Glutathione redox regulation of in vitro embryogenesis

2010 ◽  
Vol 48 (5) ◽  
pp. 319-327 ◽  
Author(s):  
Claudio Stasolla
Keyword(s):  
Redox Regulation ◽  
In Vitro Embryogenesis ◽  
Glutathione Redox

scholarly journals Sulfasalazine modifies metabolic profiles and enhances cisplatin chemosensitivity on cholangiocarcinoma cells in in vitro and in vivo models

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Malinee Thanee ◽  
Sureerat Padthaisong ◽  
Manida Suksawat ◽  
Hasaya Dokduang ◽  
Jutarop Phetcharaburanin ◽  
...  
Keyword(s):  
Redox Regulation ◽  
Treated Group ◽  
Control Group ◽  
High Recurrence Rate ◽  
Nucleic Acid Metabolism ◽  
In Vivo Models ◽  
Tryptophan Degradation ◽  
Xenograft Mice

Abstract Background Sulfasalazine (SSZ) is widely known as an xCT inhibitor suppressing CD44v9-expressed cancer stem-like cells (CSCs) being related to redox regulation. Cholangiocarcinoma (CCA) has a high recurrence rate and no effective chemotherapy. A recent report revealed high levels of CD44v9-positive cells in CCA patients. Therefore, a combination of drugs could prove a suitable strategy for CCA treatment via individual metabolic profiling. Methods We examined the effect of xCT-targeted CD44v9-CSCs using sulfasalazine combined with cisplatin (CIS) or gemcitabine in CCA in vitro and in vivo models and did NMR-based metabolomics analysis of xenograft mice tumor tissues. Results Our findings suggest that combined SSZ and CIS leads to a higher inhibition of cell proliferation and induction of cell death than CIS alone in both in vitro and in vivo models. Xenograft mice showed that the CD44v9-CSC marker and CK-19-CCA proliferative marker were reduced in the combination treatment. Interestingly, different metabolic signatures and significant metabolites were observed in the drug-treated group compared with the control group that revealed the cancer suppression mechanisms. Conclusions SSZ could improve CCA therapy by sensitization to CIS through killing CD44v9-positive cells and modifying the metabolic pathways, in particular tryptophan degradation (i.e., kynurenine pathway, serotonin pathway) and nucleic acid metabolism.

scholarly journals Determining the Rate-Limiting Step for Light-Responsive Redox Regulation in Chloroplasts

Antioxidants ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 153 ◽  
Author(s):  
Keisuke Yoshida ◽  
Toru Hisabori
Keyword(s):  
Redox Regulation ◽  
Reducing Power ◽  
Rubisco Activase ◽  
Power Transfer ◽  
Target Proteins ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting

Thiol-based redox regulation ensures light-responsive control of chloroplast functions. Light-derived signal is transferred in the form of reducing power from the photosynthetic electron transport chain to several redox-sensitive target proteins. Two types of protein, ferredoxin-thioredoxin reductase (FTR) and thioredoxin (Trx), are well recognized as the mediators of reducing power. However, it remains unclear which step in a series of redox-relay reactions is the critical bottleneck for determining the rate of target protein reduction. To address this, the redox behaviors of FTR, Trx, and target proteins were extensively characterized in vitro and in vivo. The FTR/Trx redox cascade was reconstituted in vitro using recombinant proteins from Arabidopsis. On the basis of this assay, we found that the FTR catalytic subunit and f-type Trx are rapidly reduced after the drive of reducing power transfer, irrespective of the presence or absence of their downstream target proteins. By contrast, three target proteins, fructose 1,6-bisphosphatase (FBPase), sedoheptulose 1,7-bisphosphatase (SBPase), and Rubisco activase (RCA) showed different reduction patterns; in particular, SBPase was reduced at a low rate. The in vivo study using Arabidopsis plants showed that the Trx family is commonly and rapidly reduced upon high light irradiation, whereas FBPase, SBPase, and RCA are differentially and slowly reduced. Both of these biochemical and physiological findings suggest that reducing power transfer from Trx to its target proteins is a rate-limiting step for chloroplast redox regulation, conferring distinct light-responsive redox behaviors on each of the targets.

scholarly journals Control of Cell Cycle Progression in Human Natural Killer Cells Through Redox Regulation of Expression and Phosphorylation of Retinoblastoma Gene Product Protein

Blood ◽  
1997 ◽  
Vol 89 (11) ◽  
pp. 4092-4099 ◽  
Author(s):  
Akira Yamauchi ◽  
Eda T. Bloom
Keyword(s):  
Cell Cycle ◽  
Nk Cells ◽  
Natural Killer ◽  
Gene Product ◽  
Redox Regulation ◽  
Interleukin 2 ◽  
Retinoblastoma Gene ◽  
Regulation Of Expression ◽  
Retinoblastoma Gene Product

Abstract Using thiol deprivation, we have previously shown that the response of natural killer (NK) cells to interleukin-2 (IL-2) is subject to redox regulation downstream of IL-2 binding and internalization. We have now used the IL-2–dependent cell line, NK3.3 to study redox regulation of NK cells further, and found that NK3.3 cells neither incorporated [3H]-thymidine nor completed the G1-S phase transition in medium lacking the thiol-related compounds, L-cystine, and glutathione, despite the presence of sufficient IL-2. Thiol deprivation did not alter the induction of DNA interferon-γ activated sequence (GAS)-binding activity in response to IL-2. However, the retinoblastoma gene product (RB), a cyclin-dependent kinase (CDK) substrate, was phosphorylated within 24 hours after IL-2 stimulation in standard medium, but its expression and phosphorylation were reduced in thiol-depleted medium in both NK3.3 cells and freshly isolated NK cells. These reductions were not associated with an increased level of p27Kip1, an inhibitor of CDKs CDK6/2 in association with G1 cyclins. Reducing agents, N-acetylcysteine, reduced glutathione or 2-ME restored both RB phosphorylation and DNA synthesis in thiol-deprived NK3.3 cells. The in vitro kinase activities of CDK6 and CDK2 were prematurely increased by thiol deprivation. This enhancement was associated with CDK hyperphosphorylation and prolonged phosphorylation, and could be observed before and beyond IL-2 stimulation. The data suggest the possibility that the premature and prolonged enhancement of CDK activity in thiol-deprived NK cells is associated with, and therefore may contribute to, the reduced expression and phosphorylation of RB, and the associated cell cycle arrest.

scholarly journals MICROPROPAGATION OF PHALAENOPSIS SPP. BY SOMATIC EMBRYOGENESIS TECHNIQUE

2018 ◽  
Vol 6 ◽  
pp. 1185-1191
Author(s):  
Minh Van Tran
Keyword(s):  
Somatic Embryogenesis ◽  
Somatic Cell ◽  
Embryonic Cell ◽  
Cell Suspensions ◽  
Ms Medium ◽  
Callus Initiation ◽  
Set Up ◽  
Planting Materials ◽  
In Vitro Embryogenesis

Phalaenopsis spp. was regularly produced through micropropagation by protocorm like bodies (PLBs); micropropagation takes a lot of labor, and has high cost of seedlings, energy and material. The purpose of this paper was to study the new technique of using in vitro embryogenesis culturing for microprogation. The method involved using protocorm like bodies as planting materials. PLBs were cut into slices and placed on the medium for callus initiation. The callus was initiated on the medium MS + BA (0.1 mg/l) supplemented with NAA (1 mg/l) or 2,4D (1 mg/l) and was proliferated on the medium MS + BA (0.1 mg/l) supplemented with NAA (1 mg/l). Somatic cell suspensions were initiated and proliferated on the medium MS + BA (0.1 mg/l) supplemented with NAA (0.5, 1 mg/l). Somatic cell suspensions were differentiated to embryonic cell suspensions on the MS medium supplemented with NAA (0.1 mg/l) + BA (0.5 mg/l). Embryonic cell suspensions were plated and regenerated on the medium: 1/2MS supplemented with NAA (0.1 mg/l) + BA (0.5 mg/l). Micropropagation of Phalaenopsis sp. via the embryogenesis technique was set up to produce 5,800 plantlets per one liter of somatic embryogenesis suspension.

scholarly journals Effects of emphysema and training on glutathione oxidation in the hamster diaphragm

2000 ◽  
Vol 88 (6) ◽  
pp. 2054-2061 ◽  
Author(s):  
Leo M. A. Heunks ◽  
Aalt Bast ◽  
Cees L. A. van Herwaarden ◽  
Guido R. M. M. Haenen ◽  
P. N. Richard Dekhuijzen
Keyword(s):  
Oxidative Stress ◽  
Inverse Correlation ◽  
Redox Status ◽  
Tetanic Force ◽  
Twitch Force ◽  
Glutathione Oxidation ◽  
And Training ◽  
Glutathione Redox ◽  
Maximal Tetanic Force

Loading of skeletal muscles is associated with increased generation of oxidants, which in turn may impair muscle contractility. We investigated whether the load on the hamster diaphragm imposed by pulmonary emphysema induces oxidative stress, as indicated by glutathione oxidation, and whether the degree of glutathione oxidation is correlated with contractility of the diaphragm. In addition, the effect of 12 wk of treadmill exercise training on contractility and glutathione content in the normal (NH) and emphysematous hamster (EH) diaphragm was investigated. Training started 6 mo after elastase instillation. After the training period, glutathione content and in vitro contractility of the diaphragm were determined. Twitch force and maximal tetanic force were significantly reduced (by ∼30 and ∼15%, respectively) in EH compared with NH. In sedentary hamsters, the GSSG-to-GSH ratio was significantly elevated in the EH compared with the NH diaphragm. A significant inverse correlation was found between GSSG-to-GSH ratio and twitch force in the diaphragm ( P < 0.01). Training improved maximal tetanic force and reduced fatigability of the EH diaphragm but did not alter its glutathione content. In conclusion, 1) emphysema induces oxidative stress in the diaphragm, 2) training improves the contractile properties of the EH diaphragm, and 3) this improvement is not accompanied by changes in glutathione redox status.

scholarly journals Characterization of CprK1, a CRP/FNR-Type Transcriptional Regulator of Halorespiration from Desulfitobacterium hafniense

2006 ◽  
Vol 188 (7) ◽  
pp. 2604-2613 ◽  
Author(s):  
Krisztina Gábor ◽  
Carla S. Veríssimo ◽  
Barbara C. Cyran ◽  
Paul ter Horst ◽  
Nienke P. Meijer ◽  
...  
Keyword(s):  
Dna Binding ◽  
Redox Regulation ◽  
Physiological Role ◽  
Disulfide Bridge ◽  
Reductive Dehalogenation ◽  
Receptor Protein ◽  
Oxidative Inactivation ◽  
Desulfitobacterium Hafniense

ABSTRACT The recently identified CprK branch of the CRP (cyclic AMP receptor protein)-FNR (fumarate and nitrate reduction regulator) family of transcriptional regulators includes proteins that activate the transcription of genes encoding proteins involved in reductive dehalogenation of chlorinated aromatic compounds. Here we report the characterization of the CprK1 protein from Desulfitobacterium hafniense, an anaerobic low-G+C gram-positive bacterium that is capable of reductive dechlorination of 3-chloro-4-hydroxyphenylacetic acid (Cl-OHPA). The gene encoding CprK1 was cloned and functionally overexpressed in Escherichia coli, and the protein was subsequently purified to homogeneity. To investigate the interaction of CprK1 with three of its predicted binding sequences (dehaloboxes), we performed in vitro DNA-binding assays (electrophoretic mobility shift assays) as well as in vivo promoter probe assays. Our results show that CprK1 binds its target dehaloboxes with high affinity (dissociation constant, 90 nM) in the presence of Cl-OHPA and that transcriptional initiation by CprK1 is influenced by deviations in the dehaloboxes from the consensus TTAAT----ATTAA sequence. A mutant CprK1 protein was created by a Val→Glu substitution at a conserved position in the recognition α-helix that gained FNR-type DNA-binding specificity, recognizing the TTGAT----ATCAA sequence (FNR box) instead of the dehaloboxes. CprK1 was subject to oxidative inactivation in vitro, most likely caused by the formation of an intermolecular disulfide bridge between Cys11 and Cys200. The possibility of redox regulation of CprK1 by a thiol-disulfide exchange reaction was investigated by using two Cys→Ser mutants. Our results indicate that a Cys11-Cys200 disulfide bridge does not appear to play a physiological role in the regulation of CprK1.

scholarly journals N-Acetyl Cysteine as a Novel Polymethyl Methacrylate Resin Component: Protection against Cell Apoptosis and Genotoxicity

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yu Zhang ◽  
Jian-feng Xiao ◽  
He-feng Yang ◽  
Yang Jiao ◽  
Wei-wei Cao ◽  
...  
Keyword(s):  
Dna Damage ◽  
Polymethyl Methacrylate ◽  
Cell Apoptosis ◽  
Oxidative Dna Damage ◽  
Redox Regulation ◽  
Protective Effects ◽  
Mitochondrial Apoptosis ◽  
Acetyl Cysteine ◽  
Pmma Resin

The present study investigated the antiapoptotic and antigenotoxic capabilities of N-acetyl cysteine- (NAC-) containing polymethyl methacrylate (PMMA) resin. An in vitro Transwell insert model was used to mimic the clinical provisional restorations placed on vital teeth. Various parameters associated with cell apoptosis and genotoxicity were investigated to obtain a deeper insight into the underlying mechanisms. The exposure of human dental pulp cell (hDPC) cultures to the PMMA resin (Unifast Trad™) resulted in a rapid increase in reactive oxygen species (ROS) level beginning at 1 h, which was followed by time-dependent cell detachment and overt death. The formation of γ-H2AX and cell cycle G1 phase arrest indicated that oxidative DNA damage occurred as a result of the interactions between DNA bases and ROS, beyond the capacities of cellular redox regulation. Such oxidative DNA damage triggers the activation of p53 via the ataxia telangiectasia mutated (ATM) signaling pathway and the induction of intrinsic mitochondrial apoptosis. Oxidative stress, cell apoptosis, and DNA damage induced by the PMMA resin were recovered to almost the level of untreated controls by the incorporation of NAC. The results indicate that the PMMA resin induced the intrinsic mitochondrial apoptosis as a consequence of p53 activation via the ATM pathway in response to oxidative DNA damage. More importantly, the incorporation of NAC as a novel component into the Unifast Trad™ PMMA resin offers protective effects against cell apoptosis and genotoxicity. This procedure represents a beneficial strategy for developing more biocompatible PMMA-based resin materials.

scholarly journals Biochemical identification of a neutral sphingomyelinase 1 (NSM1)-like enzyme as the major NSM activity in the DT40 B-cell line: absence of a role in the apoptotic response to endoplasmic reticulum stress

2002 ◽  
Vol 365 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Amanda C. FENSOME ◽  
Michelle JOSEPHS ◽  
Matilda KATAN ◽  
Fernando RODRIGUES-LIMA
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
B Cell ◽  
Cell Line ◽  
Redox Regulation ◽  
De Novo ◽  
Neutral Sphingomyelinase ◽  
Complete Purification ◽  
Dt40 Cells

DT40 cells have approx. 10-fold higher Mg2+-dependent neutral sphingomyelinase (NSM) activity in comparison with other B-cell lines and contain very low acidic sphingomyelinase activity. Purification of this activity from DT40 cell membranes suggested the presence of one major NSM isoform. Although complete purification of this isoform could not be achieved, partially purified fractions were examined further with regard to the known characteristics of previously partially purified NSMs and the two cloned enzymes exhibiting in vitro NSM activity (NSM1 and NSM2). For a direct comparative study, highly purified brain preparations, purified NSM1 protein and Bacillus cereus enzyme were used. Analysis of the enzymic properties of the partially purified DT40 NSM, such as cation dependence, substrate specificity, redox regulation and stimulation by phosphatidylserine, together with the localization of this enzyme to the endoplasmic reticulum (ER), suggested that this NSM from DT40 cells corresponds to NSM1. Further studies aimed to correlate presence of the high levels of this NSM1-like activity in DT40 cells with the ability of these cells to accumulate ceramide and undergo apoptosis. When DT40 cells were stimulated to apoptose by a variety of agents, including the ER stress, an increase in endogenous ceramide levels was observed. However, these responses were not enhanced compared with another B-cell line (Nalm-6), characterized by low sphingomyelinase activity. In addition, DT40 cells were not more susceptible to ceramide accumulation and apoptosis when exposed to the ER stress compared with other apoptotic agents. Inhibition of de novo synthesis of ceramide partially inhibited its accumulation, indicating that the ceramide production in DT40 cells could be complex and, under some conditions, could involve both sphingomyelin hydrolysis and ceramide synthesis.

In Vitro Embryogenesis in Plants

1996 ◽  
Vol 38 (4) ◽  
pp. 616-616
Author(s):  
J. Opatrna
Keyword(s):  
In Vitro Embryogenesis
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