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INTRODUCTION: Torsion of an undescended testis (UDT) associated with cerebral palsy (CP) and neuromuscular disease (NMD) is an uncommon condition that is not well recognized by primary care physicians or healthcare providers. OBJECTIVE: The objective of this study was to highlight the clinical importance of torsion of a UDT in children with CP and NMD. MATERIALS AND METHODS: Eleven children with testicular torsion of a UDT operated on at the study institute between 1991 and 2015 were identified. The records of seven children (63.6%) associated with CP or NMD were retrospectively reviewed. Clinical findings of testicular torsion were assessed along with the treatment outcome and testicular salvageability. RESULTS: All seven children were not identified with a UDT by public health checkup for infant and young children. No children with CP or NMD had torsion of a descended testis during the present study period. Median age at surgery was 15 years (range, 1-20 years). The testis location was at the external inguinal ring in five patients, in the inguinal canal in one, and in the superficial inguinal pouch in one. Of the contralateral testes, four were a UDT, one was a retractile testis, and two were descended testes. Orchiectomy was performed in six patients (85.7%). In the remaining patients, the testis was preserved but became atrophic. DISCUSSION: This study demonstrated that children with CP or NMD may be affected with torsion of a UDT with peak at around puberty with the poor salvage rate, even if the testes appear descended in infancy and young children. Shortcomings of this study were the retrospective design and a small series of children undergoing surgery for torsion of a UDT. CONCLUSION: Pediatric urologists need to educate primary care physicians and healthcare providers in the recognition of acquired UDTs and possibly associated testicular torsion in children with CP and NMD. Genital examination should be continued regularly until adolescence in these children to detect acquired UDT. These children should be referred to pediatric urologists to promote surgery as soon as the diagnosis of acquired UDT is carried out. It is believed that it is perhaps the best approach to prevent loss of the testis in children with CP and NMD.
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Parálisis Cerebral/complicaciones , Criptorquidismo/etiología , Enfermedades Neuromusculares/complicaciones , Torsión del Cordón Espermático/etiología , Adolescente , Niño , Preescolar , Humanos , Lactante , Masculino , Estudios Retrospectivos , Adulto JovenRESUMEN
BACKGROUND AND STUDY AIMS: The frequency of stricture after endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma with a mucosal defect involving more than three-quarters of the circumference is 70% - 90%. Stricture decreases quality of life and requires multiple endoscopic balloon dilation (EBD) sessions. We investigated the efficacy and safety of a single session of intralesional steroid injections to prevent post-ESD stricture. PATIENTS AND METHODS: We conducted a prospective study on 30 patients with esophageal squamous cell carcinoma treated by ESD, who had a more than three-quarter but less than whole circumferential defect. A single session of intralesional steroid injections was undertaken immediately after ESD. Esophagogastroduodenoscopy was performed whenever patients reported dysphagia and 2 months after ESD in patients without dysphagia. Results were compared with a historical control group of 29 patients who underwent ESD without intralesional steroid injection. The primary endpoint was the post-ESD stricture rate. Secondary endpoints were the number of EBD sessions and the complication rate. RESULTS: Compared with the historical control group, the study group had a significantly lower stricture rate (10%, 3/30 patients vs. 66%, 19/29 patients; P < 0.0001) and a lower number of EBD sessions (median 0, range 0 - 2 vs. median 2, range 0 - 15; P < 0.0001). The study group had a complication rate of 7 % (2 /30 patients), comprising a submucosal tear in one patient and bleeding in another, which were not a direct result of EBD. CONCLUSIONS: A single session of intralesional steroid injections showed promising results for the prevention of stricture after ESD for esophageal cancer.
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Carcinoma de Células Escamosas/cirugía , Endoscopía Gastrointestinal , Neoplasias Esofágicas/cirugía , Estenosis Esofágica/prevención & control , Triamcinolona Acetonida/administración & dosificación , Anciano , Endoscopía del Sistema Digestivo , Endoscopía Gastrointestinal/métodos , Femenino , Humanos , Inyecciones Intralesiones , Masculino , Complicaciones Posoperatorias/prevención & control , Estudios ProspectivosRESUMEN
Rett syndrome is a progressive neurodevelopmental disorder caused by mutations in the methyl-CpG-binding protein 2 (MeCP2) gene. Previous reports have revealed serotonergic function to be altered in the medullas of patients with Rett syndrome and in an animal model of the disease. However, it has remained unclear whether a genetic loss of MeCP2 disrupts serotonergic innervation to the forebrain. In this study, we measured levels of monoamines by high-performance liquid chromatography with electrochemical detection in selected regions of the forebrains of Mecp2-null mice (Mecp2-/y) and wild-type mice (Mecp2+/y) on postnatal day (P) 14, P28, P42 and P56. The levels of hippocampal serotonin (5-HT) and its main metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were significantly lower in Mecp2-null mice than in age-matched wild-type mice on P28, P42 and P56. Immunohistochemical analysis revealed a loss of 5-HT-immunoreactive fibers in the Mecp2-null hippocampus on P56. By contrast, in the raphe region of Mecp2-null mice, there were significant decreases in 5-HT and noradrenaline levels, but these differences later disappeared and there was no change in the number of 5-HT-immunoreactive neuronal cell bodies. Furthermore, we conducted an experiment comparing HPLC measurements in presymptomatic heterozygous females (Mecp2+/-) and wild-type female littermates (Mecp2+/+) on P56. Significant decreases in hippocampal 5-HT and 5-HIAA contents in Mecp2-heterozygous mice were revealed, and these were not accompanied by changes in 5-HT or noradrenaline contents in the raphe region. Therefore, these results indicated decreases in serotonergic innervation to the hippocampus in Mecp2-null males and Mecp2 heterozygous females. We speculate that disturbances in serotonergic neurotransmission in the hippocampus may be linked to the behavioral abnormalities seen in Rett syndrome, such as increased anxiety-like behaviors and reduced exploratory locomotion. MeCP2 may be required for stable serotonergic homeostasis and serotonergic innervation to the hippocampus during postnatal development.
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Hipocampo/crecimiento & desarrollo , Hipocampo/metabolismo , Proteína 2 de Unión a Metil-CpG/metabolismo , Prosencéfalo/crecimiento & desarrollo , Prosencéfalo/metabolismo , Serotonina/metabolismo , Envejecimiento , Animales , Modelos Animales de Enfermedad , Dopamina , Femenino , Ácido Hidroxiindolacético/metabolismo , Masculino , Proteína 2 de Unión a Metil-CpG/genética , Ratones , Ratones Noqueados , Vías Nerviosas/crecimiento & desarrollo , Vías Nerviosas/metabolismo , Neuronas/metabolismo , Norepinefrina/metabolismo , Núcleos del Rafe/crecimiento & desarrollo , Núcleos del Rafe/metabolismo , Síndrome de Rett , Caracteres SexualesRESUMEN
Neurocan is one of the major chondroitin sulfate proteoglycans expressed in nervous tissues. The expression of neurocan is developmentally regulated, and full-length neurocan is detected in juvenile brains but not in adult brains. In the present study, we demonstrated by western blot analysis that full-length neurocan transiently appeared in adult rat hippocampus when it was lesioned by kainate-induced seizures. Immunohistochemical studies showed that neurocan was detected mainly around the CA1 region although the seizure resulted in neuronal cell degeneration in both the CA1 and CA3 regions of the hippocampus. Double-labeling for neurocan mRNA and glial fibrillary acidic protein demonstrated that many reactive astrocytes expressed neurocan mRNA. The re-expression of full-length neurocan was also observed in the surgically injured adult rat brain. In contrast, the expression of other nervous tissue chondroitin sulfate proteoglycans, such as phosphacan and neuroglycan C, was not intensified but rather was either reduced in the kainate-lesioned hippocampus or in the surgically injured cerebral cortex. These observations indicate that induction of neurocan expression by reactive astrocytes is a common phenomenon in the repair process of adult brain injury, and therefore, it can be postulated that juvenile-type neurocan plays some roles in brain repair.
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Astrocitos/metabolismo , Lesiones Encefálicas/metabolismo , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Hipocampo/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Convulsiones/metabolismo , Animales , Western Blotting , Proteoglicanos Tipo Condroitín Sulfato/genética , Proteína Ácida Fibrilar de la Glía/metabolismo , Inmunohistoquímica , Ácido Kaínico , Lectinas Tipo C , Glicoproteínas de Membrana/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/genética , Neurocano , Proteoglicanos/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Proteínas Tirosina Fosfatasas Clase 5 Similares a Receptores , Convulsiones/inducido químicamente , Sindecano-3 , Factores de TiempoRESUMEN
We report here the temperature-dependent unoccupied molecular orbitals (MO's) of C60 molecules adsorbed on a Si(001)-(2 x 1) surface measured using near edge x-ray absorption fine structure (NEXAFS). At 300 K, the NEXAFS spectrum reveals that the interaction between a 1.0 monolayer (ML) C60 film and a Si(001) surface is mainly the van der Waals force. After annealing the samples at 500 K, we observe an increment in the full-width at half-maximum of unoccupied MO's, which indicates the change of the interaction. Moreover, the lowest unoccupied molecular orbital (LUMO) shifts to the higher photon energy side and the intensity of the LUMO+1 relative to that of the LUMO+3 decreases in the NEXAFS spectrum. These results suggest that the strong interaction induced at 500 K has a covalent character, to which the LUMO+1 contributes.
RESUMEN
In this report, we investigated whether reactive astrocytes produce neuregulins (glial growth factor 2/heregulin/acetylcholine receptor-inducing activity or neu differentiation factor) and its putative receptors, ErbB2 and ErbB3 tyrosine kinases, in the injured CNS in vivo. Significant immunoreactivities with anti-neuregulin, anti-ErbB2, and anti-ErbB3 antibodies were detected on astrocytes at the injured site 4 d after injury to the adult rat cerebral cortex. To elucidate the mechanisms for the upregulation of neuregulin expression in astrocytes, primary cultured astrocytes were treated with certain reagents, including forskolin, that are known to elevate the intracellular level of cAMP and induce marked morphological changes in astrocytes. Western blot analysis showed that the expression of a 52 kDa membrane-spanning form of a neuregulin protein was enhanced in cultured astrocytes after administration of forskolin. The upregulation of glial fibrillary acidic protein was also observed in astrocytes treated with forskolin. In contrast, inactivation of protein kinase C because of chronic treatment with phorbol ester 12-O-tetradecanoyl phorbol 13-acetate downregulated the expression of the 52 kDa isoform, although other splice variants with apparent molecular sizes of 65 and 60 kDa were upregulated. These results suggest that the enhancement of neuregulin expression at injured sites is induced, at least in part, by elevation in intracellular cAMP levels and/or a protein kinase C signaling pathway. The neuregulin expressed on reactive astrocytes may stimulate their proliferation and support the survival of neurons surrounding cortical brain wounds in vivo.
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Astrocitos/metabolismo , Lesiones Encefálicas/metabolismo , Corteza Cerebral/metabolismo , Neurregulinas/metabolismo , Animales , Astrocitos/citología , Astrocitos/efectos de los fármacos , Lesiones Encefálicas/patología , Células CHO , Células Cultivadas , Corteza Cerebral/patología , Colforsina/farmacología , Cricetinae , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Modelos Animales de Enfermedad , Proteína Ácida Fibrilar de la Glía/metabolismo , Traumatismos Penetrantes de la Cabeza/metabolismo , Traumatismos Penetrantes de la Cabeza/patología , Neurregulinas/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteína Quinasa C/metabolismo , Ratas , Ratas Sprague-Dawley , Receptor ErbB-2/metabolismo , Receptor ErbB-3/metabolismo , Transducción de Señal/efectos de los fármacos , Acetato de Tetradecanoilforbol , Regulación hacia ArribaRESUMEN
The initial oxygen adsorption on the Si(111)7 x 7 surface was investigated by high-resolution x-ray absorption spectroscopy. Below 220 K, a molecular adsorption species is identified by distinctive absorption resonances due to the 1 pi(g) molecular orbitals. The molecular species is metastabilized to have a lifetime of 15-35 min at 135 K only with the presence of atomic adsorbates of more than 0. 1 ML (monolayer). It is thus clearly evidenced that the very initial adsorption is dissociative even at 100 K and the molecular species is not a precursor state. The molecular adsorption structures with the coadsorbed oxygen atoms are suggested.
RESUMEN
Neuroglycan C (NGC) is a membrane-spanning chondroitin sulfate proteoglycan with an epidermal growth factor module that is expressed predominantly in the brain. Cloning studies with mouse NGC cDNA revealed the expression of three distinct isoforms (NGC-I, -II, and -III) in the brain and revealed that the major isoform showed 94. 3% homology with the rat counterpart. The NGC gene comprised six exons, was approximately 17 kilobases in size, and was assigned to mouse chromosome band 9F1 by fluorescence in situ hybridization. Western blot analysis demonstrated that, although NGC in the immature cerebellum existed in a proteoglycan form, most NGC in the mature cerebellum did not bear chondroitin sulfate chain(s), indicating that NGC is a typical part-time proteoglycan. Immunohistochemical studies showed that only the Purkinje cells were immunopositive in the cerebellum. In the immature Purkinje cells, NGC, probably the proteoglycan form, was immunolocalized to the soma and thick dendrites on which the climbing fibers formed synapses, not to the thin branches on which the parallel fibers formed synapses. This finding suggests the involvement of NGC in the differential adhesion and synaptogenesis of the climbing and parallel fibers with the Purkinje cell dendrites.
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Cerebelo/crecimiento & desarrollo , Proteínas de la Membrana/genética , Proteoglicanos/genética , Empalme Alternativo , Secuencia de Aminoácidos , Animales , Exones , Biblioteca de Genes , Biblioteca Genómica , Inmunohistoquímica , Hibridación Fluorescente in Situ , Masculino , Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/química , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Isoformas de Proteínas , Proteoglicanos/biosíntesis , Proteoglicanos/química , Células de Purkinje/química , Homología de Secuencia de Aminoácido , Distribución TisularRESUMEN
Aggrecan family proteoglycans, phosphacan/RPTPzeta/beta, and neuroglycan C (NGC) are the major classes of chondroitin sulfate proteoglycan in the developing mammalian brain. A multidomain is a common structural feature of these proteoglycans which can interact with various molecules including growth factors, cell adhesion molecules, and extracellular matrix molecules. Individual proteoglycans are distributed in the developing brain in a distinct temporal and spatial pattern, suggesting that they are involved in distinct phases of the brain development through multiple molecular interactions. This review mainly summarizes recent studies on the involvement of these three classes of proteoglycan in cell-cell and cell-substratum interactions during the brain development. Their expressions and proposed functional roles in injured brains are also mentioned. In addition, this review briefly covers potential functions of other neural chondroitin sulfate proteoglycans such as decorin, testican, NG2 proteoglycan, and amyloid precursor protein (APP) in developing and injured brains.
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Encéfalo/metabolismo , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Sistema Nervioso/metabolismo , Proteoglicanos/metabolismo , Animales , Encéfalo/crecimiento & desarrollo , Proteoglicanos Tipo Condroitín Sulfato/química , Proteoglicanos Tipo Condroitín Sulfato/genética , Humanos , Sistema Nervioso/crecimiento & desarrollo , Unión Proteica , Proteoglicanos/química , Proteoglicanos/genéticaRESUMEN
Neurocan is a nervous tissue-unique chondroitin sulfate proteoglycan (CSPG) whose expression and proteolytic cleavage are developmentally regulated. In the adult rat brain, neurocan is completely cleaved into some proteoglycan fragments including the C-terminal half known as neurocan-C and a N-terminal fragment with a 130 kDa core glycoprotein (neurocan-130). We describe here the differential distribution of these two neurocan-derived CSPGs in the adult rat cerebrum and the occurrence of neurocan-130 as a new member of a perineuronal net-constituting molecule. At the light microscopic level, neurocan-130 exhibited pericellular localization around a subset of neurons in addition to diffuse distribution in the neuropil. In contrast, neurocan-C was distributed only diffusely in the neuropil. Double staining with anti-neurocan-130 and anti-synaptophysin antibodies suggested that neurocan-130 was localized in the vicinity of the synapses, but not at the synapses. Immunoelectron microscopy showed that neurocan-130 was mainly localized in the cytoplasm of glial cell processes, the so-called glial perineuronal net, encompassing the cell bodies of certain neurons. The presence of neurocan-130 in a limited number of glial cells may reflect some functional heterogeneity of the glia.
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Química Encefálica/fisiología , Proteoglicanos Tipo Condroitín Sulfato/análisis , Proteoglicanos Tipo Condroitín Sulfato/química , Proteínas del Tejido Nervioso/análisis , Proteínas del Tejido Nervioso/química , Neuroglía/química , Neurópilo/química , Fragmentos de Péptidos/análisis , Factores de Edad , Animales , Corteza Cerebral/química , Corteza Cerebral/citología , Corteza Cerebral/crecimiento & desarrollo , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Hipocampo/química , Hipocampo/citología , Hipocampo/crecimiento & desarrollo , Lectinas Tipo C , Microscopía Inmunoelectrónica , Neostriado/química , Neostriado/citología , Neostriado/crecimiento & desarrollo , Proteínas del Tejido Nervioso/metabolismo , Neurocano , Neuroglía/ultraestructura , Neuronas/química , Neuronas/ultraestructura , Neurópilo/ultraestructura , Conejos , Ratas , Ratas Sprague-Dawley , Sinaptofisina/análisisRESUMEN
Neuroglycan C (NGC) is a 150 kDa transmembrane chondroitin sulfate proteoglycan with a 120 kDa core glycoprotein that was originally isolated from the developing rat brain. A rabbit antiserum, raised against a recombinant polypeptide representing a protein of the rat NGC core protein, recognized an NGC homolog in homogenates of brains of various vertebrates including humans. Because of the possible involvement of this proteoglycan in the etiology of a human neuronal disease, we cloned a complete coding sequence from a human brain cDNA library using a rat NGC cDNA as a probe. The predicted protein contains 539 amino acids and shows 86% homology with the rat counterpart. The domain structure characteristic of rat NGC was completely conserved in human NGC, which consisted of an N-terminal signal sequence, a chondroitin sulfate-attachment domain, an acidic amino acid cluster, an EGF-like domain, a transmembrane domain and a cytoplasmic tail. Northern blot analysis revealed that a single transcript of 2.4 kb was detectable in the brain, but not in other human tissues. By fluorescence in situ hybridization (FISH) analysis, the human NGC gene was assigned to the chromosomal 3p21.3 band, where the Sotos syndrome has been mapped. Involvement of the NGC gene in the etiology of the Sotos syndrome remains to be examined.
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Proteoglicanos Tipo Condroitín Sulfato/genética , Cromosomas Humanos Par 3/genética , Secuencia de Aminoácidos , Animales , Enfermedades del Sistema Nervioso Central/genética , Corteza Cerebral , Embrión de Pollo , Mapeo Cromosómico/métodos , Humanos , Ratones , Datos de Secuencia Molecular , Conejos , RatasRESUMEN
Chondroitin sulfate proteoglycans are present at high levels in the lower auditory system of mammals. Axon terminals on the principal neurons in the superior olivary nuclei contain chondroitin 4- and 6-sulfate, while the broad extracellular matrix around axon terminals contains chondroitin sulfate D, a highly sulfated chondroitin sulfate rich in the disaccharide unit of GlcA(2S)beta1 --> 3GalNAc(6S), in the dog. In the present study, we investigated the immunohistochemical staining of neurocan, a brain-specific proteoglycan, in the lower auditory tract of the dog, including an analysis by immunoelectron microscopy. Immunolocalization of neurocan was conspicuous in the medial and lateral superior olivary nuclei and much less intense immunostaining was seen in the cochlear nucleus and posterior colliculus. No immunoreactivity were found in other nuclei. The immunostaining in the medial and lateral superior olivary nuclei was observed as perineuronal nets around large principal neurons at the light-microscopic level, while no immunostaining was observed in the upper segment of the medial superior olivary nucleus and the medial segment of the lateral superior olivary nucleus, in which medium-sized and small neurons were located. Immunoelectron microscopy revealed the reaction products of immunostaining on cell membranes of the perikarya of principal neurons and on cell membranes of presynaptic terminals which made axo-somatic synapses on the principal cells. No immunoreactivity was detected at synaptic junctions, in the extracellular matrix or within axon terminals. In the cochlear nucleus, immunoreactive perineuronal nets were found around a small number of neurons and immunoreactive nerve fibers were scattered in the anterior ventral cochlear nucleus. In the posterior colliculus, perineuronal nets, which were weakly immunostained, were sparsely distributed in the central nucleus. These results suggest that different locations of chondroitin sulfate proteoglycans, including neurocan, may be associated with focal sites composed of neuronal surface, terminal boutons and extracellular matrix in the lower auditory tract of the adult dog.
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Proteoglicanos Tipo Condroitín Sulfato/análisis , Núcleo Coclear/metabolismo , Proteínas del Tejido Nervioso/análisis , Núcleo Olivar/metabolismo , Animales , Sulfatos de Condroitina/metabolismo , Núcleo Coclear/ultraestructura , Perros , Femenino , Inmunohistoquímica , Lectinas Tipo C , Masculino , Microscopía Electrónica , Fibras Nerviosas , Neurocano , Neuronas/metabolismo , Neuronas/ultraestructura , Núcleo Olivar/ultraestructuraRESUMEN
Monoclonal antibodies were raised to membrane-bound proteoglycans derived from rat brain and three monoclonal antibodies that recognized a 200-kDa heparan sulfate proteoglycan (designated H5-PG) with a core glycoprotein of 140 kDa were obtained. The expression of H5-PG was spatially and temporally regulated in the central nervous system. In the cerebellar cortex, H5-PG was associated mainly with the actively growing parallel fibers of granule cells. The expression was abruptly down-regulated in parallel with the formation of synapses on dendrites of Purkinje cells. In the cerebral cortex, the proteoglycan was widely distributed throughout the cortex. The temporal pattern of expression was similar to that in the cerebellar cortex; the peak level of expression was observed during the period from postnatal days 0 to 20 when neuritogenesis and synaptogenesis occur most extensively in the rat cerebral cortex. H5-PG in the central nervous system disappeared prior to adulthood except in the olfactory bulb. High-level expression was recognized on the olfactory nerves and glomeruli, where the renewal of both axons and synapses is occurring constantly. The data suggest that H5-PG is a glycoconjugate on axonal surface that is involved in axonal outgrowth and/or synaptogenesis.
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Axones/metabolismo , Membrana Celular/metabolismo , Corteza Cerebral/metabolismo , Heparitina Sulfato/metabolismo , Proteoglicanos/metabolismo , Animales , Bulbo Olfatorio/metabolismo , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
Monoclonal antibodies were raised to membrane-bound proteoglycans derived from rat brain, and four monoclonal antibodies that recognized a 150-kDa chondroitin sulfate proteoglycan with a core glycoprotein of 120 kDa were obtained. Immunohistological study revealed that the proteoglycan was associated with developing neurons. We screened rat brain cDNA libraries using the four monoclonal antibodies and isolated overlapping cDNA clones that encoded the entire core protein of 514 amino acids plus a 30-residue signal peptide. The deduced amino acid sequence suggested an integral membrane protein divided into five structurally different domains: an N-terminal domain to which chondroitin sulfate chains might be attached, a basic amino acid cluster consisting of seven arginine and two lysine residues, a cysteine-containing domain, a membrane-spanning segment, and a C-terminal cytoplasmic domain of 95 amino acids. On Northern blots, the cDNA hybridized with a single mRNA of 3.1 kilobases that was detectable in brains of neonatal and adult rats but not in kidney, liver, lung, and muscle of either. The sequence of the proteoglycan did not exhibit significant homology to any other known protein, indicating that the proteoglycan, designated neuroglycan C, is a novel integral membrane proteoglycan.
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Encéfalo/metabolismo , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Proteínas de la Matriz Extracelular , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Agrecanos , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales , Secuencia de Bases , Proteoglicanos Tipo Condroitín Sulfato/genética , Proteoglicanos Tipo Condroitín Sulfato/inmunología , Clonación Molecular , Cartilla de ADN/genética , ADN Complementario/genética , Lectinas Tipo C , Proteínas de la Membrana/genética , Proteínas de la Membrana/inmunología , Datos de Secuencia Molecular , Estructura Molecular , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/inmunología , Proteoglicanos/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
Alzheimer's beta-amyloid precursor related proteins bearing chondroitin sulfate chains were detected in the conditioned media of primary cultured astrocytes obtained from fetal rat brains by Western blotting using the monoclonal antibody 22C11 against Alzheimer's beta-amyloid precursor protein (APP), but not in the media of cortical neurons. The chondroitin sulfate proteoglycan form of APP was also detectable in a soluble proteoglycan fraction prepared from 10-day-old rat brains. However, the amount of proteoglycan form of APP in the brain was very small compared to non-proteoglycan forms at all the developmental stages from embryonic day 14 to 2 years. These observations suggest that astrocytes are one cellular source of the proteoglycan form of APP in the brain.
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Enfermedad de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Astrocitos/metabolismo , Encéfalo/metabolismo , Sulfatos de Condroitina/metabolismo , Animales , Western Blotting , Encéfalo/citología , Células Cultivadas , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Ratas , Ratas Sprague-Dawley , SolubilidadRESUMEN
Neurocan is a developmentally regulated chondroitin sulphate proteoglycan in the rat brain. In the present study, spatiotemporal patterns of expression of neurocan and the corresponding mRNA were examined in the developing cortical barrel field of the rat brain by using a monoclonal antibody that was highly specific to neurocan and a riboprobe for a portion of the mRNA. Immunohistochemical analysis revealed that neurocan was distributed throughout the cerebral cortex during early postnatal development but was excluded from the centres of cortical barrels at the time of entry and arborization of thalamocortical axons. At this developmental stage, expression of neurocan mRNA was shown by in situ hybridization to be down-regulated in the barrel centres. When a row of whisker follicles was laser-cauterized on postnatal day 1, the pattern of expression of neurocan was disturbed in the row of barrels that corresponded to the lesioned whisker follicles in the contralateral somatosensory cortex. From these observations, it appears that neuronal stimuli through early thalamocortical fibres from the sensory periphery cause reduced expression of neurocan mRNA in neurocan-producing cells in the presumptive barrel centres. Our findings also suggest that the pattern of distribution of neurocan in early postnatal barrel fields may be due mainly to the down-regulation of expression of neurocan mRNA.
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Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Proteínas del Tejido Nervioso/metabolismo , ARN Mensajero/biosíntesis , Corteza Somatosensorial/crecimiento & desarrollo , Corteza Somatosensorial/metabolismo , Vibrisas/crecimiento & desarrollo , Vibrisas/fisiología , Animales , Secuencia de Bases , Proteoglicanos Tipo Condroitín Sulfato/biosíntesis , Inmunohistoquímica , Hibridación in Situ , Lectinas Tipo C , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/biosíntesis , Neurocano , Proteínas de Neurofilamentos/metabolismo , Sondas ARN , Ratas , Ratas Sprague-Dawley , Transcripción Genética/fisiologíaRESUMEN
Neurocan is a brain-unique chondroitin sulfate proteoglycan (CSPG) whose expression and proteolytic cleavage are developmentally regulated. One of the proteolytic products (C-terminal half) is known to be a CSPG with a 150 kDa core glycoprotein (CSPG-150). To identify the N-terminal half of neurocan, we raised an anti-neurocan polyclonal antibody (PAb 291) using a synthetic peptide whose amino acid sequence matched a part of the N-terminal half of neurocan. Western blots showed that PAb 291 recognized two CSPGs, one with a 220 kDa core glycoprotein (CSPG-220, namely neurocan) and one with a 130 kDa core glycoprotein (CSPG-130) isolated from young rat brains. CSPG-130 was co-purified along with CSPG-220 by PAb 291-immunoaffinity column chromatography. The amino acid sequence of the N-terminus of the immunopurified CSPG-130 was exactly the same as the N-terminal sequence of CSPG-220. These results suggest that not only the C-terminal half (CSPG-150) but also the N-terminal half (CSPG-130) of CSPG-220 exists in a CSPG form in rat brain. Using PAb 291 and monoclonal antibody 1G2 (MAb 1G2) which recognizes CSPG-150 in addition to CSPG-220, we found that the contents of CSPG-130 and CSPG-150 in the rat brain reached maximum levels around the time of birth. Both CSPG-130 and 150 were observed, while CSPG-220 was hardly detectable in extracts from the adult rat brain. Immunohistochemical investigation showed that the PAb 291 antigen had a similar distribution pattern to the MAb 1G2 antigen.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Encéfalo/metabolismo , Proteoglicanos Tipo Condroitín Sulfato/análisis , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Proteínas del Tejido Nervioso/análisis , Fragmentos de Péptidos/análisis , Secuencia de Aminoácidos , Animales , Encéfalo/embriología , Encéfalo/crecimiento & desarrollo , Proteoglicanos Tipo Condroitín Sulfato/química , Inmunoensayo , Inmunohistoquímica , Técnicas In Vitro , Lectinas Tipo C , Datos de Secuencia Molecular , Neurocano , Fragmentos de Péptidos/aislamiento & purificación , Procesamiento Proteico-Postraduccional , Ratas , Ratas Sprague-DawleyRESUMEN
The occurrence of multiple proteoglycan species is a characteristic of the brain. The structural features of individually characterized proteoglycans in the brain are first introduced in brief, then some examples are shown that suggest a relationship between multiple proteoglycans and the many distinct cell types and neural circuits in the brain. Typical experiments demonstrated the neuronal-activity-dependent expression of neural proteoglycans during the critical developmental period of some functional systems such as the visual and vibrissal barrel systems. In addition, the binding properties of neural proteoglycans to other cell surface molecules are discussed in conjunction with their involvement in cell-cell and cell-substratum interactions. This review also covers other potential functions of proteoglycans not only in the development and maintenance of the brain but also in the pathogenesis of Alzheimer's disease. Proteoglycans are really coming of age in neuroscience.
Asunto(s)
Química Encefálica/fisiología , Encéfalo/crecimiento & desarrollo , Proteoglicanos/metabolismo , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Animales , Encéfalo/citología , Humanos , Proteoglicanos/químicaRESUMEN
The mammalian brain contains many species of proteoglycan. To identify each proteoglycan species, we have raised monoclonal antibodies against soluble chondroitin sulfate proteoglycans purified from 10-day-old rat brains. One monoclonal antibody, named monoclonal antibody 1G2, recognized two proteoglycan species with 220,000 and 150,000 mol. wt core glycoproteins (chondroitin sulfate proteoglycan-220 and chondroitin sulfate proteoglycan-150). Partial amino acid sequences of N-termini of their core proteins coincided with those of neurocan, a brain-unique chondroitin sulfate proteoglycan species, whose complete coding sequence was recently reported [Rauch et al. (1992) J. biol. Chem. 269, 19,536-19,547]. Western blots revealed that chondroitin sulfate proteoglycan-220 became detectable in the rat cerebrum on embryonic day 14, and that it disappeared from the brain around postnatal day 30. In contrast, a fairly large amount of chondroitin sulfate proteoglycan-150 remained in the mature brain. Immunohistochemical studies revealed that 1G2 antigen was first localized in the preplate zone, then both in the marginal zone and in the subplate of the rat cerebrum on embryonic day 16, prior to arrival of the first thalamic afferents at the cortex. On embryonic day 20, immunolabeling with monoclonal antibody 1G2 began to spread from the subplate into the developing cortical plate. On postnatal day 10, the neuropil of the cerebrum, except for the barrel field, was diffusely stained with the antibody, intensely in the hippocampus and superficial layers (I-III) of the cerebral cortex and weakly elsewhere. The barrel hollows were stained very weakly compared with the barrel walls at this stage. The immunoreactivity in the hippocampus and superficial cortical layers was weakened in the mature brain, so that no particular staining pattern, but weak and diffuse staining was observed in the adult rat cerebrum. The 1G2 antigen was immunohistochemically associated largely with glial fibrillary acidic protein-positive cells in primary cultures of the neonatal rat cerebrum. Both chondroitin sulfate proteoglycan-220 and chondroitin sulfate proteoglycan-150 were detected in the conditioned media not only of highly enriched cultures of fetal rat cortical neurons but also of pure cultures of mature astrocytes; more (12- to 20-fold) in the astrocyte conditioned media. Astrocytes, in addition to neurons, may be a cellular source of neurocan in brain at least under certain physiological conditions. The spaciotemporal expression pattern of 1G2 epitope-bearing proteoglycan, or neurocan, suggests that this proteoglycan species plays some roles at least in forming the elongation pathway for early cortical afferent fibers as well as the functional barrel structure in the somatosensory cortex.