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-1ß; up-regulate mRNA levels of TNF-α, IFN-γ, IL-1, IL-1ß, 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.

Natural history of depression up to 18 years after stroke: a population-based South London Stroke Register study.

Background: Current evidence on the long-term natural history of post-stroke depression (PSD) is limited. We aim to determine the prevalence, incidence, duration and recurrence rates of depression to 18-years after stroke and assess differences by onset-time and depression severity. Methods: Data were from the South London Stroke Register (1995-2019, N = 6641 at registration). Depression was defined using the Hospital Anxiety and Depression scale (scores > 7 = depression) at 3-months, then annually to 18-years after stroke. We compared early- (3-months post-stroke) vs late-onset depression (1-year) and initial mild (HADS scores > 7) vs severe depression (scores > 10). Findings: 3864 patients were assessed for depression at any time-points during the follow-up (male:55.4% (2141), median age: 68.0 (20.4)), with the number ranging from 2293 at 1-year to 145 at 18-years after stroke. Prevalence of PSD ranged from 31.3% (28.9-33.8) to 41.5% (33.6-49.3). The cumulative incidence of depression was 59.4% (95% CI 57.8-60.9), of which 87.9% (86.5-89.2) occurred within 5-years after stroke. Of patients with incident PSD at 3-months after stroke, 46.6% (42.1-51.2) recovered after 1 year. Among those recovered, 66.7% (58.0-74.5) experienced recurrent depression and 94.4% (87.5-98.2) of recurrences occurred within 5-years since recovery. Similar estimates were observed in patients with PSD at 1-year. 34.3% (27.9-41.1) of patients with severe depression had recovered at the next time-point, compared to 56.7% (50.5-62.8) with mild depression. Recurrence rate at 1-year after recovery was higher in patients with severe depression (52.9% (35.1-70.2)) compared to mild depression (23.5% (14.1-35.4)) (difference: 29.4% (7.6-51.2), p = 0.003). Interpretation: Long-term depressive status may be established by 5-years post-onset. Early- and late-onset depression presented similar natural history, while severe depression had a longer duration and quicker recurrence than mild depression. These estimates were limited to alive patients completing the depression assessment, who tended to have less severe stroke than excluded patients, so may be underestimated and not generalizable to all stroke survivors. Funding: National Institute for Health and Care Research (NIHR202339).

Copper induces oxidative stress and apoptosis through mitochondria-mediated pathway in chicken hepatocytes.

The aim of this study was to investigate the effects of excessive copper (Cu)-induced cytotoxicity on oxidative stress and mitochondrial apoptosis in chicken hepatocytes. Chicken hepatocytes were cultured in medium in the absence and presence of copper sulfate (CuSO4) (10, 50, 100 µM), in N-acetyl-L-cysteine (NAC) (1 mM), and the combination of CuSO4 and NAC for 24 h. Morphologic observation and function, reactive oxygen species (ROS) level, antioxidant indices, nitric oxide (NO) content, mitochondrial membrane potential (MMP), and apoptosis-related mRNA and protein levels were determined. These results indicated that excessive Cu could induce release of intracellular lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT); increase levels of ROS, superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), lipid peroxidation (LPO), and NO; decrease glutathione (GSH) content and MMP; upregulated Bak1, Bax, CytC, and Caspase3 mRNA and protein expression, inhibited Bcl2 mRNA and protein expression, and induced cell apoptosis in a dose effect. The Cu-caused changes of all above factors were alleviated by treatment with NAC. These results suggested that excessive Cu could induce oxidative stress and apoptosis via mitochondrial pathway in chicken hepatocytes.

Autophagy attenuates copper-induced mitochondrial dysfunction by regulating oxidative stress in chicken hepatocytes.

Copper (Cu) is an essential trace element that is required for the catalysis of several cellular enzymes. Excessive Cu could induce hepatotoxicity in humans and multiple animals. The purpose of this study was to investigate the effects of autophagy machinery on Cu-induced hepatotoxicity. Chicken hepatocytes were cultured in medium in the absence and presence of Cu sulfate (CuSO4) (0, 10, 50, and 100 µM) for 0, 6, 12, and 24 h, and in the combination of CuSO4 and N-acetyl-l-cysteine (NAC) (1 mM), rapamycin (10 nM), and 3-methyladenine (3-MA) (5 mM) for 24 h. Results showed that Cu could markedly increase the number of autophagosomes and LC3 puncta, induce autophagy-related genes (Beclin1, ATG5, LC3Ⅰ, LC3Ⅱ, mTOR, and Dynein) mRNA expression and proteins (BECN1, LC3Ⅱ/LC3Ⅰ) expression. NAC could relieve Cu-induced the changes of above genes and proteins. Additionally, rapamycin attenuated Cu-induced the increased lactic dehydrogenase (LDH), aspartate amino transferase (AST), and alanine aminotransferase (ALT) activities, and SOD-1 mRNA expression as well as the decreased cell viability, reactive oxygen species (ROS), hydrogen peroxide, total superoxide dismutase (T-SOD), malonaldehyde (MDA), catalase (CAT), HO-1 mRNA expression, adenosine triphosphate (ATP) levels, mitochondrial mass, and mitochondria membrane potential (MMP). But 3-MA had the opposite effects on above factors. Collectively, these findings provide strong evidence that Cu could induce autophagy by generating excessive ROS in hepatocytes, and autophagy might attenuate Cu-induced mitochondrial dysfunction by regulating oxidative stress.