The level at which copper becomes toxic is not clear. Several studies have indicated that copper causes oxidative stress; however, most have tested very high levels of copper exposure. We currently have only a limited understanding of the protective systems that operate in cells chronically exposed to copper. Additionally, the limits of homeostatic regulation are not known, making it difficult ...

As an essential trace element, copper can be toxic in mammalian cells when present in excess. Metallothioneins (MTs) are small, cysteine-rich proteins that avidly bind copper and thus play an important role in detoxification. Yeast CUP1 is a member of the MT gene family. The aim of this study was to determine whether yeast CUP1 could bind copper effectively and protect cells against copper stre...

Lactococcus lactis IL1403, a lactic acid bacterium widely used for food fermentation, is often exposed to stress conditions. One such condition is exposure to copper, such as in cheese making in copper vats. Copper is an essential micronutrient in prokaryotes and eukaryotes but can be toxic if in excess. Thus, copper homeostatic mechanisms, consisting chiefly of copper transporters and their re...

Sheep of the semi-feral North Ronaldsay (copper-sensitive) and domesticated Cambridge (copper-tolerant) breeds were compared in respect of pathological changes and protein expression in the liver as a result of excessive dietary copper. Acute mitochondrial damage and hepatic stellate cell (HSC) activation with collagen synthesis occurred in response to moderate copper overload in North Ronaldsa...

Rhodamine B, a fluorescent substance, was used as a tracer to investigate in vitro early microleakage from around amalgam restorations in machinable mica glass-ceramic after thermal stress. Five types of amalgam, i.e., low-copper spherical, low-copper lathe-cut, high-copper admixture, high-copper lathe-cut, and high-copper spherical, were examined in the present study. The results indicated tha...

Rootstocks of fruit trees, commonly used to regulate growth, precocity, fertility, and yield, can also be used to solve problems associated with soils pollution such as copper excess. Despite their potential use for phytoremediation, information on the physiological, biochemical, and molecular aspects of heavy metal toxicity stress on fruit tree rootstocks remains limited. In this study of Prun...

Copper is an important cofactor for many enzymes; however, high levels of copper are toxic. Therefore, bacteria must ensure there is sufficient copper for use as a cofactor but, more importantly, must limit free intracellular levels to prevent toxicity. In this study, we have used DNA microarray to identify Staphylococcus aureus copper-responsive genes. Transcriptional profiling of S. aureus SH...

Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper inf...

salicylic acid (sa) plays a key role in plant disease resistance and hyper-sensitive cell death but is also implicated in hardening responses to abiotic stress. the aim of this study is to examine the effects of salicylic acid on the growth, eco-physiological and biochemical characteristics in zinnia elegans plant exposed to copper stress. effects of copper (cu) on biomass, root length and shoo...