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At least 19 recordsLinked to original sources
PubMed1986

[Content of neuron-specific and non-neuron-specific enolase isoenzymes in human brain structures].

The distribution of neuron-specific (NSE) and non-neuronal (NNE) isoforms of glycolytic enzyme enolase (EC 4.2.I.II.) in the human brain was studied using immunoenzyme assay. The maximum NSE concentration was measured in the frontal and occipital brain cortex, hippocampus, limbic cortex and hypothalamus (12-14 micrograms/mg of water-soluble protein), the minimum level was observed in the brain stem structures (3-6 micrograms/mg). The maximum NNE content was determined in thalamus (34 micrograms/mg). The data can prove useful for the study of enolase isoform distribution in the brain of neurological and psychiatric patients.

Brain↗
PubMed1986

Immunohistochemical study of neuron-specific enolase and CA 19-9 in pancreatic disorders. The value of neuron-specific enolase as a marker for islet cell and nerve tissue.

Immunohistochemical studies of neuron-specific enolase were performed on pancreatic tissues from patients with insulinoma, nonfunctioning islet cell tumor, chronic pancreatitis, and pancreatic adenocarcinoma, and from 5 normal patients. The concentration of neuron-specific enolase was also measured in the sera of patients and in the pancreatic tissue, and the tissues were stained for carbohydrate antigen 19-9 by immunohistochemical techniques. Neuron-specific enolase was localized in nerve fibers, normal islet cells, and islet cell tumors; its concentration was elevated only in the tissue of islet cell tumors and in serum from patients with insulinoma. In the pancreatic tissue of pancreatitis or pancreatic adenocarcinoma, various changes in acini and islets were present. The altered islets stained clearly for neuron-specific enolase and could easily be distinguished from altered, unstained acini in cases of pancreatitis or pancreatic adenocarcinoma. Islets in the pancreatic tissue remained intact with various morphologic changes, although acini had degenerated severely. Carbohydrate antigen 19-9 was localized in all the carcinoma cells in the pancreatic tissue and in some of the normal pancreatic ducts. No cells were simultaneously immunostained by anti-neuron-specific enolase and anti-carbohydrate antigen 19-9 antibodies. Thus, neuron-specific enolase is a good marker for islet cell tumor, and is valuable for examining islets in pancreas with various disorders both alone and in combination with other tumor markers.

Adenocarcinoma↗
PubMed1989

Expression of synaptophysin and neuron-specific enolase during neuronal differentiation in vitro: effects of dimethyl sulfoxide.

Neural development in dissociated cell cultures of fetal rat brain can be expected to depend on synaptic interactions between cultured neurons. Therefore, an attempt was made to obtain a quantitative measure of the time course of synaptogenesis in such a culture system by assessing the level of the secretory vesicle-associated protein synaptophysin (p38). The developmental schedule of p38 was compared to that of neuron-specific enolase (NSE), an established marker of neuronal differentiation. Cultures were raised from dissociated 14 day-old fetal rat diencephalon. In cultures grown for 1-2 days in vitro (DIV), p38-immunoreactivity was preferentially located in neuronal perikarya. After 10-16 DIV, neurons in culture had formed a dense neuritic network, and almost all of the p38-immunoreactivity occurred in the form of fine punctate deposits associated with neuronal processes that often outlined neuronal cell bodies in a basket-like fashion. Electron-microscopic immunocytochemistry proved the punctate deposits to be presynaptic elements, mostly in the form of axonal varicosities. Quantitative immunoblotting showed that levels of p38 increased from the start of cultivation to DIV 4, stayed fairly constant from DIV 4 to DIV 8, and rose again steeply to peak at DIV 12. In contrast, levels of NSE rose continuously up to DIV 12. After DIV 12, levels of both p38 and NSE fell again. Treatment of cultures with dimethyl sulfoxide (DMSO), an agent known to induce differentiation in various normal and malignant cell types, resulted in a significant increase of p38 levels and in a decrease of NSE levels. The amount of p38 continued to increase beyond DIV 12, whereas NSE diminished after having reached a maximum at DIV 12.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Enzymatic determination of serum neuron-specific enolase in small cell lung cancers. Utility of the serum neuron-specific enolase/serum nonneuronal enolase ratio.

Increasing interest is shown in the determination of the serum neuron-specific enolase for the diagnosis and the follow-up studies of small cell lung cancers. We report results obtained by an enzymatic procedure that permits the simultaneous determination of the neuron and nonneuron-specific enolase and the calculation of the ratio of these two components. The utility of this ratio which characterizes elevations of the serum neuron-specific enolase from a poor or rich source of this component was tested in 38 patients with small cell lung carcinoma and in 57 subjects suffering from other bronchogenic cancers. The control group consisted of 37 blood donors and 56 patients with respiratory disease. For the diagnosis, the sensitivity and the specificity of the enzymatically determined neuron-specific enolase compared well with published results obtained by radioimmunoassay and enzymoimmunoassay. The use of the ratio clearly increases the specificity of the test, since only 5.3 percent of false positive results are found when bronchogenic tumors other than small cell carcinoma are studied. The sensitivity was 76 and 100 percent in diagnosis of limited and extensive forms, respectively. The use of this ratio in the follow-up of the patients and for the determinations in hemolyzed samples is set out.

Adult↗
PubMed1992

Distinction of two different classes of small-cell lung cancer cell lines by enzymatically inactive neuron-specific enolase.

Neuron specific enolase (NSE) is widely used as a neuro-endocrine marker. However the presence of NSE in many non-neuroendocrine tissues has raised questions on the specificity of NSE. We have investigated NSE immunoreactivity (NSA-ag), gamma-enolase activity and total enolase activity in small cell lung cancer (SCLC) cell lines. During well-controlled exponential growth comparison of NSE-ag content and gamma-enolase activity with the doubling-time (Td) and NSE-ag content with gamma-enolase and total enolase activity led to a clear distinction of two types of cell line: variant cell lines plus part of the classic cell lines (type I) and the remaining classic cell lines (type II). The distinction was based upon both an abrupt 6-fold increase of gamma-enolase activity and an 18-fold increase of NSE-ag, which for the larger part was enzymatically inactive. Within each group the increase of NSE-ag content was significantly correlated with the increase of gamma-enolase activity and both NSE-ag content and gamma-enolase activity increased linearly with Td. It is concluded that gamma-enolase seems to be associated with the regulation of growth rate and that a compound with the gamma-enolase antigen but without enzyme activity can distinguish two different classes of SCLC cell lines. Furthermore the demonstration that NSE-ag can represent the active enzyme as well as an enzymatically inactive compound may explain why a controversy about neuron- or non-specificity of NSE exists.

Carcinoma, Small Cell↗
PubMed1991

Neuronal survival factor from bovine brain is identical to neuron-specific enolase.

Neuronal survival factors in the central nervous system were investigated by using a primary culture of embryonic rat neocortical neurons. Bovine hippocampus was homogenized, and the supernatant from high-speed centrifugation was used as the starting material. At the step of DE-52 ion-exchange chromatography, neuronal survival activity was recovered in two fractions, fraction 14 (F14) and fraction 23 (F23). Antisera to the crude F14 and F23 fractions were raised in rabbits. These two antisera completely inhibited the neurotrophic activity of both fractions. Western blotting analysis revealed that anti-F14 antiserum recognized mainly a 30-kDa protein in F14 and anti-F23 antiserum recognized mainly a 44-kDa protein in F23. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis of F23, the 44-kDa protein was cut out from the gel and partial amino acid sequences of the protein fragments were determined. A GenBank data bank indicated that the amino acid sequence of the fragment was identical to that of neuron-specific enolase (NSE). In our assay system, commercially available NSE itself possessed neuronal survival activity for the cultured neocortical neurons. The effects of NSE and F23 were inhibited completely by anti-NSE polyclonal antibody. Furthermore, highly purified NSE supported the survival of cultured neurons in a dose-dependent manner, and the neurotrophic effect was inhibited by monoclonal antibody to the NSE. These results strongly suggest that NSE is one of the neuronal survival factors in the central nervous system.

Animals↗
PubMed1986

Isolation of murine neuron-specific and non-neuronal enolase cDNA clones.

cDNA clones corresponding to subunits of neuron-specific (gamma gamma and alpha gamma) and non-neuronal (alpha alpha) enolase isozymes were characterized from two mouse brain cDNA libraries. Our hybridization data revealed a partial homology of the coding sequences of mouse alpha, mouse gamma and rat gamma mRNAs. The noncoding sequences, however, appear to be specific for each mouse mRNA. Although coding for two polypeptides of the same molecular weight, the mRNA for the gamma subunit (2600 bases) is larger than that for the alpha subunit (1900 bases). The noncoding sequences for neuron-specific gamma mRNA (about 1300 bases) are therefore longer than those of the non-nervous tissue specific alpha mRNA (about 600 bases).

Animals↗
PubMed1985

Factors involved in expression of neuron-specific and non-neuronal enolase activity in developing chick brain and in primary cultures of chick neurons.

The effect of various factors affecting non-neuronal enolase (NNE) and neuron-specific enolase (NSE) was investigated in developing brain of two different chick strains, in primary cultures of pure neurons and of mixed cultures of neuronal and glial cells. NNE and NSE activities reached their maximum at an earlier stage of brain development in the fast growing Hybro strain than in the Leghorn strain. In pure neurons cultured during 6 days, NNE was stimulated by hydrocortisone in presence or in absence of serum. Dibutyryl cyclic AMP (diBcAMP) stimulated NNE only in serum-free medium. NSE activity was increased by glial cell-conditioned medium in presence of serum and by removal of serum from the medium. Hydrocortisone and diBcAMP had no effect on NSE. In mixed cultures of neurons and glial cells both enolase activities were raised in absence of serum. Hydrocortisone and diBcAMP had no effect. Steroid hormones, insulin and serum albumin also modify both enolase activities in pure neurons and in mixed cultures of neurons and glial cells. Our results suggest that NNE and NSE are regulated separately by various factors involved in nerve cell maturation.

Animals↗
PubMed1985

Neuron-specific enolase in mucosal endocrine cells and carcinoid tumours of the small intestine: a comparative study with neuron-specific enolase immunocytochemistry and silver stains.

Endocrine cells of human small intestinal mucosa, small intestinal carcinoids and carcinoid liver metastases were stained with an immunocytochemical technique using an antiserum against neuron-specific enolase (NSE), with the argyrophil technique of Grimelius and with the argentaffin technique of Masson. In the normal mucosa, scattered NSE-immunoreactive cells were seen mainly in the deeper parts of the crypts. These cells, as shown in the same sections, corresponded to the argentaffin and/or argyrophil cells indicating that they were of endocrine type. All intestinal carcinoids (16 cases) displayed NSE immunoreactivity. However, this reaction did not correlate on the cellular level with the silver techniques employed. Thus, many tumour cells were NSE immunoreactive but lacked an argentaffin or argyrophil reaction and vice versa. On the light microscopical level the silver techniques reveal the presence of neurohormonal granules in the tumour cells, while the NSE immunoreactivity appears to disclose neuroendocrine differentiation of the tumour cells irrespective of their hormone and granular content. Out of 13 carcinoid liver metastases, eight displayed strong NSE immunoreactivity, three were weakly stained and two were unreactive. Consecutive or the same tumour sections showed an argentaffin and argyrophil reaction in all carcinoid metastases. Since silver staining provides one type of information and NSE immunocytochemistry another, they provide in combination a good discriminator for neuroendocrine tumours.

Carcinoid Tumor↗
PubMed1986

Multiple calcium-activated neutral proteinases (CANP) in mouse retinal ganglion cell neurons: specificities for endogenous neuronal substrates and comparison to purified brain CANP.

Calcium-activated neutral proteinases (CANPs) and their specificities for axonally transported proteins were studied within intact axons of mouse retinal ganglion cell (RGC) neurons in vitro. Two CANP activities with markedly different properties were identified. CANP B, at endogenous calcium levels, selectively cleaved the 145,000 Da (145 kDa) neurofilament protein subunit to yield 143 and 140 kDa neurofilament proteins that are also major constituents of the axonal cytoskeleton. This process represents a posttranslational modification of the neurofilament protein subunit rather than the initial step in its degradation (Nixon et al., 1982, 1983). A second calcium-activated neutral proteinase activity, CANP A, appeared only when calcium levels in the incubating medium were 100 microM or higher. CANP A degraded most proteins in RGC axons but acted considerably more rapidly on high-molecular-weight species. In particular, a 290-320 kDa protein in the Group IV (SCb) phase of axoplasmic transport was degraded 3 X faster than other major axonal proteins, including neurofilament proteins and fodrin. When maximally expressed, CANP A activity represented an enormous proteolytic potential in RGC axons--more than 50% of the total axonal content of proteins larger than 60 kDa could be hydrolyzed within 5 min. The calcium requirements, inhibitor profile, and substrate specificity of CANP A were similar to those of mCANP, the major CANP of mouse brain purified to homogeneity, suggesting that these enzymes may be the same or highly related proteins. The existence in a single neuron type of two CANP activities with markedly different substrate specificities and enzymatic properties emphasizes the possible functional diversity of calcium-activated neutral proteinases in neurons. These functions include the posttranslational modification, as well as degradation of neuronal proteins.

Animals↗
PubMed1985

Distribution of neurofilament protein and neuron-specific enolase in peripheral neuronal tumours.

Peripheral neuronal tumours were studied by the peroxidase-antiperoxidase (PAP) method for the presence of the neurofilament protein (NFP) and neuron-specific enolase (NSE). All cases of ganglioneuromas and ganglioneuroblastomas were positive for NFP and NSE. Both markers were observed only in tumour cells showing differentiation towards ganglion cells. Of the 14 cases of neuroblastoma, 8 were positive for NFP and 12 were positive for NSE. NSE was detected in most neuroblastic tumour cells. However, NFP was found in neuroblasts with signs of differentiation, such as nuclear enlargement, but not in immature, small round cells. NFP was present in cell bodies as well as in cytoplasmic processes of partially differentiated neuroblasts. The majority of pseudorosettes showed no NFP stain. Thus, antibodies against both NFP and NSE are useful in the diagnosis of peripheral neuronal tumours. Moreover, the presence of NFP seemed to be related to the degree of tumour cell differentiation.

Brain Neoplasms↗
PubMed1991

Does steric interference between splice sites block the splicing of a short c-src neuron-specific exon in non-neuronal cells?

The neuron-specific splicing of the mouse c-src N1 exon was analyzed. Model src genes, transiently expressed in HeLa and LA-N-5 neuroblastoma cells, were assayed for the insertion of the 18-nucleotide neuron-specific N1 exon into their product mRNA. The normal clone fails to use this exon in HeLa cells but inserts the exon into 50% of the mature mRNA in LA-N-5 cells. When the exon and flanking intron sequences are placed between two adenovirus exons, the N1 exon is still only inserted in the neural cells. Thus, the neural specificity is a property of the exon itself and its immediate flanking sequences. Simply extending the length of the N1 exon to 109 nucleotides allows its efficient use in HeLa cells, implying that the exon is normally skipped because it is too short to allow spliceosomes to assemble at both ends simultaneously. This model predicts that exclusion of the exon should be sensitive to proteins or mutations that alter the relative strength of the flanking splice sites. Mutations that change these splice sites support this hypothesis.

Animals↗
PubMed1992

Heterologous monoamine reuptake: lack of transmitter specificity of neuron-specific carriers.

The effect of systemic administration of desmethylimipramine (DMI), an inhibitor of the noradrenaline (NA) reuptake carrier, and of GBR 12909, an inhibitor of the dopamine (DA) reuptake carrier, on the in vivo extracellular concentrations of dopamine (DA) was studied by transcerebral dialysis in the prefrontal cortex and in the dorsal caudate of freely moving rats. In the NA-rich prefrontal cortex only DMI increased extracellular DA concentrations whereas in the dorsal caudate only GBR 12909 was effective. Haloperidol increased extracellular DA concentrations more effectively in the dorsal caudate than in the prefrontal cortex. Pretreatment with DMI, which failed to modify the effect of haloperidol in the dorsal caudate, potentiated its action in the prefrontal cortex. The reverse was obtained after GBR 12909+ haloperidol in the two areas. 6-hydroxydopamine lesioning of the dorsal NA bundle prevented the ability of DMI to increase DA concentrations. The results suggest that reuptake into NA terminals is an important mechanism by which DA is cleared from the extracellular space in a NA-rich area such as the prefrontal cortex. The elevated extracellular concentrations of DA resulting from blockade of such mechanism by tricyclic antidepressants may play a role in the therapeutic effects of these drugs.

Animals↗
PubMed1992

CSF neuron-specific enolase as a quantitative marker of neuronal damage in a rat stroke model.

A technique for chronic cisternal cerebrospinal fluid (CSF) sampling in conscious rats was used to obtain multiple 50 microliters samples before and up to 7 days after middle cerebral artery occlusion. Neuron-specific enolase (NSE) concentrations were measured by radioimmunoassay using a readily available kit. The volume of infarction was measured by integrating the area of damage on 9 evenly spaced histological sections of the forebrain. This correlated well (r = 0.97, P less than 0.001) with the concentration of CSF neuron-specific enolase integrated over the first 5 days post occlusion, in animals with pure cortical and mixed cortical and striatal lesions. The correlation was maintained in animals given the NMDA antagonist MK-801. There was also a good correlation between the CSF NSE concentration 3 days post-MCAO and the volume of infarction (r = 0.92, P less than 0.01). It is therefore possible that CSF neuron-specific enolase may be useful as a quantitative marker of ischaemic damage in humans and provide a useful adjunct in the assessment of neuroprotective drugs in stroke.

Animals↗
PubMed1987

Neuron-specific enolase. Assessment by ELISA in patients with small cell carcinoma of the lung.

Measurement of tissue-specific enolase isoenzymes may be of assistance in identifying small cell carcinomas of the lung and in distinguishing them from other pulmonary tumors. Enolase (E.C. 4.2.1.11) is a dimeric enzyme composed of various permutations of three immunologically distinct subunits alpha, beta, and gamma. Five isoenzymes alpha alpha, beta beta, gamma gamma, alpha beta, and alpha gamma have been identified. Immunohistochemical studies using antibodies to the gamma subunit have localized alpha gamma and gamma gamma specifically within neuronal and neuroendocrine tissues. Because of this limited distribution, neuron-specific enolase (NSE) can function as a biochemical marker for neuroendocrine tumors. The authors developed an enzyme-linked immunosorbent assay (ELISA) using the double antibody sandwich method. The sandwich is composed of rabbit antirat enolase that cross-reacts to the human gamma monomer, making the test specific for the gamma gamma isoenzyme. The avidin-biotin-peroxidase complex system is used to provide increased assay sensitivity. Serum samples from patients with histologically diagnosed small cell carcinoma have concentration of NSE 20- to 30-fold greater than that found in normal serum. Studies were conducted on patients with a variety of malignant pulmonary lesions and compared with controls to determine the value of NSE as a tumor marker.

Carcinoma, Small Cell↗
PubMed1985

Preparation and characterization of monoclonal antibodies to human neuron-specific enolase.

Neuron-specific enolase (NSE) has been increasingly recognized as a marker for neuroendocrine tumors including small cell carcinoma of the lung (SCCL). To prepare monoclonal antibodies (MAbs) specific for human NSE, we first developed a simple method of purifying NSE by direct chromatofocusing of a crude extract of human brain tissue. BALB/c mice were then immunized with our preparation of NSE, and MAbs against NSE were generated utilizing a hybridoma technique. The antibodies were screened against both NSE and non-neuronal enolase (NNE) by a solid-phase radioimmunoassay (SPRIA). After cloning and subcloning of hybridomas, two groups of anti-NSE MAbs were identified by SPRIA. One group reacted specifically with NSE but not with its isoenzyme NNE, irrespective of whether antigens were glutaraldehyde fixed or unfixed. A second group reacted with both NSE and NNE when the latter were glutaraldehyde fixed, but surprisingly with neither antigen in the absence of fixation. Group I antibodies were further characterized by immunoblotting, and by immunocytochemistry of normal brain and liver sections and sections of SCCL. The results further supported the specificity of group I antibodies for NSE. These MAbs have potential utility in the diagnosis and management of neuroendocrine tumors, and in further understanding the biology of NSE.

Antibodies, Monoclonal↗
PubMed1986

Immunohistochemical localization of neurofilaments and neuron-specific enolase in 29 cases of neuroblastoma.

Twenty-nine neuroblastomas have been examined with the use of rabbit antibodies specific for each of the three neurofilament polypeptides, with a monoclonal antibody specific for the NF-L polypeptide, and with a rabbit antibody specific for neuron-specific enolase. When frozen material was used, all neuroblastomas were positive with the neurofilaments antibodies. When alcohol-fixed paraffin-embedded material was used, neurofilament staining was weaker and the fixation procedure appeared to destroy the epitopes recognized by the NF-L antibodies preferentially. Although all neuroblastomas were positive for neurone-specific enolase, so were two rhabdomyosarcomas, suggesting that NSE is not an appropriate marker to distinguish the different small blue cell tumors of children.

Adolescent↗