in MDVs, as well as accelerated the autophagosomes-lysosomes fusion. However, small RNA interference of SNX9 (the MDVs secretion inductor) and MIGA2 blocked autophagic flux induced by Cu, leading to failure of autophagosomes degradation. Co-immunoprecipitation assay further demonstrated that ATG14 was a regulation target protein of MIGA2. Overexpression and knockdown of ATG14 significantly affected the autophagosomes-lysosomes fusion induced by Cu. Meanwhile, knockdown of ATG14 dramatically reversed the effect of MIGA2-overexpression in promoting autophagosomes-lysosomes fusion, while overexpression of ATG14 shows the opposite effect. These results demonstrated that MDVs-carrying MIGA2 protein promoted autophagosomes-lysosomes fusion induced by Cu. This study demonstrated that MDVs is involved in regulating organelles-to-organelles communication, providing a new insight into the toxicity mechanism of Cu exposure on hepatocytes.

Mitochondrial DNA release mediated by TFAM deficiency promotes copper-induced mitochondrial innate immune response via cGAS-STING signalling in chicken hepatocytes

Copper (Cu) is pollution metal that is a global concern due to its toxic effects. A recent study found that the release of mitochondrial DNA (mtDNA) into the cytoplasm can activate the innate immune response, but the exact mechanisms underlying the effect of Cu exposure remains unknown. In this study, we identified that the reduction in transcription Factor A (TFAM) led to mtDNA leakage into the cytoplasm under Cu exposure in hepatocytes, accompanied by the activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway-mediated innate immunity (increased expression of cGAS, STING, TANK-binding kinase-1 (TBK1), and interferon regulatory factor-3 (IRF3)) genes and proteins, and enhanced phosphorylation levels of TBK1 and IRF3). Subsequently, silencing TFAM (siTFAM) significantly aggravated mtDNA release and the innate immune response under Cu treatment. Mitochondrial DNA depletion alleviated Cu-induced innate immunity in hepatocytes, while mtDNA transfection further enhanced the innate immune response. Notably, the inhibition of STING effectively alleviated the phosphorylation levels of the TBK1 and IRF3 proteins induced by Cu, while the upregulation of STING aggravated the Cu-induced innate immunity. Furthermore, EtBr and H-151(a STING inhibitor) treatment dramatically reversed the effect of TFAM depletion on the sharpened innate immune response induced by Cu via the cGAS-STING pathway. In general, these findings demonstrated the TFAM deficiency promotes innate immunity by activating the mtDNA-cGAS-STING signalling pathway under Cu exposure in hepatocytes, providing new insight into Cu toxicology.

Exposure to copper induces endoplasmic reticulum (ER) stress-mediated apoptosis in chicken (Gallus gallus) myocardium

Copper (Cu), an omnipresent environmental pollutant, can cause potential harm to the public and ecosystems. In order to study the cardiotoxicity caused by Cu, molecular biology techniques were used to analyze the effect of Cu on ER stress-mediated cardiac apoptosis. In vivo investigation, 240 1-day-old chickens were fed with Cu (11, 110, 220, and 330 mg/kg) diet for 7 weeks. The consequence showed that high-Cu can induce ER stress and apoptosis in heart tissue. The vitro experiments, the Cu treatment for 24 h could provoke ultrastructural damage and upregulate the apoptosis rate. Meanwhile, GRP78, GRP94, eIF2α, ATF6, XBP1, CHOP, Bax, Bak1, Bcl2, Caspase-12 and Caspase-3 genes levels, and GRP78, GRP94 and Caspase-3 proteins levels were increased, which indicated that ER stress and apoptosis in cardiomyocytes. But the mRNA level of Bcl2 were decreased after Cu exposure. Conversely, Cu-induced ER stress-mediated apoptosis can be alleviated by treatment with 4-PBA. These findings generally showed that Cu exposure can contribute to ER stress-mediated apoptosis in chicken myocardium, which clarifies the important mechanism link between ER stress and apoptosis, and provides a new perspective for Cu toxicology.

Induction of mitophagy via ROS-dependent pathway protects copper-induced hypothalamic nerve cell injury

Copper (Cu) is one of the essential trace elements in the body, but excessive amounts of Cu harm multiple organs and tissues such as liver, kidneys, testis, ovaries, and brain. However, the mechanism of hypothalamic neurotoxicity induced by Cu is still unknown. This study examined the relationship between reactive oxygen species (ROS) and mitophagy in mouse hypothalamus treated with high Cu. The results demonstrated that high levels of copper sulfate (CuSO4) could cause histopathological and neuronal changes in the mouse hypothalamus, produce a large amount of ROS, induce mitophagy, and lead to an imbalance of mitochondrial fusion/fission. The main manifestations are an increase in the expression levels of LC3-II/LC3-I, p62, DRP1, and FIS1, and a decrease in the expression levels of MFN1 and MFN2. Cu can induce mitophagy also was confirmed by LC3 co-localization with TOMM20 (mitochondrial marker). Next, the effect of oxidative stress on CuSO4-induced mitophagy was demonstrated. The results showed that ROS inhibitor N-acetylcysteine (NAC) diminished CuSO4-induced mitophagy and reversed the disturbance of mitochondrial dynamics. Additionally, a study was carried out to evaluate the role of mitophagy in CuSO4-induced hypothalamic injury. The inhibition of mitophagy using mitophagy inhibitor (Mdivi-1) decreased cell viability and promoted CuSO4-inhibited mitochondrial fusion. The aforementioned results suggested that CuSO4 induced mitophagy via oxidative stress in N38 cells and mouse hypothalamus, and that the activation of mitophagy might generate protective mechanisms by alleviating Cu-induced mitochondrial dynamics disorder. This study provided a novel approach and theoretical basis for studying and preventing Cu neurotoxicity.

Mitochondria-mediated apoptosis and endoplasmic reticulum stress are involved in the toxicity induced by copper in the porcine spleen

Copper (Cu) is one of the common heavy metal pollutants in the environment, and its toxic mechanisms have been extensively studied. However, the immunotoxicity induced by Cu remains rarely reported, and the effects of Cu on endoplasmic reticulum stress and mitochondria-mediated apoptosis have been little studied in the spleen. In this study, pigs were fed with different contents of Cu (10, 125, and 250 mg/kg Cu) for 80 days to establish a toxicity model. The results showed the Cu exposure triggered endoplasmic reticulum stress in the spleen, as evidenced by increased mRNA and protein levels of GRP94, GRP78, CHOP, XBP1, ATF6, and JNK; the positive rate of GRP78 increased by immunofluorescence analysis. Additionally, mitochondrial fission and fusion homeostasis were disrupted, the expression levels of mitochondrial dynamics-related genes Mfn1, Mfn2, and OPA1 decreased, DRP1 increased, and the positive rate of Mfn1 decreased by immunofluorescence analysis. Furthermore, Cu exposure could induce apoptosis, as demonstrated by the increased expression level of related proteins and genes Bak, Bax, Caspase-3, P53, and Cytc. In conclusion, these results suggest chronic Cu exposure can lead to endoplasmic reticulum stress and imbalance in mitochondrial dynamics and induced apoptosis of pig spleen, and these results provided new insights into the underlying mechanism of Cu exposure caused splenic toxicity, which has public health implications where humans and animals are exposed to copper contamination.

Long-Term Copper Exposure Induced Excessive Autophagy of the Porcine Spleen

Copper (Cu) is one of the essential trace elements and is widespread in the environment. However, excessive exposure will induce toxicity in animals. To investigate the potential mechanisms of Cu-induced porcine spleen toxicity, sixty 30-day-old pigs were randomly divided into three groups. The control group was fed a basal diet and two treatment groups were separately fed the diet with 125 mg/kg and 250 mg/kg of Cu for 80 days. The result of immunohistochemical staining showed that the autophagy marker p62 was significantly increased under Cu exposure, and the immunofluorescence results showed the same trend as LC33-. Meanwhile, Cu intensified autophagy by increasing the expression levels of autophagy-related genes and proteins (LC3, p62, ATG5, Beclin1, and PINK1). These results suggested that long-term Cu exposure induced excessive autophagy in the porcine spleen, laying the groundwork for future studies on Cu-induced immunotoxicity in the spleen and increasing the public safety awareness of the excessive Cu-induced contamination in the environment.

Copper-induced Genotoxicity, Oxidative Stress, and Alteration in Transcriptional Level of Autophagy-associated Genes in Snakehead Fish Channa punctatus

Copper (Cu) is an essential and important trace element for some significant life processes for most organisms. However, an excessive amount of Cu can be highly toxic. The present study was conducted to elucidate the oxidative stress-induced alteration in transcriptional level of autophagy-related genes in the liver and kidney tissue of fish Channa punctatus after treatment with three different sublethal concentrations of CuSO₄ for 28 days. All the studied enzymatic and non-enzymatic oxidative stress markers viz. superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase-GPx, glutathione reductase-GR, and glutathione-GSH showed an increase in their activity levels in the treated groups in a dose-dependent manner. Particularly SOD and CAT have shown a significant hike in activity levels. ROS levels in blood cells increased significantly (p < 0.05) in all the treated groups, i.e., Group II-1/20^th of 96 h-LC₅₀ (0.2 mg/L), Group III-1/10^th of 96 h-LC₅₀ (0.4 mg/L), and Group IV-1/5 ^h of 96 h-LC₅₀ (0.8 mg/L) of Cu²⁺ in a dose-dependent manner as compared to control (Group I). The upregulation in mRNA levels of autophagy-related genes Microtubule-associated protein 1 light chain 3 (LC3), Gamma-aminobutyric acid receptor-associated protein precursor (Gabarap), and Golgi-associated ATPase enhancer of 16 kDa (GATE16), autophagy-related 5 (ATG5) was observed while mammalian target of rapamycin (mTOR) showed downregulation in the liver and kidney tissue of fish. The decrease in mTOR and increase in ATG5 gene expression projects autophagic vesicle formation due to oxidative stress. There was significant induction in micronuclei (MN) frequency in all the treated groups. The highest frequency of MN induced by Cu²⁺ was recorded in Group IV after 28 days of the exposure period. Thus, it can be concluded that the available information about Cu²⁺-induced oxidative stress-mediated autophagy in the liver and kidney of fish C. punctatus remains largely unclear to date, so to fill the aforesaid gap, the present study was undertaken, which gives an insight for the mechanisms of autophagy induced by Cu²⁺ in fish.

Effects of Long-Term Exposure to Copper on Mitochondria-Mediated Apoptosis in Pig Liver

Copper (Cu) is listed as one of the main heavy metal pollutants, which poses potential health risks to humans. Excessive intake of Cu has shown toxic effects on the organs of many animals, and the liver is one of the most important organs to metabolize it. In this study, pigs, the mammal with similar metabolic characteristics to humans, were selected to assess the effects of long-term exposure to Cu on mitochondria-mediated apoptosis, which are of great significance for studying the toxicity of Cu to humans. Pigs were fed a diet with different contents of Cu (10, 125, and 250 mg/kg) for 80 days. Samples of blood and liver tissue were collected on days 40 and 80. Experimental results demonstrated that the accumulation of Cu in the liver was increased in a dose-dependent and time-dependent manner. Meanwhile, the curve of pig's body weight showed that a 125 mg/kg Cu diet promoted the growth of pigs during the first 40 days and then inhibited it from 40 to 80 days, while the 250 mg/kg Cu diet inhibited the growth of pigs during 80 days of feeding. Additionally, the genes and protein expression levels of Caspase-3, p53, Bax, Bak1, Bid, Bad, CytC, and Drp1 in the treatment group were higher than that in the control group, while Bcl-2, Bcl-xL, Opa1, Mfn1, and Mfn2 were decreased. In conclusion, these results indicated that long-term excessive intake of Cu could inhibit the growth of pigs and induced mitochondria-mediated apoptosis by breaking the mitochondrial dynamic balance. Synopsis: Long-term exposure to high doses of Cu could lead to mitochondrial dysfunction by breaking the mitochondrial dynamic balance, which ultimately induced mitochondria-mediated apoptosis in the liver of pigs. This might be closely related to the growth inhibition and liver damage in pigs.

Arsenic Trioxide Triggers Mitochondrial Dysfunction, Oxidative Stress, and Apoptosis via Nrf 2/Caspase 3 Signaling Pathway in Heart of Ducks

Arsenic is a common environmental pollutant and poses a serious threat to human and animal health. In this study, we used the ducks to mimic arsenic trioxide (ATO) exposure and investigated the mechanism of cardiac toxicity. The results indicated that ATO inhibited the body and organ growth of ducks, led to an increase in LDH content, and caused obvious deformity, ischemia infarction. It is found that ATO exacerbated the swell of mitochondrial and the contraction of cell nuclei in the heart of ducks through transmission electron microscopy (TEM). ATO also induced an increase in MDA content; inhibited the activation of the Nrf 2 pathway; downregulated the expression of mRNA and protein of Nrf 2, HO-1, and SOD-1; and upregulated the expression of mRNA and protein of Keap 1. At the same time, ATO induced apoptosis which not only upregulated the expression levels of mRNA and proteins (Caspase 3, Cyt-C, P53, Bax) but also decreased the mRNA and protein expression level of Bcl-2. These results indicated that ATO can lead to oxidative stress and apoptosis in the heart of ducks. In general, our research shows that ATO triggers mitochondrial dysfunction, oxidative stress, and apoptosis via Nrf 2/Caspase 3 signaling pathway in the heart of ducks.

Exposure to copper activates mitophagy and endoplasmic reticulum stress-mediated apoptosis in chicken (Gallus gallus) cerebrum

A large amount of copper (Cu) used in production activities can lead to the enrichment of Cu in the environment, which can cause toxicity to animals. However, the toxicity mechanism of Cu on the cerebrum is still uncertain. Hence, a total of 240 chickens were separated into four groups in this study to reveal the potential connection between mitophagy and endoplasmic reticulum (ER) stress-mediated apoptosis in the chicken cerebrum in the case of excess Cu exposure. The cu exposure situation was simulated by diets containing various levels of copper (11 mg/kg, control group; 110 mg/kg, group I; 220 mg/kg, group II and 330 mg/kg, group III) for 49 days. The results of histology showed that vacuolar degeneration was observed in the treated groups, and the mitochondria swell and autophagosomes formation were found under excess Cu treatment. Additionally, the expression of mitophagy (PINK1, Parkin, LC3I, LC3II and p62) and ER stress (GRP78, PERK, ATF6, IRE1α, XBP1, CHOP, and JNK) indexes were significantly upregulated under excess Cu exposure. Furthermore, the mRNA and protein expression of Bcl-2 were decreased, while Bak1, Bax, Caspase12, and Caspase3 were increased compared to the control group. In summary, this study demonstrated that an overdose of Cu could induce mitophagy and ER stress-mediated apoptosis in the chicken cerebrum. These findings revealed an important potential connection between Cu toxicity and cerebrum damage, which provided a new insight into Cu neurotoxicity.

Chronic hypoxia and Cu2+ exposure induce gill remodeling of largemouth bass through endoplasmic reticulum stress, mitochondrial damage and apoptosis

Hypoxia and Cu²⁺ pollution often occur simultaneously in aquatic ecosystems and jointly affect physiology of fish. As the respiratory and ion exchange tissue of fish, how gill responds to the stress induced by these two abiotic environmental factors is still unclear. We have conducted a study by exposing largemouth bass (Micropterus salmoides) to hypoxia (2.0 mg·L^-1) and/or Cu²⁺ (0.5 mg·L^-1) for 28 days to answer this question. We subsequently studied respiratory rate, Cu²⁺ transport, endoplasmic reticulum (ER) stress, mitochondrial damage, and morphology in gill tissue on day 7, 14, 21 and 28. We found that hypoxia exposure increased the respiratory rate of largemouth bass, reflecting the response of largemouth bass to cope with hypoxia. Of note, Cu²⁺ entered gill by specifically binding to CTR1 and its accumulation dramatically in gill disrupted the response of largemouth bass to hypoxia. Hypoxia and/or Cu²⁺ exposure led to ER stress and mitochondrial damage in gills of largemouth bass. ER stress and mitochondrial damage induced apoptosis by activating caspase-8 and caspase-9 signaling pathways, respectively. Apoptosis induced by hypoxia and Cu²⁺ exposure had a positive and synergistic effect on gill remodeling by reducing interlamellar cell masses. In addition, Cu²⁺ exposure induced hypoxia-like remodeling to gill morphology through mechanisms similar to hypoxia exposure. Most of gene expression changed mainly within 21 days and recovered to the control level on day 28, reflecting the acclimation of largemouth bass to hypoxia and/or Cu²⁺ exposure at gene expression level. Overall, our research suggests that chronic hypoxia and Cu²⁺ exposure could induce gill remodeling of largemouth bass through ER stress, mitochondrial damage and apoptosis. The outcomes could provide an insight for fish environmental adaptation and environmental toxicology.

MitomiR-504 alleviates the copper-induced mitochondria-mediated apoptosis by suppressing Bak1 expression in porcine jejunal epithelial cells

Copper (Cu), an environmental heavy metal pollutant, has been widely researched in its toxicology. Recently, an increasing number of mitochondrial microRNAs (mitomiRs) have been shown to involve in the metabolic regulation. However, the underlying mechanisms of mitomiRs on regulating apoptosis under Cu exposure are still unclear. Here, we proved that Cu induced mitochondria-mediated apoptosis in porcine jejunal epithelial cells, concomitant with distinct reduction of mitomiR-504 in vivo and in vitro. The miR-504 mimic notably enhanced the mRNA and protein expressions of Bak1, Bax, Cleaved-caspase3 and Caspase-9, and significantly decreased the apoptosis rate and Bcl-2 mRNA and protein levels, indicating that overexpression of mitomiR-504 attenuated the Cu-induced mitochondria-mediated apoptosis. Besides, Bak1 was confirmed as a direct target of mitomiR-504 by the bioinformatics analysis and dual-luciferase reporter assay. Subsequently, transfection of siRNA targeting Bak1 significantly enhanced the alleviating effect of miR-504 mimic on the Cu-induced mitochondria-mediated apoptosis. Overall, these suggested that overexpression of mitomiR-504 alleviated the Cu-induced mitochondria-mediated apoptosis in jejunal epithelial cells by suppressing Bak1 expression. These findings are conducive to elucidating the mechanism of Cu-induced jejunal epithelial pathologies, providing a new research idea for the Cu toxicology.

Molybdenum and Cadmium Co-induce Pyroptosis via Inhibiting Nrf2-Mediated Antioxidant Defense Response in the Brain of Ducks

Excess molybdenum (Mo) and cadmium (Cd) are harmful to animals, but the neurotoxic mechanism co-induced by Mo and Cd is unclear. To estimate the effects of Mo and Cd co-exposure on pyroptosis by nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant defense response in duck brains, 40 healthy 7-day-old ducks were randomly assigned to 4 groups and fed diet supplemented with Mo or/and Cd for 16 weeks, respectively. Results showed that Mo or/and Cd markedly increased Mo and Cd contents; decreased iron (Fe), copper (Cu), zinc (Zn), and selenium (Se) contents, elevated malondialdehyde (MDA) content; and decreased total-antioxidant capacity (T-AOC), total-superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities accompanied by pathological damage in brain. Additionally, Mo or/and Cd inhibited Nrf2 pathway via decreasing Nrf2, CAT, SOD1, glutathione S-transferase (GST), hemeoxygenase-1 (HO-1), NAD (P) H:quinone oxidoreductase 1 (NQO1), glutamate-cysteine ligase catalytic subunit (GCLC), and modifier subunit (GCLM) mRNA levels and Nrf2 protein level, which induced pyroptosis through upregulating nucleotide oligomerization domain-like receptor protein-3 (NLRP3), apoptosis-associated speck-like protein (ASC), gasdermin A (GSDMA), gasdermin E (GSDME), interleukin-1β (IL-1β), interleukin-18 (IL-18), Caspase-1, NIMA-related kinase 7 (NEK7) mRNA levels and NLRP3, Caspase-1 p20, gasdermin D (GSDMD), ASC protein levels and IL-1β, and IL-18 contents. Besides, the changes of these indicators were most apparent in the Mo and Cd co-treated group. Collectively, the results certificated that Mo and Cd might synergistically induce pyroptosis via inhibiting Nrf2-mediated antioxidant defense response in duck brains, whose mechanism is closely related to Mo and Cd accumulation.

Involvement of the inhibition of mitochondrial apoptotic, p53, NF-κB pathways and the activation of Nrf2/HO-1 pathway in the protective effects of curcumin against copper sulfate-induced nephrotoxicity in mice

Chronic copper exposure could cause potential nephrotoxicity and effective therapy strategies are limited. This study investigated the protective effects of curcumin on copper sulfate (CuSO4)-induced renal damage in a mouse model and the underlying molecular mechanisms. Mice were administrated orally with CuSO4 (100 mg/kg per day) in combination with or without curcumin (50, 100 or 200 mg/kg per day, orally) for 28 days. Results showed that curcumin supplementation significantly reduce the Cu accumulation in the kidney tissues of mice and improved CuSO4-induced renal dysfunction. Furthermore, curcumin supplantation also significantly ameliorated Cu exposure-induced oxidative stress and tubular necrosis in the kidneys of mice. Moreover, compared to the CuSO4 alone group, curcumin supplementation at 200 mg/kg per day significantly decreased CuSO4-induced the expression of p53, Bax, IL-1β, IL-6, and TNF-α proteins, levels of NF-κB mRNA, levels of caspases-9 and - 3 activities, and cell apoptosis, and significantly increased the levels of Nrf2 and HO-1 mRNAs in the kidney tissues. In conclusion, for the first time, our results reveal that curcumin could trigger the inhibition of oxidative stress, mitochondrial apoptotic, p53, and NF-κB pathways and the activation of Nrf2/HO-1 pathway to ameliorate Cu overload-induced nephrotoxicity in a mouse model. Our study highlights that curcumin supplementation may be a promising treatment strategy for treating copper overload-caused nephrotoxicity.

Crosstalk Between the Mitochondrial Dynamics and Oxidative Stress in Zinc-induced Cytotoxicity

Zinc is an essential trace element, which plays an important role in multiple biological activities. However, excessive exposure to zinc can cause toxic damage to living organism. Here, we investigated the relationship between oxidative stress and mitochondrial dynamics in the zinc-induced cytotoxicity. Results showed that excess exposure to zinc could significantly reduce cell viability and induce cell vacuolation in PK-15 cells. Additionally, zinc exposure caused mitochondrial dynamics disorder, manifested as mitochondrial fission, and the elevated mRNA level of Drp1 and downregulated mRNA levels of OPA1, Mfn1, and Mfn2. Meanwhile, zinc could induce oxidative damage, evidenced by the increasing levels of hydrogen peroxide, malondialdehyde, lipid peroxidation, oxidized form of nicotinamide adenine dinucleotide phosphate/nicotinamide adenine dinucleotide phosphate, oxidized glutathione/glutathione, superoxide dismutase activity, and the mRNA expression of SOD-1 and NOQ1, and decreasing levels of catalase activity, glutathione peroxidase activity, glutathione reductase activity, and the mRNA expression of CAT, and GPX1. Interestingly, N-acetyl-L-cysteine, an inhibitor for oxidative stress, could reduce the mitochondrial fission under zinc treatment. Besides, Mdivi-1, a mitochondrial fission inhibitor, could relieve oxidative stress caused by excess zinc. In general, these results suggested that mitochondrial fission and oxidative stress induced by zinc were interrelated in PK-15 cells, which is conducive to explore the new mechanism of zinc toxicity and proposes a theoretical foundation for selecting effective drugs to alleviate the toxic effects caused by zinc.

Antioxidative and anti-inflammatory effects of vitamin C on the liver of laying hens under chronic heat stress

In this study, we investigated the therapeutic effect and mechanism of action of vitamin C on chronic heat stress (CHS)-induced liver oxidative damage and inflammation in laying hens. The thermoneutral control group (TN group) was kept at a constant temperature of 22 ± 1°C, while the chronic heat stress group (CHS group) and the vitamin C supplemented group (HSV group) were exposed to heat stress (HS) (36 ± 1°C, 8 h/d). The TN and HS groups were fed the basic diet at will, and the HSV group was supplemented with 300 mg/kg of vitamin C on top of the basic diet. The experimental results showed a significant improvement in body weight and feed intake in the HSV group compared to the HS group. A significantly lower pH and higher HCO3- and PCO₂ levels were observed in the HSV group compared to the CHS group. As laying hens were supplemented with vitamin C, serum malondialdehyde (MDA) level was declined, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were increased, and total antioxidant capacity (T-AOC) was increased. Further, CHS induced an increase in the expression of inflammation-related genes and a decrease in the expression of antioxidant-related genes. In contrast, the addition of vitamin C reversed the effects of CHS, resulting in an increase in the expression of antioxidant-related genes and a decrease in the expression of inflammation-related genes. In conclusion, vitamin C can effectively alleviate CHS-induced acid-base imbalance in body fluids of laying hens and the oxidative damage and inflammatory response caused to the liver. Therefore, vitamin C can be used clinically as an effective drug to alleviate chronic heat stress in laying hens. This experiment provides clinical evidence and theoretical basis for the use of vitamin C as an effective drug to alleviate chronic heat stress in laying hens.

Effects of Copper Exposure on Oxidative Stress, Apoptosis, Endoplasmic Reticulum Stress, Autophagy and Immune Response in Different Tissues of Chinese Mitten Crab (Eriocheir sinensis)

High concentrations of copper (Cu²⁺) pose a great threat to aquatic animals. However, the mechanisms underlying the response of crustaceans to Cu²⁺ exposure have not been well studied. Therefore, we investigated the alterations of physiological and molecular parameters in Chinese mitten crab (Eriocheir sinensis) after Cu²⁺ exposure. The crabs were exposed to 0 (control), 0.04, 0.18, and 0.70 mg/L of Cu²⁺ for 5 days, and the hemolymph, hepatopancreas, gills, and muscle were sampled. The results showed that Cu²⁺ exposure decreased the antioxidative capacity and promoted lipid peroxidation in different tissues. Apoptosis was induced by Cu²⁺ exposure, and this activation was associated with the mitochondrial and ERK pathways in the hepatopancreas. ER stress-related genes were upregulated in the hepatopancreas but downregulated in the gills at higher doses of Cu²⁺. Autophagy was considerably influenced by Cu²⁺ exposure, as evidenced by the upregulation of autophagy-related genes in the hepatopancreas and gills. Cu²⁺ exposure also caused an immune response in different tissues, especially the hepatopancreas, where the TLR2-MyD88-NF-κB pathway was initiated to mediate the inflammatory response. Overall, our results suggest that Cu²⁺ exposure induces oxidative stress, ER stress, apoptosis, autophagy, and immune response in E. sinensis, and the toxicity may be implicated following the activation of the ERK, AMPK, and TLR2-MyD88-NF-κB pathways.

N-acetylcysteine combined with insulin alleviates the oxidative damage of cerebrum via regulating redox homeostasis in type 1 diabetic mellitus canine

Neurodegenerative diseases are one of the major complications of type 1 diabetes mellitus (T1DM). The effect of insulin monotherapy on controlling blood glucose and neurodegeneration associated with diabetes is unsatisfactory. It is revealed that oxidative stress is a key element in T1DM. Therefore, N-acetylcysteine (NAC) was used together with insulin to investigate the therapeutic effect on neuronal damage in T1DM in this study. A total of 40 beagles were randomly divided into 5 groups (control group, DM group, insulin monotherapy group, NAC combined with insulin group, and NAC monotherapy group) to explore the effects of NAC on alleviating the oxidative damage in cerebrum. Our results showed that the contents of H₂O₂, 8-OHdg and MDA were apparently increased in DM group, while DNA and lipid oxidative damage was alleviated by the treatment of NAC and insulin. Histopathology revealed the sparse of neurofibrils and vacuolar degeneration in DM group. Additionally, compared with the control group, the mRNA expression levels of HO-1, nqo1, GCLC and GSTM1 were significantly decreased in DM group, while the opposite trend could be shown under NAC combined with insulin treatment. Meanwhile, the tight junction proteins of ZO-1, occludin and Claudin-1 were up-regulated with the treatment of NAC combined with insulin. Additionally, NAC further alleviated oxidative damage by enhancing the activity of GSH, Trx and TrxR and reducing the activity of catalase, GSSG and Grx to maintain redox homeostasis. These results demonstrated that NAC combined with insulin exerted protective effects against T1DM-induced cerebral injury via maintaining cerebral redox homeostasis.

Molecular mechanisms and therapeutic effects of different vitamins and minerals in COVID-19 patients

COVID-19 is a rapidly spreading disease, which has caught the world by surprise. Millions of people suffer from illness, and the mortality rates are dramatically high. Currently, there is no specific and immediate treatment for this disease. Remedies are limited to supportive regiments and few antiviral and anti-inflammatory drugs. The lack of a definite cure for COVID-19 is the reason behind its high mortality and global prevalence. COVID-19 can lead to a critical illness with severe respiratory distress and cytokine release. Increased oxidative stress and excessive production of inflammatory cytokines are vital components of severe COVID-19. Micronutrients, metalloids, and vitamins such as iron, manganese, selenium, Zinc, Copper, vitamin A, B family, and C are among the essential and trace elements that play a pivotal role in human nutrition and health. They participate in metabolic processes that lead to energy production. In addition, they support immune functions and act as antioxidants. Therefore, maintaining an optimal level of micronutrients intake, particularly those with antioxidant activities, is essential to fight against oxidative stress, modulate inflammation, and boost the immune system. Therefore, these factors could play a crucial role in COVID-19 prevention and treatment. In this review, we aimed to summarize antiviral properties of different vitamins and minerals. Moreover, we will investigate the correlation between them and their effects in COVID-19 patients.

Exposure to Toxic Metals and Health Risk Assessment through Ingestion of Canned Sardines Sold in Brazil

The presence of heavy metals in the environment is increasing, which can be a danger to public health. Fish exposed to contaminated environments tend to have higher concentrations of some metals in their tissues. Monitoring these elements remains urgent as it is a matter of global concern. Canned sardines from the Brazilian market were analyzed for elements (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Ni, Pb, Se, and Zn) of metals and metalloids, including some toxic, using inductively coupled plasma optical spectrometry (ICP OES) in two types of sardines (preserved in oil and tomato sauce) from five different brands. The results were compared to limit levels for consumption set by FAO/WHO. Moreover, we assessed the associated risk regarding the elemental intake of these elements through the samples, using the hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR). All samples had unfavorable HQ and HI, primarily due to arsenic content. In the same manner, CR for arsenic was above the proposed limit of 10⁻⁴, and cadmium and chromium, which were within the acceptable limit (10⁻⁶ to 10⁻⁴), require attention. These results show that chronic consumption of canned sardines sold in Brazil is unsafe, and quality surveillance is needed to ensure there is no risk to the population that ingests these products.

A Web Application for Biomedical Text Mining of Scientific Literature Associated with Coronavirus-Related Syndromes: Coronavirus Finder

In this study, a web application was developed that comprises scientific literature associated with the Coronaviridae family, specifically for those viruses that are members of the Genus Betacoronavirus, responsible for emerging diseases with a great impact on human health: Middle East Respiratory Syndrome-Related Coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome-Related Coronavirus (SARS-CoV, SARS-CoV-2). The information compiled on this webserver aims to understand the basics of these viruses' infection, and the nature of their pathogenesis, enabling the identification of molecular and cellular components that may function as potential targets on the design and development of successful treatments for the diseases associated with the Coronaviridae family. Some of the web application's primary functions are searching for keywords within the scientific literature, natural language processing for the extraction of genes and words, the generation and visualization of gene networks associated with viral diseases derived from the analysis of latent semantic space, and cosine similarity measures. Interestingly, our gene association analysis reveals drug targets in understudies, and new targets suggested in the scientific literature to treat coronavirus.

α-Lipoic Acid Strengthens the Antioxidant Barrier and Reduces Oxidative, Nitrosative, and Glycative Damage, as well as Inhibits Inflammation and Apoptosis in the Hypothalamus but Not in the Cerebral Cortex of Insulin-Resistant Rats

The research determined the role of α-lipoic acid (ALA) in reducing the brain manifestations of insulin resistance. The mechanism of ALA action is mainly based on its ability to “scavenge” oxygen free radicals and stimulate biosynthesis of reduced glutathione (GSH), considered the most critical brain antioxidant. Although the protective effect of ALA is widely documented in various diseases, there are still no studies assessing the influence of ALA on brain metabolism in the context of insulin resistance and type 2 diabetes. The experiment was conducted on male Wistar rats fed a high-fat diet for ten weeks with intragastric administration of ALA for four weeks. We are the first to demonstrate that ALA improves the function of enzymatic and nonenzymatic brain antioxidant systems, but the protective effects of ALA were mainly observed in the hypothalamus of insulin-resistant rats. Indeed, ALA caused a significant increase in superoxide dismutase, catalase, peroxidase, and glutathione reductase activities, as well as GSH concentration and redox potential ([GSH]²/[GSSG]) in the hypothalamus of HFD-fed rats. A consequence of antioxidant barrier enhancement by ALA is the reduction of oxidation, glycation, and nitration of brain proteins, lipids, and DNA. The protective effects of ALA result from hypothalamic activation of the transcription factor Nrf2 and inhibition of NF-κB. In the hypothalamus of insulin-resistant rats, we demonstrated reduced levels of oxidation (AOPP) and glycation (AGE) protein products, 4-hydroxynoneal, 8-isoprostanes, and 3-nitrotyrosine and, in the cerebral cortex, lower levels of 8-hydroxydeoxyguanosine and peroxynitrite. In addition, we demonstrated that ALA decreases levels of proinflammatory TNF-α but also increases the synthesis of anti-inflammatory IL-10 in the hypothalamus of insulin-resistant rats. ALA also prevents neuronal apoptosis, confirming its multidirectional effects within the brain. Interestingly, we have shown no correlation between brain and serum/plasma oxidative stress biomarkers, indicating the different nature of redox imbalance at the central and systemic levels. To summarize, ALA improves antioxidant balance and diminishes oxidative/glycative stress, protein nitrosative damage, inflammation, and apoptosis, mainly in the hypothalamus of insulin-resistant rats. Further studies are needed to determine the molecular mechanism of ALA action within the brain.

The Single Nucleotide Polymorphisms of AP1S1 are Associated with Risk of Esophageal Squamous Cell Carcinoma in Chinese Population

Background

The σ1A subunit of the adaptor protein 1 (AP1S1) participates in various intracellular transport pathways, especially the maintenance of copper homeostasis, which is pivotal in carcinogenesis. It is therefore rational to presume that AP1S1 might also be involved in carcinogenesis. In this hospital-based case-control study, we investigated the genetic susceptibility to ESCC in relation to SNPs of AP1S1 among Chinese population.

Methods

A database containing a total of 1303 controls and 1043 ESCC patients were retrospectively studied. The AP1S1 SNPs were analyzed based on ligation detection reaction (LDR) method. Then, the relationship between ESCC and SNPs of AP1S1 was determined with a significant crude P<0.05. Then the logistic regression analysis was used for the calculation for adjusted P in the demographic stratification comparison if a significant difference was observed in the previous step.

Results

AP1S1 rs77387752 C>T genotype TT was an independent risk factor for ESCC, while rs4729666 C>T genotype TC and rs35208462 C>T genotype TC were associated with a lower risk for ESCC, especially in co-dominant model and allelic test for younger, male subjects who are not alcohol-drinkers nor cigarette smokers.

Conclusion

AP1S1 rs77387752, rs4729666 and rs35208462 polymorphisms are associated with susceptibility to ESCC in Chinese individuals. AP1S1 SNPs may exert an important role in esophageal carcinogenesis and could serve as potential diagnostic biomarkers.

Determination of dietary copper requirement by the monoamine oxidase activity in kidney of broilers from 1 to 21 d of age

The current dietary copper (Cu) requirement (8 mg/kg) of broilers is mainly based on growth, hemoglobin concentration, or hematocrit, which might not be the most sensitive indices to evaluate dietary Cu requirements of broilers. The present study was carried out to estimate dietary Cu requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 d of age using biochemical or molecular biomarkers. A total of 384 1-d-old Arbor Acres male broilers were randomly allocated to 1 of 6 treatments with 8 replicates and fed a Cu-unsupplemented corn-soybean meal basal diet containing 5.17 mg Cu/kg by analysis and the basal diet supplemented with 3, 6, 9, 12 or 15 mg Cu/kg as CuSO₄⋅5H₂O for 21 d. Regression analysis was performed to estimate the optimal dietary Cu level using the broken-line model. Dietary supplemental Cu level affected (P < 0.05) Cu contents in serum and liver and kidney monoamine oxidase (MAO) activity, but had no effects (P > 0.05) on the growth performance, Cu contents in heart, kidney, pancreas and spleen, Cu- and zinc-containing superoxide dismutase (CuZnSOD) activity and ceruloplasmin content in serum, CuZnSOD and cytochrome c oxidase (COX) activities and ceruloplasmin, CuZnSOD, MAO A, MAO B, COX4I1 and COX1 mRNA and protein expressions in the above tissues of broilers. As dietary supplemental Cu levels increased, Cu contents in serum and liver increased linearly (P < 0.05), but kidney MAO activity decreased linearly and quadratically (P < 0.05). The estimated dietary Cu requirement based on the fitted broken-line model (P = 0.035) of kidney MAO activity was 11.30 mg/kg. In conclusion, kidney MAO activity is a new and sensitive criterion to evaluate the dietary Cu requirement of broilers, and the dietary Cu requirement was 11.30 mg/kg for broilers fed the conventional corn-soybean meal diet from 1 to 21 d of age, which is higher than the current National Research Council (NRC) Cu requirement (8 mg/kg) of broilers.

Endoplasmic Reticulum Stress Contributes to Copper-Induced Pyroptosis via Regulating the IRE1α-XBP1 Pathway in Pig Jejunal Epithelial Cells

Copper (Cu) is a common additive in food products, which poses a potential concern to animal and human health when it is in excess. Here, we investigated the relationship between endoplasmic reticulum (ER) stress and pyroptosis in Cu-induced toxicity of jejunum in vivo and in vitro. In in vivo experiments, excess intake of dietary Cu caused ER cavity expansion, elevated fluorescence signals of GRP78 and Caspase-1, and increased the mRNA and protein expression levels related to ER stress and pyroptosis in pig jejunal epithelium. Simultaneously, similar effects were observed in IPEC-J2 cells under excess Cu treatment. Importantly, 4-phenylbutyric acid (ER stress inhibitor) and MKC-3946 (IRE1α inhibitor) significantly inhibited the ER stress-triggered IRE1α-XBP1 pathway, which also alleviated the Cu-induced pyroptosis in IPEC-J2 cells. In general, these results suggested that ER stress participated in regulating Cu-induced pyroptosis in jejunal epithelial cells via the IRE1α-XBP1 pathway, which provided a novel view into the toxicology of Cu.

Histological alterations, oxidative stress, and inflammatory response in the liver of swamp eel (Monopterus albus) acutely exposed to copper

Copper (Cu) is widely used as an essential trace element in diets as well as a therapeutic chemical. However, excessive Cu has deleterious effects on organisms, including teleosts. Although numerous toxic effects of Cu have been reported, the effects of Cu exposure on the swamp eel (Monopterus albus) as well as the underlying mechanisms have not yet been elucidated. In this study, swamp eels were acutely exposed to 100, 200, and 400 μg/L of Cu for 96 h to evaluate liver histopathology, oxidative stress, and inflammation. Dissolution of hepatocyte membrane, vacuolar degeneration, and inflammatory cell infiltration were detected in the livers of the Cu-treated swamp eels, especially in the 400 μg Cu/L group. Cu-induced hepatic dysfunction was further verified by the elevated activities of glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) and transcript levels of GOT and GPT genes. In addition, Cu exposure decreased the activities of total superoxide dismutase T-SOD and catalase (CAT) and the contents of glutathione (GSH) and total antioxidant capacity (T-AOC) and increased the levels of malondialdehyde (MDA). Cu exposure also significantly decreased the transcript levels of glutathione synthetase (GSS) and increased the transcript levels of SOD1, SOD2, CAT, and heme oxygenase-1 (HO-1) genes. Furthermore, pro-inflammatory genes such as interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), and IL-8 were significantly upregulated. These results indicate that Cu induces oxidative stress and inflammatory response and causes pathological changes in the liver of the swamp eel.

Effects of Long-Term Exposure to Copper on the Keap1/Nrf2 Signaling Pathway and Msr-Related Redox Status in the Kidneys of Rats

The objective of the present study was to examine the effects of long-term exposure on oxidative damage, Keap1/Nrf2 signaling pathway, and Msr-related redox status in the kidneys of rats. Therefore, in this experimental study, a total of 32 CD-1 rats were randomized into 4 groups and treated with 30-, 60-, and 120-mg/kg Cu for 24 weeks. Different serum biomarkers suggestive of renal functions, pathological changes, and oxidative stress were analyzed in kidney tissues. Moreover, the levels of the Keap1/Nrf2 signaling pathway and redox status-related gene mRNA and proteins were also detected. The results indicated that Cu exposure dramatically increased the contents of creatinine and carbamide. Furthermore, histopathological alterations and mitochondrial damage in kidneys of rats of different Cu-treated groups were obviously observed. In addition, Cu exposure markedly changed the levels of glutathione, catalase, and total antioxidant capacity, and upregulated the contents of protein carbonyl, nitric oxide, and malondialdehyde. Moreover, higher levels of Cu treatments significantly increased the expression of Keap1/Nrf2 signaling pathway and redox status-related genes (NQO1, SOD-1, TRX, MsrA, MsrB1, MsrB2, MsrB3). Simultaneously, the mRNA expression levels of Nrf2, HO-1, and CAT were upregulated in rats exposed to 30- and 60-mg/kg Cu, but downregulated in the 120-mg/kg Cu group compared with the control group. Moreover, the Keap1/Nrf2 signaling pathway and redox status-related protein expression levels (HO-1, SOD-1, TRX, MsrA, MsrB1, MsrB2) were significantly increased in treated rats. In summary, it is suggested that the Keap1/Nrf2 signaling pathway and activation of Msr prevent Cu-induced nephrotoxicity and attenuate oxidative damage.

Evaluation of toxic effects induced by arsenic trioxide or/and antimony on autophagy and apoptosis in testis of adult mice

Arsenic trioxide (ATO) and antimony (Sb) are well-known ubiquitous environmental contaminants and cause unpromising male reproductive effects in target and non-target exposed organisms. The main objective of this study was to investigate the effects of ATO or/and Sb on process of autophagy, apoptosis, and reproductive organ in adult mice. For this reason, a total of 32 adult mice were randomly divided into different groups like control group, ATO-treated group, Sb-treated group, and combined group. The duration of current experimental trial was 2 months. Various adverse effects of ATO or/and Sb on sperm parameters, oxidative stress, autophagy, and apoptosis were determined in testis of mice. Results indicated that parameters of sperm quality for organ coefficient, sperm count, ratio of sperm survival, testosterone level, and germ cells were significantly decreased, while malformation rate and vacuolization significantly increased in mice exposed to different treatments. Furthermore, the status of antioxidant index of T-AOC, SOD, and MsrB1 levels was reduced, while MDA increased significantly in ATO + Sb group. Results on TEM investigation determined that the autophagosomes, autolysosome, nuclear pyknosis, and chromatin condensation were prominent ailments, and the levels of autophagy and pro-apoptosis indictors including Beclin1, Atg-5, LC3B/LC3A, caspase-8, cytc, cleaved caspase-3, p53, and Bax were up-regulated in treated group, while the content of an anti-apoptosis maker (Bcl-2) was down-regulated. In conclusion, the results of our experiment suggested that abnormal process of autophagy and apoptosis was triggered by arsenic and antimony, and intensity of toxic effects increased in combined treatments of ATO and Sb.

Long-term copper exposure promotes apoptosis and autophagy by inducing oxidative stress in pig testis

Copper (Cu) is a heavy metal which is being used widely in the industry and agriculture. However, the overuse of Cu makes it a common environmental pollutant. In order to investigate the testicular toxicity of Cu, the pigs were divided into three groups and were given Cu at 10 (control), 125, and 250 mg/kg body weight, respectively. The feeding period was 80 days. Serum hormone results showed that Cu exposure decreased the concentrations of follicular stimulating hormone (FSH) and luteinizing hormone (LH) and increased the concentration of thyroxine (T4). Meanwhile, Cu exposure upregulated the expression of Cu transporter mRNA (Slc31a1, ATP7A, and ATP7B) in the testis, leading to increase in testicular Cu and led to spermatogenesis disorder. The Cu exposure led to an increased expression of antioxidant-related mRNA (Gpx4, TRX, HO-1, SOD1, SOD2, SOD3, CAT), along with increase in the MDA concentration in the testis. In LG group, the ROS in the testis was significantly increased. Furthermore, the apoptotic-related mRNA (Caspase3, Caspase8, Caspase9, Bax, Cytc, Bak1, APAF1, p53) and protein (Active Caspase3) and the autophagy-related mRNA (Beclin1, ATG5, LC3, and LC3B) expression increased after Cu exposure. The mitochondrial membrane potential in the testicular tissue decreased, while the number of apoptotic cells increased, as a result of oxidative stress. Overall, our study indicated that the Cu exposure promotes testicular apoptosis and autophagy by mediating oxidative stress, which is considered as the key mechanism causing testicular degeneration as well as dysfunction.

Copper induces mitochondria-mediated apoptosis via AMPK-mTOR pathway in hypothalamus of Pigs

Copper (Cu), one of the heavy metals, is far beyond the carrying capacity of the environment with Cu mining, industrial wastewater discharging and the use of Cu-containing pesticides. Intaking excess Cu can cause toxic effects on liver, kidney, heart, but few studies report Cu toxicity on brain tissue. It is noteworthy that most toxicity tests are based on rodent models, but large mammals chosen as animal models has no reported. To explore the relationship of the Cu toxicity and mitochondria-mediated apoptosis on hypothalamus in pigs, the content of Cu, histomorphology, mitochondrial related indicators, apoptosis, and AMPK-mTOR signaling pathway were detected. Results showed that Cu could accumulate in hypothalamus and lead to mitochondrial dysfunction, evidenced by the decrease of ATP production, activities of respiratory chain complex I-IV, and mitochondrial respiratory function in Cu-treated groups. Additionally, the genes and proteins expression of Bax, Caspase-3, Cytc in treatment group were higher than control group. Furthermore, the protein level of p-AMPK was enhanced significantly and p-mTOR was declined, which manifested that AMPK-mTOR signaling pathway was activated in Cu-treated groups. In conclusion, this study illuminated that the accumulation of Cu could cause mitochondrial dysfunction, induce mitochondria-mediated apoptosis and activate AMPK-mTOR pathway in hypothalamus.

Arsenic (III) and/or Antimony (III) induced disruption of calcium homeostasis and endoplasmic reticulum stress resulting in apoptosis in mice heart

Arsenic (As) and antimony (Sb) are known as an environmental contaminant with cardiotoxicity properties. The endoplasmic reticulum (ER) is the largest calcium reservoir in the cell, and its calcium homeostasis disorder plays a vital role in endoplasmic reticulum stress (ERS) and apoptosis. The objective of this study was to investigate whether As and Sb induced apoptosis via endoplasmic reticulum stress (ERS) linked to calcium homeostasis disturbance. In this study, thirty-two adult mice were gavage-fed daily with As₂O₃ (4 mg/kg), SbCl₃ (15 mg/kg) and co-treat with SbCl₃ (15 mg/kg) and As₂O₃ (4 mg/kg) daily for 60 days. It was observed that As or/and Sb caused histopathological lesions and ER expansion of the heart. Meanwhile, the gene expression of ER Ca²⁺ release channels (RyR2 and IP3R) and calmodulin-dependent protein kinase II (CaMKII) increased while the levels of mRNA and protein of ER Ca²⁺ uptake channel (SERCA2) downregulated significantly compared to the controls. Then, As or/and Sb induced ERS and triggered the ER apoptotic pathway by activating unfolded protein response (UPR)-associated genes ((PERK, ATF6, IRE1, XBP1, JNK, GRP78), and apoptosis-related genes (Caspase12, Caspase3, p53, CHOP). Above indicators in As + Sb group became more severe than that of As group and Sb group. Overall, our results proved that the cardiotoxicity caused by As or/and Sb might be concerning disturbing calcium homeostasis, which induced apoptosis through the ERS pathway.

Metabolomics analysis reveals the effects of copper on mitochondria-mediated apoptosis in kidney of broiler chicken (Gallus gallus)

Copper (Cu) is one of the ubiquitous environmental pollutants which have raised wide concerns about the potential toxic effects and public health threat. For deeply investigating the nephrotoxicity induced by Cu, the effects of Cu on mitochondria-mediated apoptosis in kidney were first to analyze by combining metabolomics and molecular biology techniques. In this study, broiler chicks were fed with different contents of Cu (11, 110, 220, and 330 mg/kg Cu) for 49 d. The results of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining and transmission electron microscope showed that Cu could induce apoptosis in kidney, characterized by the increasing of TUNEL-positive cells and mitochondrial vacuolation. Additionally, a total of 62 differential metabolites were detected by liquid chromatography-mass spectrometry (LC-MS), and mainly enriched in the metabolic pathways including riboflavin metabolism, glutathione metabolism, sphingolipid metabolism, and glycerophospholipid metabolism, which were closely to mitochondrial metabolism. Meanwhile, the decreased mitochondrial membrane potential (MMP), increased mitochondrial membrane permeability and the change of mRNA and protein expression levels associated with mitochondria-mediated apoptosis and mitochondrial dynamics confirmed that Cu could induce mitochondria-mediated apoptosis. Therefore, our results demonstrated that Cu induced mitochondria-mediated apoptosis in kidney. Moreover, this study highlighted the metabolic characteristics of Cu to kidney, which suggested that mitochondrial metabolism could be considered as an important factor influencing toxicity.

Hot-melt extruded copper sulfate affects the growth performance, meat quality, and copper bioavailability of broiler chickens

Objective

This study was conducted to evaluate the effects of the supplementation of diets of broiler chickens with hot-melt extruded CuSO₄ (HME-Cu) on their growth performance, nutrient digestibility, gut microbiota, small intestinal morphology, meat quality, and copper (Cu) bioavailability.

Methods

A total of 225 broilers (Ross 308), one-day old and initial weight 39.14 g, were weighed and distributed between 15 cages (15 birds per cage) in a completely randomized experimental design with 3 treatments (diets) and 5 replicates per treatment. Cages were allotted to three treatments including control (without supplemental Cu), IN-Cu (16 mg/kg of CuSO₄), and HME-Cu (16 mg/kg of HME processed CuSO₄).

Results

The HME-Cu treatment tended to increase the overall body weight gain (p<0.10). The apparent digestibility of Cu was increased by supplementation of HME-Cu at phase 2 (p<0.05). The Escherichia coli count in cecum tended to decrease with the supplementation with Cu (p<0.10). In addition, the HME-Cu treatment had a higher pH of breast meat than the control and IN-Cu treatments (p<0.05). Significant increases in the cooking loss, water-holding capacity, and lightness in the breast were observed in the HME-Cu treatment compared to the control (p<0.05). The Cu content of excreta increased with the Cu supplementation (p<0.05). The concentration of excreta Cu in broilers was decreased in the HME-Cu compared to the IN-Cu in phase 2 (p<0.05). The Cu concentration in the liver was increased with the HME-Cu supplementation, compared with the control diets (p<0.05).

Conclusion

This study showed that HME-Cu supplementation at the requirement level (16 mg/kg diets) in broiler diets did not affect the growth performance and the physiological function of Cu in broilers. However, supplementation of Cu in HME form improved the meat quality and the bioavailability of Cu.

Cinnamon Extract and Probiotic Supplementation Alleviate Copper-Induced Nephrotoxicity via Modulating Oxidative Stress, Inflammation, and Apoptosis in Broiler Chickens

The present study aimed to assess the potential protective effects of cinnamon (Cinnamomum zeylanicum, Cin) and probiotic against CuSO₄-induced nephrotoxicity in broiler chickens. One-day-old Cobb chicks were assigned into seven groups (15 birds/group): control group, fed basal diet; Cin group, fed the basal diet mixed with Cin (200 mg/kg); PR group, receiving PR (1 g/4 L water); Cu group, fed the basal diets mixed with CuSO₄ (300 mg/kg); Cu + Cin group; Cu + PR group; and Cu + Cin + PR group. All treatments were given daily for 6 weeks. Treatment of Cu-intoxicated chickens with Cin and/or PR reduced (p < 0.05) Cu contents in renal tissues and serum levels of urea, creatinine, and uric acid compared to the Cu group. Moreover, Cin and PR treatment decreased lipid peroxidation and increased antioxidant enzyme activities in chickens' kidney. Additionally, significant reduction (p < 0.05) in the mRNA expression of tumor necrosis factor alpha (TNF-α), interleukin (IL-2) and Bax, and in cyclooxygenase (COX-II) enzyme expression, and significant elevation (p < 0.05) in mRNA expression of IL-10 and Bcl-2 were observed in kidneys of Cu + Cin, Cu + PR, and Cu + Cin + PR groups compared to Cu group. Conclusively, Cin and/or PR afford considerable renal protection against Cu-induced nephrotoxicity in chickens.

Metabolomics analysis reveals the effect of copper on autophagy in myocardia of pigs

Among different synthetic compounds copper (Cu) is persistently and frequently used as growth promoter, antibacterial, antifungal and antiparasitic agent and has become common environmental pollutant. Therefore, this study explores the cardio-toxic effects of control group (10 mg/kg bw Cu) and treatment group (125 and 250 mg/kg bw Cu), and it association with process of autophagy and metabolomics in myocardium of pigs kept in three different experimental treatments for a period of 80 days. The results of serum biochemical parameters showed a significantly increase in creatinine kinase (CK), creatine kinase-MB (CK-MB), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C) and aspartate aminotransferase (AST) in pigs exposed to 125 mg/kg bw and 250 mg/kg bw Cu. Meanwhile, the severe structural abnormalities in cardiomyocytes were found when exposed to 250 mg/kg Cu at day 80. In addition, the mRNA and proteins (Beclin1, ATG5 and LC3II) expression levels were significantly increased and p62 was significantly decreased in cardiomyocytes exposed to 250 mg/kg Cu at day 80 of the trial. Further, UPLC-QTOF/MS technique showed that 7 metabolites were up-regulated and 37 metabolites were down-regulated in cardiomyocytes after 250 mg/kg Cu treatment, with a principal impact on the metabolic pathways including glycerophospholipid metabolism, one carbon pool by folate, fatty acid elongation and fatty acid degradation, which were related to autophagy. Overall, our study identified the autophagy processes and metabolites in metabolic pathways in Cu-induced myocardium injury, which provided useful evidence of myocardium toxicity caused by Cu exposure via metabolomics and multiple bioanalytic methods.

Exposure to copper induces mitochondria-mediated apoptosis by inhibiting mitophagy and the PINK1/parkin pathway in chicken (Gallus gallus) livers

Copper (Cu), a transition metal with essential cellular functions, exerts toxic effects when present in excess by inducing oxidative stress. However, the Cu-induced crosstalk between mitophagy and apoptosis and the underlying mechanisms are unknown. Here, the mechanism of Cu-induced hepatotoxicity mediated by mitophagy and apoptosis was explored in vivo and in vitro. In in vivo experiments, chickens were fed a diet with various levels of Cu (11, 110, 220, and 330 mg/kg) for 7 weeks, which led to ultrastructural damage, mitophagy, and apoptosis in liver tissue. In vitro experiments on primary chicken hepatocytes showed that Cu treatment for 24 h increased the numbers of mitophagosomes and upregulated PINK1, parkin, and p62 mRNA levels and parkin and p62 protein levels, inducing mitophagy. Moreover, treatment with 3- methyladenine (3-MA) aggravated Cu-induced S-phase arrest in cell cycle; increased the apoptotic rate; increased p53, Bak1, Bax, Cyt C, and Caspase3/cleaved-caspase3 mRNA and protein levels; and decreased Bcl2 mRNA and protein levels. However, rapamycin (Rapa) had the opposite effects on the above factors. In general, the results reveal that Cu exposure can cause mitophagy through the PINK1/Parkin pathway in chicken livers, and that mitophagy might attenuate Cu-induced mitochondrial apoptosis.

Effects of N-acetyl-l-cysteine on heat stress-induced oxidative stress and inflammation in the hypothalamus of hens

The purpose of this study was to discuss the effects of N-acetyl-l-cysteine (NAC) on heat stress-induced oxidative stress and inflammation in the hypothalamus of hens in different periods. A total of 120 Hy-Line variety brown laying hens (12 weeks old) were randomly assigned to 4 groups with 6 replicates. The control group (C group) (22 ± 1 °C) received a basal diet, the NAC-treated group (N group) (22 ± 1 °C) received a basal diet with 1000 mg/kg NAC, and 2 heat-stressed groups (36 ± 1 °C for 10 h per day and 22 ± 1 °C for the remaining time) were fed a basal diet (HS group) or a basal diet with 1000 mg/kg NAC (HS + N group) for 21 consecutive days. The influence of NAC on histologic changes, oxidative stress and proinflammatory cytokine production was measured and analysed in hens with heat stress-induced hypothalamic changes. NAC effectively alleviated the hypothalamic morphological changes induced by heat stress. In addition, NAC attenuated the activity of the Nf-κB pathway activated by heat stress and decreased the expression of the proinflammatory cytokines IL-6, IL-18, TNF-α, IKK, and IFN-γ. In addition, NAC treatment regulated the expression of HO-1, GSH, SOD2 and PRDX3 by regulating the activity of Nrf2 at different time points to resist oxidative stress caused by heat exposure. In summary, dietary NAC may be an effective candidate for the treatment and prevention of heat stress-induced hypothalamus injury by preventing Nf-κB activation and controlling the Nrf2 pathway.

Chronic tribasic copper chloride exposure induces rat liver damage by disrupting the mitophagy and apoptosis pathways

Despite the fact that copper (Cu) is a vital micronutrient to maintain body function, high doses of Cu through environmental exposure damage various organs, especially the liver, which is the main metabolic organ. To investigate the influence of long-term Cu-induced toxicity on mitophagy and apoptosis in rat liver, 96 seven-month-old male Sprague-Dawley rats were fed TBCC for 24 weeks. The results revealed that exposure to high Cu concentrations could promote oxidative stress liver injury by increasing the hepatic function index (ALT, AST and ALP) and MDA content, while reducing the activity of antioxidant enzymes (T-SOD, GSH-Px and CAT) related to oxidative stress. Consistent with histopathological observations, proper dietary Cu (15-60 mg/kg) could improve antioxidant stress levels and induce a dose-dependent increase in the mRNA expression of mitophagy-related genes, whereas a high Cu concentration (120 mg/kg) could cause severe liver impairment and ultrastructural changes and a reduction in mitophagosomes, accompanied by downregulation of Atg5, Beclin1, Pink1, Parkin, NIX, P62 and LC3B. The expression of apoptosis-related genes (Bax, Bax/Bcl-2, Caspase3, Cytc and p53) and proteins (Caspase3 and p53) was upregulated with the addition of dietary Cu. The results demonstrated that an appropriate dose of TBCC could improve liver function by promoting mitophagy and Cu enzymes that play antioxidative roles, while the accumulation of excess Cu could induce liver lesions by enhancing apoptosis and inhibiting mitophagy pathways.

Copper induces hepatocyte autophagy via the mammalian targets of the rapamycin signaling pathway in mice

Although copper is among the indispensable trace elements in animal physiological processes, it exerts toxicity upon over-exposure. The present study aimed to investigate hepatocyte autophagy induced by CuSO₄ and its potential mechanism. A total of 240 ICR mice (four-week-old, 120 males and 120 females) were randomly divided into four groups, in which mice separately received 0, 4, 8, and 16 mg/kg of Cu (Cu²⁺-CuSO₄) for 42 d. The results of increased autophagosomes and autophagy marker LC3B brown cell staining showed that excessive intake of Cu enhanced hepatocyte autophagy. Simultaneously, Cu inhibited the activity of mTOR through suppressing mRNA and protein expressions in mTOR, which in turn up-regulated expression levels of ULK1 and initiated autophagy. Also, over-exposure to Cu increased mRNA and protein expressions of Beclin1, Atg12, Atg5, Atg16L1, Atg7, Atg3, and LC3 and decreased mRNA and protein expressions of p62. These results indicate that excess Cu can enhance hepatocyte autophagy via inhibiting the mTOR signaling pathway and regulating mRNA and protein expressions of factors implicated to autophagy in mice.

Copper induces energy metabolic dysfunction and AMPK-mTOR pathway-mediated autophagy in kidney of broiler chickens

To explore the effects of copper (Cu) on energy metabolism and AMPK-mTOR pathway-mediated autophagy in kidney, a total of 240 one-day-old broiler chickens were randomized into four equal groups and fed on the diets with different levels of Cu (11, 110, 220, and 330 mg/kg) for 49 d. Results showed that excess Cu could induce vacuolar degeneration and increase the number of autophagosomes in kidney, and the adenosine triphosphate (ATP) level and mRNA levels of energy metabolism-related genes were decreased with the increasing dietary Cu level. Moreover, immunohistochemistry and immunofluorescence showed that the positive expressions of Beclin1 and LC3-II were mainly located in cytoplasm of renal tubular epithelial cells and increased significantly with the increasing levels of Cu. The mRNA levels of Beclin1, Atg5, LC3-I, LC3-II, Dynein and the protein levels of Beclin1, Atg5, LC3-II/LC3-I and p-AMPKα1/AMPKα1 were markedly elevated in treated groups compared with control group (11 mg/kg Cu). However, the mRNA and protein levels of p62 and p-mTOR/mTOR were significantly decreased with the increasing levels of Cu. These results suggest that impaired energy metabolism induced by Cu may lead to autophagy via AMPK-mTOR pathway in kidney of broiler chickens.

Copper Induces Apoptosis Through Endoplasmic Reticulum Stress in Skeletal Muscle of Broilers

The purpose of this research was to investigate whether copper (Cu) exposure could induce apoptosis via endoplasmic reticulum stress (ERS) in skeletal muscle of broilers. A total of 240 one-day-old chickens were randomly divided into four groups by free access; the diets are as follows: control diet (Cu 11 mg/kg, control group) and high level of Cu diets (Cu 110 mg/kg, group I; Cu 220 mg/kg, group II; Cu 330 mg/kg, group III). The skeletal muscle tissues were collected on day 49 for further examination. The content of Cu, histopathology, and the expression levels of the genes and proteins related to ERS and apoptosis were detected. Results showed that the Cu levels in skeletal muscle were increased in a dose-dependent manner. Meanwhile, the spaces between the muscle fibers were wider with the increase of Cu content, and the myolysis was observed in group III. Besides, the mRNA expression levels of GRP78, GRP94, eIF2α, ATF6, XBP1, CHOP, Caspase-12, and Caspase3 were markedly increased in treated groups compared with control group, and the protein expression levels of GRP78, Caspase3, Active-Caspase3 and JNK were significantly elevated with the increase of dietary Cu. In summary, these findings suggested that Cu could induce apoptosis through ERS in skeletal muscle of broilers.

Hydrogen peroxide-induced oxidative stress impairs redox status and damages aerobic metabolism of breast muscle in broilers

Oxidative stress has always been a hot topic in poultry science. However, studies concerning the effects of redox status and glucose metabolism induced by hydrogen peroxide (H₂O₂) in the breast muscle of broilers have been rarely reported. This study was aimed to evaluate the impact of intraperitoneal injection of H₂O₂ on oxidative damage and glycolysis metabolism of breast muscle in broilers. We also explored the activation of the nuclear factor erythroid 2–related factor 2 (Nrf2) signaling pathway to provide possible mechanism of the redox imbalance. Briefly, a total of 320 one-day-old Arbor Acres chicks were randomly divided into 5 treatments with 8 replicates of 8 birds each (noninjected control, 0.75% saline-injected, 2.5, 5.0, and 10.0% H₂O₂-injected treatments). Saline group was intraperitoneally injected with physiological saline (0.75%) and H₂O₂ groups received an intraperitoneal injection of H₂O_2. The dosage of the injection was 1.0 mL/kg BW. All birds in the saline and H₂O₂ groups were injected on days 16 and 37 of the experimental period. At 42 d of age, 40 birds (8 cages per group and one chicken per cage) were selected to be stunned electrically (50 V, alternating current, 400 Hz for 5 s each one), and then immediately slaughtered via exsanguination. The results showed that broilers in the H₂O₂ injection group linearly exhibited higher contents of reactive oxygen species, carbonyl and malondialdehyde, and lower total antioxidant capacity and glutathione peroxidase activities. With the content of H₂O₂ increased, the H₂O₂ groups linearly downregulated the mRNA expressions of GPX, CAT, HMOX1, NQO1, and Nrf2 and its downstream target genes. In addition, H₂O₂ increased serum activities of creatine kinase and lactate dehydrogenase. Meanwhile, in the pectoral muscle, the glycogen content was linearly decreased, and the lactate content was linearly increased in muscle of broilers injected with H₂O₂. In addition, the activities of glycolytic enzymes including pyruvate kinase, hexokinase, and lactate dehydrogenase were linearly increased after exposure to H₂O₂. In conclusion, H₂O₂ injection could impair antioxidant status and enhance anaerobic metabolism of breast muscle in broilers.

As3+ or/and Cu2+ exposure triggers oxidative stress imbalance, induces inflammatory response and apoptosis in chicken brain

Arsenic (As) and copper (Cu) are common environmental pollutants in nature. When they are excessively present in living organisms, they can cause heavy metal poisoning. There were relatively few studies of the toxicological concentrations of As and Cu in the brain using chicken as a model. Therefore, in this study, arsenic trioxide or/and copper sulfate were added to chicken diets for a 12-week toxicity test. The test results showed that excessive intake of As or/and Cu led to a significant reduction in the total antioxidant capacity (T-AOC), catalase (CAT) and hydroxyl radicals. And significant increase in nitric oxide synthase (NOS) indicates an imbalanced oxidation reaction. In addition, the increase in heat shock protein (HSPs), the increase of NF-κB pathway-related pro-inflammatory mediators, the change of apoptosis factors on the death receptor and mitochondrial apoptosis pathway show that, As or/and Cu exposure induced chicken brain has heat shock response (HSP), tissue inflammation and apoptosis. This damage is inseparable from the oxidative imbalance. It is worth noting that these injury changes are time-dependent, and the combined effect of these two metals is more severe than that of a single group of injuries. Our findings can inform the regulation of animal feed additives and avoid agricultural economic losses or biological health damage.

Copper induces oxidative stress with triggered NF-κB pathway leading to inflammatory responses in immune organs of chicken

Copper (Cu) is a necessary trace mineral due to its biological activity. Excessive Cu can induce inflammatory response in humans and animals, but the underlying mechanism is still unknown. Here, 240 broilers were used to study the effects of excessive Cu on oxidative stress and NF-κB-mediated inflammatory responses in immune organs. Chickens were fed with diet containing different concentrations of Cu (11, 110, 220, and 330 mg of Cu/kg dry matter). The experiment lasted for 49 days. Spleen, thymus, and bursa of Fabricius (BF) on day 49 were collected for histopathological observation and assessment of oxidative stress status. Additionally, the mRNA and protein levels of NF-κB and inflammatory cytokines were also analyzed. The results indicated that excess Cu could increase the number and area of splenic corpuscle as well as the ratio of cortex and medulla in thymus and BF. Furthermore, excessive Cu intake could decrease activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px); but increase contents of malondialdehyde (MDA), TNF-α, IL-1, IL-1β; up-regulate mRNA levels of TNF-α, IFN-γ, IL-1, IL-1β, IL-2, iNOS, COX-2, NF-κB and protein levels of TNF-α, IFN-γ, NF-κB, p-NF-κB in immune organs. In conclusion, excessive Cu could cause pathologic changes and induce oxidative stress with triggered NF-κB pathway, and might further regulate the inflammatory response in immune organs of chicken.