Результаты поиска

Conformational dynamics in specialized C2H2 zinc finger domains enable zinc-responsive gene repression in S. pombe.

Loz1 is a zinc-responsive transcription factor in fission yeast that maintains cellular zinc homeostasis by repressing the expression of genes required for zinc uptake in high zinc conditions. Previous deletion analysis of Loz1 found a region containing two tandem C2H2 zinc-fingers and an upstream "accessory domain" rich in histidine, lysine, and arginine residues to be sufficient for zinc-dependent DNA binding and gene repression. Here we report unexpected biophysical properties of this pair of seemingly classical C2H2 zinc fingers. Isothermal titration calorimetry and NMR spectroscopy reveal…

Soil (microbial) disturbance affect the zinc isotope biogeochemistry but has little effect on plant zinc uptake.

Zinc (Zn) is an important micronutrient but can be toxic at elevated concentrations. We conducted an experiment to test the effect of plant growth and soil microbial disturbance on Zn in soil and plants. Pots were prepared with and without maize and in an undisturbed soil, a soil that was disturbed by X-ray sterilization and a soil that was sterilized but reconditioned with the original microbiome. The Zn concentration and isotope fractionation between the soil and the soil pore water increased with time, which is probably due to physical disturbance and fertilization. The presence of maize in…

Copper and zinc metallation status of copper-zinc superoxide dismutase from amyotrophic lateral sclerosis transgenic mice.

Mutations in the metalloenzyme copper-zinc superoxide dismutase (SOD1) cause one form of familial amyotrophic lateral sclerosis (ALS), and metals are suspected to play a pivotal role in ALS pathology. To learn more about metals in ALS, we determined the metallation states of human wild-type or mutant (G37R, G93A, and H46R/H48Q) SOD1 proteins from SOD1-ALS transgenic mice spinal cords. SOD1 was gently extracted from spinal cord and separated into insoluble (aggregated) and soluble (supernatant) fractions, and then metallation states were determined by HPLC inductively coupled plasma MS. Insolub…

Interleukin-4-Усиленная дифференциация олигодендроцитов зависит от внеклеточного Zinc Uptake через ZIP11.

Дифференциация олигодендроцитов и милелинации усиливается с помощью интерлейкина-4, противовоспалительного цитокина, закрытого от иммунных клеток или поврежденных нейронов, и пероксисомного пролижиратора, активирующего рецептор, служит центральным движущим фактором. В то время как в последнее время, согласно сообщениям, внутриклеточные концентрации цинка динамично меняются в процессе развития олигодендроцитов, роль цинка в интерлейкин-4-усиленной дифференциации олигодендроцитов не изучалась. Используя первичные олигодендроглиевые клетки и олигодендроглиальную клеточную линию CG4, мы показываем

Совпадение в аннотации оригинала
Differentiation of oligodendrocytes and myelination are enhanced by interleukin-4, an anti-inflammatory cytokine secreted from immune cells or injured neurons, and peroxisome proliferator-activated receptor γ serves as a central effector. While intracellular zinc concentrations have recently been reported to change dynamically during oligodendrocyte developm…

Zinc-specific autometallographic in vivo selenium methods: tracing of zinc-enriched (ZEN) terminals, ZEN pathways, and pools of zinc ions in a multitude of other ZEN cells.

In vivo-applied sodium selenide or sodium selenite causes the appearance of zinc-selenium nanocrystals in places where free or loosely bound zinc ions are present. These nanocrystals can in turn be silver enhanced by autometallographic (AMG) development. The selenium method was introduced in 1982 as a tool for zinc-ion tracing, e.g., in vesicular compartments such as synaptic vesicles of zinc-enriched (ZEN) terminals in the central nervous system, and for visualization of zinc ions in ZEN secretory vesicles of, e.g., somatotrophic cells in the pituitary, zymogene granules in pancreatic acinar …

Sex-specific associations of urinary zinc, iron, and zinc-to-iron ratio with obesity indicators and phenotypes.

BACKGROUND: Trace elements such as zinc (Zn) and iron (Fe) may influence obesity risk; however, the role of their balance, reflected by the urinary zinc-to-iron ratio (ZIR), remains unclear. METHODS: We analyzed baseline data from 14,761 adults aged 30-79 years in the China Multi-Ethnic Cohort. Urinary zinc and iron concentrations were normalized using urinary specific gravity to account for variations in urine dilution. RESULTS: Urinary Zn and the ZIR were positively associated with waist circumference and general obesity. Urinary Fe was linked to increased hip circumference (β = 0.196, 95%…

Theaflavins as Electrolyte Additives for Inhibiting Zinc Dendrites and Hydrogen Evolution in Aqueous Zinc-Ion Batteries.

The cycling stability and widespread practical implementation of aqueous zinc ion batteries (AZIBs) are impeded by dendrite growth and the hydrogen evolution reaction (HER). Herein, theaflavins, a low-cost organic bio-compounds and a major component of tea, were innovatively introduced as an electrolyte additive for AZIBs to address these challenges. When added into the electrolyte, theaflavins, with their strong de-solvation capability, facilitated the more uniform and stable diffusion of zinc ions, effectively suppressing dendrite formation and HER. This, in turn, significantly enhanced the …

Zinc-metallochaperones of Aspergillus fumigatus are involved in ROS production and folate biosynthesis during zinc deficiency.

The filamentous fungus Aspergillus fumigatus is equipped with an efficient zinc uptake system that allows this fungus to survive and grow within the very zinc-limiting environment provided by the lungs of immunosuppressed patients. To deal with zinc scarcity, A. fumigatus deploys a homeostatic and adaptive response that enables it to scavenge for and uptake zinc from host tissues. Finally, zinc ions are distributed intracellularly and lodged in fungal proteins that require them for normal functioning. It is believed that most zinc-requiring proteins acquire zinc ions to become properly metalat…

Serum Zinc Level and Efficacy of Zinc Therapy in Cutaneous Leishmaniasis: a Systematic Review and Meta-analysis.

Cutaneous leishmaniasis is a parasitic skin disease prevalent in many parts of the world. Zinc has been investigated for its potential role in the immune response against Leishmania parasites. This study aimed to systematically review the literature and conduct meta-analyses to evaluate the serum zinc level and efficacy of zinc therapy in cutaneous leishmaniasis. A comprehensive search of electronic databases was performed to find studies reporting serum zinc levels and the efficacy of zinc therapy in cutaneous leishmaniasis. Meta-analyses were conducted using RevMan software (version 5.4), ca…

Comparative study on the effects of micro- and nano-sized zinc oxide supplementation on zinc-deficient mice.

BACKGROUND: Zinc (Zn) is an essential cofactor for physiological homeostasis in the body. Zn oxide (ZnO), an inorganic compound that supplies Zn, exists in various sizes, and its bioavailability may vary depending on the size in vivo. However, comparative studies on the nutritional effects of micro-sized ZnO (M-ZnO) and nano-sized ZnO (N-ZnO) supplementation on Zn deficiency (ZnD) animal models have not been reported. OBJECTIVES: This study investigated the nutritional bioavailability of N-ZnO and M-ZnO particles in dietary-induced ZnD mice. METHODS: Animals were divided into six experimenta…

Zinc and iron adequacy and relative importance of zinc/iron storage and intakes among breastfed infants.

Neonatal nutrient storage and supplies from breast milk contribute to nutrient status and growth of infants during their early life. This study investigated the adequacy of zinc and iron intakes among breastfed infants during the first 4 months and determined the relative importance of zinc/iron storage versus nutrient intakes with infant's biochemical status and growth. A longitudinal study followed lactating women and their breastfed infants from birth to 4 months postpartum. Cord zinc and ferritin concentrations, as indicators of nutrient storages, were determined. Zinc and iron intakes fro…

The response of zinc transporter gene expression of selected tissues in a pig model of subclinical zinc deficiency.

This study compared the relative mRNA expression of all mammal zinc (Zn) transporter genes in selected tissues of weaned piglets challenged with short-term subclinical Zn deficiency (SZD). The dietary model involved restrictive feeding (450 g/animal*day-1) of a high-phytate diet (9 g/kg) supplemented with varying amounts of zinc from ZnSO4*7H2O ranging from deficient to sufficient supply levels (total diet Zn: 28.1, 33.6, 38.8, 42.7, 47.5, 58.2, 67.8, 88.0 mg Zn/kg). Total RNA preparations comprised jejunal and colonic mucosa as well as hepatic and nephric tissue. Statistical modelling involve…

Serum zinc levels and efficacy of zinc treatment in acne vulgaris: A systematic review and meta-analysis.

Oral and topical zinc have been used for the treatment of acne, but there is a lack of definitive evidence for their efficacy. (a) To determine if mean serum zinc levels differ between acne patients and controls and (b) to determine the efficacy of zinc preparations in the treatment of acne. A systematic review and meta-analysis was performed according to recommended PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses] guidelines. Subjects with acne had significantly lower serum zinc levels compared to controls. Patients who were treated with zinc had a significant impro…

Zinc Absorption and Endogenous Fecal Zinc Losses in Bangladeshi Toddlers at Risk for Environmental Enteric Dysfunction.

OBJECTIVES: Environmental enteric dysfunction (EED) impairs zinc absorption from food, and zinc deficiency may contribute to the poor growth associated with EED. We examined zinc absorption from a standardized aqueous zinc dose, and habitual daily endogenous fecal zinc excretion (EFZ) and compared these outcomes between children grouped by the lactulose to mannitol ratio (L:M). METHODS: Bangladeshi toddlers (18-24 months) with low (<0.09) and high (≥0.09) L:M were administered isotope-labeled 3 mg aqueous zinc in the fasted state. Fractional absorption of zinc (FAZ) and EFZ were measured by d…

The histidine-rich loop in the extracellular domain of ZIP4 binds zinc and plays a role in zinc transport.

The Zrt-/Irt-like protein (ZIP) family mediates zinc influx from extracellular space or intracellular vesicles/organelles, playing a central role in systemic and cellular zinc homeostasis. Out of the 14 family members encoded in human genome, ZIP4 is exclusively responsible for zinc uptake from dietary food and dysfunctional mutations of ZIP4 cause a life-threatening genetic disorder, Acrodermatitis Enteropathica (AE). About half of the missense AE-causing mutations occur within the large N-terminal extracellular domain (ECD), and our previous study has shown that ZIP4-ECD is crucial for optim…

Effect of hypothyroidism on intestinal zinc absorption and renal zinc disposal in five-sixths nephrectomized rats.

Both hypothyroid (Hypo) and hypozincemia are commonly observed in patients and animals with chronic renal failure (CRF). In CRF whether the hypothyroid plays a role in the pathogenesis of hypozincemia is unclear. This study is designed to investigate the effects of hypothyroid on intestinal zinc absorption and urinary zinc excretion in 5/6 nephrectomized (Nx) rats, because plasma zinc balance is attained through a controlled rate of intestinal uptake as well as renal reabsorption. Intestinal zinc absorption was carried out in jejunum and ileum segments by an in vivo perfusion technique and the…

Effect of intragastric pH on the absorption of oral zinc acetate and zinc oxide in young healthy volunteers.

BACKGROUND: Zinc is an important nutrient and is necessary to maintain a multitude of physiologic processes. Mineral supplements that provide physiologic doses of zinc may be used when dietary zinc is inadequate. Zinc is also used in pharmacologic doses to treat zinc deficiency and diseases such as Wilson's disease and acrodermatitis enteropathica. Although there are several zinc salts available, they are not equal in solubility, which is thought to be a key factor in zinc absorption. Moreover, the solubility of the salts is affected by pH, which may vary between pH 1 and 7 under various physi…

Silicon-zinc interactions and potential roles for dietary zinc and copper in minimizing silica urolithiasis in rats.

Two 8-wk experiments were conducted with Sprague-Dawley weanling rats to determine whether interactions occurring between Zn and Si, or a nutritional deficiency of either Cu or Zn, affect silica urolith formation. In Exp. 1, concentrations of 0, 540, and 2,700 mg of Si/kg of diet from tetraethylorthosilicate were used with dietary Zn concentrations of 4, 12, and 500 mg/kg of diet in a 3 x 3 factorial arrangement. In Exp. 2, copper at 1 or 5 mg/kg of diet and Zn at 4, 12, and 500 mg/kg of diet were used in a 2 x 3 factorial arrangement. All diets in Exp. 2 contained 2,700 mg of Si/kg. Silica ur

Comparative photoactivity of tin and zinc porphyrin inhibitors of heme oxygenase: pronounced photolability of the zinc compounds.

Metalloporphyrin inhibitors of heme oxygenase may also have photosensitizing properties in vivo. To assess photoactivity in serum, the relative ability to mediate photooxidation of tryptophan or other oxidizable targets, presumably by singlet oxygen production, was measured for tin mesoporphyrin, zinc mesoporphyrin, and zinc deuteroporphyrin bisglycol in aqueous solution and when bound to human serum albumin. While tin mesoporphyrin sensitized at the greatest initial rate in aqueous solution, the zinc compounds sensitized at a greater initial rate in detergent micelles or when bound to albumin…

The effect of cadmium on the composition and metabolism of hepatic fatty acids in zinc-adequate and zinc-deficient rats.

Exposure to cadmium (Cd) caused changes in the fatty acid composition of phospholipids, such as increases in levels of saturated and (n-6) fatty acids and decreases in levels of (n-9) fatty acids, in the liver phospholipids of rats fed a fat-free diet. These changes were similar to those caused by dietary zinc deficiency. The changes in fatty acid composition after administration of Cd were greater in zinc-deficient (ZD) rats than zinc-adequate (ZA) rats. When [14C]18:0 was injected intravenously in order to examine the metabolism of (n-9) fatty acids, a decrease in the rate of conversion of […