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Biomedical subjects

E Moczar

Publications and source records attributed to E Moczar.

At least 19 recordsLinked to original sources
PubMed1996

Inhibition of human immunodeficiency virus infection by heparin derivatives.

Heparin (Hep) and sulfated polysaccharides (SPs) have been reported to inhibit HIV infection in vitro. In vivo, anticoagulant activity and reduced bioavailability were found to limit the antiviral effects of Hep. In this investigation, three nonanticoagulant N-acylated Hep conjugates [OI1:3Hep, Pal1:5Hep, and Pal1:5Hep(SO4)] were compared to Hep for their ability to interact with HIV replication in CD4-positive cell lines and PBMCs. Resulfated palmitoyl-Hep [Pal1:5Hep(SO4)] exhibited the strongest anti-HIV effects. For instance, no provirus HIV DNA was detected in the genome of HIV-1-LAI-infected PBMCs treated with this heparin derivative. Cell-to-cell fusion and RT activity were explored to explain these differences. Hep and Pal1:5Hep(SO4) derivative exerted identical effects on cell-to-cell fusion. On the other hand, Pal1:5Hep(SO4) displayed the strongest inhibitory effects in the acellular RT inhibition assay. This suggests that RT might be a second target for N-acylated Hep, even though SP uptake and the preferential effects of SPs on RT as opposed to DNA polymerase have not yet been demonstrated. Nevertheless, considering the anticoagulant, antiviral, and antiinflammatory effects of N-acylated Hep, the N-acylated Hep derivatives might be excellent candidates as new anti-HIV pharmacological tools.

Antiviral Agents↗
PubMed1993

Inhibition of human leucocyte elastase by fatty acyl-benzisothiazolinone, 1,1-dioxide conjugates (fatty acyl-saccharins).

Derivatives of benzisothiazolinone 1,1-dioxide (saccharin) N-acetylated with aliphatic and aromatic substituted aliphatic acyl groups were prepared. The inhibitory activity of the compounds was assayed against human leucocyte elastase (EC 3.4.21.37) and several other proteases. The IC50 values for inhibition of the human leucocyte elastase decreased with increasing length of the acyl residue, and reached a minimum value at C16 (2 microM). This phenomenon and the decrease of the inhibition by surfactants or by saturation of the enzyme with palmitic acid, indicates that in addition to acylation, hydrophobic interactions are also involved in the inhibition of this proteinase by compounds substituted with acyl groups containing at least 12 carbon atoms. The inhibitory activity of N-palmitoyl-benzisothiazolinone 1,1-dioxide (palmitoyl-saccharin) is about 14 times higher toward human leucocyte elastase than for thrombin (EC 3.4.21.5), and several hundred times, compared to porcine pancreatic elastase (EC 3.4.21.36) and to plasmin (EC 3.4.21.7). Fatty acylated saccharin derivatives were seen to bind in a saturable fashion to insoluble elastin, and decreased the susceptibility of this protein to hydrolysis by human leucocyte elastase.

Amino Acid Sequence↗
PubMed1993

Protective effect of oleoyl peptide conjugates against elastolysis by neutrophil elastase and kappa elastin-induced monocyte chemotaxis.

Elastin can impair the human neutrophil elastase (HNE) inhibitory capacity of elastase inhibitors. We synthesized oleoyl-alanyl-alanyl-prolyl-valine (Ol-Ala-Ala-Pro-Val-OH) (oleoyl peptide) and the amides (NH2 and NH-C3H7) of this peptide and studied their HNE-inhibitory potencies using succinyl-alanyl-alanyl-alanine-p-nitroanilide (Suc-Ala-Ala-Ala-pNA) or 3H-labeled elastin as substrates, as well as cryostat sections of rabbit skin as an ex vivo substrate. Using Suc-Ala-Ala-Ala-pNA, Ol-Ala-Ala-Pro-Val-OH had an IC50 of 3 microM. When the COOH terminal of the oleoyl peptide was derivatized to amide forms, the compound lost its ability to interact with HNE while keeping its elastin-protecting function: IC50 values for NH2 and NH-C3H7 derivatives were 22 and 17 microM, respectively. Also, the HNE-inhibitory capacity of Ol-Ala-Ala-Pro-Val-OH was only reduced 2-fold by using elastin as a substrate. This decrease was much lower than those determined with other HNE inhibitors of similar potency and could be accounted for by the ability of oleoyl peptide to bind to elastin. Cryostat sections of rabbit skin were also used as an ex vivo substrate for assessing the elastin-protecting property of Ol-Ala-Ala-Pro-Val-OH. Preincubating HNE and oleoyl peptide before application to tissue sections led to an IC50 of 8 microM, close to the value determined with elastin as a substrate. Treatment of sections with oleoyl peptide before adding HNE gave a lower IC50 (4 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

A lipophilic heparin derivative protects elastin against degradation by leucocyte elastase.

An oleolylated derivative (I) of partially N-desulphated heparin was prepared containing an average number of three oleoyl residues for one molecule of heparin. The inhibitory capacity of I (IC50 = 0.55 microM) for leucocyte elastase resembles that of heparin (IC50 = 0.2 microM). In contrast to heparin, I is also an inhibitor of porcine pancreatic elastase (IC50 = 0.68 microM) and it also has the capacity to protect elastin fibres against the degradation by leucocyte elastase. When insoluble elastin is pretreated with I its degradation by leucocyte elastase is inhibited by almost 90% while pretreatment of elastin with heparin exhibited only a moderate effect on elastolysis (10% inhibition).

Amino Acid Sequence↗
PubMed1991

Heparin-binding sites of rat rhabdomyosarcoma cells with low and high metastatic capacity.

Proteins able to bind the iduronate containing glycosaminoglycans: heparin, heparan sulfate and dermatan sulfate, were detected in strongly (RMS 0) and weakly (RMS 8) metastatic rat rhabdomyosarcoma cell lines. The 35S-methionine-labeled proteins solubilized from the cell membranes were chromatographed on Heparin-Ultrogel affinity column. The main retained protein migrated with an apparent molecular size of 19 kDa on polyacrylamide gel electrophoresis from both cell lines. The 19 kDa protein exhibited a higher affinity for iduronate containing glycosaminoglycans than for the glucuronate containing chondroitin sulfates. It was immunologically distinct from acid and basic fibroblast growth factors. The membranes of the RMS 8 cells contained about a two times higher amount of labeled 19 kDa protein than the membranes of the RMS 0 cells. The decreased amount of the labeled heparin-binding proteins in the highly metastatic cell line is in agreement with the previously evidenced decreased receptor-mediated binding of the iduronate containing glycosaminoglycans by these cells.

Animals↗
PubMed1990

Galactosylated glycan expression and macrophage sensitivity of Lewis lung tumor cells with different metastatic phenotype.

Biochemical and cytochemical analysis of Lewis lung tumor variants revealed that the low metastatic cells contained more galactose/N-acetylgalactosamine residues in a high-molecular-mass (15-20 kDa) mixed N- and O-glycan fraction than the highly metastatic ones. It was also found that the highly metastatic variant was less sensitive to macrophage cytotoxicity in vitro. The cytotoxicity against the low metastatic target cells was inhibited by asialofetuin (10-20 microM), and, to a small degree--and at much higher concentration--by lactose, while galactose and other monosaccharides were ineffective. We suppose that complex galactosylated tumor cell membrane glycans could play a role in the antitumoral cytotoxicity of macrophages.

Animals↗
PubMed1990

Interactions of exogenous heparan sulfate with tumor cells of different metastatic phenotype.

Heparan sulfate (HS) enhanced the growth of the highly metastatic (HM) 3LL cell line, but not that of the low metastatic (LM) counterpart, in a dose-dependent way. Heparin, chondroitin sulfate, hyaluronate did not produce this effect. At 4 degrees C both cell lines exhibited high affinity binding sites (Kd 10(-8) M) for exogenous HS. Unlike LM cells, the HM ones lost half of the surface-bound HS during the 24-hour incubation at 37 degrees C. HM cells in the exponential growth phase took up the bound HS at lower rate than the LM counterparts. Both cell lines fragmented the exogenous HS intracellularly, but only the HM cells were able to degrade it at the cell surface. The HM cells contained much more heparin-binding proteins--especially in the cell membrane and nuclear fraction--than the LM ones. These results clearly demonstrate that the interactions of tumor cells with exogenous HS are influenced by the invasive phenotype. We suggest also that there could be a correlation between the surface degradation, the slow uptake and the growth-promoting effect of the exogenous HS.

Animals↗
PubMed1989

Binding and internalization of exogenous glycosaminoglycans in weakly and highly metastatic rhabdomyosarcoma cells.

The fate of exogenous glycosaminoglycans in cultures of strongly (RMS 0) and weakly (RMS 8) metastatic rat rhabdomyosarcoma cells was studied. The time course and concentration dependence of binding and internalization of the radiolabeled sulfated glycosaminoglycans were determined. Weakly metastatic cells took up heparin, heparan and dermatan sulfates into their pericellular compartment at a higher rate than the strongly metastatic RMS 0 cells. The RMS 8 cells exhibited about two times more binding sites for these iduronic acid containing glycosaminoglycans, and internalized higher amounts of them than the RMS 0 cells. The uptake of the chondroitin sulfate into the peri- and intracellular compartments of both cell types was about 5-15% of that of the other glycosaminoglycans studied. The specificity of displacement of the pericellular heparin and dermatan sulfate by the unlabeled glycosaminoglycans indicates the involvement of specific structural features of the polysaccharide chains in the interactions of glycosaminoglycans with the surface of rhabdomyosarcoma cells, beside ionic forces due to the polyanionic character of the glycosaminoglycans. Heparin and heparan sulfate degradation products, mainly large oligosaccharides, were recovered from the surface of RMS 0 cells but were absent on the surface of the RMS 8 cells. About 30% of the internalized heparin and heparan sulfate was present in the partially degraded form in both cell types. Oligosaccharides derived from glycosaminoglycans were not released into the medium. The decrease in the amount of iduronic acid containing glycosaminoglycans internalized by the highly invasive cells seems to be correlated with an increased cell-associated degradation and with an apparent loss of glycosaminoglycan binding sites on the cell surface.

Animals↗
PubMed1987

Inhibition by elastase inhibitors of the formyl Met Leu Phe-induced chemotaxis of rat polymorphonuclear leukocytes.

Rat leukocyte elastase has been purified successively by AH-Sepharose Kappa-elastin affinity chromatography and by ion exchange chromatography on a carboxymethyl Sephadex resin. It has great similarities with human leukocyte elastase in its molecular weight, substrate specificity and inhibitory profile. The effect of rat leukocyte elastase inhibitors in influencing the chemotactic response of rat PMN to fMetLeuPhe has been compared to that of other proteinase inhibitors. The results indicated that oleoyl (Ala)2ProValCH2Cl, a specific inhibitor of human and rat leukocyte elastases and Eglin C, which also inhibits human and rat cathepsin G, are among the powerful inhibitors of rat PMN chemotaxis induced by the formyl oligopeptide. This suggests that these neutral proteinases, in addition to their known participation in connective tissue catabolism, could play a role in PMN locomotion and chemotaxis.

Animals↗
PubMed1986

Cell surface glycosaminoglycans of rat rhabdomyosarcoma lines with different metastatic potentials and of non-malignant rat myoblasts.

Glycosaminoglycans of cultured nickel-induced rat rhabdomyosarcoma cell lines with different metastatic potentials and of non-malignant myoblasts, grown in the presence or in the absence of hydrocortisone, were studied comparatively. The newly formed [3H]glucosamine-labelled cell surface proteoglycans and glycosaminoglycans were separated by ion exchange chromatography and partially characterized. The overall incorporation of the label in the glycosaminoglycan fractions and the average molecular weight of the heparan and of the chondroitin sulfate proteoglycans was lower in the malignant cells than in the non-malignant L6 myoblasts. The strongly metastatic 9-4/0 parental line and the 6 subline were relatively richer in chondroitin sulfate and poorer in dermatan sulfate labels than the very weakly metastatic 8 subline and the L6 myoblasts. Hyaluronic acid and heparan sulfate labels were inversely related to the metastatic capacity of the cell lines studied. Hydrocortisone treatment induced an increase in the cell surface chondroitin and dermatan sulfate labels in the case of the strongly metastatic lines, and a decrease of the same parameters in the case of the weakly metastatic 8 line.

Animals↗
PubMed1986

Solubilization and degradation of extracellular matrix by various metastatic cell lines derived from a rat rhabdomyosarcoma.

Examination by use of WAG syngeneic female rats was made on 4 rat rhabdomyosarcoma sublines expressing different metastatic potentials for their abilities to degrade proteoglycans and glycoproteins of the extracellular matrix (ECM), deposited by corneal endothelial cells and metabolically labeled with [3H]glycosamine and [35S]sulfate. Of the label incorporated in ECM, 10-20% was released in the culture medium in 3 days by the cell lines studied. The proteoglycans, glycosaminoglycans, and glycoproteins released by the cells from ECM were separated and partially characterized. Most of the ECM glycoproteins were recovered in the region of 200,000 (200K) on gel chromatography. Glycopeptides of 10K-20K apparent molecular weight were minor components. The glycosaminoglycan chains of the proteoheparan sulfate were partially hydrolyzed to 20K fragments. Tumor cells increased also the solubilization of the nondegraded matrix macromolecules. About 5-8% of the radioactivity of the ECM remained associated with the tumor cells detached from the ECM. ECM degrading activity of the sublines did not correlate with their ability to colonize the lungs after iv injection but did correlate with their ability to metastasize to the lungs from the primary subcutaneous site.

Animals↗
PubMed1985

Primary structure of two major glycans of bovine fibrinogen.

After pronase digestion of bovine fibrinogen, the asparagine-linked glycans were released from the resulting glycopeptides by hydrazinolysis, and subsequently re-N-acetylated. Two sialylated glycans were isolated by ion-exchange chromatography. Their primary structure has been determined by methylation analysis and 360-MHz 1H-NMR spectroscopy. The structures proposed to be present in the native glycoprotein are as follows: (formula: see text).

Animals↗
PubMed1985

Fatty acid peptide derivatives as model compounds to protect elastin against degradation by elastases.

Peptide sequences which fit the extended binding sites of porcine pancreatic elastase and human leukocyte elastase were covalently coupled to oleic acid. These compounds behave as competitive inhibitors towards both elastases. The coupling of fatty acid moiety to the peptide greatly decreases its inhibitor constant (Ki) vs human leukocyte elastase (Ki for Oleoyl(Ala)2ProValine: 3.0 (10(-6)M). It is less active on porcine pancreatic elastase (Ki for Oleoyl(Ala)2ProAlanine: 3.8 10(-4)M). The modifications of the carboxylic end group of the peptide to an aldehyde further greatly enhanced the inhibition capacity of the compound towards leukocyte elastase (Ki for Oleoyl(Ala)2ProAlaninal: 0.7 microM). Oleoyl peptide derivatives were seen to bind in a saturable fashion to purified insoluble elastin, and decreased the susceptibility of the macromolecule to hydrolysis by both pancreatic and leukocyte elastases. As stoichiometric quantities of elastase (vs inhibitor) could not desorb 3H-oleoyl(Ala)2Pro-Val bound to insoluble elastin, it is postulated that oleoyl peptide derivatives may act as bifunctional agents. This contention was further strengthened by the comparison of the adsorption curves of elastase to untreated insoluble elastin and elastin saturated with oleoyl peptide derivatives respectively. It was shown finally that Oleoyl(Ala)2Pro-Valine was also capable of inhibiting elastases in their adsorbed form to insoluble elastin.

Adsorption↗
PubMed1985

Problems of differential diagnosis in a case of bone lesions caused by myelosclerosis associated with hyperparathyroidism.

The authors present a report on the case of a female patient with myelofibrosis where X-ray examinations of the bone skeleton predominantly showed such osteolytic changes which are no typical of myelosclerosis. Morphological criteria rather would have corresponded to osteitis fibrosa cystica generalisata. Laboratory examinations partially indicated primary hyperparathyroidism, this assumption could not be confirmed by other examinations. Also histological findings of repeated bone biopsies did not lead to a uniform diagnosis. Autopsy confirmed the presence of both diseases. The authors consider the synergistic effect of both diseases to be the cause for the development of those bone changes mentioned above.

Bone Resorption↗
PubMed1984

[Experimental study of cancer metastasis].

Chemotherapeutic assays, using nitrosoureas, performed on tumor bearing rats have shown a regression of local tumor, accompanied with an amplification of pulmonary metastases, demonstrating that the treatment of metastasis differs from the treatment of a local tumor. Cells organizing a tumor are heterogeneous for their drug resistance, and for a series of properties including their ability to form metastasis. Metastatic cells have to leave the tumoral tissue, to traverse biological barriers, to resist to immune system, to implant and growth in the target tissue. An experimental model has been used to characterize metastatic cells. Metastatic potential has been defined as the ability to invade lungs. Highly metastatic cloned cell lines, such as subline 6, were strongly stimulated to proliferate by EGF, expressed fibronectin, actively degraded the extracellular matrix, rapidly attached to endothelial vascular cells, and resisted to natural killer lymphocytes. Inversely, weakly metastatic lines, such as subline 8, were preferentially stimulated by FGF and EDGF, poorly expressed fibronectin, did not degrade extracellular matrix, slowly attached to vascular cells, and were killed by NK lymphocytes. Studies on a large series of clones showed a diversity between them, and that no one property was determinant. Modulation of these characters by growth factors, hormones and immune state of the host is discussed, and leads to conclude that the expression of metastatic potential of a tumor depends on genetically defined characters and also on influences excerted by the host.

Animals↗