bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extracellular matrix of central nervous system white matter: Demonstration of an hyaluronate‐protein complex
Authors: Asher R. , Perides G. , Vanderhaeghen J.‐J. , Bignami A. 
Published: January 2005

AbstractMonoclonal antibodies were raised against human glial hyaluronate‐binding protein (GHAP), a major CNS‐specific glycoprotein known to bind hyaluronate in vitro. Frozen sections of dog and human spinal cord were digested with Streptomyces hyaluronidase in order to ascertain whether GHAP is bound to hyaluronate in vivo. Digestion with hyaluronidase, prior to staining of the sections by conventional indirect immunofluorescence, led to a drastic reduction in the intensity of the staining reaction. Chondroitinase ABC (protease‐free) was also effective in bringing about the release of GHAP from tissue sections. This enzyme also degrades hyaluronate. The effects of the chondroitinase were completely reversed by the addition of 1 mM Zn2+ a known inhibitor of this enzyme.The intact protein was released into the soluble fraction of human brain homogenates by testicular hyaluronidase. An immunoreactive species of 70 kD was released into the soluble fraction of dog spinal cord homogenates by Streptomyces hyaluronidase. Dog GHAP was isolated from spinal cord by means of ion exchange and affinity chromatography. This protein bound efficiently to hyaluronate in vitro. Dog and human GHAP had identical isoelectric points and similar peptide maps but different molecular weights. Dog GHAP (70 kD) was larger than its human counterpart (60 kD).These findings imply that GHAP exists in association with hyaluronate in CNS white matter. Immunoelectron microscopy revealed that GHAP fills the space between myelin sheaths in dog spinal cord white matter. One is led to conclude therefore that an hyaluronate based extracellular matrix exists in CNS white matter.
Isolation and structural characterization of the murine tryptophan hydroxylase gene
Authors: Stoll J. , Goldman D. 
Published: January 2005

AbstractThe mouse tryptophan hydroxylase gene was isolated and its intron/exon boundaries and putative regulatory sequences identified. To isolate the gene a mouse mastocytoma cDNA clone encoding tryptophan hydroxylase was used to identify and isolate ten overlapping DNA fragments from a mouse genomic library. Restriction mapping and sequence analysis of the clones revealed that the gene contains 11 exons and covers a region of DNA of approximately 21 kb. The transcription initiation site was mapped and the major site of initiation yields an untranslated leader sequence of 124 nucleotides. A minor initiation site is located 9 nucleotides 3′ of the major site. The 5′ untranslated sequence is interrupted by the first intron. Analysis of the sequence upstream of the initiation site showed the presence of several putativepromoter and regulatory sequences. Nine of the ten intron/exon boundaries of tryptophan hydroxylase are conserved with tyrosine hydroxylase and phenylalanine hydroxylase, further delineating the evolutionary relationship of these three genes.
Cytochrome P‐45011β rat brain
Authors: Ozaki H. S. , Iwahashi K. , Tsubaki M. , Fukui Y. , Ichikawa Y. , Takeuchi Y. 
Published: January 2005

AbstractThe presence of cytochrome P‐45011β in rat brain was studied by immunohistochemistry using polyclonal rabbit antibodies raised against purified bovine adrenocortical P‐45011β, which is involvedin the steroid 11β‐hydroxylation and glucocorticoid formation. The results showed that cytochrome P‐45011β immunoreactivity is selectively localized to the tracts of myelinated fibers throughout the brain. The specificity of immunohistochemical stainings with P‐45011β antibodies was established by control tests including nonimmune rabbit immunoglobulin Gs and P‐45011β antibodies absorbed with purified antigen.Western immunoblots of homogenates from different brain areas with P‐45011β antibodies, together with biochemical enzymatic assays for cytochrome P‐45011β}monooxygenase activity in these homogenates, confirmed the selective localization of this enzyme observed with immunohistochemistry. Cytochrome P‐45011β and 11β‐hydroxylase activity were detected in a homogenate from the cortical white matter (brain area rich in myelinated fibers) as in that from the rat adrenal, but were not detectable in a homogenate from the cerebral cortex (brain area poor in myelinated fibers). Furthermore, quantitation of the P‐45011β bands on the immunoblots by the areal density revealed that the cortical white matter contains approximately 1.4 pmol of cytochrome P‐45011β/mg of tissue protein, the value of which was about one sixth ofthe corresponding value estimated in the rat adrenal. This relatively highcontent of cytochrome P‐45011β was also reflected in a relatively high level of 11β‐hydroxylase activity measured in a homogenate ofthis brain area by biochemical enzymatic assays using [4‐14C]‐11‐deoxycorticosterone.Thus, from the present data it can be concluded that rat brain containscytochrome P‐45011β in myelinated tracts, in which the 11β‐hydroxylation mechanism (corticosterone synthesis) occurs as in adrenal cortex. This enzyme was detected in the same brain structures in which cytochrome P‐450scc (an enzyme involved in cholesterol side‐chain cleavage and preg‐nenolone synthesis) has been previously shown to be present, which suggests an important role of myelinated tracts for the biosynthesis of steroid hormones within the brain.
Stereotaxic injection of GD1a ganglioside induces limited recovery of striatal dopaminergic system in MPTP‐treated aging mice
Authors: Date I. , Notter M. F. D. , Felten S. Y. , Felten D. L. 
Published: January 2005

AbstractThe systemic administration of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) to young (2 months old) and aging (12 months old) C57BL/6 mice (4 × 20 mg/kg i.p. given 12 hr apart) reduced tyrosine hydroxylase (TH)‐immunoreactive (IR) fibers in the striatum and reduced dopamine (DA) concentration to 35% of controls in young and 22% of controls in aging mouse brain 5 weeks after administration. Stereotaxic injection of GDla ganglioside (3 × 100 μg, 5 days apart) into the striatum of MPTP‐treated young mice restored striatal DA concentration to 52% of the control concentration 5 weeks after MPTP injection. Similar injections of GDla ganglioside restored striatal DA concentration of MPTP‐treated aging mice to only 31% of the control concentration. Immunocytochemical analysis showed significant recovery of TH‐IR fibers in the striatum of MPTP‐depleted young mice treatedwith GDla ganglioside, while TH‐IR fibers in the striatum of MPTP‐depleted aging mice treated with GDla ganglioside showed less recovery. We conclude that treatment of MPTP‐deleted again mice with GD1a ganglioside results in more limited recovery in the nigrostriatal DA system than in young mice.
O‐2A glial progenitors from mature brain respond to CNS neuronal cell line‐derived growth factors
Authors: Hunter S. F. , Bottenstein J. E. 
Published: January 2005

AbstractDuring development, myelin‐forming oligodendrocytes and type 2 astrocytes are believed to arise from bipotential (O‐2A) glial progenitors. Previously we found that conditioned medium (CM) from the B 104 rat CNS neuronal cell line promotes growth of neonatal rat O‐2A progenitors in scrum‐free culture conditions with subsequent increases in differentiated progeny. We now report that O‐2A progenitors are present in mature rat brains and that this CM promotes the growth, motility, and bipolar morphology of these cells from 30‐ and 65‐day‐old rat brains, as shown by quantitative studies using double immunostaining and [3H]thymidine‐autoradiography. dition, the growth‐promoting action of B104 CM is not neutralized by antibodies to platelet‐derived growth factor, a proposed progenitor mitogen. Subsequent to the proliferation of these O‐2A progenitors, increases in oligodendrocytes and type 2 astrocytes occur. These data suggest a novel therapeutic strategy for some demyelinating diseases, e.g., multiple sclerosis, where there isa deficit in oligodendrocytes. Although it has been proposed by others thatmature brain O‐2A progenitors are less proliferative and thereby incapable of adequately replenishing lost oligodendrocytes in these diseases, we present in vitro evidence for continued response of mature brain O‐2A progenitors to this neuronal cell line‐derived mitogen.
Selective extraction, solubilization, and reversed‐phase high‐performance liquid chromatography separation of the main proteins from myelin using tetrahydrofuran/water mixtures
Authors: Díaz R. S. , Regueiro P. , Monreal J. , Tandler C. J. 
Published: January 2005

AbstractThe number of solvents capable of dissolving myelin and proteolipid protein (PLP) and of being used as a mobile phase for the separation of myelin proteins by reversed‐phase high‐performance liquid Chromatography (RP‐HPLC) is very limited. In a thorough study, we found that aqueous tetrahydrofuran (THF) fulfilled such a requirement. The maximal amount of protein extracted corresponded to a THF/water ratio of 4:1 v/v and a polarity index of 5.16. This mixture dissolved a purified PLP preparation completely, 60% of proteins from fresh myelin, and 20% of white matter total proteins. Sodium dodecyl sulphate‐poly‐acrylamide gel electrophoresis (SDS‐PAGE) of those extracts, followed by densitometric analysis, showed that the amount and type of proteins dissolved depended on the polarity (i.e., the content of water) of the solvent mixture used. This selective effect was greater for basic protein in myelin preparations. Crude extracts highly enriched in basic protein can be prepared. In addition, the solvent system THF/ water proved to be very useful as a mobile phase in RP‐HPLC for separating myelin proteins. Using a C3 column and a linear gradient from 30% to 100% THF in water, both containing 0.1% trifluoroacetic acid (TFA), we separated completely the three main protein fractions of central nervous system (CNS) myelin in a short period of time. The high solubility power of THF/water mixtures prolonged greatly the life of the column.
Effects of L‐β‐N‐methylamino‐L‐alanine (L‐BMAA) on the cortical cholinergic and glutamatergic systems of the rat
Authors: Rakonczay Z. , Matsuoka Y. , Giacobini E. 
Published: January 2005

AbstractNeurotoxic properties of L‐β‐methylamino‐alanine (L‐BMAA) after chronic intracerebroventricular (i.c.v.) (500 μg/day) administration up to 60 clays were investigated in the cerebral cortex of the rat. At day 16, there was a significant decrease in acetylcho‐linesterase (AChE) activity, 3H‐QNB binding, 3H‐glu‐tamate (GLU) binding, and 3H‐glutamate binding in the presence of quisqualate (QA). Choline acetyl‐transferase (ChAT) activity and 3H‐nicotine binding were increased at day 16; however, ChAT activity decreased below control levels, at days 40 and 60. 3H‐Nicotine and 3H‐AMPA binding were significantly lower than controls at both days 40 and 60. These significant neurochemical differences from unoper‐ated controls were seen in both drug‐injected and non‐injected sides of the cortex suggesting a generalized cortical damage to glutamatergic and cholinergic systems. In the presence of bicarbonate, L‐BMAA inhibited in vitro both glutamate and AMPA binding sites. L‐BMAA treatment elicited behavioral changes such as splay, jerking movements, and rigidity. These symptoms were present for a period of at least 6 days after daily administration. After this period, symptoms were gradually attenuated and at day 10 the behavior of the L‐BMAA‐treated animals was not different from that of Na‐bicarbonate injected controls. Our results are interpreted as an activation of quisqualate (AMPA) receptors by L‐BMAA involving NMDA as well as non‐NMDA receptors.
Differential expression of MAG isoforms during development
Authors: Pedraza L. , Frey A. B. , Hempstead B. L. , Colman D. R. , Salzer J. L. 
Published: January 2005

AbstractThe myelin‐associated glycoproteins (MAG) mediate the cell interactions of oligodendrocytes and Schwann cells with axons that are myelinated. MAG exists in two developmentally regulated isoforms: large MAG (L‐MAG) and small MAG (S‐MAG). In this paper, we have studied the tissue‐specific and developmentally regulated alternative splicing of these isoforms using monospecific antibodies that recognize epitopes common to both isoforms or that are present only on L‐MAG. In the central nervous system (CNS), L‐MAG is the major form synthesized early in development, and it persists as a significant proportion of the MAG present in the adult. In the peripheral nervous system (PNS), L‐MAG is expressed at modest levels during development; it is virtually absent in the adult. Thus, the expression of L‐MAG is not limited to the CNS, as was formerly believed, suggesting that it plays a common role during the early stages of myelin formation by both oligodendrocytes and Schwann cells. In both the CNS and PNS, S‐MAG is the predominant isoform in the adult. A higher‐molecular‐weight form of MAG is present in the PNS at low abundance, that is developmentally regulated, and appears to be a glycosylation variant. An analysis of the carbohydrate residues on MAG demonstrates that it contains both N‐linked and O‐linked sugars that could be modulated during development. These results suggest a possible mechanism for the regulation of MAG function during myelinogenesis via the expression of alternative isoforms and carbohydrate modifications.
Differential regulation of S100β and mRNAS coding for S100‐like proteins (42A and 42C) during development and after lesion of rat sciatic nerve
Authors: León M. De , Eldik Linda J. Van , Shooter E. M. 
Published: January 2005

AbstractThe changes in the levels of S1007beta; (a protein that stimulates neurite extension and neuronal survival) and 42A and 42C (S100‐like proteins whose mRNAs are induced in PC 12 cells by nerve growth factor) during development and after rat sciatic nerve lesions were analyzed. S100β, 42A, and 42C mRNAs showed differential regulation during development. S100β mRNA was present both in sciatic nerve and brain, and increased more than 11‐fold during the first 3 wk of nerve postnatal development. 42A and 42C mRNAs were essentially restricted to sciatic nerve, with little found in either embryonic or adult brain. The levels of 42C and 42A mRNAs in sciatic nerve increased 4 ‐and 14 ‐fold, respectively, by postnatal day 23 compared to postnatal day 2. 42A, 42C, and S100β mRNAs also showed a differential regulation during sciatic nerve degeneration and regeneration. Axotomized and control sciatic nerves were examined by Northern blots at various times after a crush or cut injury. 42A and 42C mRNA levels increased rapidly in the distal segment of axotomized nerve, remained two‐ to five‐fold higher than controls at day 14 after injury but returned to control levels by 40 days. In contrast, S100β mRNA showed a three‐fold decrease in the axotomized nerve between days 1 and 3 after injury, and slowly returned towards control levels over the next few weeks. The decrease in S100β mRNA was reflected by a corresponding decrease in S100β protein levels. The induction of 42A and 42C mRNAs and repression of S100β mRNA remained if nerve regeneration was prevented. These data suggest that, in spite of the high degree of sequence homology, S100β and its two homologues 42A and 42C play different roles in neuronal development and regeneration.
Chondroitin sulfate proteoglycan surrounds a subset of human and rat CNS neurons
Authors: Bertolotto Antonio , Rocca G. , Canavese G. , Migheli A. , Schiffer D. 
Published: January 2005

AbstractChondroitin sulfate proteoglycan (CS‐PG) bearing glycosaminoglycan (GAG) chains containing unsulfate (COS) and 6‐sulfate (C6S) disaccharides was immunolocalized in rat and human CNS by using monoclonal antibodies (MAb) specific for the two disaccharides. The immunostaining with both MAb was restricted to the periphery of a neuronal subset in rat and human CNS. Double immunofluorescence showed codistribution of the antigens around the same neuronal population. The staining with anti‐COS MAb was stronger than with anti‐C6S MAb, suggesting that the proteoglycan (PG) contains mainly COS disaccharjdes. In different rat cortical areas, 40–;60/mm2 positive interneurons were found, the visual cortex showing the highest value. In human cortex, positivity was also observed around the soma of some pyramidal cells. In the rat, positive neurons were also localized in deep cerebellar nuclei, reticular nucleus of the thalamus, and other structures of the midbrain and hindbrain. CA3 region of hippocampus and the external layer of pyriform cortex were characterized by positivity of the neuropil.Immunoelectronmicroscopy showed the antigens in the extracellular space around the neuronal soma, the synaptic elements and the cell processes of the neuropil. The neuronal surface of the soma and of the proximal dendrites were positive, but the pre‐ and postsynaptic membranes and clefts were negative.
Antibodies to the retina N‐acetylgalactosaminylphosphotransferase inhibit neurite outgrowth
Authors: Gayá‐González L. , Balsamo J. , Swaminathan N. , Lilien J. 
Published: January 2005

AbstractThe neural retina N‐acetylgalactosaminylphospho‐transferase (GalNAcPTase) is a cell surface molecule (Balsamo and Lilien, 1980, 1983; Balsamo et al., 1986a) that is tightly associated with, and glycosy‐lates, the calcium‐dependent, cell‐cell adhesion molecule, N‐cadherin (Balsamo and Lilien, 1990). N‐cad‐herin has been implicated in neuronal attachment and neurite outgrowth when at the surface of cels (Bixby et al., 1987, 1988; Matsunaga et al., 1988; Neugebauer et al., 1988; Tomaselli et al., 1988). The intimate association of the GalNAcPTase and N‐cadherin prompted us to test the possibility that the GalNAcPTase is also involved in the process of neurite outgrowth. We tested the effect of one polyclonal and two monoclonal anti‐GalNAcPTase antibodies in cultures of chick neural retina cells extending neurites on substrates requiring N‐cadherin, beta inte‐grin receptors, or the chicken homologue of L1, G4. The length and number of neurites produced were dramatically reduced on all of these substrates by the polyclonal and one of the monoclonal anti‐GalNAcPTase antibodies. The second monoclonal antibody bound to the cell surface but was not inhibitory, indicating that it reacts with a different epitope. The mechanism through which the retina cell surface GalNAcPTase may modulate neurite outgrowth on many substrates is discussed.
Establishment of pure neuronal cultures from fetal rat spinal cord and proliferation of the neuronal precursor cells in the presence of fibroblast growth factor
Authors: Deloulme J. C. , Baudier J. , Sensenbrenner M. 
Published: January 2005

AbstractA primary culture system of nearly pure neuronal cells from 14‐day‐old fetal rat spinal cord has been developed by combining a preplating step, the use of a chemically defined serum‐free medium, and bo‐rated polylysine‐coated dishes that prevented the formation of cell aggregates. About 98% of the cells were found to be immunostained with neuron‐specific enolase antibodies, confirming their neuronal nature. The cultures are composed essentially of a population of non‐motoneurons and contain few motoneurons, characterized by their large size and multipolar aspect, the presence of acetylcholinesterase (AChE), and the intense immunoreaction for growth‐associated protein GAP‐43. Neuronal precursor cells are also present in these cultures and proliferate during the first 3 days. The addition of bovine brain basic fibroblast growth factor (bFGF) stimulates their proliferation over a period of 2 days, as determined, by measurement of [125I]iododeoxyuridine incorporation and by immunocytochemical reaction after bro‐modeoxyuridine incorporation into nuclei. The proliferating cells were characterized as neurons by immunostaining against neuron‐specific enolase. Re‐combinant human bFGF and bovine brain acidic FGF (aFGF) exerted similar effects. Other growth factors, including epidermal growth factor (EGF), transforming growth factor β1 (TFG‐β1), and thrombin, were without effect on the proliferative activity of these neuronal cells. bFGF has no effect on the survival of motoneurons and on the fiber outgrowth of the whole neuronal population. However, bFGF affects the development of bipolar AChE‐pos‐itive neurons, probably belonging to the non‐motoneuron population. The data indicate that bFGF and aFGF are mitogens for neuroblasts from rat spinal cord in culture and that bFGF influences the development of a subpopulation of spinal neurons that are AChE‐positive.
Acidic fibroblast growth factor (aFGF) is expressed in the neuronal and glial spinal cord cells of adult mice
Authors: Tourbah A. , Oliver L. , Jeanny J. C. , Gumpel M. 
Published: January 2005

AbstractFibroblast growth factors (FGFs) are known to be synthesized in the central nervous system (CNS) and to act on CNS cells in vitro, but less is known about their synthesis, expression, and role in vivo. In this work, using specific anti‐acidic fibroblast growth factor (aFGF) antibodies, we have shown for the first time., by immunohistochemistry, that aFGF is expressed in spinal cord cells of young adult normal mice. This expression is predominant in the cell nucleus. Using immunohistochemical double staining procedures, we identified the cell type expressing aFGF as neurons, astrocytes, and oligodendrocytes, : but for each type, cells were not all positively immunostained.
Expression of the neurofilament protein NF‐H in L cells
Authors: Soifer D. , Nicoletti V. , Cabane K. , Mack K. , Poulos B. 
Published: January 2005

AbstractWe have inserted a Not1‐Sal1 fragment of the mouse gene coding for the neurofilament protein NF‐H behind the dexamethasone‐inducible transcription promoter of MMTV in a vector derived from pMAMneo (Clonetech Labs). This construct, which includes all four exons of the NF‐H gene, was amplified and in corporated into liposomes for transfection of L cells. Transfectants were selected in G418‐containing medium and cloned. Clones were grown in serum‐containing medium and screened for expression of the NF‐H mRNA by extraction of total RNA, generation of cDNAs by reverse transcription, and amplification of a 900‐base portion of the NF‐H cDNA by PCR. Positive clones were detected by the presence of a band of the correct size on agarose gels. This was confirmed by Southern blotting of the gels probed with a 185‐base segment of the amplified region. Immunofluorescent analysis of two positive clones, C33 and C34, showed that C33 cells grown in serum‐containing medium or in serum‐free medium in the presence of dexamethasone have a network of SMI32 (Sternberger/Meyer Inc.– monoclonal antibody against a nonphosphorylated epitope on NF‐H)‐positive filaments with the same distribution as filaments stained with antibodies to vimentin, while C34 cells do not react with antibodies against neurofilament proteins. Neither clone reacted with antibodies against highly phosphorylated NF‐H (SMI31).