scholarly journals Intracellular Iron Concentration and Distribution Have Multiple Effects on Cell Cycle Events

2020 ◽  
Author(s):  
Paul Seligman ◽  
Gamini Siriwardana
Keyword(s):  
Cell Cycle ◽  
Iron Concentration ◽  
Intracellular Iron ◽  
Intracellular Iron Concentration

Effects of Mouse Hepcidin 1 Treatment on Osteoclast Differentiation and Intracellular Iron Concentration

Inflammation ◽  
2014 ◽  
Vol 38 (2) ◽  
pp. 718-727 ◽  
Author(s):  
Guo-yang Zhao ◽  
Dong-hua Di ◽  
Bo Wang ◽  
Xi Huang ◽  
You-jia Xu
Keyword(s):  
Osteoclast Differentiation ◽  
Iron Concentration ◽  
Intracellular Iron ◽  
Intracellular Iron Concentration

scholarly journals Postgenomic Analysis of Streptococcus thermophilus Cocultivated in Milk with Lactobacillus delbrueckii subsp. bulgaricus: Involvement of Nitrogen, Purine, and Iron Metabolism

2008 ◽  
Vol 75 (7) ◽  
pp. 2062-2073 ◽  
Author(s):  
Luciana Herve-Jimenez ◽  
Isabelle Guillouard ◽  
Eric Guedon ◽  
Samira Boudebbouze ◽  
Pascal Hols ◽  
...  
Keyword(s):  
Iron Concentration ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Delbrueckii ◽  
Growth Stages ◽  
Intracellular Iron ◽  
Associative Behavior ◽  
Regulator Genes ◽  
Kinetics Of ◽  
Intracellular Iron Concentration ◽  
Lactobacillus Delbrueckii Subsp

ABSTRACT Streptococcus thermophilus is one of the most widely used lactic acid bacteria in the dairy industry, in particular in yoghurt manufacture, where it is associated with Lactobacillus delbrueckii subsp. bulgaricus. This bacterial association, known as a proto-cooperation, is poorly documented at the molecular and regulatory levels. We thus investigate the kinetics of the transcriptomic and proteomic modifications of S. thermophilus LMG 18311 in response to the presence of L. delbrueckii subsp. bulgaricus ATCC 11842 during growth in milk at two growth stages. Seventy-seven different genes or proteins (4.1% of total coding sequences), implicated mainly in the metabolism of nitrogen (24%), nucleotide base (21%), and iron (20%), varied specifically in coculture. One of the most unpredicted results was a significant decrease of most of the transcripts and enzymes involved in purine biosynthesis. Interestingly, the expression of nearly all genes potentially encoding iron transporters of S. thermophilus decreased, whereas that of iron-chelating dpr as well as that of the fur (perR) regulator genes increased, suggesting a reduction in the intracellular iron concentration, probably in response to H2O2 production by L. bulgaricus. The present study reveals undocumented nutritional exchanges and regulatory relationships between the two yoghurt bacteria, which provide new molecular clues for the understanding of their associative behavior.

scholarly journals Toxicity of holotransferrin but not albumin in proximal tubule cells in primary culture.

1998 ◽  
Vol 9 (1) ◽  
pp. 77-84 ◽  
Author(s):  
L Chen ◽  
R A Boadle ◽  
D C Harris
Keyword(s):  
Lipid Peroxidation ◽  
Lactate Dehydrogenase ◽  
Proximal Tubule ◽  
Iron Concentration ◽  
Intracellular Iron ◽  
Proximal Tubule Cells ◽  
Fe Uptake ◽  
Tubule Cells ◽  
Rat Proximal Tubule ◽  
Intracellular Iron Concentration

Proteinuria has been invoked as a cause of tubulointerstitial injury in chronic renal disease, and in vivo studies have suggested indirectly the particular nephrotoxicity of one urinary protein holotransferrin (Tf-Fe). However, to date there has been no direct evidence for the nephrotoxicity of Tf-Fe. To examine the potential cytotoxicity of Tf-Fe and the mechanism involved, and to compare this to another urinary protein albumin, rat proximal tubule cells were studied in primary culture. Tf-Fe at pH 6.0 caused functional and ultrastructural injury, but no cytotoxicity was seen with cells exposed to albumin, apotransferrin (transferrin), or Tf-Fe at pH 7.4. The influence of pH on Tf-Fe-induced cytotoxicity was not due to pH per se, but could be explained by an effect on Tf-Fe uptake. At pH 6.0, uptake of 125I-Tf-Fe (3.55 +/- 0.05 versus 1.25 +/- 0.10 fmol/dish, P < 0.01) and intracellular iron concentration (1.14 +/- 0.25 versus 0.46 +/- 0.23 nmol/dish, P < 0.01) were increased compared with values at pH 7.4. In contrast, pH 6.0 did not increase iron uptake from FeCl3. Lysine (100 mM) inhibited Tf-Fe uptake, decreased intracellular iron concentration, and attenuated Tf-Fe-induced cytotoxicity. The iron chelator des-ferrioxamine (200 microM) and hydroxyl radical scavenger dimethylpyrroline N-oxide (32 mM) abolished lactate dehydrogenase leakage induced by Tf-Fe at pH 6.0. Lipid peroxidation, as assessed by production of malondialdehyde, preceded lactate dehydrogenase leakage. In summary, holotransferrin, but not albumin, is toxic to rat proximal tubule cells, a pH-dependent effect involving its uptake into tubule cells, its iron moiety, and its lipid peroxidation.

scholarly journals Estrogen-induced disruption of intracellular iron metabolism leads to oxidative stress, membrane damage, and cell cycle arrest in MCF-7 cells

Tumor Biology ◽  
2017 ◽  
Vol 39 (10) ◽  
pp. 101042831772618 ◽  
Author(s):  
Khuloud Bajbouj ◽  
Jasmin Shafarin ◽  
Maher Y Abdalla ◽  
Iman M Ahmad ◽  
Mawieh Hamad
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Iron Metabolism ◽  
Membrane Damage ◽  
Intracellular Iron ◽  
Cycle Arrest ◽  
Mcf 7

scholarly journals Transcriptional regulation of Mycobacterium tuberculosis hupB gene expression

Microbiology ◽  
2014 ◽  
Vol 160 (8) ◽  
pp. 1637-1647 ◽  
Author(s):  
Satya Deo Pandey ◽  
Mitali Choudhury ◽  
Manjula Sritharan
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Iron Homeostasis ◽  
Iron Concentration ◽  
Dna Interaction ◽  
Intracellular Iron ◽  
Mobility Shift ◽  
Dna Footprinting ◽  
Sequence Of Events ◽  
Electrophoretic Mobility Shift Assays

The influence of iron levels on the transcription of the hupB gene in Mycobacterium tuberculosis is the focus of this study. Studies in our laboratory showed HupB to be co-expressed with the two siderophores in low-iron organisms. Mycobactin biosynthesis is repressed by the IdeR–Fe2+ complex that binds the IdeR box in the mbtB promoter. Recently, we demonstrated the positive regulatory effect of HupB on mycobactin biosynthesis by demonstrating its binding to a 10 bp HupB box in the mbtB promoter. Earlier, we observed that HupB, expressed maximally in low-iron media (0.02 µg Fe ml−1; 0.36 µM Fe) was still detectable at 8 µg Fe ml−1 (144 µM Fe) when the siderophores were absent and complete repression was seen only at 12 µg Fe ml−1 (216 µM Fe). In this study, we observed elevated levels of hupB transcripts in iron-limited organisms. IdeR, and not FurA, functioned as the iron regulator, by binding to two IdeR boxes in the hupB promoter. Interestingly, the 10 bp HupB box, first reported in the mbtB promoter, was identified in the hupB promoter. Using DNA footprinting and electrophoretic mobility shift assays, we demonstrated the functionality of the HupB box and the two IdeR boxes. The high hupB transcript levels expressed by the organism and the in vitro protein–DNA interaction studies led us to hypothesize the sequence of events occurring in response to changes in the intracellular iron concentration, emphasizing the roles played by IdeR and HupB in iron homeostasis.

Iron Chelation, Cell Cycle-Dependent Kinases and HIV-1 Transcription.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1550-1550
Author(s):  
Tatyana Ammosova ◽  
Zufan Debebe ◽  
Xiaomei Niu ◽  
Des R. Richardson ◽  
Marina Jerebtsova ◽  
...  
Keyword(s):  
Cell Cycle ◽  
T Cells ◽  
Rna Polymerase Ii ◽  
Iron Chelation ◽  
Iron Chelators ◽  
Intracellular Iron ◽  
Cyclin T1 ◽  
Protein Levels ◽  
Cycle Dependent ◽  
Hiv 1

Abstract Iron chelation leads to reduced cell cycle-dependent kinase 2 (CDK2) activity (reviewed in Biochim Biophys Acta2002;1603:31–46). Elongation of HIV-1 transcription is mediated by the interaction of HIV Tat with host cell cycle-dependent kinase 9 (CDK9)/cyclin T1, which phosphorylates the C-terminal domain of RNA polymerase II, and our recent studies indicate that CDK2 is also required for Tat-dependent transcription. We hypothesized that iron chelation may inhibit HIV transcription via reduced activity of cell cycle-dependent kinases. We utilized 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311; previously shown to inhibit CDK2 expression) and 4-[3,5-bis-(hydroxyphenyl) -1,2,4-triazol-1-yl]-benzoic acid (ICL670) to chelate intracellular iron. We analyzed the effect of these chelators on HIV-1 transcription using HeLa MAGI and CEM-GFP T-cells containing an integrated HIV-1 promoter and infected with adenovirus expressing HIV-1 Tat protein. Both chelators inhibited Tat-induced HIV-1 transcription, most profoundly in CEM-GFP T-cells. The chelators also inhibited one round of HIV-1 replication in CEM-T cells infected with pseudotyped HIV-1 virus. Treatment of HeLa MAGI and CEM-GFP T-cells with iron chelators decreased CDK9 protein levels and, to a lesser extent, CDK2 protein levels. Our findings provide evidence that iron chelators may inhibit HIV-1 transcription by altering expression of CDK9 and CDK2.

scholarly journals Iron metabolism in the Belgrade rat

Blood ◽  
1986 ◽  
Vol 67 (3) ◽  
pp. 623-628 ◽  
Author(s):  
J Edwards ◽  
H Huebers ◽  
C Kunzler ◽  
C Finch
Keyword(s):  
Iron Metabolism ◽  
Iron Uptake ◽  
Iron Concentration ◽  
Release Mechanism ◽  
Iron Release ◽  
Intracellular Iron ◽  
Plasma Iron ◽  
Body Tissues ◽  
Erythroid Hyperplasia ◽  
Iron Deficient

Iron metabolism in the Belgrade rat was examined in the intact animal and in the reticulocyte suspensions. The plasma iron turnover was increased. However, when allowance was made for the effect of the elevated plasma iron concentration, erythroid marrow capacity for iron uptake was at basal levels. Numbers of erythroid cells in marrow and spleen measured by the radioiron dilution technique were increased. Thus iron uptake was not proportionate to the erythroid hyperplasia in the b/b rat, despite a more than adequate plasma iron supply. This relative deficiency in iron uptake was reflected in a severe microcytosis and elevated red cell protoporphyrin. Reticulocyte incubation studies demonstrated an unimpaired uptake of the transferrin- iron-receptor complex but a marked reduction in iron accumulation. The diferric transferrin molecule, when it did give up iron within the cell, released both of its iron atoms so that only apotransferrin was returned to the media. In contrast to the nearly complete release of iron within the normal reticulocyte, the major portion of iron taken up by the Belgrade reticulocyte was returned to the plasma. The release mechanism that can be impaired in iron-deficient reticulocytes by EDTA or cadmium was shown to be affected by lower concentrations of these substances in the Belgrade reticulocyte. It is concluded that the Belgrade rat has an abnormality of iron release within the absorptive vacuole that is responsible for a state of intracellular iron deficiency, involving the erythron and other body tissues.

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