bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of gonadotropin‐releasing hormone (GnRH)‐immunoreactive protein in the rat pineal gland
Authors: Park M. K. , Kogo H. , Kawashima S. , Wakabayashi K. 
Published: January 2005

AbstractThe aim of the present study was to characterize GnRH‐like substance(s) in the rat pineal gland using a monoclonal antibody, LRH13, as a probe. The epitope of LRH13 is between 2nd and 5th amino acid residues of the mammalian GnRH, and its immunological characters were previously defined by us. LRH13 could show strong immunological signal on the rat pineal gland. Immunoblot after SDS‐PAGE of the pineal gland preparations showed a LRH13 immunoreactive band with apparent mol wt 52 kiloDalton (kD), which is much bigger than that of hypothalamic GnRH precursor (10 kD). The 52 kD protein, however, was detected from insoluble fraction of the pineal homogenate and liberated from the fraction by Triton X‐100 (2%) treatment. On the other hand, NaCl (140 mM and 500 mM) or EDTA (10 mM) treatment failed to liberate. Two‐dimensional gel electrophoresis showed that the 52 kD protein is a mixture of two proteins with different isoelectric points (pI approximately 6.8 and 7.0). Both proteins showed identical patterns of peptide mapping by V8 protease digestion, and they might be originated from the same peptide. These results suggest that the rat pineal GnRH‐immunoreactive substance has a unique property as a membrane associate protein. © 1995 Wiley‐Liss, Inc.
Glial fibrillary acidic protein mRNA isotypes: Expression in vitro and in vivo
Authors: Galea E. , Dupouey P. , Feinstein D. L. 
Published: January 2005

AbstractGlial fibrillary acidic protein (GFAP) and its mRNA, primarily expressed in astrocytes, are also expressed in peripheral nervous system Schwann cells as well as in certain non‐neural tissues. Schwann cells express a GFAP mRNA (GFAP‐β) which differs from the CNStype mRNA (GFAP‐β) by the presence of an extended 5′ untranslated region. We have developed a polymerase chain reaction assay which allows distinction of these two GFAP mRNAs, as well as quantitative analysis of their levels. In the cultured rat Schwannoma cell line RT4‐D6, GFAP‐b̃ was the major GFAP mRNA species, accounting for at least 75% of total GFAP (α+β) mRNA. GFAP‐b̃ was also detected in primary rat astrocyte cultures, where it constituted approximately 5% of the total GFAP mRNA, as well as in RNA samples prepared from normal rat cerebral cortex, and from hamster and human brain. In rat cortex, the temporal expression of GFAP‐β mRNA paralleled that of total GFAP mRNA, with plateau levels reached between postnatal days 15 and 20. In astrocyte cultures, the relative levels of GFAP‐α and ‐β mRNAs were differentially regulated by exposure to interferon‐γ (10 to 25 units/ml), which caused an increase in GFAP‐β levels while at the same time no change or a small decrease in total GFAP levels. In rat brain cortical slices, 4 hr exposure to 25 units/ml interferon‐γ decreased total GFAP mRNA levels over tenfold, while GFAP‐b̃ levels were unaffected. These data indicate that a second form of the GF AP mRNA is expressed in astrocytes both in vivo and in vitro and provide evidence for independent regulation of these two GFAP mRNA species. © 1995 Wiley‐Liss, Inc.
Collagen implants and cortico‐spinal axonal growth after mid‐thoracic spinal cord lesion in the adult rat
Authors: Joosten E. A. J. , Bär P. R. , Gispen W. H. 
Published: January 2005

AbstractWe describe an experimental model to study regeneration of lesioned corticospinal tract (CST) fibers in the adult rat spinal cord. After transection of all CST fibers at mid‐thoracic level the gap is grafted with a sterile, cell‐free collagen matrix. Two methods of collagen‐application are used: (1) injection of a fluid collagen solution into the lesioned area which self‐assembles in situ and (2) implantation of a solid collagen gel. At 4 weeks post‐implantation CST axons are anterogradely labelled with horseradish‐peroxidase (HRP). The collagen implant is evaluated for ingrowth of CST axons. The histopathological reaction (gliotic response) around the lesion and within the matrix is also studied. After application of a fluid collagen solution into the lesion area HRP‐labelled CST axons can be visualized within the implant. In addition, astroglial and reactive microglial cells invade the collagen‐matrix. On the other hand, if collagen is implanted as an already self‐assembled gel, no ingrowth of labelled CST axons nor of astroglial/reactive microglial cells is observed. Both methods of collagenapplication result in a considerable reduction of the gliotic response as compared to the ungrafted animals.We conclude that the method of application of collagen (i.e., fluid or gel) considerably affects the response of lesioned CST axons. The application of a fluid collagen graft which in situ self‐assembles is beneficial for the regrowth of lesioned CST axons in rat spinal cord. In this respect the formation ' of an astroglial scaffolding structure within the (fluid) collagen, probably due to optimal integration between host and graft, is very important. The inability of injured CST fibers to enter the solid collagen graft may be related to the absence of an astroglial scaffolding structure within the implant. © 1995 Wiley‐Liss, Inc.
Laminin oligopeptide derivatized agarose gels allow three‐dimensional neurite extension in vitro
Authors: Bellamkonda R. , Ranieri J. P. , Aebischer P. 
Published: January 2005

AbstractThe phenotypic expression of various neural cells is influenced by extracellular matrix (ECM) molecules. This study aims to develop a three‐dimensional gel tailored to support neurite extension from neural cells. Laminin‐derived (LN) oligopeptides CDP‐GYIGSR, a 19‐mer IKVAV containing sequence, GRGDSP, a cocktail of the three aforementioned LN peptides (PEPMIX), and a control peptide sequence GGGGG were covalently linked to an agarose hydrogel backbone using the bi‐functional coupling agent 1′1, carbonyldiimidazole. Embryonic day 9 chick DRGs and PC12 cells were suspended in three dimensions in underivatized and derivatized agarose gels and neurite extension was analyzed. Agarose gels derivatized with CDPGYIGSR and PEPMIX enhanced neurite outgrowth from DRGs while GRGDSP and IKVAV derivatized gels inhibited neurite extension when compared to underivatized agarose gels. The IKVAV derivatized gels significantly enhanced neurite outgrowth from PC12 cells in comparison to underivatized and other LN peptide derivatized gels. Agarose hydrogels carrying covalently immobilized LN oligopeptides thus evoke specific responses from cells which contain receptors to the peptides used. Agarose hydrogels derivatized with neurite promoting peptide sequences may find applications in various models of in vivo regeneration of nervous tissue. © 1995 Wiley‐Liss, Inc.
Syngeneic bone marrow transplantation eliminates Vβ8.2 T lymphocytes from the spinal cord of Lewis rats with experimental allergic encephalomyelitis
Authors: Burt R. K. , Burns W. , Ruvolo P. , Fischer A. , Shiao C. , Guimaraes A. , Barrett J. , Hess A. 
Published: January 2005

AbstractExperimental allergic encephalomyelitis (EAE), an animal model for multiple sclerosis (MS), is a paralytic disease of the central nervous system (CNS) mediated by T‐lymphocytes reactive to myelin basic protein (MBP). Lewis rats actively immunized with fragment 68 to 82 of guinea pig MBP develop a monophasic disease with spontaneous recovery. Lymphocyte recognition of the primary encephalitogenic sequence of MBP (fragment 68 to 82) is Vβ8.2 T cell receptor (TCR) skewed [1–3].Lewis rats in clinical remission at 1 month and 3 months after spontaneous resolution of EAE retain Vβ8.2 T‐lymphocytes in the CNS when analyzed by reverse transcriptase polymerase chain reaction or in situ hybridization. In contrast, I and 3 months after clinical remission from syngeneic bone marrow transplantation, Vβ8.2 T lymphocytes are absent from the CNS.During clinically active EAE and inflammatory breakdown of the blood‐brain barrier, immune ablation and reconstitution with syngeneic bone marrow results in clinical tolerance of the new immune system to myelin. © 1995 Wiley‐Liss, Inc.
Spatial distribution of ω‐agatoxin IVA binding sites in mouse brain slices
Authors: Nakanishi S. , Fujii A. , Kimura T. , Sakakibara S. , Mikoshiba K. 
Published: January 2005

AbstractA peptide toxin derived from funnel‐web spider venom, ω‐agatoxin IVA, blocks voltage‐sensitive calcium channels. Many pharmacological and electrophysiological studies have shown that these channels are widely distributed in both the central nervous system (CNS) and neuromuscular junctions. However, a direct morphological demonstration of the binding sites of this toxin is still lacking. To identify which cells have the binding sites, a biologically active, biotin‐conjugated ω‐agatoxin IVA was applied to mouse cerebellar and hippocampal slices. Confocal microscopy revealed that ω‐agatoxin IVA binding sites were distributed on the somata of Purkinje cells, cerebellar granule cells and interneurons, as well as on the dendrites of Purkinje cells. In the hippocampus, the binding sites were localized on the somata of pyramidal cells of the CA1–CA4 region and on the somata of granule cells in the dentate gyrus. A sequential competitive reaction confirmed the specificity of the binding in the cerebellum and CA1 pyramidal cells, and also suggested a difference in the binding affinity between CA1 and CA3 pyramidal cells. Since a high concentration of ω‐agatoxin IVA (2 μM) was needed for the present study, the ω‐agatoxin IVA binding sites presented in this study may represent “P‐type” and “Q‐type” calcium channels. © 1995 Wiley‐Liss, Inc.
Selective in vitro blockade of neuroepithelial cells proliferation by methylazoxymethanol, a molecule capable of inducing long lasting functional impairments
Authors: Cattaneo E. , Reinach B. , Caputi A. , Cattabeni F. , Di Luca M. 
Published: January 2005

AbstractIn order to characterize the antiproliferative effect of methylazoxymethanol neuroepithelial cells derived from the rat striata primordia at embryonic day 14 have been exposed to graded doses of this compound. It was found that methylazoxymethanol application to striatal neuroblasts elicits a blockade of cell proliferation at a dose which does not interfere with cell survival. By using synchronized cells and short term exposures to this compound, we found that the antiproliferative effect of methylazoxymethanol is strikingly correlated to the number of cells actively dividing in culture, thus indicating that the cells targeted by methylazoxymethanol must be in an active mitotic phase. To test for the selectivity of actien of Methylazoxymethanol for dividing neuroblasts either cultures composed of mature proliferating astrocytes or muscle cells have been subjected to the same treatment. It has been observed that astrocytes proliferation was not affected by the dose of methylazoxymethanol shown to be effective on neuroepithelial cells. Finally we demonstrated that methylazoxymethanol is able only transiently to interfere with smooth muscle cell division, further supporting its selectivity of action within the developing CNS. © 1995 Wiley‐Liss, Inc.
Expresgions of nerve growth factor and p75 low affinity receptor after transient forebrain ischemia in gerbil hippocampal CA1 neurons
Authors: Lee T.‐H. , Abe K. , Kogure K. , Itoyama Y. 
Published: January 2005

AbstractExpressions of nerve growth factor (NGF) and low affinity p75 NGF receptor (p75 NGFR) in gerbil hippocampal neurons after 3.5‐min transient forebrain ischemia were studied. Most hippocampal CAI neurons were lost (neuronal density = 44 ± 12/mm) at 7 days after recirculation, while no cell death was found in the sham‐control neurons (220 ± 27/min). NGF immunoreactivity was normally present in the sham‐control hippocampal neurons. However, it decreased in hippocampal CAI neurons, and slightly decreased in the neurons of CA3 and dentate gyrus areas from 3 hr after recirculation. By 7 days, NGF immunoreactivity returned almost completely to the sham‐control level in the CA3 and dentate gyrus neurons but decreased markedly in the CAI neurons. In contrast, p75 NGFR immunoreactivity was scarcely present in the sham‐control hippocampal neurons but was induced from 1 hr after recirculation in the CAI and CA3 neurons and from 3 hr in the dentate gyrus. At 7 days, p75 NGFR immunoreactivity was expressed greatly in the surviving CAI neurons and the reactive astrocytes but was not seen in the other hippocampal neurons.The markedly decreased NGF and greatly induced p75 NGFR immunoreactivity found in the CAI neurons after transient forebrain ischemia suggests that NGF and p75 NGFR may be involved in the mechanism of delayed neuronal death. © 1995 Wiley‐Liss, Inc.
GapIII, a new brain‐enriched member of the GTPase‐activating protein family
Authors: Baba H. , Fuss B. , Urano J. , Poullet P. , Watson J. B. , Tamanoi F. , Macklin W. B. 
Published: January 2005

AbstractRas GTPase‐activating proteins (GAPs) are negative regulators of ras, which controls proliferation and differentiation in many cells. Ras GAPs have been found in a variety of species from yeast to mammals. We describe here a newly identified mammalian GAP, GapIII, which was obtained by differential screening of a rat oligodendrocyte cDNA library. GapIII putatively encodes a 834 amino acid protein with a predicted molecular weight of 96 kDa, which contains a consensus GAP‐related domain (GRD). The protein encoded by this cDNA has high homology with Gap1m, which was recently identified as a putative mammalian homolog of Drosophila Gapl. These proteins contain three structural domains, an N‐terminal calcium‐dependent phospholipid binding domain, GRD, and a C‐terminal PH/Btk domain. Because of the sequence homology and the structural similarities of this protein with Gaplm, we hypothesize that GapIII and Gap1m may be members of a mammalian GAP gene family, separate from p120GAP, neurofibromin (NF1), and IQGAP. To confirm the GapIII protein activity, constructs containing different GapIII‐GRD domains were transformed into iral mutant yeast to determine their relative ability to replace IRA1 functionally. Constructs that contained essentially the full‐length protein (all three domains), the GRD alone, or the GRD plus PH/Btk domain suppressed heat shock sensitivity of iral, whereas constructs that contained the GRD with part of the PH/Btk domain had only a weak ability to suppress heat shock sensitivity. These results suggest that the GapIII GRD itself is sufficient to down‐regulate ras proteins in yeast. Expression of GapIII mRNA (4.2 kb) was examined by Northern analysis and in situ hybridization. This mRNA was expressed at highest levels in the brain, where its expression increased with development. Lower levels of the mRNA were expressed in the spleen and lung. Among neural cells, GapIII mRNA was expressed in neurons and oligodendrocytes, but not in astrocytes. Interestingly, the expression pattern in brain is reminiscent of type 1 NF1 expression reported by Gutmann et al. (Cell Growth Differ in press, 1995). We propose that in addition to p120GAP and neurofibromin, the GapIII/Gaplm family may be important for modulating ras activity in neurons and oligodendrocytes during normal brain development and in particular in the adult brain. © 1995 Wiley‐Liss, Inc.
Neurotoxicity of the human immunodeficiency virus type 1 Tat transactivator to PC12 cells requires the Tat amino acid 49‐58 basic domain
Authors: Weeks B. S. , Lieberman D. M. , Johnson B. , Roque E. , Green M. , Loewenstein P. , Oldfield E. H. , Kleinman H. K. 
Published: January 2005

AbstractThe acquired immunodeficiency syndrome (AIDS) frequently involves the central nervous system (CNS) and manifests as dementia due to encephalitis or diffuse neurodegeneration. Human immunodeficiency virus type 1 (HIV‐1) proteins, potentially transported into the CNS by mononuclear inflammatory cells, have been implicated in the etiology of this HIV‐1 associated neurological dysfunction. Here we investigate the neurotoxicity of the essential HIV‐1 regulator protein Tat in vivo after microinfusion into the rat brain and in vitro using PC12, NG108‐15, and GT17 neuronal cell lines. Infusion of either chemically synthesized Tat (Tat86) or recombinant Tat (rTat) into the striatal gray matter in Sprague‐Dawley rats resulted in postural deviation ipsilateral to the infusion, a clinical presentation in rats associated with complete striatal dysfunction. Histologic examination 3 days after infusion revealed massive necrosis in the area of the distribution of the infusion. Infusion of heat denatured rTat, peptide Tat49‐58, or peptide Tat57‐86 did not result in clinically or histologically detectable brain damage. After 3 days incubation in vitro, the lethal dose for half (LD50) of PC 12 cells due to rTat was 5 μg/ml. The LD50 for Tat86 under the same conditions was 10 μg/ml. Tat49‐58 and Tat57‐86 peptides were not toxic in vitro even at 10‐fold higher doses. At 5 μg/ml, rTat was toxic to 100% of GT17 cells after 24 hr. At 5 μg/ml, Tat86 was toxic to 90% of the NG108‐15 cells after 7 days of treatment. Prior experiments have shown Tat49‐58 is specifically recognized by a cell surface protein that mediates Tat uptake. Here we show that Tat toxicity is inhibited by cotreatment with excess Tat49‐58, suggesting Tat neurotoxicity requires binding to its surface ligand. Chloroquine, which increases nuclear accumulation of Tat, enhances Tat toxicity to PC 12 cells, suggesting that Tat internalization is a required step in the mechanism of its toxicity. © 1995 Wiley‐Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of America.
Distribution of transforming growth factor‐β isoforms in the mammalian retina
Authors: Anderson D. H. , Guerin C. J. , Hageman G. S. , Pfeffer B. A. , Flanders K. C. 
Published: January 2005

AbstractThe distribution of transforming growth factor‐beta (TGF‐β) was examined in the posterior segment of the monkey, human, and feline eye using antisera to TGF‐β, TGF‐β, or TGF‐β. A number of different antibodies, tissue processing methods, immunolocalization techniques, and microscopic imaging systems were used in an attempt to gain a more comprehensive picture of TGF‐β isoform distribution in the retina and retinal pigmented epithelium (RPE). The results are generally consistent in identifying one or more of the three TGF‐β isoforms in the cytoplasm of a small, overlapping subset of cells. RPE cells, photoreceptors, Mueller cells, ganglion cells, hyalocytes, and cells associated with choroidal and retinal vessels are all represented in this immunoreactive population. No evidence of extracellular labeling was noted. The intracellular distribution of the three isoforms is distinctly different in photoreceptors. Anti‐TGF‐β precursor and anti‐TGF‐β immunoreactivity is confined primarily to rod outer segments, whereas anti‐TGF‐β immunoreactivities are restricted to mitochondria within inner segments. In the RPE, clusters of anti‐TCF‐β positive cytoplasmic granules are located near the cells' lateral borders, whereas anti‐TGF‐β labeling is concentrated apically. These results provide baseline information from which new hypotheses regarding the function(s) of TGF‐β isoforms in the retina can be formulated. © 1995 Wiley‐Liss, Inc.
Insulin‐like growth factor I is an afferent trophic signal that modulates calbindin‐28kD in adult Purkinje cells
Authors: Nieto‐Bona M. P. , Busiguina S. , Torres‐Aleman I. 
Published: January 2005

AbstractRecent evidence suggests that Purkinje cells are specific targets of insulin‐like growth factor I (IGF‐I) through their entire life span. During development, Purkinje cell numbers and their calbindin‐28kD content increase after IGF‐I treatment in culture. In the adult, part of the IGF‐I present in the cerebellum is transported from the inferior olive, and modulates Purkinje cell function. We investigated whether IGF‐I produced by inferior olive neurons and transported to the contralateral cerebellum through climbing fibers may modulate the levels of calbindin‐28kD in the cerebellum of adult animals. Twenty‐four hr after injection of an antisense oligonucleotide of IGF‐I into the inferior olive, both IGF‐I and calbindin‐28kD levels in the contralateral cerebellar lobe were significantly reduced, while the number of calbindin‐positive Purkinje cells was unchanged. The effect of the antisense on IGF‐I levels was fully reversed 3 days after its injection into the inferior olive, with a postinhibitory rebound observed at this time, while calbindin‐28kD levels slowly returned to control values. A control oligonucleotide did not produce any change in either IGF‐I or calbindin‐28kD content in the cerebellum. These results indicate that normal levels of IGF‐I in the inferior olive are necessary to maintain appropriate levels of IGF‐I in the cerebellum and of calbindin‐28kD in the Purkinje cell. These results also extend our previous findings on the existence of an olivo‐cerebellar IGF‐I‐containing pathway with trophic influence on the adult Purkinje cell. © 1995 Wiley‐Liss, Inc.
Cloning and characterization of MVP17: A developmentally regulated myelin protein in oligodendrocytes
Authors: Kim T. , Fiedler K. , Madison D. L. , Krueger W. H. , Pfeiffer S. E. 
Published: January 2005

AbstractThe remarkable quantities of myelin membrane produced by oligodendrocytes has led us to examine the mechanisms involved in the sorting and transport of proteins and lipids during myelinogenesis. Noting that it has been proposed that proteins destined for the apical surface of polarized epithelial cells co‐cluster with glycolipid‐rich microdomains during sorting and transport from the trans‐Golgi network (Simons and van Meer: Biochemistry 27:6197‐6202, 1988; Simons and Wandinger‐Ness: Cell 62:207‐210, 1990), we hypothesized that the glycolipid‐rich oligodendrocytes may adopt this mechanism for myelinogenesis. Protein‐lipid complexes from oligodendrocytes and myelin were isolated utilizing detergent insolubility and two‐dimensional gel electrophoresis. A developmentally regulated protein, MVP17 (myelin vesicular protein of 17 kDa), was identified. Microsequencing of the N‐terminal peptide revealed a high homology to human T‐cell MAL protein (Alonso and Weissman: Proc Nati Acad Sci USA 84:1997‐2001, 1987). The corresponding MVP17 cDNA was isolated from an oligodendrocyte cDNA library. The predicted protein sequence showed 88.9% identity with MAL, and the hydrophobicity profile suggested four transmembrane domains. In vitro translation demonstrated a signal at the deduced Mr of 17 kDa. Northern analyses indicated that MVP17 mRNA expression is restricted to brain and kidney and that this expression is up‐regulated in oligodendrocytes and brain during the period of active myelination. These data suggest that MVP17 is involved in myelin biogenesis and/or myelin function. © 1995 Wiley‐Liss, Inc.