scholarly journals Cadmium interference with iron sensing reveals transcriptional programs sensitive and insensitive to reactive oxygen species

2020 ◽  
Author(s):  
Samuel A. McInturf ◽  
Mather A. Khan ◽  
Arun Gokul ◽  
Norma A. Castro-Guerrero ◽  
Ricarda Hoehner ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Networks ◽  
Feedback Regulation ◽  
Fe Deficiency ◽  
Specific Gene ◽  
Negative Feedback Regulation ◽  
The Stability ◽  
Essential Heavy Metal ◽  
Cd Exposure ◽  
And Oxidative Stress

AbstractIron (Fe) is an essential micronutrient whose uptake is tightly regulated to prevent either deficiency or oxidative stress. Cadmium (Cd) is a non-essential heavy metal that induces both Fe-deficiency and oxidative stress; however, the mechanisms underlying these Cd-induced responses are still elusive. Here we explored Cd-induced Fe-associated responses in wildtype Arabidopsis and opt3-2, a mutant that over-accumulates Fe. Gene expression profiling revealed a large overlap between transcripts induced by Fe-deficiency and Cd exposure in wildtype plants and the opt3 mutant. Interestingly, vascular-localized Fe-responsive genes were found to be highly induced by Cd even in the presence of high Fe and H2O2 levels, suggesting that Cd impairs Fe sensing. It was recently shown that Fe-S cluster-containing proteins AtNEET, play a role in Fe sensing. Our data shows that Cd negatively impacts both the stability and Fe-S transfer activity of AtNEET. Altogether, our data indicate that Fe-deficiency responses are governed by multiple inputs and that a hierarchical regulation of Fe-deficiency responses prevents the induction of specific gene networks when Fe and H2O2 levels are high. Other Cd/Fe-responsive genes however, are insensitive to this negative feedback regulation suggesting that their induction is the result of an impaired Fe sensing as opposed to the traditional view of Cd/Fe uptake competition at the root level.HighlightCadmium induces an iron-deficiency response often explained by root uptake competition; here we show that Cd also impairs Fe sensing in leaves, even when Fe is in sufficient quantities.

scholarly journals RrmA regulates the stability of specific transcripts in response to both nitrogen source and oxidative stress

2013 ◽  
Vol 89 (5) ◽  
pp. 975-988 ◽  
Author(s):  
Kinga Krol ◽  
Igor Y. Morozov ◽  
Meriel G. Jones ◽  
Tomasz Wyszomirski ◽  
Piotr Weglenski ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitrogen Source ◽  
The Stability ◽  
And Oxidative Stress

scholarly journals The SUMO ligase Su(var)2-10 controls eu- and heterochromatic gene expression via establishment of H3K9 trimethylation and negative feedback regulation

2019 ◽  
Author(s):  
Maria Ninova ◽  
Baira Godneeva ◽  
Yung-Chia Ariel Chen ◽  
Yicheng Luo ◽  
Sharan J. Prakash ◽  
...  
Keyword(s):  
Gene Expression ◽  
Negative Feedback ◽  
Feedback Regulation ◽  
Specific Gene ◽  
Negative Feedback Regulation ◽  
Tissue Specific ◽  
Tissue Specific Gene ◽  
H3k9 Trimethylation ◽  
Sumo Ligase ◽  
Host Genes

AbstractChromatin is critical for genome compaction and gene expression. On a coarse scale, the genome is divided into euchromatin, which harbors the majority of genes and is enriched in active chromatin marks, and heterochromatin, which is gene-poor but repeat-rich. The conserved molecular hallmark of heterochromatin is the H3K9me3 modification, which is associated with gene silencing. We found that in Drosophila deposition of most of the H3K9me3 mark depends on SUMO and the SUMO-ligase Su(var)2-10, which recruits the histone methyltransferase complex SetDB1/Wde. In addition to repressing repeats, H3K9me3 also influences expression of both hetero- and euchromatic host genes. High H3K9me3 levels in heterochromatin are required to suppress spurious non-canonical transcription and ensure proper gene expression. In euchromatin, a set of conserved genes is repressed by Su(var)2-10/SetDB1-induced H3K9 trimethylation ensuring tissue-specific gene expression. Several components of heterochromatin are themselves repressed by this pathway providing a negative feedback mechanism to ensure chromatin homeostasis.Highlights-Proper expression of host genes residing in heterochromatin requires Su(var)2-10-dependent installation of the H3K9me3 mark to suppress spurious non-canonical transcription.-A set of euchromatic host genes is repressed by transposon-independent installation of H3K9me3 in a process that depends on Su(var)2-10 and SUMO.-Installation of H3K9me3 via Su(var)2-10 ensures tissue-specific gene expression.-H3K9me3-dependent silencing of genes encoding proteins involved in heterochromatin formation provides negative feedback regulation to maintain heterochromatin homeostasis.

scholarly journals Nitric Oxide Prevents Fe Deficiency-Induced Photosynthetic Disturbance, and Oxidative Stress in Alfalfa by Regulating Fe Acquisition and Antioxidant Defense

Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1556
Author(s):  
Md Atikur Rahman ◽  
Ahmad Humayan Kabir ◽  
Yowook Song ◽  
Sang-Hoon Lee ◽  
Mirza Hasanuzzaman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Antioxidant Defense ◽  
Fe Deficiency ◽  
Negative Effects ◽  
No Donor ◽  
Antioxidant Genes ◽  
H2o2 Accumulation ◽  
Fe Homeostasis ◽  
And Oxidative Stress

Iron (Fe) deficiency impairs photosynthetic efficiency, plant growth and biomass yield. This study aimed to reveal the role of nitric oxide (NO) in restoring Fe-homeostasis and oxidative status in Fe-deficient alfalfa. In alfalfa, a shortage of Fe negatively affected the efficiency of root andshoot length, leaf greenness, maximum quantum yield PSII (Fv/Fm), Fe, S, and Zn accumulation, as well as an increase in H2O2 accumulation. In contrast, in the presence of sodium nitroprusside (SNP), a NO donor, these negative effects of Fe deficiency were largely reversed. In response to the SNP, the expression of Fe transporters (IRT1, NRAMP1) and S transporter (SULTR1;2) genes increased in alfalfa. Additionally, the detection of NO generation using fluorescence microscope revealed that SNP treatment increased the level of NO signal, indicating that NO may act as regulatory signal in response to SNP in plants. Interestingly, the increase of antioxidant genes and their related enzymes (Fe-SOD, APX) in response to SNP treatment suggests that Fe-SOD and APX are key contributors to reducing ROS (H2O2) accumulation and oxidative stress in alfalfa. Furthermore, the elevation of Ascorbate-glutathione (AsA-GSH) pathway-related genes (GR and MDAR) Fe-deficiency with SNP implies that the presence of NO relates to enhanced antioxidant defense against Fe-deficiency stress.

scholarly journals Different resource allocation in a Bacillus subtilis population displaying bimodal motility

2021 ◽  
Author(s):  
Leendert W. Hamoen ◽  
Biwen Wang ◽  
Jojet Staal ◽  
Yongqiang Gao ◽  
Remco Kort ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Exponential Growth ◽  
Microscopic Analysis ◽  
Feedback Regulation ◽  
Ribosomal Gene ◽  
Threshold Concentration ◽  
Negative Feedback Regulation ◽  
Continuous Increase ◽  
Motile Cells ◽  
The Stability

To cope with sudden changes in their environment, bacteria can use a bet-hedging strategy by dividing the population into cells with different properties. This so-called bimodal or bistable cellular differentiation is generally controlled by positive feedback regulation of transcriptional activators. Due to the continuous increase in cell volume, it is difficult for these activators to reach an activation threshold concentration when cells are growing exponentially. This is one reason why bimodal differentiation is primarily observed from the onset of the stationary phase when exponential growth ceases. An exception is the bimodal induction of motility in Bacillus subtilis, which occurs early during exponential growth. Several mechanisms have been put forward to explain this, including double negative-feedback regulation and the stability of the mRNA molecules involved. In this study, we used fluorescence-assisted cell sorting to compare the transcriptome of motile and non-motile cells and noted that expression of ribosomal genes is lower in motile cells. This was confirmed using an unstable GFP reporter fused to the strong ribosomal rpsD promoter. We propose that the reduction in ribosomal gene expression in motile cells is the result of a diversion of cellular resources to the synthesis of the chemotaxis and motility systems. In agreement, single-cell microscopic analysis showed that motile cells are slightly shorter than non-motile cells, an indication of slower growth. We speculate that this growth rate reduction can contribute to the bimodal induction of motility during exponential growth.

scholarly journals Effects of Transport Temperature on the Stability of Inflammatory, Hemostasis, Endothelial Function, and Oxidative Stress Plasma Biomarker Concentrations

Shock ◽  
2017 ◽  
Vol 47 (6) ◽  
pp. 715-719 ◽  
Author(s):  
Octavia M. Peck Palmer ◽  
Melinda Carter ◽  
Chung-Chou H. Chang ◽  
Nicole Lucko ◽  
Vanessa M. Jackson ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Function ◽  
Plasma Biomarker ◽  
The Stability ◽  
And Oxidative Stress

scholarly journals Influence of supplemented coated-cysteamine on morphology, apoptosis and oxidative stress status of gastrointestinal tract

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Hongnan Liu ◽  
Miaomiao Bai ◽  
Bie Tan ◽  
Kang Xu ◽  
Rong Yu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Caspase 3 ◽  
Control Diet ◽  
Control Group ◽  
Lesion Score ◽  
Positive Effects ◽  
Oxidative Stress Status ◽  
Mucosal Morphology ◽  
The Stability ◽  
And Oxidative Stress

Abstract Background Cysteamine was coated to cover its odor and maintain the stability. However, coated cysteamine (CC) has not been clearly evaluated for its effects on the gastrointestinal mucosa status. We hypothesize that the appropriate CC supplementation in diet impacts the stomach and intestinal mucosa variously through regulating the morphology, apoptosis, and oxidative stress status in model of pigs. Results The results showed that villus height increased (P < 0.05), and crypt depth decreased (P < 0.05) in the ileum when pigs were fed the diet with low cysteamine (LCS) compared with the control diet. The ileal lesion score in the LCS group was significantly (P < 0.01) lower than that in the control group, while the gastric lesion score in the CC group was significantly (P < 0.01) higher compared with that of the control group. It also showed that the activities of total superoxide dismutase (T-SOD) and diamine oxidase (DAO) were upregulated (P < 0.05) in the LCS group. In addition, Bax and caspase 3 immunore-activity increased (P < 0.01), and Bcl-2 immunoreactivity decreased (P < 0.01) in the gastric mucosa of pigs fed the diet with high cysteamine (HCS). The Bax and caspase 3 immunoreactivity decreased (P < 0.01), and Bcl-2 immunoreactivity increased (P < 0.01) in ileum mucosa of pigs fed the HCS diet. Conclusions Although moderate dietary coated cysteamine showed positive effects on GI mucosal morphology, apoptosis, and oxidative stress status, the excess coated cysteamine may cause apoptosis leading to GI damage in pigs.

A Novel Role for Flotillin-Containing Lipid Rafts in Negative-Feedback Regulation of Thyroid-Specific Gene Expression by Thyroglobulin

Thyroid ◽  
2016 ◽  
Vol 26 (11) ◽  
pp. 1630-1639 ◽  
Author(s):  
Yuqian Luo ◽  
Takeshi Akama ◽  
Akiko Okayama ◽  
Aya Yoshihara ◽  
Mariko Sue ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lipid Rafts ◽  
Negative Feedback ◽  
Feedback Regulation ◽  
Specific Gene ◽  
Negative Feedback Regulation ◽  
Specific Gene Expression

scholarly journals Copper–zinc imbalance induces kidney tubule damage and oxidative stress in a population exposed to chronic environmental cadmium

2019 ◽  
Vol 93 (3) ◽  
pp. 337-344 ◽  
Author(s):  
Sang-Yong Eom ◽  
Dong-Hyuk Yim ◽  
Mingai Huang ◽  
Choong-Hee Park ◽  
Guen-Bae Kim ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Geometric Mean ◽  
Reference Level ◽  
Tubular Damage ◽  
Exposure Level ◽  
Renal Tubular Damage ◽  
Essential Metal ◽  
Renal Tubular ◽  
Cd Exposure ◽  
And Oxidative Stress

Abstract Purpose This cross-sectional study aimed to assess the effect of environmental cadmium (Cd) exposure and essential metal imbalance on renal tubular damage and oxidative stress in 979 adults living in a Cd-polluted area near an abandoned copper (Cu) refinery. Methods We analyzed urinary Cd concentrations, renal tubular damage and oxidative stress markers, such as beta-2 microglobulin (β2-MG) and N-acetyl-β-d-glucosaminidase (NAG) activity and urine malondialdehyde (MDA) levels. The serum copper-to-zinc ratio (CZR) was used as an essential metal imbalance indicator. We divided the subjects into two Cd exposure groups based on the reference level of urinary Cd for renal dysfunction (2 μg/g creatinine). Results The geometric mean concentration of urinary Cd in all subjects was 2.25 μg/g creatinine. In both low and high Cd exposure groups, urinary Cd levels were positively correlated with urinary NAG activity, but not with serum CZR. After multivariate adjustment, serum CZR was strongly associated with urinary β2-MG levels in the low Cd exposure group (β = 1.360, P = 0.019) and was significantly associated with urinary MDA levels, regardless of Cd exposure level. In addition, the risk of renal tubular damage was significantly associated with urinary Cd level, particularly in the lowest or highest CZR tertile groups. Conclusions Essential metal imbalance may be a determinant of oxidative stress and renal tubular damage in a chronically Cd-exposed population, and proper zinc supplementation will be effective in preventing adverse health effects due to Cd exposure.

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