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)

Chondroitin sulfate is known to be present in normal and leukemic myeloid cells; however, its definitive subcellular location and association with other glycosaminoglycans (GAGs) has not been demonstrated. We have studied the type and distribution of GAGs in neutrophil granule subpopulations of normal and leukemic myeloid cells using ultrastructural, cytochemical, immunologic, and biochemical methods. At the ultrastructural level, high-iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP) stained sulfated glycoconjugates selectively in immature primary granules of normal promyelocytes and Auer rods and immature granules of leukemic myeloblasts. Staining was weak or absent in mature primary granules, whereas tertiary granules stained moderately. Primary granule staining with HID-TCH-SP was greatly diminished by prior treatment of the specimens with chondroitinase ABC and/or nitrous acid, indicating the presence of chondroitin sulfate and N-sulfated glycosaminoglycan. Immunostaining of myeloid cells with a rabbit antichondroitin 4-sulfate and ferritin-conjugated goat anti-rabbit IgG sequence resulted in staining of most primary granules. Biochemical analysis of GAGs from leukemic myeloblasts containing primary granules and Auer rods, but lacking secondary and tertiary granules, revealed 8 x 10(-17) mole of uronic acid/cell and electrophoretic and sulfaminohexose analysis showed 60%-70% chondroitin sulfate AC of heterogeneous molecular weight, 20%-30% of a GAG that most closely resembled heparan sulfate, and 10% dermatan sulfate. The lack of significant HID-TCH-SP staining of sulfate iin sites other than Auer rods and primary granules in leukemic myeloblasts indicates that these granules contain the chondroitin, dermatan, and heparan sulfate isolated from the same specimen. Similar GAGs are present in primary granules of normal cells as evidenced by their cytochemical and immunostaining properties. Thus, these studies demonstrate a heterogeneous population of GAGs not previously identified and localize these substances to the primary granule of leukemic and normal cells.
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PMID:Glycosaminoglycans in human neutrophils and leukemic myeloblasts: ultrastructural, cytochemical, immunologic, and biochemical characterization. 640 32

The surface of rat arterial smooth muscle cells was characterized with respect to some of its chemical and functional properties. The effects of selective enzymic degradations (hyaluronidase, chondroitinases, heparitinase or neuraminidase) on [35S]sulphate-prelabelled cells and on binding sites for cationized ferritin (CF) were examined to assess the presence and relative importance of individual species of macromolecules on the cell surface. The results indicate that about half of the strongly anionic sites on the cell surface (binding CF at pH 2.0) could be ascribed to sulphate groups of glycosaminoglycans and about half to carboxyl groups of sialic acid residues in glycoproteins and/or glycolipids. Weaker anionic sites (binding CF at pH 7.0) largely originated from carboxyl groups of glycosaminoglycans. Chondroitin sulphate and heparan sulphate were the main glycosaminoglycans. The surface of cells from young animals showed a higher glycosaminoglycan and a lower sialic acid content than that of cells from adult animals. Continuous treatment of the cultures with neuraminidase stimulated serum-induced initiation of DNA synthesis, while treatment with hyaluronidase or heparitinase inhibited it. Addition of hyaluronic acid, heparin or heparan sulphate to the culture medium inhibited initiation of DNA synthesis as well as cell proliferation. The effect was more marked in cultures of cells from young animals than from adults, although the latter cells were found to grow at a higher rate and to higher densities. These results suggest a role for cell-surface and pericellular glycoconjugates in growth regulation. A possible mechanism of action is that these molecules, due to their anionic charge or by steric exclusion, interfere with the binding of platelet-derived growth factor, a highly cationic polypeptide, to its cell-surface receptor.
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PMID:Cell surface components and growth regulation in cultivated arterial smooth muscle cells. 642 Apr 21