Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nine cases of Spitz's nevi, compound type, that had large homogeneous eosinophilic globules at the dermo-epidermal junction were stained with anti-fibronectin antibodies by the biotin-avidin indirect immunofluorescence technique. Fibronectin was demonstrated in all nine cases. This study demonstrates that fibronectin, which is present in the extracellular matrix material, is also localized in a homogeneous pattern in the eosinophilic globules of the Spitz's nevi.
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PMID:Fibronectin in eosinophilic globules of Spitz's nevi. 608 58

Alpha-2-macroglobulin (alpha 2M) is a major mammalian plasma proteinase inhibitor and a well-established suppressor of T cell blastogenesis. Its role in modulating T cell-mediated lymphokine production is less well documented. We have isolated and characterized guinea-pig plasma alpha 2M in order to study its role in regulating the elicitation of macrophage agglutination factor (MAggF), a T cell-dependent inflammatory lymphokine closely related to fibronectin. Alpha-2-macroglobulin was purified by a combination of gel chromatography and immunoadsorption to remove contaminating IgM. Purified alpha 2M showed a double band on polyacrylamide gel electrophoresis. It had a molecular weight of 714,000 which fell to 190,000 on reduction, a pI of 4.8 and bound up to 1.3 moles of trypsin or elastase per mole. The elicitiation of MAggF from 25 X 10(6) purified protein derivative (PPD)-stimulated guinea-pig lymph node cells was inhibited 99% by 2-3 micrograms of biologically active alpha 2M only if the proteinase inhibitor was added to the lymph node cells at the same time as antigen. No inhibition of MAggF production was observed when active alpha 2M was added at the end of culture or when biologically inactive alpha 2M was added to the cultures at any time. MAggF was not elicited from normal cells by PPD, nor did alpha 2M have any effect on these cultures. Purified alpha 2M had no direct effect on MAggF activity in culture supernatants. We suggest that alpha 2M may be involved in modulating antigen-elicited lymphokine production in vivo.
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PMID:Regulation of macrophage agglutination factor production by alpha 2-macroglobulin. 619 93

In recent years the interaction between tumour cells and the surrounding extracellular matrix in the process of tumour development, invasion and metastasis has been a focus of interest. We studied frozen sections of nine naevocellular naevi (junctional, compound and intradermal), 40 dysplastic naevi, six pagetoid in situ melanomas and 12 superficial spreading melanomas in order to determine the expression of: the basement membrane proteins collagen type IV and laminin, the interstitial collagen types I, III and VI, and fibronectin and tenascin. An indirect immunoperoxidase technique was used. In the various stages of melanocytic tumour progression we observed: 1 loss of type IV collagen and laminin within dermal melanocytic cell nests; 2 de novo expression of basement membrane type IV collagen and increased expression of the interstitial collagen types I, III and VI, as well as tenascin and fibronectin in the dermal stroma surrounding dysplastic naevus cells and melanoma cells; 3 presence of extracellular matrix components in close association with intra-epidermally located invading atypical melanocytes. These data demonstrate the complex alterations of the composition of the extracellular matrix from bland naevi through lesions with progressive atypia to invasive melanoma. The changes described result in a molecular environment which melanocytes with an altered adhesion molecule profile are able to invade.
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PMID:The extracellular matrix in pigmented skin lesions: an immunohistochemical study. 751 60

Fibroblasts were grown from explants of normal gingiva and foreskin, and from walls of dentigerous, radicular and residual cysts, as well as keratocysts of basal-cell naevus syndrome and non-syndrome origin. Dentigerous-cyst fibroblast adhesion to poly-L-lysine-coated glass was unaffected by all adhesion-related glycoproteins. Chondroitin sulphate, fibronectin and heparan sulphate enhanced attachment of all other fibroblasts. Chondroitin-sulphate and fibronectin-enhanced adhesion was blocked by an arg-gly-asp peptide. Fibronectin, chondroitin sulphate and laminin all promoted collagen lattice contraction using normal gingival fibroblasts and low-serum media. Fibronectin had a greater effect than chondroitin sulphate and laminin. In media with standard serum, all cyst fibroblast lines examined demonstrated similar gel contraction curves with the exception of dentigerous cyst-derived fibroblasts, which contracted at decreased rates. Suppression of gel contraction was seen with dentigerous-cyst fibroblasts with all extracellular matrix glycoproteins and low serum. Dentigerous-cyst fibroblast attachment to glass and behaviour in gel lattices suggest that these cells express different functional attachment factors from other cyst fibroblast types.
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PMID:Differences in adhesion and collagen gel contraction between fibroblasts from various types of odontogenic cyst. 806 Feb 61

Thrombospondin 1 is a multidomain trimeric glycoprotein from platelets and a variety of normal and transformed cells of both mesenchymal and epithelial origin, which functions in cell adhesion and cell-cell interactions. We have recently shown that human thrombospondin 1 binds and inhibits the neutrophil enzymes, neutrophil elastase [Hogg, P.J., Owensby, D.A., Mosher, D.F., Misenheimer, T.M., & Chesterman, C.N. (1993a) J. Biol. Chem. 268, 7139-7146] and cathepsin G [Hogg, P.J., Owensby, D.A., & Chesterman, C.N. (1993b) J. Biol. Chem. 268, 21811-21818]. One mole of thrombospondin 1 trimer binds 3 mol of neutrophil elastase or up to 6 mol of cathepsin G, with site-binding dissociation constants around the nanomolar range, and the enzymes have been shown to interact with thrombospondin 1 in the vicinity of the calcium-binding type 3 repeats. None of the protein modules in this region, or within the whole thrombospondin 1 molecule, have previously been implicated in the inhibition of proteinases. We noted that there are two stretches of eight amino acids each in the human thrombospondin 1 type 3 repeats, residues 735-742 and 794-801, that have striking similarity to a reactive-site consensus sequence derived from selected members of the Kazal and Streptomyces subtilisin inhibitor families. Synthetic peptides corresponding to the putative P5 through P4' residues of both proposed reactive centers interacted efficiently with the active site of cathepsin G and were competitive inhibitors of the fibronectin-degrading and platelet-activating activities of this enzyme, while only the peptide corresponding to residues 793-801 efficiently interacted with the active site of neutrophil elastase and competitively inhibited its fibronectin-degrading activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification of possible inhibitory reactive centers in thrombospondin 1 that may bind cathepsin G and neutrophil elastase. 820 88

Closure of large skin wounds (i.e., burns, congenital giant nevus, reconstruction of traumatic injury) with split-thickness skin grafts requires extensive harvesting of autologous skin. Composite grafts consisting of collagen-glycosaminoglycan (GAG) substrates populated with cultured dermal fibroblasts and epidermal keratinocytes were tested in a pilot study on full-thickness burn wounds of three patients as an alternative to split-thickness skin. Light microscopy and transmission electron microscopy showed regeneration of epidermal and dermal tissue by 2 weeks, with degradation of the collagen-GAG implant associated with low numbers of leukocytes, and deposition of new collagen by fibroblasts. Complete basement membrane, including anchoring fibrils and anchoring plaques, is formed by 2 weeks, is mature by 3 months, and accounts for the absence of blistering of healed epidermis. All skin antigens tested (involucrin, filaggrin, laminin, collagens IV and VII, fibronectin, and chondroitin-sulfate) were expressed by 16 days after grafting. This cultured skin analogue provides an experimental alternative to split-thickness skin graft that develops histiotypic markers of skin anatomy and antigen expression after wound closure.
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PMID:Skin anatomy and antigen expression after burn wound closure with composite grafts of cultured skin cells and biopolymers. 844 17

Thrombospondin, a glycoprotein of three identical disulfide-bonded subunits, is a constituent of platelet alpha-granules and a variety of normal and transformed cells and binds to cell surfaces and becomes incorporated into extracellular matrix. It has been implicated in processes such as wound healing and tumor growth and metastasis. In addition, thrombospondin was shown recently to be an inhibitor of the fibrinolytic enzyme, plasmin. In the cause of studying the effects of thrombospondin on other serine proteinases, we found that thrombospondin binds neutrophil elastase in an active-site-dependent manner and competitively inhibits the activity of the enzyme. In a competitive binding assay, neutrophil elastase bound to thrombospondin with a dissociation constant of 17 +/- 7 nM, expressed per mole of thrombospondin trimer, or 52 +/- 20 nM, expressed per mole of thrombospondin subunit. In kinetic studies of the inhibition of the amidolytic activity of neutrophil elastase by thrombospondin, 2.7 +/- 0.3 mol of elastase interacted with 1 mol of thrombospondin trimer with a site-binding constant of 57 +/- 13 nM. Lower limits for the on rate constant of 5 x 10(6) M-1 s-1 and off rate constant of 0.27 s-1 were established. Affinity of binding of neutrophil elastase to thrombospondin was sensitive to ionic strength and calcium ions. Thrombospondin was cleaved by neutrophil elastase, but the site(s) of the limited cleavage are independent of the competitive inhibition of elastase activity by thrombospondin. Neutrophil elastase inactivated with phenylmethylsulfonyl fluoride did not compete with active elastase for binding to thrombospondin, implying that a functional active site is important for the interaction of elastase with thrombospondin. Thrombospondin protected fibronectin from cleavage by neutrophil elastase. In summary, the binding of neutrophil elastase to thrombospondin is tight, reversible, and close enough to the active site of elastase to exclude small synthetic tripeptidyl p-nitroanilide substrates and macromolecular protein substrates. Two potential reactive centers that may be involved in binding elastase have been identified in the calcium-binding type 3 domains of thrombospondin. Neutrophil elastase is the enzyme primarily responsible for degrading and solubilizing connective tissue during inflammatory processes. These findings suggest a previously unsuspected mechanism for regulation of elastase activity at inflammatory sites.
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PMID:Thrombospondin is a tight-binding competitive inhibitor of neutrophil elastase. 846 50

It has been postulated that acquired nevi undergo life span continuous evolution from junctional, presumably in radial expanding phase at the dermal epidermal junction, to compound and then to dermal nested nevi. In an attempt to correlate the morphology of nevi with biological data, we have investigated whether migratory and adhesive phenotypes of nevus cells could account for histological patterns and possible spatiotemporal changes in nevi. Nevus cells were cultured from compound and dermal nevi and compared to normal epidermal cultured melanocytes from children and adults. AR nevus cells showed similar in vitro adhesive and migratory indexes on laminin-1, laminin-5/nicein, fibronectin, or collagen IV substrates, suggesting that these intrinsic characteristics do not account for the tendency to dermal nesting and/or to radial growth along the dermal-epidermal junction. The cells from epidermal and dermal parts of compound nevi migrated similarly across a reconstituted basement membrane. The results show that intrinsic adhesive and migratory behaviors of nevus cells were not associated with a histological type of nevus. Interestingly, differences in migratory phenotype and intercellular adhesion capacities between nevus cells and normal melanocytes indicated that they could represent different melanocytic cell subpopulations. Finally, melanocytes from adults and children expressed similar levels of the same integrins as all nevus cells but showed differences in function of both alpha3 and alpha6 integrin subunits and in migratory/adhesive behaviors, which may suggest different states of melanocyte maturation.
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PMID:Adhesive and migratory behaviors of nevus cells differ from those of epidermal melanocytes and are not linked to the histological type of nevus. 875 61

Monolayers of dipalmitoyl-phosphatidylethanolamine (DPPE) mixing with various mole percentages of distearoyl-phosphatidylethanolamine (DSPE)-conjugated poly-(ethylene glycol) (PEG m.w. 750-5000) were deposited on DPPE-coated glass surfaces by the Langmuir-Blodgett method. Increasing percentages of grafted PEG in these supported lipid surfaces increasingly inhibit the adsorption of bovine serum albumin (BSA), laminin, and fibronectin. Increasing percentages of grafted PEG also inhibit the adhesion of erythrocytes, lymphocytes, and macrophages to these supported lipid surfaces. The adsorption of proteins on lipid coated glass surfaces were assayed by the fluorescence of FITC-labelled proteins. Cell adhesion was measured mainly by microscopic counting. The concentration of PEG-grafted lipids required for the inhibition of erythrocyte adhesion decreases with increasing molecular weight of the grafted PEG. The inhibitory effects are strongly dependent on the graft density of PEG at low concentrations, but weakly dependent on graft density at higher concentrations. For DSPE-PEG5000, the change of graft density dependency occurs approximately at the complete coverage of the lipid surface by the grafted polymer in the mushroom conformation (0.7 mol%), and the transition to partial brush conformation. The change-overs become less distinctive for grafted PEG of lower molecular weights, probably due to the failure of strictly mushroom and brush models of the polymer. The relative inhibitory efficiency is protein or cell dependent. The implication on the function of stealth liposomes is discussed.
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PMID:Grafted poly-(ethylene glycol) on lipid surfaces inhibits protein adsorption and cell adhesion. 921 54

Melanocytic nevi may microscopically associate with clefts or slits of the nests resembling lymphatic or vascular spaces. This unique histologic feature has been known as an artifact of injection or tissue-processing. We present a case of melanocytic nevus with a prominent vascular space-like structure. We also studied whether intralesional injection of local anesthetic could reproduce similar histologic findings. A 45-year-old Japanese female visited us with a solitary, brownish papule on the chest. Histology revealed numerous nests composed of round to oval-shaped nevus cells throughout the entire dermis. In the mid-dermis, nevus cells were lined up in a layer anastomosing and forming a vascular space-like structure. These nevus cells were uniformly stained with vimentin and S100 protein but not with factor VIII-related antigen. They were also positively immunoreactive with anti-type IV collagen and anti-fibronectin. There were no significant differences in staining intensity in the nevus cells between the solid portion and the vascular space-like structure. In the experimental study, eight melanocytic nevi were removed under local anesthesia. The local anesthetic solution was then injected into the excised nevus. Intralesional injection of a considerable volume of local anesthetic was capable of causing slits or clefts of the nests and dermal edema; however, it failed to reproduce a vascular space-like structure similar to that in the present case. These findings suggest that a vascular space-like structure in melanocytic nevus is not caused by the injection alone. Some other factor(s) may play a major role in the development of such structures in melanocytic nevus.
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PMID:The vascular space-like structure in melanocytic nevus is not an injection artifact: report of a case and an experimental study. 957 74


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