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)

The articular surface of adult BALB/c mouse femoral heads is covered by a fine granular electron dense material containing negative charges that bind electrostatically cationized ferritin. The material is of proteidic nature being digested by trypsin and chymopapain and resistant to testicular and microbial hyaluronidase, keratanase, chondroitinase ABC and AC. Mammalian collagenase disrupted the surface without digesting the material and allowed the penetration of cationized ferritin in the subsurface layers, where the label was bound on residual fibers. Sequential digestion with collagenase and chondroitinase ABC showed that the charges associated with the subsurface fibers are proteoglycans.
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PMID:Effects of enzymatic digestions on the negative charge of articular cartilage surfaces. 408 65

Seventeen patients with early rheumatoid synovitis underwent synovial biopsy to assess the interrelationship between both ferritin (the intracellular iron storage protein) and Perls' positive iron (ferric iron in loose combination with protein), on the activity and course of rheumatoid disease. The amount of ferritin was associated to a significant degree with the activity of the disease at the time of biopsy, but showed no relation to the way the disease progressed over the following year. In contrast, the amount of Perls' iron bore no relation to the activity of the disease at biopsy, but its presence was associated with persistent disease. It is argued that this association is direct, that ferritin production may fail in a population of synovial macrophages, and that Perls' ferric iron may either be reduced to the ferrous form and promote the formation of toxic free radical species, or stimulate collagenase and prostaglandin release from synovial macrophages.
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PMID:The effect of synovial iron on the progression of rheumatoid disease. A histologic assessment of patients with early rheumatoid synovitis. 620 3

Recently, several authors have emphasized the role of negative sites located in th laminae rarae of the glomerular basement membrane (GBM), in restricting glomerular permeability to anionic macromolecules. In this work, we point out that ultrafiltration properties involve integrity of the GBM. Indeed after intravenous perfusion of bacterian collagenase, anionic ferritin permeates the GBM though negative site distribution (as shown by fixation of colloidal iron) is unaffected.
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PMID:[Effect of collagenase on the permeability of the glomerular basement membrane in the rat kidney]. 626 16

The labeling of the articular surface with cationized ferritin (CF), an electron-dense marker, visualizes the anionic sites and may disclose abnormal penetration of the large CF molecule into the subsurface layers. Various areas of cartilage selected by unaided eye examination were taken from femoral heads excised in three cases of osteoarthritis and two cases of hip fracture. The fragments were examined by optical microscopy and by electron microscopy after labeling with CF. The labeling with and the penetration of CF were correlated with the morphological features of the surface. The surfaces belonging to the erosion border were disrupted and the CF penetrated approximately 2 microns into the matrix along the collagen fibers and in areas containing a patchy dense material. Prefixation with Karnovsky's fixative prevents CF penetration. The fragments taken at a distance from the erosion border showed at electron microscopical examination either an intact appearance of the surface that was labeled without penetration or a disrupted surface with penetration of the label. The osteophytes and the regeneration buds surface were labeled showing little or no penetration. The fragments from cartilage of hip fractures had either an intact surface regularly labeled or a slightly or moderately disrupted surface with moderate penetration of CF. The penetration of large molecules of CF in damaged cartilage demonstrates important permeability changes that may be significant for the pathogenetic mechanism of osteoarthritis. Similar permeability changes were previously shown in mice femoral heads treated in vitro with collagenase or trypsin and labeled with CF.
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PMID:Labeling of articular cartilage surface with cationized ferritin: aged human normal and osteoarthritic cartilage. 649 9

Glomus cells were dissociated from the carotid bodies of adult rats by enzymatic digestion with collagenase. The cells were then incubated at 37 degrees C for 30 minutes to 3 hours in the continuous presence of cationized ferritin (CF) as a membrane marker and extracellular tracer to study the intracellular route of endocytosis in this cell type. After 30 minutes of incubation with CF, occasional solitary CF-containing vesicles were observed at the cell periphery and also in the Golgi region. After 2-3 hours of incubation with CF, cell viability was still preserved and CF-labeled vesicles were abundant in the Golgi region. CF particles were also seen in some vesicles having a dense core. The core of these labeled vesicles appeared to be less electron-dense than that of typical secretory granules. It is suggested that the Golgi apparatus is involved in membrane recycling in glomus cells and that the membrane is then possibly further transported to an immature type of storage vesicle for reusage.
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PMID:Endocytosis of cationized ferritin to vesicles in the Golgi region of the glomus cells dissociated from the adult rat carotid body. 665 Aug 69

Liposomes encapsulating uranyl acetate or ferritin were injected intravenously into mice. At periods of 20 min, 1 h and 4 h post-injection, animals were killed, and livers were excised. Transmission electron micrographs of liver tissue showed association of oligolamellar liposomes with mitochondria for each time period. At 1 h post-injection, an average of one out of ten mitochondria was associated with liposomes. In most cases, the liposomes were clearly enclosed in a cytoplasmic vacuole. Phagocytosis by Kupffer cells as well as fusion with primary lysosomes and inclusion in secondary lysosomes was observed. No difference in intracellular fate was observed when lactosylceramide was incorporated in the liposome bilayers, suggesting that the differences observed in biochemical studies are at the level of liposome-plasma membrane interaction. When liposomes containing uranyl acetate were intravenously injected and hepatocytes were isolated by collagenase perfusion one hour later, transmission EM revealed the presence of liposomes in these cells, in cytoplasmic vacuoles in the cytoplasm and in association with mitochondria. A freeze-fracture-etching analysis of liver tissue excised 20 min after injection of liposomes encapsulating ferritin, further supported the observation that liposomes associate with mitochondria in the liver.
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PMID:Liposomes injected intravenously into mice associate with liver mitochondria. 674 53

Glomus cells from carotid bodies of adult rats dissociated by means of collagenase or collagenase + trypsin were used to study by electron microscopy the endocytotic uptake of cationized ferritin (CF) tracer into subcellular compartments. The glomus cells were incubated with the tracer (1) in a basic salt medium (BM), or (2) in the BM into which calcium ionophore A23187 had been added, or (3) in a potassium-rich medium. Incubation of the cells in BM containing CF for 30 min resulted in attachment of the tracer to the cell membrane and uptake of a few solitary tracer particles into small vesicles and multivesicular bodies. No uptake into the cisternae of the Golgi apparatus was observed. Further incubation in BM containing CF for another 30 min resulted in increased uptake of the tracer into small vesicles and multivesicular bodies. A similar pattern of uptake was observed when the dissociated glomus cells were first preincubated in BM with CF for 30 min and then incubated for 1 min or 30 min in the BM solution containing both the ionophore and CF. Upon such incubation, CF particles were seen to penetrate into coated pits and sites of exocytosis at the cell surface. When the 30-min preincubation in BM was followed by incubation in a CF-containing potassium-rich medium for 15-30 min, uptake into vesicles, small lysosomes and occasionally also into profiles of the smooth endoplasmic reticulum was seen. Endocytotic mechanisms of the glomus cells are outlined.
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PMID:Endocytotic uptake of cationized ferritin tracer into glomus cells dissociated from the adult rat carotid body. 681 57

Cationized ferritin (CF) was injected interstitially to study the distribution of anionic sites on the basement membrane and abluminal aspect of the endothelium in the fenestrated capillaries of the mouse pancreas and intestinal mucosa. Extensive, but uneven removal of the basement membrane was obtained by collagenase perfusion of the vasculature before CF labeling. In the absence of collagenase treatment, CF label was essentially restricted to the lamina rara externa of the basement membrane and occurred in clusters distributed in a relatively ordered planar lattice. After collagenase digestion, labeling of the lamina rara interna and of the abluminal aspect of the endothelium became possible. In the lamina rara interna, the CF label occurred in clusters with a distribution comparable to that found in the lamina rara externa. On the abluminal aspect of the endothelium, the plasmalemma proper was extensively, though variably, labeled. Coated pits were heavily labeled, whereas the membranes and stomatal diaphragms of plasmalemmal vesicles and transendothelial channels remained free of CF decoration. In contradistinction with the heavy labeling of their luminal aspects, the abluminal surface of the fenestral diaphragms were free of any CF decoration. Pronase treatment removed all anionic sites detectable by CF binding. The findings establish the existence of differentiated microdomains on the abluminal aspect of the endothelial plasmalemma and suggest that the capillary wall selects permeant macromolecules according to charge, in addition to size.
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PMID:Preferential distribution of anionic sites on the basement membrane and the abluminal aspect of the endothelium in fenestrated capillaries. 681 7

Alcohol abuse is known to cause disturbances to iron homeostasis in man and is associated with elevated serum ferritin levels. We have previously shown that ethanol metabolism in the rat hepatocyte is associated with an immediate reduction in ferritin uptake by this cell. In this study we have examined the effect of pair-feeding the Lieber-DeCarli liquid alcohol diet on ferritin uptake by rat hepatocytes. Rat liver ferritin was radiolabeled with 59Fe in vivo and isolated by conventional techniques. Rats were pair-fed the Lieber-DeCarli liquid alcoholic diet for 4-6 weeks. Hepatocytes, isolated from their livers by collagenase perfusion, were incubated with [59Fe]ferritin in L-15 medium at 37 degrees C and 4 degrees to measure ferritin uptake and binding. The in vitro effect of ethanol on these hepatocytes was also studied. Ferritin and iron parameters were measured in the sera and hepatocytes of these animals and a comparable group of normal chow-fed rats. The rate of ferritin uptake by hepatocytes from alcohol-fed rats was significantly faster than that of their pair-fed controls (0.743 +/- 0.061 vs. 0.540 +/- 0.042 ng/min/10(6) cells, p < 0.05). However, the rats on Lieber-DeCarli control diet exhibited a lower hepatocyte ferritin uptake rate than chow-fed animals (79.3 +/- 8.1% of the control values, p < 0.01). In vitro incubation of cells in 100 mM ethanol resulted in less inhibition of ferritin uptake by hepatocytes from alcoholic rats than from their pair-fed controls (11 +/- 7.1% inhibition vs. 43.6 +/- 10.7% for controls, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of chronic alcohol feeding on hepatic iron status and ferritin uptake by rat hepatocytes. 848 84

Regulation of the excurrent ducts of the testis is not well understood, particularly in avian species. To investigate the role of steroid hormones in the male reproductive tract, we developed a primary cell culture of epithelia isolated from rooster ductuli efferentes (efferent ductules). Efferent ductules of the avian testis comprise 77% of the epididymal region and form a mass of tubules containing a heavily folded epithelium enmeshed in connective tissue. The epididymal region was separated by microdissection and small epithelial plaques isolated by serial digestion with collagenase, elastase and repeated pipetting. Isolated cell plaques were cultured in a bicameral chamber on Millicell-CM inserts coated with two layers of basement membrane matrix, consisting primarily of laminin and Types I and IV collagen. Active ciliary beat was observed before plating and this activity was maintained for 14 days in culture. Cell plaques attached within 24 h and outgrowths formed a confluent monolayer by 5-6 days. The epithelial nature of cultured cells was demonstrated by immunocytochemical staining for cytokeratin. Light and electron microscopy confirmed that morphology and polarity of the original epithelial cells were maintained in culture. Cultured efferent ductal epithelium was cuboidal in shape and maintained many of the cytoplasmic organelles typical of these cells in vivo. The uptake of cationic ferritin indicated the endocytotic activity of these cultured cells was maintained. Estrogen receptor mRNA expression was maintained in cultured cells. These data demonstrate avian efferent ductal epithelium can be isolated and grown in defined culture medium for the purpose of determining the role of hormones and other factors in regulating the function of the epididymal region in the bird.
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PMID:Morphology and function of rooster efferent ductule epithelial cells in culture. 983 79


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