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)

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

The biochemical properties and distribution of a Cdc2-related kinase, KKIALRE, were studied in brain tissues and cultured cells with antibodies to a subregion of KKIALRE protein deduced from cDNA. In adult human brain, the KKIALRE-immunoreactive protein consisted of four or five isoforms having a molecular size of 40-52 kDa, whereas in fetal brain, there was one protein of approximately 48 kDa. Cultured astrocytes, neuroblastoma cells, and mouse brains contained the fetal form of KKIALRE protein. KKIALRE-immunoreactive proteins were capable of phosphorylating histone and synthetic peptides with the X-Ser-Pro-X motif, indicating that these proteins belong to the proline-directed Ser/Thr protein kinase family. The KKIALRE immunoreactivity was detected primarily in fibrous astrocytes in white matter and perivascular and subpial spaces, as well as in Bergmann glia in the cerebellum. In fetal brains radial glia were weakly immunoreactive. Reactive astrocytes were more intensely labeled than other glia. Neurons in normal brains and brains with Alzheimer's disease (AD) displayed no KKIALRE immunoreactivity. KKIALRE immunoreactivity was similar in neurons with and without neurofibrillary tangles. The results indicate that in CNS, the KKIALRE protein is mainly a glial protein that is up-regulated in gliosis and that it probably plays no role in the hyperphosphorylation of tau in AD brains.
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PMID:The distribution and biochemical properties of a Cdc2-related kinase, KKIALRE, in normal and Alzheimer brains. 759 54

The Alzheimer amyloid precursor (APP) protein is a member of a family of glycoproteins that includes the amyloid precursor-like proteins (APLPs). Previously, we showed that in C6 glioma cell cultures, secreted APP nexin II occurs as the core protein of a chondroitin sulfate proteoglycan (CSPG). Here, we report that among seven untransfected cell lines, expression of secreted APP CSPG was restricted to two cell lines of neural origin, namely, C6 glioma and Neuro-2a neuroblastoma (N2a) cells. Addition of dibutyryl cyclic AMP in N2a cultures, a treatment that induces the neuronal phenotype in these cells, resulted in a significant reduction in the amount of the secreted APP CSPG, although secretion of APP was only marginally affected. Growth in the presence of serum increased the size of the secreted APP CSPG, suggesting that the number and/or length of the chondroitin sulfate (CS) chains attached to the core APP varies with growth conditions. Extensive mapping with epitope-specific antibodies suggested that a CS chain is attached within or proximal to the A beta sequence of APP. In contrast to the restricted expression of the APP CSPG, expression of secreted APLP2 CSPGs was observed in all cell lines examined. After chondroitinase treatment, two core proteins of approximately 100 and 110 kDa were obtained that reacted with an APLP2-specific antiserum, suggesting that non-transfected cell lines contain at least two endogenous APLP2 CSPGs, probably derived by alternative splicing of the APLP2 KPI domain. The fraction of the APLP2 proteins in the CSPG form was dependent on the particular cell line examined.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Expression of the chondroitin sulfate proteoglycans of amyloid precursor (appican) and amyloid precursor-like protein 2. 761 33

The 39- to 43-amino acid amyloid beta-protein (A beta) is deposited as amyloid in Alzheimer's disease. Recent studies have suggested that short A beta (A beta 39 or A beta 40) and long A beta (A beta 42 or A beta 43) play different roles in Alzheimer-type pathology. However, little attempt has been made to investigate the cellular mechanisms underlying the generation of short and long A beta individually. In the present report, we first measured the amount of short and long A beta that are secreted from wild-type human and rodent cells with neuron- or glia-like properties using highly sensitive sandwich-ELISAs that discriminate long A beta from short A beta. The results showed that long A beta secreted by all cells constitutes approximately 10% of the total A beta. To identify the molecular species of long A beta, we next isolated the A beta species secreted from human neuroblastoma IMR-32 cells by affinity chromatography, gel-filtration HPLC, and reverse-phase HPLC. Mass spectrometric analysis demonstrated unequivocally that IMR-32 cells produce A beta 1-42 together with A beta 1-37, A beta 1-38, A beta 1-39, and most predominantly, A beta 1-40. Finally, to investigate the cellular mechanisms that generate A beta 1-42, we studied the effects of brefeldin A and monensin on the production of A beta 1-40 and A beta 1-42 in IMR-32 cells. These reagents reduced the production of both A beta 1-40 and A beta 1-42 simultaneously in a concentration-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Long amyloid beta-protein secreted from wild-type human neuroblastoma IMR-32 cells. 764 Feb 83

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

Stimulation of muscarinic m1 or m3 receptors can, by generating diacylglycerol and activating protein kinase C, accelerate the breakdown of the amyloid precursor protein (APP) to form soluble, nonamyloidogenic derivatives (APPs), as previously shown. This relationship has been demonstrated in human glioma and neuroblastoma cells, as well as in transfected human embryonic kidney 293 cells and PC-12 cells. We now provide evidence that stimulation of metabotropic glutamate receptors (mGluRs), which also are coupled to phosphatidylinositol 4,5-bisphosphate hydrolysis, similarly accelerates processing of APP into nonamyloidogenic APPs. This process is demonstrated both in hippocampal neurons derived from fetal rats and in human embryonic kidney 293 cells transfected with cDNA expression constructs encoding the mGluR 1 alpha subtype. In hippocampal neurons, both an mGluR antagonist, L-(+)-2-amino-3-phosphonopropionic acid, and an inhibitor of protein kinase C, GF 109203X, blocked the APPs release evoked by glutamate receptor stimulation. Ionotropic glutamate agonists, N-methyl-D-aspartate or S(-)-5-fluorowillardiine, failed to affect APPs release. These data show that selective mGluR agonists that initiate signal-transduction events can regulate APP processing in bona fide primary neurons and transfected cells. As glutamatergic neurons in the cortex and hippocampus are damaged in Alzheimer disease, amyloid production in these regions may be enhanced by deficits in glutamatergic neurotransmission.
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PMID:Amyloid precursor protein processing is stimulated by metabotropic glutamate receptors. 764 42

Alzheimer's-afflicted neurons contain phosphorylated forms of tau that are not present in healthy adults. these can be recognized with great specificity by monoclonal antibodies such as paired helical filament-1 (PHF-1) [Greenberg S. G. and Davies P. (1990) Proc. natn. Acad. Sci. U.S.A. 87, 5827-5831; Greenberg S. G. et al. (1992) J. biol. Chem. 267, 564-569]. The PHF-1 phospho-tau epitope is also present in immature neurons undergoing axodendritic differentiation [Pope W. B. et al. (1993) Expl Neurol. 120, 106-113]. Analogous to its presence in immature neurons, we report here that the PHF-1 tau epitope spontaneously occurs in the human neuroblastoma cell line SHSY5Y, where its level can be regulated by differentiation and by molecules found in the extracellular matrix. Confocal immunofluorescence studies showed PHF-1 epitope to be constitutively expressed in the somatic cytoplasm as well as in short neurites typical of undifferentiated SHSY5Y cells. Induction of differentiation with retinoic acid produced cells with a neuronal morphology and a redistribution of the expression of PHF-1 tau in the long neurites. Protracted exposure to retinoic acid decreased the levels of PHF-1 immunofluorescence without a loss of neurites, similar to the developmental down-regulation seen in situ. The effects of retinoic acid on PHF-1 immunofluorescence were modifiable by fibronectin, which can be released by some neuroblastoma cell lines [Ciccarone V. et al. (1989) Cancer Res. 49, 219-225; Yoshihara T. et al. (1992) Int. J. Cancer 51, 620-626]. Exogenous human fibronectin caused a marked up-regulation of PHF-1 immunofluorescence. Quantitative analysis of 15 multicellular areas, from six different cultures, per experimental condition showed a 16-fold increase compared to untreated controls. Up-regulation by fibronectin was also evident in undifferentiated cells. Cell counts indicated no proliferative effects of the fibronectin under the conditions used. Laminin also caused an increase of PHF-1 tau in retinoic acid-treated cells. Data obtained from immunoblots verified the results observed with immunofluorescence. The data show that the PHF-1 tau epitope is spontaneously expressed by non-degenerating human neuroblastoma cells, down-regulated by cellular differentiation, induced by retinoic acid and up-regulated by the extracellular matrix components fibronectin and laminin. One explanation of the data is that fibronectin maintains a population of SHSY5Y cells in a biochemical state of differentiation in which PHF-1 tau is expressed.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Alzheimer's-associated phospho-tau epitope in human neuroblastoma cell cultures: up-regulation by fibronectin and laminin. 765 8

In Alzheimer's disease, Tau proteins are abnormally phosphorylated. In this paper, we describe a cellular model producing such pathological Tau proteins. After differentiation by NGF and treatment with okadaic acid (an inhibitor of phosphatases 1 and 2 A), neuroblastoma SKNSH-SY 5Y cells produced Tau proteins with an increased apparent molecular weight and a more acidic isoelectric point when compared to Tau proteins from control cells. These modified tau proteins bore Alzheimer-type epitopes detectable by antibodies specific to phosphorylated Alzheimer epitopes. This model is the first step toward a pharmacological approach of neuroprotection.
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PMID:[Detection of Alzheimer type pathological epitopes on Tau proteins of neuroblastoma cells after treatment with okadaic acid]. 769 12

Human neuroblastoma cells, LAN, were used to study the phosphorylation and dephosphorylation of tau proteins. These cells contained mainly a form of tau comparable to fetal brain tau in molecular weight (55 kDa). Neuroblastoma tau reacted with antibodies that recognize epitopes spanning the whole tau molecule (E-1, Alz50, Tau-1, and Tau46), and antibodies (PHF-1, NP8, and T3P) that recognize hyperphosphorylated tau (PHF-tau) in Alzheimer's disease (AD) brains. Exposure of the cells to 45 degrees C heat stress resulted in dephosphorylation of the epitopes recognized by PHF-1, NP8, and T3P. Transfer of the heat-stressed cells to 37 degrees C led to rephosphorylation of the dephosphorylated epitopes. Cells that had been treated with okadaic acid (OA), regardless of whether they were subsequently subjected to heat stress or heat stress and recovery, all contained tau with a molecular weight similar to that of control cells. These tau proteins, similar to tau in control cells, also reacted with antibodies to phosphorylated epitopes. However, unlike the tau from control or heat-stressed cells, the OA-treated and heat-stressed tau had decreased reactivity with Tau-1. Alteration of Tau-1 immunoreactivity has been reported to be an early event in AD neurodegeneration. The reduction of Tau-1 immunoreactivity observed in OA-treated samples could be restored by incubation of electroblots of isolated tau with alkaline phosphatase, indicating an induction of the Tau-1 epitope phosphorylation by OA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Reversible heat stress-related loss of phosphorylated Alzheimer-type epitopes in Tau proteins of human neuroblastoma cells. 769 94

Tacrine (THA) and physostigmine (PHS) have been used in Alzheimer's disease therapy for their anticholinesterasic activity. Here we show that THA is taken up in rat lysosomes in an energy-dependent manner, and that it is also accumulated in acidic compartments of rat thymocytes and neuroblastoma cells. A concentration of THA less than 1 mM dissipated the pH gradient (delta pH) in all the above mentioned in vitro systems. On the contrary higher concentrations of PHS (1-2 mM) were ineffective. The accumulation of THA in acidic organelles of the cell may be relevant for the pharmacological action of THA in Alzheimer's treatment.
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PMID:Anticholinesterasic drugs: tacrine but not physostigmine, accumulates in acidic compartments of the cells. 772 36


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