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PubMed1994

Neuron-specific enolase expression during eye development in the chicken embryo.

Neuron-specific enolase has been used by others as a marker for the identification of cells of presumed neural crest origin in the human eye. The contributions of neural crest to the ocular tissues have been studied most definitively in the chicken embryo. The developing chicken eye was therefore chosen to further investigate the usefulness of neuron-specific enolase as a neural crest marker. Chicken embryos of various development stages were processed for the immunohistochemical localization of neuron-specific enolase with two different specific antisera. The nerve fiber layer of the neural retina and the optic nerve reacted positively. The first weak staining was found at day 10; it became rapidly stronger during the next 2 days. A positive reaction was also observed in the ciliary ganglion. In contrast, no staining was found in tissues of known neural crest origin. Cornea, sclera, trabecular tissues and iris stroma remained negative throughout the developmental stages studied. Therefore, neuron-specific enolase can not be used as a reliable marker of neural crest derived cells, at least in the chicken embryo. Unexpectedly the lens epithelium showed moderate neuron-specific enolase activity beginning on day 5. alpha-Enolase is an important crystallin in the lens of some species, particularly the turtle. It has also been demonstrated to be present in the chicken lens in a fairly high concentration. It is possible, that neuron-specific or gamma-enolase has a similar role in the chicken lens.

Animals↗
PubMed1994

Glial-derived S100b protein selectively inhibits recombinant beta protein kinase C (PKC) phosphorylation of neuron-specific protein F1/GAP43.

Protein F1/GAP43 is neuron-specific, associated with neurite outgrowth during development and a substrate for PKC. This protein is present in high levels in serotonergic neurons which in culture sprout in response to the glial-derived S100b, the beta-beta homodimer. As an initial step in determining whether S100b acts on F1/GAP43 we studied the regulation by S100b of PKC phosphorylation of F1/GAP43. Either the S100b or a mixture of S100a and S100b, both from a brain glial cell source, inhibited in vitro phosphorylation of purified F1/GAP43 by purified PKC in a dose-dependent manner. Using recombinant PKC subtypes, purified S100b preferentially inhibited the F1/GAP43 phosphorylation by the beta subtype. The IC50 of S100b for beta I and beta II PKC was 8 microM while for alpha and gamma PKC it was 64 microM. S100b inhibition was thus subtype-selective. Histone III-S phosphorylation by the four PKC subtypes was not inhibited by S100b. S100b inhibition was thus substrate-selective. Moreover, the effect of S100b on phosphorylation could not be explained by a direct inhibition of kinase activity. Together with earlier studies implicating a role for S100 in synaptic plasticity and neurite outgrowth, the present results suggest that S100b may regulate such functions through its inhibition of neuron-specific PKC substrate (F1/GAP43) phosphorylation. The regulation of this neuron-specific substrate phosphorylation by glial S100 suggests the potential for a novel neuro-glial interaction. Finally, the location of S100 gene on chromosome 21, trisomic in Down's syndrome, and over-expressed in this disorder, as well as in Alzheimer's disease, suggests a link to cognitive impairments in human.

Animals↗
PubMed1988

Neuron-specific enolase in comatose children.

Sequential examination of neuron-specific enolase in cerebrospinal fluid and serum was performed in 20 comatose children with acute encephalitis, acute encephalopathy, or Reye's syndrome. Neuron-specific enolase activities corresponded to the degree of brain damage. As neuron-specific enolase levels increased to greater than 80 ng/mL, patients had more severe impairment or died. Neuron-specific enolase may be a useful marker for evaluating the degree of neuronal damage and prognosis.

Acute Disease↗
PubMed1996

Methodological and clinical evaluation of two automated enzymatic immunoassays as compared with a radioimmunoassay for neuron-specific enolase.

We evaluated the clinical and methodological features of the neuron-specific enolase radioimmunoassay (NSE RIA) (Pharmacia = Ph) with the neuron-specific enolase enzyme immunoassay (NSE EIA) on the ES 700 (Boehringer Mannheim = BM) and the NSE EIA on the Cobas Core System (Roche = Ro). A total of 253 serum samples obtained from 37 healthy persons, 45 patients with benign lung diseases, 124 patients with lung cancer (42 with small cell lung cancer, 23 with adenocarcinoma, 21 with squamous cell carcinoma, 11 with large cell carcinoma, and 27 with unknown histology), 34 with lung metastases, 7 patients with sarcoma and 6 patients with malign lymphatic diseases were stored at -80 degrees C and assayed retrospectively. The intra- and inter-assay imprecisions were lower for the automatized test systems than for the RIA. Correlation between the EIA's and the RIA was better for NSE (Ro) than for NSE (BM) (BM/Ph: r = 0.93 and slope = 0.54; Ro/Ph: r = 0.95, slope = 0.79), but weaker than the correlation between the two EIA's: over the whole range r = 0.96, neuron-specific enolase < 50 micrograms/l: r = 0.97, neuron-specific enolase < 20 micrograms/l: r = 0.92. Fixing the specificity at 95% versus benign lung diseases we found a cut off value of 11.9 micrograms/l for NSE RIA (Ph), 15.9 micrograms/l for NSE EIA (BM) and 13.5 micrograms/l for NSE EIA (Ro). Based on this specificity of 95% versus benign lung diseases as the clinically relevant reference group, the sensitivity for NSE RIA was 32% for all lung cancer and 45% for small cell lung cancer, for NSE EIA (BM) 35% for all lung cancer and 43% for small cell lung cancer, the NSE EIA (Ro) had a sensitivity of 42% for all lung cancer and 57% for small cell lung cancer. In a follow-up study of two patients with small cell lung cancer a good comparability for all three assays in the kinetics, but a marked difference in the neuron-specific enolase value levels was found. The results show that the NSE EIA (Ro) on Cobas Core system is the most sensitive assay for the detection of small cell lung cancer.

Enzyme-Linked Immunosorbent Assay↗
PubMed1997

Astrocyte-specific but not neuron-specific transmembrane TNF triggers inflammation and degeneration in the central nervous system of transgenic mice.

To study the involvement of TNF in cerebral pathology in vivo and to define cellular interactions within the central nervous system (CNS) that promote TNF signaling, we have expressed this cytokine either as a wild-type or a mutant transmembrane form in astrocytes or neurons of transgenic mice. Mice expressing wild-type human TNF in either of these cell types spontaneously develop a neurologic disorder manifested by ataxia, seizures, and paralysis and bear histologic evidence of chronic CNS inflammation and degeneration. Moreover, astrocyte-specific expression of transmembrane TNF triggers a similar neurologic phenotype. Interestingly, transgenic mice producing a high level of transmembrane TNF in their neurons develop no apparent phenotypic abnormalities, suggesting that appropriate cellular interactions should form to allow for contact-dependent TNF signals to induce CNS pathology. These results demonstrate that target cells mediating the neuroinflammatory activities of TNF localize in the vicinity of astrocytes rather than neurons.

Animals↗
PubMed1991

Serum neuron-specific enolase levels after subarachnoid hemorrhage.

We examined serum levels of neuron-specific enolase by enzyme immunoassay in 29 patients with subarachnoid hemorrhage due to ruptured cerebral aneurysm. Serum neuron-specific enolase levels were significantly higher in patients with a poor neurological status than in patients with a good neurological status on admission, and the greater the amount of subarachnoid blood, the higher the serum neuron-specific enolase level. Patients with a good outcome had low serum neuron-specific enolase levels throughout their courses. Serum neuron-specific enolase levels increased with development of delayed ischemic neurological deficits and, especially in poor outcome patients, high levels persisted until 3 weeks after the subarachnoid hemorrhage.

Adult↗
PubMed2005

[Clinical and prognostic significance of tumor markers cytokeratin 19 fragment, carcinoembryonic antigen, and neuron-specific enolase in lung cancer].

OBJECTIVE: To evaluate the clinical and prognostic significance of the tumor markers cytokeratin 19 fragment, carcinoembryonic antigen and neuron-specific enolase in lung cancer patients. MATERIALS AND METHODS: Serum levels of cytokeratin 19 fragment, carcinoembryonic antigen and neuron-specific enolase were measured using electrochemical luminescence immunoassay in 46 lung cancer patients. Serum levels of cytokeratin 19 fragment, carcinoembryonic antigen, and neuron-specific enolase higher than 3.6 ng/ml, 5.0 ng/ml and 13.0 ng/ml, respectively, were considered as elevated. RESULTS: Cytokeratin 19 fragment, carcinoembryonic antigen, and neuron-specific enolase were elevated in 19.6%, 43.5%, and 63% of patients, respectively. Elevated levels of neuron-specific enolase were detected more frequently in smokers than in ex-smokers (p=0.003). Likewise preoperative levels of carcinoembryonic antigen (p=0.023) and neuron-specific enolase (p=0.007) were statistically higher in smokers than in ex-smokers. A significant correlation was detected between the level of cytokeratin 19 fragments and smoking cumulative exposure (r=0.542, p=0.037). The number of patients with elevated levels of cytokeratin 19 fragment and neuron-specific enolase was higher in more advanced disease than in early lung cancer (p=0.036 and p=0.036, respectively). Preoperative levels of cytokeratin 19 fragment (p=0.017 and p=0.016, respectively) and neuron-specific enolase (p=0.03 and p=0.006, respectively) were significantly associated with more advanced disease and tumor size, as well as tumor histology in non-small cell lung cancer (p=0.03 and p=0.016, respectively). Preoperative levels of cytokeratin 19 fragments were higher in squamous cell carcinoma than in adenocarcinoma (p=0.026). Elevated preoperative serum levels of cytokeratin 19 fragment predict a poor prognosis for lung cancer patients (p=0.007). CONCLUSION: Alteration of serum tumor markers cytokeratin 19 fragment, carcinoembryonic antigen and neuron-specific enolase is associated with particular tumor histology, smoking habit, more advanced disease and poor prognosis.

Adenocarcinoma↗
PubMed1990

The diagnostic value of neuron-specific enolase and carcino-embryonic antigen analyses in patients with carcinoma of the lung.

Neuron-specific enolase and carcino-embryonic antigen were quantified simultaneously in sera of 135 patients attending the Department of Respiratory Diseases for diagnostic bronchoscopy. Fifteen small cell lung carcinomas, 24 non-small cell lung carcinomas and 96 benign pulmonary diseases were investigated. Lung biopsies or bronchial washings were obtained from about 75% of the patients, including all patients with neoplastic diseases. Serum neuron-specific enolase was measured by a recently introduced enzyme-immuno assay (WaKo NS-Enolase EIA-II testkit). The results obtained with this kit were similar to those based on RIA assays. Receiver Operating Characteristic curves (ROC curves) were constructed for comparison of the discriminating ability of neuron-specific enolase and carcino-embryonic antigen in small cell lung carcinomas and non-small cell lung carcinomas. For small cell lung carcinomas the sensitivity and the specificity of neuron-specific enolase (cutoff value: 10 micrograms/l) were 87% and 88%, respectively, and for carcino-embryonic antigen values 60% and 77% were obtained. There was no correlation between neuron-specific enolase and carcino-embryonic antigen in small cell lung carcinoma patients. The diagnostic value of neuron-specific enolase and carcino-embryonic antigen in non-small cell lung carcinomas is illustrated by sensitivities of 13% and 58%, respectively. An extensive literature survey is included to allow comparison with other studies. The use of ROC curves is recommended for the determination of optimal cutoff values for the assays employed.

Carcinoembryonic Antigen↗
PubMed1999

Alternatively spliced isoforms of FE65 serve as neuron-specific and non-neuronal markers.

FE65 is predominantly expressed in brain and is especially rich in the regions with the highest densities of neurons. The FE65 protein binds to an intracellular domain of the beta-amyloid precursor protein (betaPP) and may modulate the production of beta-amyloid peptide (AP). One of FE65 exons, a mini-exon (exon 9, 6 bp), is alternatively spliced, giving rise to two isoforms varying only in 6 base pairs. We quantitated the two isoforms by a sensitive reverse transcription-competitive polymerase chain reaction technique, and characterized their expressions in various tissues and cell cultures, and the kinetics of expression of the two isoforms in P19 embryonal carcinoma cell lines during neuronal differentiation. Our results show that the exon 9-inclusive (E9) form, the more abundant form in brain, was exclusively expressed in neurons, while the exon 9-exclusive (DeltaE9) form was widely expressed in all non-neuronal cells, but was not expressed in differentiated neurons. When P19 cells were differentiated to neurons, expression of FE65 was significantly up regulated ( approximately 30-fold) and the splicing pattern of the FE65 pre-mRNA was switched from the DeltaE9 pattern to the E9 form. Based upon their distinctive expression patterns, these two isoforms may serve as neuronal and non-neuronal markers, and determination of their ratios may have applications in neuropathological diagnosis.

Aged↗
PubMed1992

Neuron-specific enolase reflects metabolic activity in mesencephalic neurons of the rat.

Numerous studies on the local rate of energy metabolism of various brain regions during development and following experimental manipulation have been conducted using 2-deoxyglucose uptake and cytochrome oxidase (CO) histochemistry, both considered to be reliable indicators of long-term and short-term alterations in neuronal activity, respectively. Another method which has been related to neuronal activity is neuron-specific enolase (NSE) immunohistochemistry. An isoenzyme of enolase, a key element in the glycolytic pathway, NSE is present in neurons and neural-related cells e.g. neuroendocrine cells, pituicytes, and many tumor cells, but not in glia. The distribution on adjacent tissue sections of immunoreactive NSE and histochemically determined CO were mapped in the rat mesencephalon and adrenal medulla. Both methods showed highly restricted localization of staining which coincided with few exceptions in the most reactive areas, namely the superior colliculus, medial and lateral geniculate nuclei, red nucleus, lateral mammillary nucleus, interpeduncular nucleus and substantia nigra pars lateralis and pars reticulata. Immunoreactivity of varying intensity for NSE was also observed in perikarya and in processes of numerous scattered neurons throughout the mesencephalon, including the substantia nigra pars compacta, and reticular formation. The general correspondence in staining patterns between CO and NSE in the midbrain, supports the utility of NSE as a useful index of metabolic activity in neurons.

Animals↗
PubMed1995

The POU homeodomain transcription factor Oct-1 is essential for activity of the gonadotropin-releasing hormone neuron-specific enhancer.

The mechanisms of specification of gene expression in a complex tissue such as the brain remain poorly understood. To provide a model system for the study of gene regulation in a specific subpopulation of differentiated neurons, we have derived cell lines from tumors created in transgenic mice by targeting simian virus 40 T antigen expression by using the regulatory regions of the gene for gonadotropin-releasing hormone (GnRH), a decapeptide released from specialized neurons in the hypothalamus. Transfections into the cultured GnRH-secreting hypothalamic neuronal cell line GT1 have identified a neuron-specific enhancer, 1.5 kb upstream of the GnRH gene, which binds multiple GT1 nuclear proteins. In particular, one AT-rich protein-binding region, AT-a, is critical for enhancer activity. In this study, we used electrophoretic mobility shift assays to detect a GT1 nuclear protein complex that binds the AT-a region. Close inspection of the AT-a bottom-strand sequence revealed homology to the octamer motif, a sequence known to bind members of the POU homeodomain transcription factor family. Although we demonstrate expression of a number of POU homeodomain genes in GT1 cells, a supershift assay with Oct-1 antibody demonstrates that Oct-1 is the protein binding the enhancer. Finally, specific mutations in the AT-a region that affected Oct-1 binding were correlated with decreased transcription. Thus, Oct-1 binds to the GnRH enhancer in vitro, and this binding is critical to the transcriptional activity of this neuron-specific enhancer in GT1 cells.

Animals↗
PubMed1995

The neuron-restrictive silencer factor (NRSF): a coordinate repressor of multiple neuron-specific genes.

The neuron-restrictive silencer factor (NRSF) binds a DNA sequence element, called the neuron-restrictive silencer element (NRSE), that represses neuronal gene transcription in nonneuronal cells. Consensus NRSEs have been identified in 18 neuron-specific genes. Complementary DNA clones encoding a functional fragment of NRSF were isolated and found to encode a novel protein containing eight noncanonical zinc fingers. Expression of NRSF mRNA was detected in most nonneuronal tissues at several developmental stages. In the nervous system, NRSF mRNA was detected in undifferentiated neuronal progenitors, but not in differentiated neurons. NRSF represents the first example of a vertebrate silencer protein that potentially regulates a large battery of cell type-specific genes, and therefore may function as a master negative regulator of neurogenesis.

Amino Acid Sequence↗
PubMed1998

Amniotic fluid neuron-specific enolase: a role in predicting neonatal neurologic injury?

OBJECTIVE: To determine the relationship between amniotic fluid (AF) neuron-specific enolase and the development of neonatal intraventricular hemorrhage and periventricular leucomalacia. METHODS: Thirty-nine AF samples, obtained from women in preterm labor between 24 and 32 weeks' gestation, were analyzed for neuron-specific enolase. All women delivered preterm neonates who had neurosonograms on the 3rd and 7th days of life. The results of the neurosonograms were used to divide the study population first into normal and abnormal groups, then into normal, minor, and major brain lesion groups. The groups were compared for the median neuron-specific enolase, proportion with values of 6 microg/L or more, and other demographic characteristics. RESULTS: There were no differences between the groups' maternal and neonatal characteristics. However, the abnormal group had significantly higher median value of neuron-specific enolase than the normal group (9.5 microg/L and 2.0 microg/L, respectively; P < .001). The median neuron-specific enolase levels for the major, minor, and normal groups were 9.75 microg/L, 6.5 microg/L and 2.0 microg/L, respectively (P < .001). The optimum cutoff point, with a sensitivity of 89% and specificity of 100%, was 6 microg/L; 89% of the abnormals had values of 6 microg/L or more, compared with none of the normals (P < .001). The risk of developing intraventricular hemorrhage or periventricular leucomalacia was 11.5 times greater when AF neuron-specific enolase levels were 6 microg/L or more. CONCLUSION: Amniotic fluid neuron-specific enolase is a useful marker of neonatal neurologic injury.

Adult↗
PubMed1988

Neuron-specific enolase is a marker of cerebral ischemia and infarct size in rat cerebrospinal fluid.

Neuron-specific enolase concentrations were measured in samples of rat cerebrospinal fluid obtained repeatedly before and after occlusion of the middle cerebral artery. A method for reliable, repeated sampling of cisternal cerebrospinal fluid was developed for this purpose. Occlusion of the middle cerebral artery induced cerebral infarcts of slightly variable size with good correlation to raised neuron-specific enolase concentrations. Sham operation caused only superficial cortical damage at the site of surgery and was followed by an early, slight, and transient increase in neuron-specific enolase concentration. With our technique, the development of cerebral infarcts can be studied in individual rats under experimentally controlled conditions over an extended period of time. Analysis of neuron-specific enolase can be used in trials of drugs for mitigating the effect of ischemia. Information concerning the release of neuron-specific enolase from ischemic cerebral tissue to the cerebrospinal fluid is important because neuron-specific enolase in the cerebrospinal fluid can be determined in patients suffering from cerebrovascular insult.

Animals↗
PubMed1987

The structure and expression of neuron-specific enolase gene.

Neuron-specific (gamma gamma) enolase (NSE) is an isoenzyme form of glycolytic enzyme, enolase. We isolated genomic clones for NSE and clarified NSE gene structures. The NSE-gene spanned about 9 kb and consisted of twelve exons and eleven introns. Multiple transcriptional start points were identified by a combination of S1 nuclease mapping and primer extension analysis. In the 5'-flanking region we found a TATA-like sequence TCTATAGGC which was only partially homologous to the consensus sequence, but we did not find a CAAT box. The sequence in the immediate 5'-flanking region was of a relatively high G + C content and contained GC-box-like clusters that did not correspond to the typical GC box. In addition, we found seven classes of the repeated sequences. In the introns 1, 5 and 10 there were tandem repeats (GT)33, (GT)21 and (GT)24, respectively. The 3' end contains a single polyadenylation site and an identifier sequence 2 kb downstream from the poly(A)-addition site. The in vitro cell-free transcription of the truncated genomic DNA fragment using HeLa cell extract showed that the transcription start points have been correctly identified and the putative promoter sequences appear to be functional.

Amino Acid Sequence↗
PubMed1995

Promoter elements conferring neuron-specific expression of the beta 2-subunit of the neuronal nicotinic acetylcholine receptor studied in vitro and in transgenic mice.

Several genes encoding subunits of the neuronal nicotinic acetylcholine receptors have been cloned and regulatory elements involved in the transcription of the alpha 2 and alpha 7-subunit genes have been described. Yet, the detailed mechanisms governing the neuron-specific transcription and the spatio-temporal expression pattern of these genes remain largely uninvestigated. The beta 2-subunit is the most widely expressed neuronal nicotinic receptor subunit in the nervous system. We have studied the structural and regulatory properties of the 5' sequence of this gene. A fragment of 1163 bp of upstream sequence is sufficient to drive the cell-specific transcription of a reporter gene in both transient transfection assays and in transgenic mice. Deletion analysis and site-directed mutagenesis of this promoter reveal two negative elements and one positive element. The positively-acting sequence includes one functional E-box. One of the repressor elements is located in the transcribed region and is the NRSE/RE1 sequence already described in promoters of neuronal genes. In this paper, we describe the neuron-specific promoter of the gene encoding the neuronal nicotinic acetylcholine receptor beta 2-subunit.

Animals↗
PubMedDate not supplied

Age dependence and prognostic impact of neuron specific enolase (NSE) in children with neuroblastoma.

Serum neuron specific enolase (NSE) was determined in 159 patients with neuroblastoma at diagnosis and in 183 children of various age groups. We found an age dependence of reference intervals for NSE and defined the 95th percentiles as upper normal limits. The specificity was 91.3% and the sensitivity 73.0%. The incidence of abnormal NSE levels increased with stage. The NSE serum levels were not influenced by histologic differentiation. Neuron specific enolase proved to be a reliable tumor-marker for monitoring the disease. Moreover, abnormal NSE values at diagnosis were of prognostic significance for patients with localized neuroblastoma (stages I-III) and for children with metastatic disease (stage IV), but not for infants with stage IV S. In comparison to catecholamine metabolite determination neuron specific enolase appeared to be a slightly less specific, equally sensitive tumor marker but with prognostic information for children with neuroblastoma.

Age Factors↗
PubMed1982

Neuron specific enolase: a common marker for the endocrine cells and innervation of the gut and pancreas.

Neuron specific enolase, the most acidic isoenzyme of the glycolytic enzyme enolase, was first believed to be present exclusively in central neurons. More recently, it has been found in peripheral autonomic nerves and in a number of endocrine cells. An immunocytochemical study was carried out concerning the distribution of neuron specific enolase in the gastrointestinal tract and pancreas of humans and rats. In addition, immunocytochemistry and histochemistry were used to obtain a characterization of the different types of cells and nerves in which neuron specific enolase can be detected. Neuron specific enolase was found in all currently identifiable endocrine cell types and nerves of the gut and pancreas. Neuron specific enolase is therefore a common marker for both endocrine cells and enteric nerves, thus providing a simple means for their simultaneous demonstration and examination of their morphologic characteristics and integration.

Animals↗