Redox-active Cu(II)-Aβ causes substantial changes in axonal integrity in cultured cortical neurons in an oxidative-stress dependent manner

Effects of dose and duration of dietary copper administration on hepatic lipid peroxidation and ultrastructure alteration in piglets' model

BACKGROUND

Copper is an essential microelement for animals and has been used at pharmacological doses in weaned piglets to improve growth performance. However, it also induces systemic oxidative stress after short-term feeding. The aim of this study was to investigate the effects of dose and duration of dietary copper on lipid peroxidation and oxidative stress status in model of weaned piglets.

METHODS

A total of 48 crossbred piglets (weaned at 21d, weight ∼8.2 kg) were randomly assigned into 4 groups of 12 in each. The control group and 3 treatment groups fed with basal diet supplemented with 20, 100 and 200 mg/kg copper as copper sulfate for 3 and 6 weeks, respectively.

RESULTS

Dietary copper supplementation significantly affected the activities of ALP, LDH, LIPC and the levels of Ca and TG in serum as well as the copper and zinc deposition in liver. Increased MDA concentrations, and decreased GPX, CP and CAT concentrations in serum were found in 0, 100 and 200 mg Cu/kg diet groups at 3 weeks post weaning. Hepatic lipid peroxidation was also induced in these groups indicated from hepatic SOD1, GPX1, CAT, CP, MT1A and MT2A transcriptional levels. Those adverse symptoms were alleviative at 6 weeks post weaning. The hepatic Cu and Zn concentrations, serum MDA concentrations, and serum CAT and GPX activities were significantly correlated with Actinobacillus, Lactobacillus, Sarcina, Helicobacter, Campylobacterales, which could affect the intestinal health further.

CONCLUSION

These results indicated that copper deficiency or over supplementation would affect the systemic lipid peroxidation. These adverse changes were not observed when the dietary copper concentration at 20 mg Cu/kg diet. The results suggested the appropriate dietary copper concentration is around 20 mg Cu/kg diet, and its range might be much stricter than we thought.

Methylene blue upregulates Nrf2/ARE genes and prevents tau-related neurotoxicity

Methylene blue (MB, methylthioninium chloride) is a phenothiazine that crosses the blood brain barrier and acts as a redox cycler. Among its beneficial properties are its abilities to act as an antioxidant, to reduce tau protein aggregation and to improve energy metabolism. These actions are of particular interest for the treatment of neurodegenerative diseases with tau protein aggregates known as tauopathies. The present study examined the effects of MB in the P301S mouse model of tauopathy. Both 4 mg/kg MB (low dose) and 40 mg/kg MB (high dose) were administered in the diet ad libitum from 1 to 10 months of age. We assessed behavior, tau pathology, oxidative damage, inflammation and numbers of mitochondria. MB improved the behavioral abnormalities and reduced tau pathology, inflammation and oxidative damage in the P301S mice. These beneficial effects were associated with increased expression of genes regulated by NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE), which play an important role in antioxidant defenses, preventing protein aggregation, and reducing inflammation. The activation of Nrf2/ARE genes is neuroprotective in other transgenic mouse models of neurodegenerative diseases and it appears to be an important mediator of the neuroprotective effects of MB in P301S mice. Moreover, we used Nrf2 knock out fibroblasts to show that the upregulation of Nrf2/ARE genes by MB is Nrf2 dependent and not due to secondary effects of the compound. These findings provide further evidence that MB has important neuroprotective effects that may be beneficial in the treatment of human neurodegenerative diseases with tau pathology.

Inflammation and programmed cell death in Alzheimer's disease: comparison of the central nervous system and peripheral blood

Although the central nervous system (CNS) has been defined as a privileged site in Alzheimer's disease (AD), periphery can be more than simply witness of events leading to neurodegeneration. The CNS and peripheral blood can mutually communicate through cells and factors trafficking from the circulation into the brain and vice versa. A number of articles have reviewed inflammatory profiles and programmed cell death (PCD) in AD, separately in the CNS and at the peripheral level. This review does not provide an exhaustive account of what has been published on inflammation and PCD in AD. Rather, the aim of this review is to focus on possible linkages between the central and the peripheral compartments during AD progression, by critically analyzing, in a comparative manner, phenomena occurring in the CNS as well as the peripheral blood. In fact, growing evidence suggests that CNS and peripheral inflammation might present common features in the disease. Microarrays and metabolomics revealed that dysfunction of the glycolytic and oxidative pathways is similar in the brain and in the periphery. Moreover, dysregulated autophagosome/lysosomal molecular machinery, both at the CNS and the peripheral level, in AD-related cell damage, has been observed. Possible implications of these observations have been discussed.