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PubMed1989

Malignant peripheral nerve sheath tumors and spindle cell sarcomas: an immunohistochemical analysis of multiple markers.

An immunocytochemical study using a panel of commercially available antisera, has been performed to distinguish on the basis of their immunoreactivity a series of spindle cell sarcomas diagnosed solely on the histologic features: 11 malignant schwannomas (MS), 8 leiomyosarcomas (LMS) and 3 malignant fibrous histiocytomas (MFH). The results have been compared with those obtained in 12 benign and 8 malignant peripheral nerve sheath tumors (MPNST) in which the microscopic diagnosis was supported by their origin in a nerve trunk and/or in von Recklinghausen's (vR) disease. The following antisera were used: anti-S-100 protein, anti-Leu-7, anti-neuron specific enolase (NSE), anti-myelin basic protein (MBP), anti-glial fibrillary acidic protein (GFAP) and anti-actin. S-100 protein was present in 100% of benign and malignant peripheral nerve tumors and in 7/11 (63%) of MS diagnosed on histological basis only and in 3/8 (37%) LMS. MFH were negative. Leu-7 positivity was observed in 8/12 (66%) and 6/8 (75%), respectively, in benign and malignant PNS neoplasms, in 5/11 (45%) MS, 4/8 (50%) LMS and 2/3 (66%) MFH. NSE was present in 7/12 (58%) and 6/8 (75%), respectively, in benign and malignant PNS tumors, in 6/11 (54%) MS and in 1/8 (12%) LMS. MFH were negative. MBP resulted negative in peripheral nerve neoplasms and spindle cell sarcomas. GFAP positivity was observed in 2/12 (16%) and 1/8 (12%), respectively, in benign and malignant PNS neoplasms. All spindle cell sarcomas were negative. All cases of MPNST and spindle cell sarcomas showed actin immunoreactivity. These results indicate that: (1) MBP, Leu-7 and NSE do not represent markers of schwannian differentiation; (2) GFAP, although rarely expressed, may indicate schwannian differentiation, and (3) malignant peripheral nerve neoplasms and LMS share immunoreactivity for S-100, Leu-7, NSE and actin, therefore they cannot be differentiated on immunocytochemical basis using commercially available antisera.

Actins↗
PubMedDate not supplied

[Peripheral neuroepithelioma].

Neuroepithelioma of the soft tissues of the right parietotemporal region in the 25-year-old male patient is described. The tumor grew through the cranial bones into the dura mater. The patient died 1.5 months after the appearance of the first clinical signs of the disease of brain edema and invasion of the cerebellum into the great foramen occipitalis with compression of the medulla oblongata. The histological structure of the tumor and expression of neuron-specific enolase, synaptophysin, S-100 protein and glial fibrillary acidic protein by tumor cells prove its neurogenic origin.

Adult↗
PubMed1974

Calorimetric studies of the role of magnesium ions in yeast enolase catalysis.

The binding of magnesium ions and of the competitive inhibitor 3-phospho-D-glyceric acid to yeast enolase (2-phospho-D-glycerate hydrolyase, EC 4.2.1.11) has been studied calorimetrically. Thermal titration of the apoprotein with magnesium ions provides evidence that two magnesium ions bind immeasurably tightly to the dimeric enzyme, either anticooperatively to interacting sites or to two independent, nonidentical sites. Measurements of the saturation heat in buffers with different enthalpies of protonation are consistent with the release of two protons when the metal-binding sites are filled at pH 7.5. The enthalpy of binding of the two magnesium ions, corrected for the release of two protons, is +11.7 kcal (+49.0 kJ) per mole of dimeric protein. Thermal titration of the magnesium-saturated enzyme with 3-phosphoglyceric acid corroborates the conclusion of Spring and Wold [Biochemistry (1971) 10, 4655-4660] that the enolase dimer possesses two equivalent and independent substrate-binding sites. The dissociation constant for the enzyme-inhibitor complex calculated from the thermal data is 2 mM. The thermal studies of 3-phosphoglyceric acid binding also confirm that metal ions are required for substrate binding and that substrate binds at the two specific metal-binding sites on the apoprotein. Experiments in buffers with different enthalpies of ionization provide evidence for proton uptake when 3-phosphoglyceric acid is bound.

Apoproteins↗
PubMed2005

Distribution and cellular localization of insulin-regulated aminopeptidase in the rat central nervous system.

Central infusions of angiotensin IV enhance spatial learning, memory retention and retrieval, neurotransmitter release, and long-term potentiation via interaction with a specific, high-affinity binding site. This site was recently purified and identified as the insulin-regulated aminopeptidase (IRAP). This enzyme was previously characterized as the marker protein of specialized insulin-responsive vesicles containing GLUT4 in muscle and adipose tissue. The present study provides the first comprehensive description of IRAP distribution in the adult rat brain. By using immunohistochemistry, IRAP was found to be highly expressed in selected olfactory regions, in septal and hypothalamic nuclei, throughout the hippocampal formation and cerebral cortex, and in motor and motor associated nuclei. IRAP was expressed exclusively in neurons in these regions. At the cellular level, IRAP was localized within cell bodies, excluding the nucleus, in a punctate vesicular pattern of expression. IRAP-positive immunoreactivity was also found in some proximal processes but was not detected in synaptic nerve terminals. The neurochemical composition of IRAP-containing neurons was further characterized by dual-label immunohistochemistry. IRAP was expressed in cholinergic cell bodies of the medial septum, a source of cholinergic projections to the hippocampus and cerebral cortex. The distribution of IRAP in motor and motor-associated nuclei; the colocalization of the enzyme with potential in vivo substrates, oxytocin and vasopressin in the hypothalamus; and the colocalization with GLUT4 in selected nuclei all suggest diverse physiological roles for IRAP in the rat central nervous system.

Aminopeptidases↗
PubMed2004

Systemic administration of N-acetylcysteine protects dopaminergic neurons against 6-hydroxydopamine-induced degeneration.

The results of several in vitro studies have shown that cysteine prodrugs, particularly N-acetylcysteine, are effective antioxidants that increase the survival of dopaminergic neurons. N-acetylcysteine can be systemically administered to deliver cysteine to the brain and is of potential use for providing neuroprotection in the treatment of Parkinson's disease. However, it has also been reported that an excess of cysteine may induce neurotoxicity. In the present study, we injected adult rats intrastriatally with 2.5 microl of 6-hydroxydopamine (7.5 microg) and N-acetylcysteine (240 mM) or cysteine (240 mM) or intraventricularly with 6-hydroxydopamine (200 microg) and subcutaneously with N-acetylcysteine (10 and 100 mg/kg). We studied the effects of these compounds on both the nigrostriatal dopaminergic terminals and the surrounding striatal tissue. The tissue was stained with fluoro-jade (a marker of neuronal degeneration) and processed by immunohistochemistry to detect tyrosine hydroxylase, neuronal and glial markers, and the stress protein heme-oxygenase-1. After intrastriatal injection, both cysteine and N-acetylcysteine had clear neuroprotective effects on the striatal dopaminergic terminals, but also led to neuronal degeneration (as revealed by fluoro-jade staining) and astroglial and microglial activation, as well as intense induction of heme-oxygenase-1 in astrocytes and microglial cells. Subcutaneous administration of N-acetylcysteine also induced significant reduction of the dopaminergic lesion (about 30% reduction). However, we did not observe appreciable N-acetylcysteine-induced fluoro-jade labeling in striatal neurons or any of the above-mentioned changes in striatal glial cells. The results suggest that low doses of cysteine prodrugs may be useful neuroprotectors in the treatment of Parkinson's disease.

Acetylcysteine↗
PubMed2005

Involvement of glial cell line-derived neurotrophic factor in activation processes of rodent macrophages.

The physiological roles of glial cell line-derived neurotrophic factor (GDNF) expressed in the microglia/macrophages of the injured spinal cord have not yet been clarified. mRNA expression of chemokines, including monocyte chemoattractant protein (MCP)-1, was evoked within 1 hr after transection of the spinal cord, and GDNF mRNA expression was similarly up-regulated. Immunohistochemical analysis showed that GDNF was coexpressed with MCP-1 in the CD11b-positive cells. Therefore, we examined further the effects of GDNF on cultured rat peritoneal macrophages. GDNF enhanced the phagocytic activity of the macrophages via GFRalpha-1, glycosylphosphatidylinositol-anchored specific binding site of GDNF, in a c-Ret-independent manner. The influence of autocrine and/or paracrine GDNF synthesis was evaluated by performing activation experiments using macrophages cultured from heterozygous (+/-) GDNF gene-deficient mice or wild-type (+/+) mice. There were no morphological differences dependent on genetic types or stimulators. However, the GDNF mRNA level, but not the MCP-1 or GFRalpha-1 mRNA level, was substantially lower in the mutant macrophages than in the +/+ cells irrespective of stimulation with MCP-1 or lipopolysaccharide (LPS). The phagocytic activity enhanced by MCP-1 or LPS was significantly lower in the mutant cells (+/-) than in the +/+ ones, demonstrating the involvement of endogenous GDNF in the activation processes of macrophages in vitro and suggesting that not only neuroprotective function but also activation of macrophages is effected by the GDNF produced after a spinal cord injury.

Animals↗
PubMed1994

Synthetic peptide corresponding to 30 amino acids of the C-terminal of neuron-specific enolase promotes survival of neocortical neurons in culture.

Neuron-specific enolase (NSE), one of the glycolytic enzymes, is a gamma gamma-isozyme of enolase that is specifically expressed in neurons. Our previous studies demonstrated that NSE promotes survival of rat embryonic neocortical neurons in culture but that the alpha alpha-isozyme (non-neuronal enolase; NNE) has no effect. In this study, we found that a synthetic peptide corresponding to the C-terminal portion of NSE (404-433) also promotes the survival of neocortical neurons. By contrast, a synthetic peptide of the C-terminal portion of NNE (404-433) has no effect on neuronal survival. These findings would be important for further analysis of the neurotrophic mechanism of NSE.

Amino Acid Sequence↗
PubMed1990

The primary structure of rabbit muscle enolase.

The primary amino acid sequence of rabbit muscle enolase has been determined by standard spinning-cup sequencing techniques applied to peptides produced by chemical (cyanogen bromide and mild acid hydrolysis) and enzymatic fragmentation of the enzyme. The 433 amino acid sequence has been compared to other available enolase sequences from eukaryotic and prokaryotic sources, confirming a high degree of conserved sequence identity; the three mammalian muscle sequences (mouse and rat deduced from c-DNA sequences and rabbit) show 94% identity.

Amino Acid Sequence↗
PubMed1990

Raman spectroscopic studies of hen egg-white lysozyme at high temperatures and pressures.

In situ high-temperature, high-pressure Raman experiments on 3 mM (pH 5) aqueous solutions of hen egg-white (HEW) lysozyme show a decrease in the relative height of the 505 cm-1 band associated with S-S stretching vibrations at 72 degrees C (1 bar). The peak height changes are accompanied by significant band broadening, and the integrated band intensity does not change within experimental error. The effect of increased pressure at 72 degrees C was to hinder broadening of the 505 cm-1 band. HEW lysozyme (2.4 mM, pH 5) was also heated at 76 degrees C, 80 degrees C, and 95 degrees C for different periods of time, and aliquots were quenched to room temperature for Raman and enzymatic activity measurements. After 9 hr at 76 degrees C, the protein exhibits enzyme activity less than 50% of the initial value, and approximately 50% reduction in activity is achieved after 3 hr at 80 degrees C or 1 hr at 95 degrees C. The Raman results suggest that different irreversibly denatured conformations are attained during prolonged exposures at these different temperatures. It is apparent from these studies that the S-S stretch intensity is decreased irreversibly.

Amino Acid Sequence↗
PubMed1995

Purification and properties of pig liver and muscle enolases.

Enolases (2-phospho-D-glycerate hydrolase, EC 4.2.1.11) were purified from both pig liver and muscle. Graphs of 1n C vs. r2 from sedimentation equilibrium experiments are linear, which suggests homogeneous preparations of liver and muscle enolases. From these data the molecular weight of liver enolase is calculated to be approximately 92,000 D and that of muscle enolase to be approximately 85,000 D. SDS-PAGE experiments give a molecular weight value of 46,000 D for liver enolase and a value of 44,000 D for muscle enolase. These molecular weight values for liver and muscle enzymes are within the range for other enolases and show that both of these pig enolases are dimers. Amino acid composition data support the sedimentation equilibrium data and also give a smaller molecule weight (84,968 D) for muscle enolase compared to that of the liver enzyme (89,021 D). The two enzymes differ in their content of lysine [liver enolase (L) = 94 residues, muscle enolase (M) = 68 residues], histidine (L = 13, M = 21), serine (L = 53, M = 36), proline (L = 52, M = 34), and cysteine (L = 4, M = 21). Partial specific volumes of 0.737 ml/g for liver enolase and 0.735 ml/g for muscle enolase were calculated from the amino acid composition data. Pig liver and muscle enolases differ radically in their isoelectric points (pI = 6.4-6.5 for liver enolase, and pI = 8.8-9.0 for muscle enolase), and in their degree of inactivation by 740 mM LiCl (liver enolase is inactivated to a greater degree than the muscle enolase). Despite these physical and chemical differences, the kinetic constants [KM values for Mg2+, 2-phosphoglyceric acid, and phospho(enol)pyruvate] appear not to be significantly different for these two forms of enolase. The physical, chemical, and kinetic data for pig liver and muscle enolases are compared to similar data for pig kidney enolase.

Amino Acids↗
PubMed2005

Cell-specific DNA fragmentation may be attenuated by a survivin-dependent mechanism after traumatic brain injury in rats.

Survivin attenuates apoptosis by inhibiting cleavage of some cell proteins by activated caspase-3. We recently discovered strong up-regulation of survivin, primarily in astrocytes and a sub-set of neurons, after traumatic brain injury (TBI) in rats. In this study we characterized co-expression of survivin with activated caspase-3 and downstream DNA fragmentation (TUNEL) in astrocytes and neurons after TBI. Western blot analysis revealed significant time-dependent increases in active caspase-3 between 5 and 14 days post-injury. No difference was observed between the proportion of survivin-positive and survivin-negative cells labeled with active caspase-3 at 5 or 7 days post-injury, as indicated by dual fluorescent immunostaining. Labeling of survivin-negative cells with TUNEL was, however, significantly greater than for survivin-positive cells, suggesting that expression of survivin may attenuate DNA cleavage and progression of apoptosis. A higher proportion of astrocytes than neurons accumulated active caspase-3. In contrast, co-localization with TUNEL was significantly higher for neurons than for astrocytes. These data suggest that survivin expression may attenuate DNA cleavage and cell death, and that this mechanism operates in a cell type-specific manner after TBI.

Animals↗
PubMed2004

Activation of murine cytomegalovirus immediate-early promoter in mouse brain after transplantation of the neural stem cells.

Cytomegalovirus (CMV) is the most significant infectious cause of congenital infection and fatal diseases in immunocompromised patients. We have previously described a transgenic mouse model of the murine CMV (MCMV) immediate-early (IE) gene promoter fused with the lacZ reporter gene (MCMV-IE-pro1) for the analysis of spatiotemporal changes of the promoter activity during brain development. Since expression of the IE genes play a pivotal role in latency and reactivation, we transplanted the transgene-expressing neural stem cells (NSCs) into neonatal mouse brains after labeling with bromodeoxyuridine (BrdU). The activation of MCMV-IE pro1 was detected in the subventricular zone (SVZ) soon after transplantation, and the number of MCMV IE pro1-activated cells was decreased as the development proceeded. Cells that were MCMV IE pro1-activated and glial fibrillary acidic protein positive, but not stained with BrdU, were found in the cortex 4 weeks after transplantation, while BrdU-positive but not MCMV IE pro1-activated cells still existed in the SVZ. MCMV IE promoter activity tended to be easily detected in the cortex after allogenic transplantation in BALB/c mouse. These results suggest that the SVZ is the most susceptible site for activation of the MCMV IE promoter in neonatal mice in the early period after transplantation and that the cerebral cortex is also susceptible to the activation in the late period after transplantation. It may be important to avoid the use of NSCs latently infected with CMV as donor cells.

Animals↗
PubMed1978

Neuronal, non-neuronal and hybrid forms of enolase in brain: structural, immunological and functional comparisons.

Three forms of the glycolytic enzyme, enolase [2-phospho-D-glycerate hydrolase (E.C. No. 4.2.1.11)] have been prepared from rat whole brain extract. The most acidic enolase form is neuron specific enolase (NSE) which had previously been designated neuron specific protein (NSP). The least acidic form designated non-neuronal enolase (NNE) has been purified and compared structurally, immunologically and functionally to NSE. NNE is a dimer of 86,500 M.W. consistint of two very similar subunits. The data establish that NNE is larger than NSE which has been shown to be composed of two apparently identical 39,000 molecular weight subunits (78,000). NNE is less acidic than NSE having a pI of 5.9 compared to the value of 4.7 for NSE. Structural and immunological analysis establishes that the NNE subunit is distinct from the NSE subunit, and are therfore products of two separate genes. The structural designation of NSE is (gammagamma) and that of NNE (alpha' alpha'). NSE is strictly localized in neurons indicating that the gene coding for the gamma subunit is only expressed in neuronal cells. The intermediate brain enolase form has been partially purified; structural and immunological evidence indicate that it is a hybrid molecule consisting of one NNE subunit and one NSE subunit (alpha'gamma).

Amino Acid Sequence↗
PubMed2006

Müller glial cells express nestin coupled with glial fibrillary acidic protein in experimentally induced glaucoma in the rat retina.

This study was aimed to investigate reactive changes of Müller glial cells in rats subjected to experimentally induced glaucoma. In the latter, it is well documented that elevated intraocular pressure leads to the loss of ganglion cells as confirmed in this study. The present results have shown that Müller glial cells as well as astrocytes closely associated with the ganglion cells reacted vigorously to increased intraocular pressure as manifested by the induced and upregulated expression of nestin and glial fibrillar acidic protein. A major finding in glaucomatous rats was the induced expression of nestin together with glial fibrillar acidic protein with the rise of the intraocular pressure beginning at 2 h. The marked nestin expression appeared to be most intense at 1 week after operation and was sustained at 3 weeks. Induced nestin expression in Müller glial cells was demonstrated unequivocally in whole-mount preparation of the retina. In the same tissue preparation, nestin expression was also detected in some astrocytes. Western blotting analysis confirmed a marked increase in expression of nestin and glial fibrillar acidic protein. Present results suggest that nestin as well as glial fibrillar acidic protein is a useful biomarker for retina injury. The induced expression of these intermediate filament proteins in Müller glial cells especially at their end-feet and also in some astrocytes adjoining the neuronal injury suggests a potential neuroprotective mechanism in response to acute rise in intraocular pressure resulting in neuronal degeneration.

Animals↗
PubMed2006

Human astrocytes can be induced to differentiate into cells with neuronal phenotype.

Several recent studies have proposed that astrocytes may contribute to neurogenesis, not only as a source of trophic substances regulating it, but also as stem cells themselves. In order to better understand these mechanisms, primary astrocyte cultures were established from human fetal brain. After 3-4 weeks in culture, astrocytes (about 95% GFAP+; neurofilament, NF-; neuro-specific enolase, NSE-) were treated with a cocktail of protein kinase activators and FGF-1. After 5 h of treatment, most cells showed morphological changes that increased progressively up to 24-48 h, exhibiting a round cell body with long processes. Immunocytochemistry showed that treatment-induced NF and NSE expression in about 40% of cells. Nestin expression increased after treatment, whereas GFAP immunostaining was not significantly modified. Western blot and RT-PCR confirmed the results. No neuronal electrophysiological properties were observed after treatment, suggesting an incomplete maturation under these experimental conditions. Understanding the regenerative capability and neurogenic potential of astrocytes might be useful in devising therapeutic approaches for a variety of neurological disorders.

1-Methyl-3-isobutylxanthine↗
PubMed2002

Enhanced activation of bound plasminogen on Staphylococcus aureus by staphylokinase.

Activation of plasminogen (plg) to plasmin by the staphylococcal activator, staphylokinase (SAK), is effectively regulated by the circulating inhibitor, alpha2-antiplasmin (alpha2AP). Here it is demonstrated that intact Staphylococcus aureus cells and solubilized staphylococcal cell wall proteins not only protected SAK-promoted plg activation against the inhibitory effect of alpha2AP but also enhanced the activation. The findings suggest that the surface-associated plg activation by SAK may have an important physiological function in helping staphylococci in tissue dissemination. Amino acid sequencing of tryptic peptides originating from the 59-, 56- and 43-kDa proteins, isolated as putative plg-binding proteins, identified them as staphylococcal inosine 5'-monophosphate dehydrogenase, alpha-enolase, and ribonucleotide reductase subunit 2, respectively.

Amino Acid Sequence↗