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)

We have used the monoclonal antibodies 2A4 (specific for the H subunit of human ferritin) and LO3 (specific for the L subunit) for immunocytochemical detection of ferritin in bone marrow and peripheral blood cells from normal subjects and patients with various haematological disorders. Formalin-fixed slides were stained by the immunoalkaline phosphatase procedure (APAAP). In normal subjects, ferritin could be found only in bone marrow smears and appeared to be largely confined to erythroid precursors and reticuloendothelial cells. The more immature erythroid precursors contained higher concentrations of cellular ferritin. Although evaluation could be only semiquantitative, erythroblast ferritin appeared to be more reactive with the monoclonal 2A4 (15 +/- 7% positive erythroblasts) than with the monoclonal LO3 (6 +/- 5% positive erythroblasts), indicating that H-type ferritin was predominant, particularly in proerythroblasts and basophilic erythroblasts. By contrast, the ferritin present in reticuloendothelial cells appeared to be predominantly of L-type. Patients with iron deficiency showed low levels of positive erythroblast, whereas the reverse was true in patients with transfusional iron overload. Intense positivity for reticuloendothelial cell ferritin was found in patients with anaemia of chronic disease. In myelodysplastic syndromes and acute myeloid leukaemia (AML), ferritin positivity was generally very strong at any stage of erythroblast development, particularly with the monoclonal antibody 2A4. Perls-positive perinuclear granules of ring sideroblasts were not stained, confirming that mitochondrial iron deposition is not in the form of ferritin. In AML and myelodysplastic syndromes with excess of blasts, ferritin could be detected also in immature myeloid cells. These data indicate that: (a) in normal conditions ferritin is mainly expressed in red cell precursors and reticuloendothelial cells, and this is in keeping with the peculiar role of these cells in iron metabolism; (b) abnormal cell ferritin contents can be observed in both iron overload and malignancy.
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PMID:Immunocytochemical detection of ferritin in human bone marrow and peripheral blood cells using monoclonal antibodies specific for the H and L subunit. 226 53

Using radioimmunoassay methods the authors assayed the concentration of biochemical neoplasm markers (BMN) in 106 patients with neurological diseases (M-56, F-50) in the serum, and in 20 cases in the cerebrospinal fluid. In certain cases these markers were present, and sometimes their concentration was raised: ferritin in multiple sclerosis from 200 to 1365 ng/ml, in ischaemic stroke up to 327.9 ng/ml, in Parkinson's disease up to 423 ng/ml in the serum. In some cases of other diseases the levels of carcinoembryonic antigen (CEA), acid prostatic phosphatase (PAP) and alpha-fetoprotein (AFP) were raised, similarly as that of human chorionic gonadotropin (HCG). Further studies are being conducted on BMN, including also other markers (CA 125, CA 199), with monoclonal antibodies, beta-endorphins and prostaglandins in neurological diseases, including multiple sclerosis. It is suggested (Nowak) that BMN may have an indirect role in the aetiology and pathogenesis of certain diseases of the nervous system and that they may have connections with prostaglandins.
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PMID:[Biochemical neoplasm markers in selected neurological diseases]. 243 40

Glycoproteins bearing a single N-acetylglucosamine (GlcNAc) residue attached by an O-glycosidic linkage to the polypeptide chain (Holt, G. D., and Hart, G. W. (1986) J. Biol. Chem. 261, 8049-8057) have been found to be enriched in the nuclear and soluble fractions of rat liver. Our goal was to determine the localization and membrane topography of proteins bearing O-linked GlcNAc using galactosyltransferase and wheat germ agglutinin (WGA) as membrane-impermeant probes. Latency of the enzyme mannose-6-phosphatase was used to quantitatively confirm the intactness of the nuclear envelope during incubations with galactosyltransferase or WGA. The O-linked GlcNAc residues of nuclei were fully accessible to modification by galactosyltransferase under conditions where the nuclear envelope mannose-6-phosphatase was 70% latent. Addition of detergent destroyed the permeability barrier but did not increase galactosylation of the O-linked GlcnAc. The major polypeptides bearing O-linked GlcNAc residues on nuclei were peripheral rather than integral membrane proteins with apparent molecular masses ranging from 210 to 54 kDa. The proteins were also detected on sealed nuclei using conjugates of WGA. WGA-rhodamine labeled intact nuclei when examined by immunofluorescence; WGA-peroxidase was used to identify the nuclear glycoproteins after transfer to nitrocellulose. WGA-ferritin selectively labels the cytoplasmic and nucleoplasmic faces of the nuclear pore complex when examined by electron microscopy. Taken together, these data strongly suggest that proteins bearing cytoplasmically oriented O-linked GlcNAc are components of the nuclear pore complex, thereby raising the possibility that cytoplasmic and nucleoplasmic glycoproteins are involved in the assembly or functioning of the nuclear pore.
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PMID:O-linked N-acetylglucosamine is attached to proteins of the nuclear pore. Evidence for cytoplasmic and nucleoplasmic glycoproteins. 311 Jan 63

In this paper the clinical usefulness of CEA and ferritin in the diagnosis of pancreatic cancer was pointed out. CEA was found to be increased in 51% of patients with pancreatic cancer; it was also abnormal in 22% of chronic pancreatitis and 31% of extra-pancreatic diseases. In patients with metastatic pancreatic cancer CEA was found to be more elevated than in those with localized tumor. CEA correlated with the age of the subjects in all material; in liver cirrhosis with IgG and in extra-pancreatic gastro-intestinal malignancies with alkaline-phosphatase. Ferritin was found to be increased in 73% of pancreatic cancer patients; it was also abnormal in 40% of chronic pancreatitis and in 38% of extra-pancreatic diseases. Patients with chronic pancreatitis studied during a relapsing phase all had elevated serum ferritin. We can conclude that neither CEA nor ferritin are useful indices of pancreatic malignancy, due to the lack of sensitivity or specificity. Both are influenced by several factors: CEA mainly by age and liver dysfunction, ferritin by the presence of an acute inflammation with cell necrosis.
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PMID:Limits of CEA and ferritin in the diagnosis of pancreatic cancer. 320 64

The localization of the purple tartrate-resistant, iron-containing acid phosphatase in the bovine spleen was studied by enzyme histochemistry at the light and electron microscopic levels as well as by immunohistochemistry. The purple phosphatase was localized only in lysosome-like-organelles of cells belonging to the reticulo-phagocytic system. The same cells were identified as containing large iron(III)-deposits as ferritin in homogeneously granular accumulations and freely in the cytoplasm, or as hemosiderin in siderosomes. The phagocytosing cells containing purple phosphatase and ferritin often had close contact with clusters of aged and deformed erythrocytes. A possible catabolic role of the purple enzyme as a phosphatase degrading phosphoproteins of the erythrocyte membrane and the cytoskeleton was assumed.
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PMID:Histochemical investigations on the localization of the purple acid phosphatase in the bovine spleen. 330 51

Plant lectin concanavalin A conjugated with ferritin (Con A-F) injected i.v. was used for the detection of the specific monosaccharide residues (alpha-D-mannosyl and alpha-D-glucosyl) on the luminal surface of endothelial cells (ECs) in brain micro-blood vessels (MBVs). Both normal mice and animals with mechanically damaged blood-brain barrier (BBB) were used in this study. In addition, the activity of 5'-nucleotidase (5'N), the putative receptor for Con A, was studied cytochemically. Various methodologic experiments indicated that the reaction product formed on the luminal plasmalemma of ECs after incubation of samples in the cytochemical medium for the detection of 5'N activity results from the action of unspecific phosphatase hydrolyzing both specific and nonspecific substrates. The abluminal side of the wall of MBVs seems to be a major location of 5'N activity. Thus, no correlation between cytochemically demonstrable 5'N activity and Con A receptor sites on the luminal surface of ECs was noted. After damage of the BBB, extensive internalization of the luminal plasmalemma forming the limiting membranes of pinocytotic vesicles, vacuoles, and endothelial channel-like structures was observed. This process was represented by a relatively rapid translocation of Con A receptors from luminal surface into the interior of the ECs and to the abluminal side of the vessel wall.
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PMID:Ultrastructural studies of concanavalin A receptors and 5'-nucleotidase localization in normal and injured mouse cerebral microvasculature. 608 99

During the last week of gestation of the fetal rat, the epithelium of the colon is rapidly remodeled. At 16 days a primitive stratified epithelium surrounds a small central lumen. Over the next 3 days, the main lumen extends narrow clefts down to the basal cell layer and small secondary lumina appear within the stratified epithelium between these clefts. At 19 and 20 days, secondary lumina enlarge but remain discrete; an infusion of cationic ferritin into the main lumen does not enter secondary lumina. During the 2 days prior to birth (21-22), the secondary lumina join the main lumen as superficial cells are sloughed, and the epithelium becomes simple columnar. Freeze-fracture replicas indicate that luminal and nonluminal membrane domains of epithelial cell plasma membranes are separated by continuous tight junctions throughout the conversion process. Cytochemical analysis of tissue slices from 16- to 22-day fetal colon demonstrated the appearance and segregation of two phosphatases on apical and basolateral membrane domains during epithelial conversion. Cysteine-sensitive pH 9.0 (alkaline) phosphatase activity was first detected along the luminal membranes of cells bordering both primary and secondary lumina at 18 days gestation and increased to a maximum at 20-21 days; weaker activity was present on basolateral membranes. Phosphatase activity at pH 8.0 also appeared at 18 days and increased thereafter, but was localized primarily on nonluminal membranes. At pH 8.0, reaction product appeared on both inner and outer sides of the membrane, and was only partially abolished by omission of K+ or addition of ouabain; thus the reaction may be only partially due to K+-dependent ATPase activity. Biochemical analysis of the cytochemical media confirmed the appearance of phosphatase activities at 18 days. Thus, plasma membrane phosphatase activities appear while the epithelium is still stratified, but are segregated to luminal and nonluminal membrane domains at the onset of activity. Segregation is maintained throughout the process of conversion of a simple columnar epithelium.
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PMID:Epithelial differentiation in the fetal rat colon. I. Plasma membrane phosphatase activities. 630 78

The endocytic-lysosomal system of proliferating and differentiated astrocytes in primary culture was investigated using a combination of cytochemical, immunocytochemical and biochemical procedures. These included impregnation with osmium tetroxide and potassium iodide, phosphotungstic acid staining, cytochemical demonstration of acid phosphatase and thiamine pyrophosphatase activities and incorporation of cationized ferritin. The acid phosphatase activity was also analyzed using biochemical techniques. Our results indicate that while all astrocytes in primary culture have a developed endocytic-lysosomal system, this system is different in proliferating cells from that in differentiated astrocytes. Whereas in proliferating astrocytes it appears to be composed mainly of a variety of vacuoles and vesicles displaying a heterogeneous osmium tetroxide staining pattern, differentiated cells are characterized by the presence of small size vesicles showing an intense reaction. Both types of astrocyte showed abundant lysosomes, including multivesicular bodies, which presented an intense phosphatase acid activity. Biochemical analyses demonstrated that this activity increase during the proliferation period, reaching a maximum at 15 days of culture. Incorporation of cationized ferritin revealed that lysosomes and endosomes constitute separate systems. Finally, we have also found that the activity of thiamine pyrophosphatase, a marker for the Golgi complex, increases throughout the culture period. These results indicate that astrocytes could play an important role in regulating the macromolecular composition of the extracellular space.
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PMID:Analysis of the endocytic-lysosomal system (vacuolar apparatus) in astrocytes during proliferation and differentiation in primary culture. 751 24

Reactive oxygen intermediates (ROIs), including superoxide anion (O2.-) and hydrogen peroxide (H2O2), are by-products of aerobic metabolism with potential toxicity towards cellular macromolecules, including lipids, proteins and DNA. Excess ROIs, a condition referred to as oxidative stress, is considered to be a major contributor to ageing, degenerative diseases and reperfusion injury. The reactivity of H2O2 with iron (Fenton reaction) intimately connects oxidative stress and cellular iron metabolism. We have found a novel oxidative stress response pathway in mammalian cells which links oxidative stress to the regulation of iron metabolism. Exposure of cells to H2O2 leads to reduced synthesis of the intracellular iron storage protein ferritin and stimulates transferrin receptor (TfR) mRNA expression. Both responses are post-transcriptional and result from induction of iron regulatory protein (IRP) binding to iron-responsive elements (IREs) in ferritin and TfR mRNAs. IRP induction by H2O2 appears to involve the disassembly of its cubane 4Fe-4S cluster and occurs even in the presence of the protein synthesis inhibitor cycloheximide. The induction kinetics by H2O2 far exceed those by iron starvation. The response requires cellular integrity and cannot be elicited in cell extracts. Whereas the activation of IRP by iron depletion is insensitive to okadaic acid, the rapid induction by H2O2 is blocked by this inhibitor of type I/IIa protein phosphatases. Thus okadaic acid separates the activation pathways by iron depletion and oxidative stress, suggesting the involvement of stress-induced kinase/phosphatase pathways in the latter.
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PMID:Rapid responses to oxidative stress mediated by iron regulatory protein. 779 17

Solar UVB (290-320 nm) and particularly UVA (320-380 nm) radiations have a capacity to generate reactive chemical species, including free radicals, in cells. These intermediates have been shown to be involved in various biological effects in cultured human skin cells (e.g. cell death) and skin (e.g. erythema). Endogenous glutathione is a critical molecule in protection against the cytotoxic effects of both wavelength ranges. Although there is evidence from cellular studies for the involvement of an oxidative component of UVC/UVB radiations in activation of several genes, the doses used are generally extremely cytotoxic and could cause aberrant signalling. Genes activated by sublethal doses of UVA radiations (e.g. haem oxygenase 1 and the CL100 phosphatase) are clearly redox regulated. The strong induction of haem oxygenase 1 in human fibroblasts has been implicated in an adaptive response to oxidative membrane damage that involves increased synthesis of the iron storage protein, ferritin.
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PMID:Ultraviolet radiation and free radical damage to skin. 866 Apr 2


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