Disease relevance of citric acid

• Two mechanisms of iron uptake from transferrin by melanoma cells. The effect of desferrioxamine and ferric ammonium citrate [1].
• Iron accumulation, iron-mediated toxicity and altered levels of ferritin and transferrin receptor in cultured astrocytes during incubation with ferric ammonium citrate [2].
• Two sources of exogenous iron (hemin and ferric ammonium citrate) were able to stimulate ferritin synthesis in both oligodendrocytes and HOG in the absence of hypoxia [3].
• Mycobacteria with a growth requirement for ferric ammonium citrate, identified as Mycobacterium haemophilum [4].
• To investigate storage of ferritin and its transition to hemosiderin under conditions of iron overload, rats were either given multiple injections of iron dextran over 4 to 5 weeks or fed a diet containing 1.3% Fe as ferric ammonium citrate for 60 days [5].

High impact information on citric acid

• Growth factor stimulation of DNA synthesis and electron transport are restored by addition of di- or trivalent iron to the cells in the form of ferric ammonium citrate, ferrous ammonium sulfate, or diferric transferrin [6].
• After adding iron as ferric ammonium citrate to the medium, latent ferritin H- and L-mRNAs were extensively transferred to polyribosomes, accompanied by increased uptake of [35S]methionine into ferritin protein [7].
• Furthermore, cytoplasmic or mitochondrial Fe loading of induced Friend cells with ferric ammonium citrate, or the heme synthesis inhibitor, succinylacetone, respectively, also had no effect on frataxin expression [8].
• Similarly, treatment with soluble iron as ferric ammonium citrate did not increase steady state levels of PKC-beta mRNA, despite producing a marked increase in cellular ferritin content [9].
• The levels of receptor were reduced by at least 50 and 35% of that of the control in cells treated with diferric Tf and ferric ammonium citrate, respectively [10].

Chemical compound and disease context of citric acid

• Sinefungin, an antifungal and antiparasitic antibiotic, is produced efficiently from ammonium citrate by prototrophic strains of Streptomyces incarnatus [11].
• The cell death observed was prevented by the iron chelators deferoxamine, 1,10-phenathroline, or 2,2'-dipyridyl, whereas preincubation with ferric ammonium citrate increased the toxicity of peroxide treatments [12].
• Ex novo enzymic synthesis of the two 4Fe-4S clusters of Clostridium pasteurianum ferredoxin has been achieved by incubation of the apoprotein with catalytic amounts of the sulfurtransferase rhodanese in the presence of thiosulfate, DL-dihydrolipoate and ferric ammonium citrate [13].
• Using this qualitative assay we have shown that all species of Listeria are able to reduce ferric iron when presented as ferric ammonium citrate whereas most other species of Gram-positive and Gram-negative bacteria are not [14].

Biological context of citric acid

• The regulation of ferritin synthesis by iron was examined in the reticulocytes of bullfrog tadpoles where the induction was 40- to 50-fold, increasing from 0.17 +/- 0.05% of total protein synthesis ([3H]leucine incorporation in cell suspension) to 7.4 +/- 1.6% following intraperitoneal injection of ferric ammonium citrate [15].
• Intraperitoneal LD50 of the luxSVv mutant increased by 10- and 750-fold in ferric ammonium citrate-non-overloaded and ferric ammonium citrate-overloaded mice respectively [16].
• Competition studies with unlabelled ligand or impermeable ferric ammonium citrate gave an IC50 of 1-15 micrograms Fe3+/ml for this process [17].
• Effect of hemoglobin and of ferric ammonium citrate on the virulence of periodontopathic bacteria [18].
• The effect of iron loading on membrane potential and cellular contractility was examined in cultured heart cells obtained from newborn rat ventricles exposed to ferric ammonium citrate at iron concentrations of 20, 40, and 80 micrograms/ml for 24 hours [19].

Anatomical context of citric acid

• In the present report we demonstrate that treatment of cultured human skin fibroblasts with low concentration of iron 2-20 microm (ferric ammonium citrate) induced a significant increase in the synthesis of tropoelastin and deposition of insoluble elastin [20].
• Addition of iron salts (ferric ammonium citrate) in activated T-lymphocyte cultures causes a marked enhancement of both [3H]uridine and [3H]thymidine incorporation [21].
• When HeLa cells were grown in the presence of hemin, transferrin receptor number decreased to a greater degree than when cells were grown in equivalent amounts of iron supplied as ferric ammonium citrate [22].
• Isolated rat hepatocytes increased their non-haem iron content from 70 to 470 p.p. b. following incubation with ferric ammonium citrate (<=100 microgram/ml) [23].
• Abeta and 1.0 mM iron (as ferric ammonium citrate) were coinjected into rat cerebral cortex, and the neuronal loss was compared with that produced by pure Abeta or pure iron [24].

Associations of citric acid with other chemical compounds

• In vitro translations of polyadenylated mRNA isolated from cells incubated with desferrioxamine showed a 2.5-fold increase in translatable mRNA for the receptor, whereas treatment of cells with ferric ammonium citrate and diferric Tf resulted in a 25 and 50% reduction, respectively, in translatable mRNA for this receptor [10].
• Exogenous iron (ferric ammonium citrate or ferricyanide) and forskolin increased the level of HO-1, which was inhibited by PKA inhibitor N-[2-(4-bromocinnamylamino)ethyl]-5-isoquinoline (H89) [25].
• We describe a method for improving the homogeneity of MALDI samples prepared for analysis of small, single-stranded oligonucleotides using the widely used DNA matrix system, 3-hydroxypicolinic acid/picolinic acid/ ammonium citrate [26].
• Under optimized separation conditions (0.2 mM cetyltrimethylammonium bromide (CTAB), 1 mM ammonium citrate, pH 3.5), gentamicin was separated into three major peaks (C1, C1a, and C2+C2a) within 15 min [27].
• Intake of Na3 citrate/citric acid solution or K3 citrate solution, but not ammonium citrate/citric acid solution, prevented a decline in GFR in three-month-old rats with PKD [28].

Gene context of citric acid

• These data conclusively demonstrate that two entirely different mechanisms of iron uptake from Tf exist in melanoma cells and that ferric ammonium citrate may be a useful experimental tool to further characterize the specific and nonspecific mechanisms of Fe uptake from Tf [1].
• Significantly, the effect of chelation on reducing nuclear p21(CIP1/WAF1) was reversed by the Fe donor ferric ammonium citrate, indicating that p21(CIP1/WAF1) translation was dependent on intracellular Fe levels [29].
• In contrast, these tonB mutants were able to utilize an iron chelate (ferric ammonium citrate) for growth [30].
• The growth of pathogenic and non-pathogenic strains of V. parahaemolyticus on iron-limited agar plates was stimulated by ferritin, lactoferrin and transferrin at 30 microM, and also by hemin, hemoglobin and ferric ammonium citrate at 100 microM [31].
• Treatment of murine J774 macrophages with increasing concentrations of ferric ammonium citrate significantly enhanced the amount of MMP-9 secreted [32].

Analytical, diagnostic and therapeutic context of citric acid

• These results suggest that ammonium sulphate and ammonium citrate might be very suitable precipitants for crystallization studies of the ternary complex [33].
• By addition of Fe3+ (50 microM ferric ammonium citrate) to an acidified aqueous mobile phase, we have successfully separated a series of hydroxypyridones-including CP20-and the related pyrones maltol and ethylmaltol by HPLC on microBondapak C18 [34].
• M0s in culture were exposed to iron as either ferric ammonium citrate or iron dextran, and ferritin synthesis was determined by measurement of 3H-leucine incorporation after isolation of ferritin by a quantitative immunoadsorbent technique [35].

References