THE JOURNAL OF BIOLOGICAL CHEMISTRY: The Biochemical Behavior of LeadL I. Influence of Calcium, Phosphorus, and Vitamin D on Lead in Blood and Bone

In this review we will explore recent advances in the design and application of excited-state intramolecular proton-transfer (ESIPT) based fluorescent probes. Fluorescence based sensors and imaging agents (probes) are important in biology, physiology, pharmacology, and environmental science for the selective detection of biologically and/or environmentally important species. The development of ESIPT-based fluorescence probes is particularly attractive due to their unique properties, which include a large Stokes shift, environmental sensitivity and potential for ratiometric sensing.

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Excited-state intramolecular proton-transfer (ESIPT) based fluorescence sensors and imaging agents

Serine supports many biosynthetic pathways, including the one-carbon cycle. This Review discusses how cancer cells acquire and use serine, and explores novel therapeutic approaches to limit serine metabolism. The non-essential amino acid serine supports several metabolic processes that are crucial for the growth and survival of proliferating cells, including protein, amino acid and glutathione synthesis. As an important one-carbon donor to the folate cycle, serine contributes to nucleotide synthesis, methylation reactions and the generation of NADPH for antioxidant defence. Many cancer cells are highly dependent on serine, a trait that provides several novel therapeutic opportunities, either through the inhibition of de novo serine synthesis or by limiting the availability or uptake of exogenous serine.

Serine and one-carbon metabolism in cancer.

The physiological roles played by the tripeptide glutathione have greatly advanced over the past decades superimposing the research on free radicals, oxidative stress and, more recently, redox signaling. In particular, GSH is involved in nutrient metabolism, antioxidant defense, and regulation of cellular metabolic functions ranging from gene expression, DNA and protein synthesis to signal transduction, cell proliferation and apoptosis. This review will be focused on the role of GSH in cell signaling by analysing the more recent advancements about its capability to modulate nitroxidative stress, autophagy, and viral infection.

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Glutathione: new roles in redox signaling for an old antioxidant

With the emergence of manufactured nanomaterials, it is urgent to carry out researches on their potential environmental impacts and biological effects To better understand the potential ecotoxicological impacts of metal oxide nanoparticles released to aquatic environments, the zebrafish 96-h embryo-larval bioassay was used to assess and compare the developmental toxicities of nanoscale zinc oxide (nZnO), titanium dioxide (nTiO(2)) and alumina (nAl(2)O(3)) aqueous suspensions Toxicological endpoints such as zebrafish embryos or larvae survival, hatching rate and malformation were noted and described within 96 h of exposure Meanwhile, a comparative experiment with their bulk counterparts (ie, ZnO/bulk, TiO(2)/bulk and Al(2)O(3)/bulk) was conducted to understand the effect of particle size on their toxicities The results showed that: (i) both nZnO and ZnO/bulk aqueous suspensions delayed zebrafish embryo and larva development, decreased their survival and hatching rates, and caused tissue damage The 96-h LC(50) of nZnO and ZnO/bulk aqueous suspensions on the zebrafish survival are 1793 mg/L and 1550 mg/L respectively; and the 84-h EC(50) on the zebrafish embryo hatching rate are 2065 mg/L and 2066 mg/L respectively Serious tissue ulceration was found on zebrafish larvae exposed to nZnO and ZnO/bulk aqueous suspensions (ii) In contrast, neither nTiO(2) and TiO(2)/bulk nor nAl(2)O(3) and Al(2)O(3)/bulk showed any toxicity to zebrafish embryos and larvae under the same experimental condition It revealed that the metal oxide nanoparticles with different chemical composition have different zebrafish developmental toxicities (iii) Exposures of nTiO(2), nZnO and nAl(2)O(3) produced toxic effects on zebrafish embryos and larvae, which was not different from the effects caused by exposing to their bulk counterparts This is the first study about the developmental toxicity of metal oxide nanoparticles, and the results demonstrate that nZnO is very toxic to zebrafish embryos and larvae, which highlights the need to evaluate the potential eco-toxicity of these manufactured nanomaterials (MNMs)

Comparative toxicity of several metal oxide nanoparticle aqueous suspensions to Zebrafish (Danio rerio) early developmental stage

Glutathione (GSH) plays an important role in a multitude of cellular processes, including cell differentiation, proliferation, and apoptosis, and as a result, disturbances in GSH homeostasis are implicated in the etiology and/or progression of a number of human diseases, including cancer, diseases of aging, cystic fibrosis, and cardiovascular, inflammatory, immune, metabolic, and neurodegenerative diseases. Owing to the pleiotropic effects of GSH on cell functions, it has been quite difficult to define the role of GSH in the onset and/or the expression of human diseases, although significant progress is being made. GSH levels, turnover rates, and/or oxidation state can be compromised by inherited or acquired defects in the enzymes, transporters, signaling molecules, or transcription factors that are involved in its homeostasis, or from exposure to reactive chemicals or metabolic intermediates. GSH deficiency or a decrease in the GSH/glutathione disulfide ratio manifests itself largely through an increased susceptibility to oxidative stress, and the resulting damage is thought to be involved in diseases, such as cancer, Parkinson's disease, and Alzheimer's disease. In addition, imbalances in GSH levels affect immune system function, and are thought to play a role in the aging process. Just as low intracellular GSH levels decrease cellular antioxidant capacity, elevated GSH levels generally increase antioxidant capacity and resistance to oxidative stress, and this is observed in many cancer cells. The higher GSH levels in some tumor cells are also typically associated with higher levels of GSH-related enzymes and transporters. Although neither the mechanism nor the implications of these changes are well defined, the high GSH content makes cancer cells chemoresistant, which is a major factor that limits drug treatment. The present report highlights and integrates the growing connections between imbalances in GSH homeostasis and a multitude of human diseases.

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Glutathione dysregulation and the etiology and progression of human diseases.

Base of the Thumb Domain Modulates Epithelial Sodium Channel Gating

Epithelial Na + channels (ENaCs) are comprised of subunits that have large extracellular regions linked tomembrane spanning domains where the channel pore and gate reside. A variety of external factors modify channel activityby interacting at sites within extracellular regions that lead to conformational changes that are transmitted to the channelgate and alter channel open probability. Our review addresses two external factors that have important roles in regulatingchannel activity, proteases and laminar shear stress.

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ENaC regulation by proteases and shear stress.

Extracellular finger domain modulates the response of the epithelial sodium channel to shear stress.

Na+ absorption and K+ secretion in the distal segments of the nephron are modulated by the tubular flow rate. Epithelial Na+ channels (ENaC), composed of α-, β-, and γ-subunits respond to laminar s...

https://www.physiology.org/doi/pdf/10.1152/ajprenal.00610.2010

Shujie Shi

Papers

Glutathione dysregulation and the etiology and progression of human diseases.

Base of the Thumb Domain Modulates Epithelial Sodium Channel Gating

ENaC regulation by proteases and shear stress.

Extracellular finger domain modulates the response of the epithelial sodium channel to shear stress.

Second transmembrane domain modulates epithelial sodium channel gating in response to shear stress