Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mouse neuroblastoma Neuro 2a cells are known to extend neurite-like processes in response to gangliosides added to the culture medium. We compared the structural features of proteoglycans (PG) synthesized by conventional Neuro 2a cells with those of neurite-bearing cells. Two different proteoglycans labeled with [35S]sulfate, namely, chondroitin sulfate proteoglycan (CS-PG) and heparan sulfate proteoglycan (HS-PG), were found both in the cell layer and in the culture medium of the conventional cells. CS-PG isolated from the cell layer had a Kav value of 0.38 on Sepharose CL-6B, and had CS side chains with Mr of 27,000. HS-PG in the cell layer was slightly larger (Kav of 0.33) in terms of hydrodynamic size than CS-PG, and the apparent Mr of the heparan sulfate side chains was 10,000. The structural parameters of CS-PG and HS-PG isolated from the medium were almost identical to those of the PGs in the cell layer. In addition to these PGs, single-chain HS, with an average Mr of 2,500, was observed only in the cell layer and this component was the major sulfated component in the cell layers of both control and ganglioside treated cells. The neurite-bearing cells also synthesized both CS-PG and HS-PG which were very similar in hydrodynamic size to those synthesized by the conventional cells, but the size of HS side chains was greater. Radioactivity, as 35S, of each sulfated component from the ganglioside-treated culture seemed to be slightly less than that of the corresponding component from the control culture. These findings indicate that the marked morphological change in Neuro 2a cells, induced by gangliosides is not accompanied by major changes in the synthesis of PGs.
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PMID:Sulfated proteoglycans synthesized by Neuro 2a neuroblastoma cells: comparison between cells with and without ganglioside-induced neurites. 281 49

Human neuroblastoma cells (Platt and La-N1) adhere and extend neurites on a ganglioside GM1-binding substratum provided by cholera toxin B (CTB). These adhesive responses, similar to those on plasma fibronectin (pFN), require the mediation of one or more cell-surface proteins [G. Mugnai and L. A. Culp (1987) Exp. Cell Res. 169, 328]. The involvement of two pFN receptor molecules in ganglioside GM1-mediated responses on CTB have now been tested. In order to test the role of cellular FN binding to its glycoprotein receptor integrin, a soluble peptide containing the Arg-Gly-Asp-Ser (RGDS) sequence was added to the medium. It did not inhibit attachment on CTB but completely inhibited formation of neurites; in contrast, the RGDS peptide minimally inhibited attachment or neurite formation on pFN. Once formed, neurites on CTB became resistant to the peptide. In order to test the role of cell-surface heparan sulfate proteoglycan (HS-PG), two approaches were used. First, the HS-binding protein platelet factor-4 (PF4) was used to dilute CTB or pFN on the substratum or, alternatively, added to the medium. Diluting the substratum ligand with PF4 had no effects on attachment on either CTB or pFN. However, neurite formation on CTB was readily inhibited and on pFN partially inhibited; the effects of PF4 were far greater than a similar dilution with nonbinding albumin. When PF4 was added to the medium of cells, attachment on either substratum was unaffected as was neurite outgrowth on pFN, revealing differences in PF4's inhibition as the substratum-bound or medium-borne component. In contrast, PF4 in the medium at low concentrations (1 microgram/ml) was highly inhibitory for neurite formation on CTB. The second approach utilized the addition of bovine cartilage dermatan sulfate proteoglycan (DS-PG), shown to bind to pFN as well as to substratum-bound CTB by ELISA, or cartilage chondroitin sulfate/keratan sulfate proteoglycan (CS/KS-PG) to the substratum or to the medium. At low concentrations, DS-PG but not CS/KS-PG actually stimulated neurite formation on CTB while at higher concentrations DS-PG completely inhibited attachment and neurite formation. While DS-PG partially inhibited attachment on pFN, it had no effect on neurite formation of the attached cells. Neuroblastoma cells adhered to some extent to substrata coated only with DS-PG, indicating "receptors" for PGs that permit stable interaction.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Ganglioside-dependent adhesion events of human neuroblastoma cells regulated by the RGDS-dependent fibronectin receptor and proteoglycans. 296 69

Tissue culture substratum adhesion sites from EGTA-detached Platt human neuroblastoma cells were extracted with a buffer containing ocytlglucoside, NaCl, guanidine hydrochloride, and a variety of protease inhibitors, an extraction which resulted in quantitative solubilization of the 35SO4 = -radiolabeled proteoglycans and 3H-leucine-radiolabeled proteins. Of the sulfate-radiolabeled material, the vast majority was heparan sulfate proteoglycan (Kav = 0.15 on Sepharose C14B columns) and the remainder was chondroitin sulfate chains (no single chains of heparan sulfate were observed). This extract was then fractionated on DEAE-Sephadex columns under two different buffer elution conditions. Under DEAE-I conditions in low ionic strength acetate buffer, two major peaks of 35SO4 = -radiolabeled material (A,B) and a minor peak (C) could be resolved in the NaCl gradient; however, three-fourths of the material required 4 M guanidine hydrochloride to elute it from the column (peak D). Under DEAE-II conditions in acetate buffer supplemented with 8 M urea, the vast majority of the proteoglycan material could be eluted in the NaCl gradient as peak AB. Peak D material was shown to contain aggregated proteoglycan, along with nonproteoglycan protein, which high concentrations of urea or guanidine could dissociate, but not nonionic or zwitterionic detergents. Three different affinity chromatography systems were used to further characterize these components. Approximately 60% of peak A heparan sulfate proteoglycan from DEAE-I binds to the hydrophobic matrix, octyl-Sepharose, while 80% of the proteoglycan in DEAE-I peak D binds to this hydrophobic column. A sizable fraction of peak A proteoglycan fails to bind to plasma fibronectin but does bind to platelet factor-4 affinity columns. In contrast, peak AB proteoglycan from DEAE-II columns yields a much higher proportion of molecules which do bind to fibronectin. To examine the basis for these differences in affinity binding, nonproteoglycan protein from these adhesion sites was mixed with peak AB proteoglycan prior to affinity chromatography; proteoglycan binding to fibronectin decreased markedly while binding to platelet factor-4 was unaffected. This modulating activity involves the binding of nonproteoglycan protein in adhesion site extracts to both fibronectin on the column, as well as to heparan sulfate proteoglycan itself, and it could not be mimicked by a number of known proteins in adhesion site extracts or several other proteins. These results demonstrate selectivity and specificity in this modulation and indicate that a previously unidentified protein(s) is responsible.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Heparan sulfate proteoglycans in the substratum adhesion sites of human neuroblastoma cells: modulation of affinity binding to fibronectin. 296 1

Human neuroblastoma cells (Platt) were detached from tissue culture substrata with a Ca2+ chelating agent, and then the suspended cells were extracted with a sodium dodecyl sulfate (SDS)-containing buffer to maximally solubilize their sulfate-radiolabeled proteoglycans. The majority of the high-molecular-weight material in these dissociative extracts was heparan sulfate proteoglycan, which resolves into two heterodisperse size classes upon gel filtration on columns of Sepharose CL4B. After removal of SDS from these extracts by hydrophobic chromatography on Sep-Pak C18 cartridges, extracts were further fractionated on various affinity matrices. All of the sulfate-radiolabeled material eluted as one peak from DEAE-Sephadex ion-exchange columns. In contrast, affinity fractionation on Sepharose columns derivatized with the heparan sulfate-binding protein, platelet factor-4, resolved three major and one minor subsets of these components. The nonbinding fraction contained some heparan sulfate proteoglycan and some chondroitin sulfate. The weak-binding fraction contained principally heparan sulfate proteoglycan, as well as a small amount of chondroitin sulfate proteoglycan; the gel-filtration properties of these proteoglycans before or after alkaline borohydride treatment indicated that they were small in size, containing perhaps 2 to 4 glycosaminoglycan chains. The high-affinity fraction eluted from platelet factor 4-Sepharose was composed entirely of "single-chain" heparan sulfate. A portion of the heparan sulfate proteoglycan of the original extract bound to the hydrophobic affinity matrix, octyl-Sepharose, and this hydrophobic proteoglycan partitioned into the nonbinding and weak-binding fractions of the platelet factor 4-Sepharose affinity columns. These studies reveal that the majority of the proteoglycan made by these neuronal cells in culture is of the heparan sulfate class, is small in size when compared to other characterized proteoglycans, and can be resolved into several overlapping subsets when fractionated on affinity matrices.
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PMID:Heparan sulfate proteoglycans of human neuroblastoma cells: affinity fractionation on columns of platelet factor-4+. 623 9

The effect of several basement membrane components on the aggregation of acetylcholine (ACh) receptors on cultured myotubes was studied. Cultures were incubated for 16 to 24 hr with laminin, a heparan sulfate proteoglycan, collagen types IV and V, or fibronectin, alone, or together with medium conditioned by NG108-15 neuroblastoma X glioma hybrid cells (NCM). The number of ACh receptor aggregates per myotube was assayed by fluorescence microscopy of cultures stained with tetramethylrhodamine-labeled alpha-bungarotoxin. Laminin induced ACh receptor aggregation on primary rat myotubes and on myotubes formed by G8-1 clonal rat muscle cells. Laminin enhanced the receptor-aggregating activity of NCM in a concentration-dependent manner (0.6 to 6.0 micrograms/ml) and the number of aggregates formed in the presence of laminin and NCM together was greater than the sum of the aggregates induced by NCM and laminin separately. The aggregation factor in NCM is probably not laminin, since less than 10 ng/ml of laminin-like immunoreactivity was detected in NCM, and antiserum against laminin blocked the effects of laminin but had little effect on NCM aggregation activity. Collagen type V enhanced the receptor aggregation activity of NCM, but less strongly than laminin, and had little or no effect by itself. The other basement membrane components did not induce receptor aggregation or enhance the effect of NCM. Experiments in which ACh receptors were labeled before exposure of cultures to NCM and laminin indicated that laminin enhanced the rearrangement of receptors at the cell surface. Immunofluorescence microscopy indicated that laminin binds to the myotubes within 30 min and forms patches on the cell surface over a period of hours. Laminin bound to the myotube surface enhanced receptor aggregation as well as laminin continuously present in the culture medium. The results suggest the possibility that laminin could enhance the receptor aggregation activity of a neuronal factor(s) released at the developing neuromuscular junction.
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PMID:Laminin induces acetylcholine receptor aggregation on cultured myotubes and enhances the receptor aggregation activity of a neuronal factor. 634 13

Both polyvalent and hybridoma-produced antibodies to fibronectin (Fn) were used to 'map' the immunoaccessible subsets of cell surface fibronectin on virus-transformed murine fibroblast SVT2 and rat neuroblastoma B104 cells. As one approach to this end, attachment and spreading responses of cells were measured on tissue culture substrata coated with antibody or with plasma fibronectin to compare their adhesive responses. Both SVT2 and B104 cells adhere poorly to polyvalent anti-Fn-coated substrata over short time intervals, but within several hours changes occur which permit cells to attach and spread as well on anti-Fn as on Fn (post-adsorption of the anti-Fn with Fn also generates a maximal response). This adhesive response could be completely prevented by predigesting the cells with Flavobacterium heparanase, but not with chondroitinase ABC, indicating that the cell surface Fn responsible for antibody-mediated adhesion is associated with heparan sulfate proteoglycans on the cell surface. The compositions of the substratum-attached material (left bound after EGTA-mediated detachment of cells) from cells attaching to anti-Fn or Fn were analysed by SDS-PAGE and found to be identical within the same cell type for the two different substrata. Three hybridoma-produced antibodies, which recognize different determinants on Fn, generated different adhesive responses for SVT2 or B104 cells when adsorbed to the substratum. SVT2 cells adhered well to antibody no. 32-coated substrata but poorly to antibodies 92 or 136; on the other hand, B104 cells responded similarly to all three antibodies over short times of attachment but much better to no. 32 after a several hour incubation. These experiments indicate that (1) much of the cell surface fibronectin is complexed with heparan sulfate proteoglycan and is initially inaccessible to bind to polyvalent antibody on the substratum to promote adhesion; (2) the surface of neuroblastoma cells contains a fibronectin-like molecule which is important in their substratum adhesion; and (3) monoclonal antibodies are valuable tools in 'mapping' the orientation of cell surface molecules like fibronectin by measuring adhesive responses to antibody-coated substrata.
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PMID:Adhesive responses of fibroblast and neuroblastoma cells to substrata coated with polyvalent or monoclonal antibody to fibronectin. 686 9

Congo red and certain sulfated glycans are potent inhibitors of protease-resistant PrP accumulation in scrapie-infected cells. One hypothesis is that these inhibitors act by blocking the association between protease-resistant PrP and sulfated glycosaminoglycans or proteoglycans (e.g., heparan sulfate proteoglycan) that is observed in amyloid plaques of scrapie-infected brain tissue. Accordingly, we have investigated whether the apparent precursor of protease-resistant PrP, protease-sensitive PrP, binds to Congo red and heparin, a highly sulfated glycosaminoglycan with an inhibitory potency like that of heparan sulfate. Protease-sensitive PrP released from the surface of mouse neuroblastoma cells bound to heparin-agarose and Congo red-glass beads. Sucrose density gradient fractionation provided evidence that at least some of the PrP capable of binding heparin-agarose was monomeric. Free Congo red blocked PrP binding to heparin and vice versa, suggesting that these ligands share a common binding site. The relative efficacies of pentosan polysulfate, Congo red, heparin, and chondroitin sulfate in blocking PrP binding to heparin-agarose corresponded with their previously demonstrated potencies in inhibiting protease-resistant PrP accumulation. These results are consistent with the idea that sulfated glycans and Congo red inhibit protease-resistant PrP accumulation by interfering with the interaction of PrP with an endogenous glycosaminoglycan or proteoglycan.
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PMID:Binding of the protease-sensitive form of PrP (prion protein) to sulfated glycosaminoglycan and congo red [corrected]. 751 Nov 69

Previously, we demonstrated in cultured dorsal root ganglion neurons that, in the presence of beta-migrating very low density lipoproteins (beta-VLDL), apolipoprotein (apo) E4, but not apoE3, suppresses neurite outgrowth. In the current studies, murine neuroblastoma cells (Neuro-2a) were stably transfected with human apoE3 or apoE4 cDNA, and the effect on neurite outgrowth was examined. The stably transfected cells secreted nanogram quantities of apoE (44-89 ng/mg of cell protein in 48 h). In the absence of lipoproteins, neurite outgrowth was similar in the apoE3- and apoE4-secreting cells. The apoE4-secreting cells, when incubated with beta-VLDL, VLDL, cerebrospinal fluid lipoproteins (d < 1.21 g/ml), or with triglyceride/phospholipid (2.7:1 (w/w)) emulsions, showed a reduction in the number of neurites/cell, a decrease in neurite branching, and an inhibition of neurite extension, whereas in the apoE3-secreting cells in the presence of a lipid source, neurite extension was increased. Uptake of beta-VLDL occurred to a similar extent in both the apoE3- and apoE4-secreting cells. With low density lipoproteins or with dimyristoylphosphatidylcholine emulsions, either alone or complexed with cholesterol, no differential effect on neurite outgrowth was observed. A slight differential effect was observed with apoE-containing high density lipoproteins. The differential effect of apoE3 and apoE4 in the presence of beta-VLDL was blocked by incubation of the cells with heparinase and chlorate, with lactoferrin, or with receptor-associated protein, all of which prevent the uptake of lipoproteins by the low density lipoprotein receptor-related protein (LRP). The data suggest that the secreted and/or cell surface-bound apoE interact with the lipoproteins and facilitate their internalization via the heparan sulfate proteoglycan-LRP pathway. The mechanism by which apoE3 and apoE4 exert differential effects on neurite outgrowth remains speculative. However, the data suggest that apoE4, which has been shown to be associated with late onset familial and sporadic Alzheimer's disease, may inhibit neuronal remodeling and contribute to the progression of the disease.
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PMID:Stable expression and secretion of apolipoproteins E3 and E4 in mouse neuroblastoma cells produces differential effects on neurite outgrowth. 759 57

Inflammation and the response to injury may play an important role in the process of amyloidosis in Alzheimer's disease. We investigated the effect of interleukin-1 (IL-1) and nerve growth factor (NGF) on the metabolism of neuroblastoma proteoglycans. IL-1 and NGF increased the net charge and the net secretion of neuroblastoma proteoglycans. NGF also specifically increased the relative amount of cell-associated and secreted heparan sulfate proteoglycans in these cells. We previously demonstrated that neuroblastoma heparan sulfate proteoglycan binds specifically to the amyloid beta-amyloid peptide involved in Alzheimer's disease. Heparan sulfate glycosaminoglycans synthesized by IL-1-stimulated cells demonstrated an increased relative binding affinity for the beta-amyloid peptide. Thus, IL-1 and NGF induce the hypersecretion and hypersulfation of neuroblastoma heparan sulfate proteoglycans which bind beta-amyloid. These studies link the process of inflammation and repair with alterations in the metabolism of heparan sulfate proteoglycans and amyloid formation in Alzheimer's disease and other disorders.
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PMID:Interleukin-1 and nerve growth factor induce hypersecretion and hypersulfation of neuroblastoma proteoglycans which bind beta-amyloid. 764 43

Proteoglycans (PGs) may play a fundamental role in all forms of amyloidosis. In Alzheimer's disease, proteoglycans are found deposited in senile plaques and in neurofibrillary tangles. However, the cellular source of these deposited PGs and their role in amyloidosis in Alzheimer's disease is unknown. Proteoglycans were purified from conditioned medium of human neuroblastoma cells (SKNSH-SY 5Y). Two species of proteoglycans were identified by enzyme susceptibility including a heparan sulfate proteoglycan and a dermatan sulfate proteoglycan. A monoclonal antibody to the protein core of a vascular basement membrane heparan sulfate proteoglycan found in senile plaques in Alzheimer's disease cross-reacted with the proteoglycans secreted by human neuroblastoma cells. Binding between 35SO4-labelled neuroblastoma proteoglycans and the Alzheimer amyloid (A4) peptide was demonstrated by affinity chromatography. Specificity studies demonstrated that binding of human neuroblastoma proteoglycans to the amyloid peptide was specific for a heparan sulfate glycosaminoglycan, with some binding to a dermatan sulfate proteoglycan. Binding to A4 was also demonstrated by a chemically deglycosylated protein core preparation. No significant binding of neuroblastoma proteoglycans was found to two other basic peptides derived from the extracellular domain of the beta-amyloid precursor, demonstrating the specificity of proteoglycan binding to the A4 peptide. Human neuroblastoma proteoglycans may bind to the-Alzheimer amyloid A4 peptide in a region with a heparin binding consensus sequence [VHHQKL] which also contains the cleavage site of the beta-amyloid precursor protein. Neuronal proteoglycans may either regulate the secretion of the amyloid protein precursor or modify the binding of the amyloid protein precursor to other cellular adhesion molecules. Alterations in this binding may be related to the pathogenesis of amyloid deposition in Alzheimer's disease.
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PMID:Binding of secreted human neuroblastoma proteoglycans to the Alzheimer's amyloid A4 peptide. 843 62


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