Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Accumulation of radioactive iron (59Fe) into isolated fragments of rat small intestine in the presence of two hydroxypyrones, maltol and ethyl maltol, was compared with that in the presence of another chelator of iron(III), nitrilotriacetic acid (NTA). The characteristics of uptake were similar with all three ligands. Between 10(-6) and 10(-4) M, iron uptake showed saturable kinetics. The uptake was partially inhibited by metabolic inhibitors. Above 10(-4) M a non-saturable uptake, unaffected by metabolic inhibitors became evident in the presence of the pyrones. The distribution of 59Fe after uptake was determined by gel filtration. At low iron concentrations (10(-6) M), 35-40% of absorbed iron was associated with proteins of molecular weights similar to those of ferritin and transferrin. At high concentrations (10(-3) M), the majority of 59Fe was found in a low molecular weight fraction. At each concentration, a small amount of 59Fe was bound to a membrane fraction. 5% Polyethylene glycol, which reduces glycocalyx viscosity enhanced uptake at low iron concentrations (10(-6) M) but did not affect the non-saturable diffusion seen at higher concentrations (10(-3) M). The iron(II) chelator, bathophenanthroline sulphonate (10(-3) M), decreased uptake at low iron concentrations but did not affect the non-saturable uptake. It is suggested that conversion of iron(III) to iron(II) may take place at the mucosal cell surface before uptake via the saturable system. Apparent Km values for iron uptake via the saturable system were higher in the presence of maltol and ethyl maltol than in the presence of NTA, presumably since the iron binds more avidly to the hydroxypyrones and so is less readily donated. Excess ligand, either pyrone or NTA, reduced the rate at which 59Fe was donated to the uptake system. The Vmax value for uptake from the pyrones was greater than from NTA. It is concluded that maltol, ethyl maltol and NTA can hold iron(III) in solution and donate it to an endogenous uptake system. But, the hydroxypyrones may be more suitable ligands for the oral administration of iron since, when complexed with iron, they lack the toxic effects associated with iron(III)-NTA and with iron(II) preparations.
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PMID:Characteristics of iron(III) uptake by isolated fragments of rat small intestine in the presence of the hydroxypyrones, maltol and ethyl maltol. 337 10

The in vitro selfassembly of apoferritin after previous dissociation and unfolding in 7.2M guanidinium chloride, pH 3.5, yields up to 80% of a protein complex exhibiting the molecular mass of the native icositetramer of greater than or equal to 450 kDa. After removal of high molecular mass byproducts, the final reassembly product proves to be indistinguishable from native apoferritin with respect to its functional and conformational properties. These refer to the intrinsic fluorescence and to the far and near UV circular dichroism. The unfolding transitions of the native and reassembled protein in aqueous guanidinium chloride or at acid pH coincide within the range of error. The reassembled protein is also able to catalyze the oxidation of Fe(II). Higher polymers of the apoferritin complex represent most of the residual 20% of the reconstituted protein. They are stabilized by non-covalent (preferentially hydrophobic) interactions, and may be disassembled to the icositetramer by preferential solvation of the protein in the presence of less than or equal to 50% (v/v) ethylene glycol. The change in fluorescence emission accompanying polymerization reflects altered surface properties of the apoferritin subunits compatible with those reported for the ferritin----hemosiderin transition.
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PMID:Assembly of apoferritin from horse spleen: comparison of the protein in its native and reassembled state. 360 23

Various precipitating agents were examined in order to crystallize horse heart and spleen ferritins. Cadmium sulfate induced the crystallization of the spleen ferritin, while 2-methyl-2,4-pentanediol and poly(ethylene glycol) only induced that of the heart ferritin. Isoelectric focusing analysis showed that the crystals grown from cadmium sulfate contained only the more acidic isoferritins, and those grown from methyl pentanediol only the less acidic isoferritins. Heart ferritin crystallizes in a cubic space group, as previously reported for spleen ferritin crystals grown from cadmium sulfate.
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PMID:Selective crystallization of horse isoferritins. 683 99

Urinary recovery of intratracheally instilled polyethylene glycol polymers (PEG:s) in the molecular weight range 722-1294 Da (PEG 1000) was studied under normal conditions and during experimentally induced lung damage in rats. The urinary PEG recoveries were between 30-60% under normal conditions, with a selectivity for smaller PEG:s. No significant differences in the urinary PEG molecular weight profiles were found between 30 days old and adult rats; i.e. they had similar PEG 1162/810 (molecular weights) urinary recovery ratios (0.78 +/- 0.25 and 0.69 +/- 0.27, respectively, p > 0.05). In rats instilled with PEG 1000 and ferritin (5 mg.kg-1 body weight), the urinary recovery was increased for PEG:s with molecular weights greater than 1030 Da; i.e. a higher PEG 1162/810 recovery ratio (1.44 +/- 0.58, p < 0.01) was obtained. Rats instilled with PEG 1000 and crocidolite asbestos fibres (5 mg.kg-1 body weight) showed higher urinary recoveries for PEG:s greater than 854 Da, resulting in a higher PEG 1162/810 ratio (1.47 +/- 0.59, p < 0.01). By adding the iron-chelator, desferrioxamine, to the crocidolite-instillate, the urinary recoveries and the PEG 1162/810 ratio (0.97 +/- 0.47) were reduced, indicating a restored molecular weight selectivity of the lung. Thus, in rats, PEG 1000 passes via the respiratory tract in large amounts which is dependent on the molecular weight. This passage was increased after ferritin- or crocidolite instillation, indicating that the barrier function of the respiratory tract was impaired due to local tissue damage, and that iron may play an important role in this.
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PMID:Increased lung to blood passage of polyethylene glycols after intratracheal instillation of ferritin and asbestos fibres in the rat. 838 Oct 92

By observing increases in the transepithelial paracellular permeability of a range of radiolabeled solutes and electron dense dyes, changes in molecular sieving caused by the cytokine, TNF (tumor necrosis factor), and the phorbol ester, TPA (12-0-tetra-decanoylphorbol-13-acetate), were characterized. Using 14C-labeled mannitol (mw 182), raffinose (mw 504), PEG (polyethylene glycol; mw 4000), and dextran (mw 10,000, 70,000 and 2,000,000), the transepithelial flux rates of these compounds were determined at the peak of the transepithelial electrical resistance (TER) changes caused by these two agents. TNF treatment resulted in increased permeability across LLC-PK1 epithelial cell sheets only to relatively small solutes, with an upper limit of approximately 4,000 mw. The low molecular weight "ceiling" for the TNF-treated epithelium is further evidence against TNF increasing transepithelial permeability by means of inducing nonspecific, microscopic "holes" in the epithelium, for which a "ceiling" would not exist. TPA treatment increases transepithelial paracellular permeability to a much broader range of solutes, extending well beyond 2 million mw. Transmission electron micrographs provide evidence that even the electron-dense dye complex, ruthenium red, can cross tight junctions of TPA-treated cell sheets. However, cationic ferritin cannot cross tight junctions of TPA-treated cell sheets. This shows that there is an upper limit to solutes able to cross TPA-treated cell sheets, but that this upper limit will include most proteins, which would then be able to cross tumor promoter-exposed (protein kinase C-activated) epithelial layers at accelerated rates. The biomedical implications for a high molecular weight cutoff in tumor promoter action in epithelial carcinogenesis, and for a low molecular weight cutoff in cytokine-induced epithelial apoptosis in inflammation, are discussed.
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PMID:Different size limitations for increased transepithelial paracellular solute flux across phorbol ester and tumor necrosis factor-treated epithelial cell sheets. 913 Apr 71

Single crystals of ferritin extracted from Listeria innocua have been obtained by the vapour-diffusion method using PEG 1000 as precipitant. The crystals are orthorhombic, space group P212121, with unit-cell dimensions a = 87.7, b = 137.5, c = 173.1 A. The crystals diffract to 2.9 A resolution on a rotating-anode X-ray source and to 2.35 A resolution on a synchrotron X-ray source. The asymmetric unit contains one molecule formed by 12 subunits, corresponding to a packing density of 2.41 A3 Da-1
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PMID:Crystallization and preliminary X-ray crystallographic analysis of the unusual ferritin from Listeria innocua. 1008 76

The aim of this study was to produce monoclonal and polyclonal antibodies against a nonspecific tumor marker, human ferritin. Hyperimmune ICR mice produced polyclonal antibodies after injection with 0.5 mL pristane, and were injected with NS-1 myeloma cells 2 weeks later. Hyperimmune Balb/c mice were used for the production of monoclonal antibodies (MAbs). Mice were immunized four times, given a final boost, and their spleen cells were collected and fused with NS-1 myeloma cells under the presence of PEG 1500. The fused cells were then selected in the HAT-RPMIX medium. Anti-ferritin antibody-secreting hybridoma cell lines with high titer were cloned by enzyme-linked immunoadsorbent assay (ELISA) and then subcloned by limiting dilution in 15% fetal bovine serum (FBS) HT-RPMIX medium. Five murine hybridoma-producing antiferritin MAbs were obtained and designated 1AD11F9, 1AD11E11, 2AD11D2, 2AD11A5, and 3AD11G8. Isotypes of these MAbs were identified as IgM heavy chain and kappa light chain. Hitrap Protein A and Hitrap IgM purification column were used for the purification of polyclonal and monoclonal antibodies, respectively.
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PMID:Monoclonal and polyclonal antibodies against human ferritin, a nonspecific tumor marker. 1128 29

Disease progression in multiple sclerosis occurs within the interface of glial activation and gliosis. This study aimed to investigate the relationship between biomarkers of different glial cell responses: (i) to disease dynamics and the clinical subtypes of multiple sclerosis; (ii) to disability; and (iii) to cross-validate these findings in a post-mortem study. To address the first goal, 51 patients with multiple sclerosis [20 relapsing remitting (RR), 21 secondary progressive (SP) and 10 primary progressive (PP)] and 51 neurological control patients were included. Disability was assessed using the ambulation index (AI), the Expanded Disability Status Scale score (EDSS) and the 9-hole PEG test (9HPT). Patients underwent lumbar puncture within 7 days of clinical assessment. Post-mortem brain tissue (12 multiple sclerosis and eight control patients) was classified histologically and adjacent sites were homogenized for protein analysis. S100B, ferritin and glial-fibrillary acidic protein (GFAP) were quantified in CSF and brain-tissue homogenate by ELISA (enzyme-linked immunosorbent assay) techniques developed in-house. There was a significant trend for increasing S100B levels from PP to SP to RR multiple sclerosis (P < 0.05). S100B was significantly higher in RR multiple sclerosis than in control patients (P < 0.01), whilst ferritin levels were significantly higher in SP multiple sclerosis than in control patients (P < 0.01). The S100B : ferritin ratio discriminated patients with RR multiple sclerosis from SP, PP or control patients (P < 0.05, P < 0.01 and P < 0.01, respectively). Multiple sclerosis patients with poor ambulation (AI > or =7) or severe disability (EDSS >6.5) had significantly higher CSF GFAP levels than less disabled multiple sclerosis or control patients (P < 0.01 and P < 0.001, respectively). There was a correlation between GFAP levels and ambulation in SP multiple sclerosis (r = 0.57, P < 0.01), and between S100B level and the 9HPT in PP multiple sclerosis patients (r = -0.85, P < 0.01). The post-mortem study showed significantly higher S100B levels in the acute than in the subacute plaques (P < 0.01), whilst ferritin levels were elevated in all multiple sclerosis lesion stages. Both GFAP and S100B levels were significantly higher in the cortex of multiple sclerosis than in control brain homogenate (P < 0.001 and P < 0.05, respectively). We found that S100B is a good marker for the relapsing phase of the disease (confirmed by post-mortem observation) as opposed to ferritin, which is elevated throughout the entire course. GFAP correlated with disability scales and may therefore be a marker for irreversible damage. The results of this study have broad implications for finding new and sensitive outcome measures for treatment trials that aim to delay the development of disability. They may also be considered in future classifications of multiple sclerosis patients.
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PMID:Markers for different glial cell responses in multiple sclerosis: clinical and pathological correlations. 1207 97

Chlorhexidine (CHX) is a bis-bis-guanide with anphipatic and antiseptic properties and is largely used in dentistry, mainly for management of periodontal problems and in oral pre-operatory procedures. The present study concerns the effect of CHX on lipid peroxidation, mitochondrial permeability transition (MPT), and the interaction of CHX with ferritin (HoSF). CHX (100 microM) increased iron release from HoSF by approximately 13-fold when compared to control values. CHX also increased iron-dependent lipid peroxidation. MPT induced by CHX was protected by ethylene glycol-bis(beta-aminoethyl-ether)-N,N,N',N'-tetraacetic acid (EGTA), dithiothreitol (DTT), and cyclosporin A (CsA), showing a Ca2+-dependent effect, in which oxidation of thiol groups is involved, as well as the involvement of the transmembrane proteinaceous pore. BHT, catalase or o-phenanthroline did not protect MPT induced by CHX. This suggests that a ROS-independent mechanism is involved in the induction of MPT.
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PMID:New data on biological effects of chlorhexidine: Fe2+ induced lipid peroxidation and mitochondrial permeability transition. 1526 85

The combination of PEG-interferon and ribavirin is currently recommended for the treatment of chronic hepatitis C, which is a common cause of morbidity and mortality worldwide. Hair disorders have often been described during interferon therapy, which include reversible hair discoloration, hypertricosis and alopecia. Ribavirin is reported to cause photoallergic reactions. We report two cases of alopecia universalis, with complete hair loss extended to the whole body, secondary to PEG-interferon and ribavirin combination therapy for chronic hepatitis C virus infection. Both female patients were infected by genotype 1 and presented alopecia during the second half of a 48-week therapy, concurrently with low levels of ferritin and thyroid dysfunction (patient 1) or depression (patient 2). Patient 1 withdrew from the therapy on week 26 and, due to the occurrence of maculo-erythematous cutaneous eczema, underwent corticosteroid therapy with complete hair regrowth. Patient 2 completed the scheduled therapy and showed a spontaneous complete hair regrowth. It should be noted that in spite of an early (within 4 weeks of therapy) virological response, patient 1 had a disease relapse after therapy withdrawal and corticosteroid therapy, while patient 2 maintained a sustained virological response. In conclusion, interferon therapy may trigger reversible alopecia universalis in susceptible patients. However, given the benign and reversible nature of this side effect, patients who achieve a virological response should be strongly advised to complete the treatment in order to prevent disease relapse.
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PMID:Reversible alopecia universalis during treatment with PEG-interferon and ribavirin for chronic hepatitis C. 1592 Sep 8


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