scholarly journals A Simple Fluorescence Assay for Cystine Uptake via the xCT in Cells using Selenocystine and a Fluorescent Probe

2021 ◽  
Author(s):  
Takashi Shimomura ◽  
Norio Hirakawa ◽  
Yuya Ohuchi ◽  
Munetaka Ishiyama ◽  
Masanobu Shiga ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Fluorescent Probe ◽  
Redox Balance ◽  
Fluorescence Assay ◽  
Simple Method ◽  
Cellular Redox ◽  
Glutathione Synthesis ◽  
Intracellular Glutathione ◽  
Inhibitory Efficiency ◽  
Uptake Activity

ABSTRACTThe cystine/glutamate antiporter (xCT) is a crucial transporter that maintains cellular redox balance by regulating intracellular glutathione synthesis via cystine uptake. However, no robust and simple method to determine the cystine uptake activity of xCT is currently available. We have developed a method to measure the xCT activity via the reaction of selenocysteine and fluorescein O,O′-diacrylate (FOdA). Selenocystine, a cystine analog, is transported into cells through xCT on the cell membrane. The amount of the transported selenocystine was then determined by a reaction using tris(2-carboxyethyl)phosphine (TCEP) and FOdA in a weak acidic buffer at pH 6. Using this method, the cystine uptake activity of xCT in various cells, and the inhibitory efficiency of xCT inhibitors, were evaluated.

scholarly journals Differential Expression of Peroxisomal Proteins in Distinct Types of Parotid Gland Tumors

2021 ◽  
Vol 22 (15) ◽  
pp. 7872
Author(s):  
Malin Tordis Meyer ◽  
Christoph Watermann ◽  
Thomas Dreyer ◽  
Steffen Wagner ◽  
Claus Wittekindt ◽  
...  
Keyword(s):  
Redox Balance ◽  
Matrix Proteins ◽  
Parotid Tumor ◽  
Gene Expressions ◽  
Tissue Samples ◽  
Cellular Redox ◽  
Tumor Subtypes ◽  
Parotid Tumors ◽  
Aggressive Tumors

Salivary gland cancers are rare but aggressive tumors that have poor prognosis and lack effective cure. Of those, parotid tumors constitute the majority. Functioning as metabolic machinery contributing to cellular redox balance, peroxisomes have emerged as crucial players in tumorigenesis. Studies on murine and human cells have examined the role of peroxisomes in carcinogenesis with conflicting results. These studies either examined the consequences of altered peroxisomal proliferators or compared their expression in healthy and neoplastic tissues. None, however, examined such differences exclusively in human parotid tissue or extended comparison to peroxisomal proteins and their associated gene expressions. Therefore, we examined differences in peroxisomal dynamics in parotid tumors of different morphologies. Using immunofluorescence and quantitative PCR, we compared the expression levels of key peroxisomal enzymes and proliferators in healthy and neoplastic parotid tissue samples. Three parotid tumor subtypes were examined: pleomorphic adenoma, mucoepidermoid carcinoma and acinic cell carcinoma. We observed higher expression of peroxisomal matrix proteins in neoplastic samples with exceptional down regulation of certain enzymes; however, the degree of expression varied between tumor subtypes. Our findings confirm previous experimental results on other organ tissues and suggest peroxisomes as possible therapeutic targets or markers in all or certain subtypes of parotid neoplasms.

scholarly journals Regulation of intracellular glutathione levels in erythrocytes infected with chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum

2002 ◽  
Vol 368 (3) ◽  
pp. 761-768 ◽  
Author(s):  
Svenja MEIERJOHANN ◽  
Rolf D. WALTER ◽  
Sylke MÜLLER
Keyword(s):  
Oxidative Stress ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Differential Susceptibility ◽  
Protozoan Parasite ◽  
Chloroquine Resistance ◽  
Glutathione Metabolism ◽  
Glutathione Synthesis ◽  
Intracellular Glutathione ◽  
Glutamylcysteine Synthetase

Malaria is one of the most devastating tropical diseases despite the availability of numerous drugs acting against the protozoan parasite Plasmodium in its human host. However, the development of drug resistance renders most of the existing drugs useless. In the malaria parasite the tripeptide glutathione is not only involved in maintaining an adequate intracellular redox environment and protecting the cell against oxidative stress, but it has also been shown that it degrades non-polymerized ferriprotoporphyrin IX (FP IX) and is thus implicated in the development of chloroquine resistance. Glutathione levels in Plasmodium-infected red blood cells are regulated by glutathione synthesis, glutathione reduction and glutathione efflux. Therefore the effects of drugs that interfere with these metabolic processes were studied to establish possible differences in the regulation of the glutathione metabolism of a chloroquine-sensitive and a chloroquine-resistant strain of Plasmodiumfalciparum. Growth inhibition of P. falciparum 3D7 by d,l-buthionine-(S,R)sulphoximine (BSO), an inhibitor of γ-glutamylcysteine synthetase (γ-GCS), and by Methylene Blue (MB), an inhibitor of gluta thione reductase (GR), was significantly more pronounced than inhibition of P.falciparum Dd2 growth by these drugs. These results correlate with the higher levels of total glutathione in P. falciparum Dd2. Short-term incubations of Percoll-enriched trophozoite-infected red blood cells in the presence of BSO, MB and N,N1-bis(2-chloroethyl)-N-nitrosourea and subsequent determinations of γ-GCS activities, GR activities and glutathione disulphide efflux revealed that maintenance of intracellular glutathione in P. falciparum Dd2 is mainly dependent on glutathione synthesis whereas in P. falciparum 3D7 it is regulated via GR. Generally, P. falciparum Dd2 appears to be able to sustain its intracellular glutathione more efficiently than P. falciparum 3D7. In agreement with these findings is the differential susceptibility to oxidative stress of both parasite strains elicited by the glucose/glucose oxidase system.

A novel cell membrane-targeting fluorescent probe for imaging endogenous/exogenous formaldehyde in live cells and zebrafish

The Analyst ◽  
2021 ◽  
Author(s):  
Wenlong Sheng ◽  
Xue Zhang ◽  
Miaohui Yu ◽  
Meng Jin ◽  
Ning Li ◽  
...  
Keyword(s):  
Economic Development ◽  
Cell Membrane ◽  
Human Health ◽  
Fluorescent Probe ◽  
Live Cells ◽  
Membrane Targeting ◽  
Health It ◽  
Global Pollutant

Formaldehyde (FA) is not only an economic chemical but also a global pollutant. Although it brings economic development, it poses a threat to human health. It is also a kind...

scholarly journals Cisplatin inhibits SIRT3-deacetylation MTHFD2 to disturb cellular redox balance in colorectal cancer cell

2020 ◽  
Vol 11 (8) ◽  
Author(s):  
Xingyou Wan ◽  
Chao Wang ◽  
Zhenyu Huang ◽  
Dejian Zhou ◽  
Sheng Xiang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cell ◽  
Redox Balance ◽  
Colorectal Cancer Cell ◽  
Cellular Redox

scholarly journals A standardized extract of Asparagus officinalis stem improves HSP70-mediated redox balance and cell functions in bovine cumulus-granulosa cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Khoi Thieu Ho ◽  
Kohei Homma ◽  
Jun Takanari ◽  
Hanako Bai ◽  
Manabu Kawahara ◽  
...  
Keyword(s):  
Cell Function ◽  
Redox Balance ◽  
Asparagus Officinalis ◽  
Hsp70 Expression ◽  
Ros Generation ◽  
Cellular Redox ◽  
Pheochromocytoma Cells ◽  
Cell Functions ◽  
Progesterone Synthesis ◽  
Hsp70 Induction

AbstractHeat shock (HS) protein 70 (HSP70), a well-known HS-induced protein, acts as an intracellular chaperone to protect cells against stress conditions. Although HS induces HSP70 expression to confer stress resistance to cells, HS causes cell toxicity by increasing reactive oxygen species (ROS) levels. Recently, a standardized extract of Asparagus officinalis stem (EAS), produced from the byproduct of asparagus, has been shown to induce HSP70 expression without HS and regulate cellular redox balance in pheochromocytoma cells. However, the effects of EAS on reproductive cell function remain unknown. Here, we investigated the effect of EAS on HSP70 induction and oxidative redox balance in cultured bovine cumulus-granulosa (CG) cells. EAS significantly increased HSP70 expression; however, no effect was observed on HSP27 and HSP90 under non-HS conditions. EAS decreased ROS generation and DNA damage and increased glutathione (GSH) synthesis under both non-HS and HS conditions. Moreover, EAS synergistically increased HSP70 and HSF1 expression and increased progesterone levels in CG cells. Treatment with an HSP70 inhibitor significantly decreased GSH level, increased ROS level, and decreased HSF1, Nrf2, and Keap1 expression in the presence of EAS. Furthermore, EAS significantly increased progesterone synthesis. Thus, EAS improves HSP70-mediated redox balance and cell function in bovine CG cells.

scholarly journals NOV-002, a Glutathione Disulfide Mimetic, as a Modulator of Cellular Redox Balance

2008 ◽  
Vol 68 (8) ◽  
pp. 2870-2877 ◽  
Author(s):  
D. M. Townsend ◽  
L. He ◽  
S. Hutchens ◽  
T. E. Garrett ◽  
C. J. Pazoles ◽  
...  
Keyword(s):  
Redox Balance ◽  
Glutathione Disulfide ◽  
Cellular Redox

Lipid hydroperoxide‐induced apoptosis in human colonic CaCo‐2 cells is associated with an early loss of cellular redox balance

2000 ◽  
Vol 14 (11) ◽  
pp. 1567-1576 ◽  
Author(s):  
Tong‐Gang Wang ◽  
Yudai Gotoh ◽  
Merilyn Ho Jennings ◽  
Carol Ann Rhoads ◽  
Tak Yee Aw
Keyword(s):  
Lipid Hydroperoxide ◽  
Redox Balance ◽  
Cellular Redox ◽  
Early Loss ◽  
Induced Apoptosis

scholarly journals N-Acetylcysteine as Modulator of the Essential Trace Elements Copper and Zinc

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1117
Author(s):  
Theresa Wolfram ◽  
Maria Schwarz ◽  
Michaela Reuß ◽  
Kristina Lossow ◽  
Mario Ost ◽  
...  
Keyword(s):  
Trace Elements ◽  
Redox Homeostasis ◽  
Redox Balance ◽  
Cellular Redox ◽  
Essential Trace Elements ◽  
Nrf2 Activation ◽  
Zn And Cu In ◽  
Cu And Zn

N-acetylcysteine (NAC) is a frequently prescribed drug and known for its metal chelating capability. However, to date it is not well characterized whether NAC intake affects the homeostasis of essential trace elements. As a precursor of glutathione (GSH), NAC also has the potential to modulate the cellular redox homeostasis. Thus, we aimed to analyze effects of acute and chronic NAC treatment on the homeostasis of copper (Cu) and zinc (Zn) and on the activity of the redox-sensitive transcription factor Nrf2. Cells were exposed to 1 mM NAC and were co-treated with 50 μM Cu or Zn. We showed that NAC treatment reduced the cellular concentration of Zn and Cu. In addition, NAC inhibited the Zn-induced Nrf2 activation and limited the concomitant upregulation of cellular GSH concentrations. In contrast, mice chronically received NAC via drinking water (1 g NAC/100 mL). Cu and Zn concentrations were decreased in liver and spleen. In the duodenum, NQO1, TXNRD, and SOD activities were upregulated by NAC. All of them can be induced by Nrf2, thus indicating a putative Nrf2 activation. Overall, NAC modulates the homeostasis of Cu and Zn both in vitro and in vivo and accordingly affects the cellular redox balance.

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