Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The chronic survival and differentiation of the conditionally immortalized neuronal cell line, RN33B, was examined following transplantation into the adult and neonatal rat hippocampus and cerebral cortex. In clonal culture, differentiated RN33B cells express p75NTR and trkB mRNA and protein, and respond to brain-derived neurotrophic factor treatment by inducing c-fos mRNA. Transplanted cells, identified using immunohistochemistry to detect beta-galactosidase expression, were seen in most animals up to 24 weeks posttransplantation (the latest time point examined). Stably integrated cells with various morphologies consistent with their transplantation site were observed. In the cerebral cortex, many RN33B cells differentiated with morphologies similar to pyramidal neurons and stellate cells. In the hippocampal formation, many RN33B cells assumed morphologies similar to pyramidal neurons characteristic of CA1 and CA3 regions, granular cell layer neurons of the dentate gyrus, and polymorphic neurons of the hilar region. Identical morphologies were observed in both adult and neonatal hosts, although a greater percentage of beta-galactosidase immunoreactive cells had differentiated in the neonatal brains. These results suggest that RN33B cells have the developmental plasticity to respond to local microenvironmental signals and that the adult brain retains the capacity to direct the differentiation of neuronal precursor cells in a direction that is consistent with that of endogenous neurons.
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PMID:The adult CNS retains the potential to direct region-specific differentiation of a transplanted neuronal precursor cell line. 747 27

Stable transfer of genetic information into neurons is a powerful strategy to elucidate specific mechanisms of neurophysiology and to develop therapies for neurological disorders. To evaluate the optimal parameters for efficient gene delivery of defective herpes simplex virus type one (HSV-1) vectors into a specific brain region, an HSV-1 vector expressing E. coli beta-galactosidase was used to infect organotypic cultures of hippocampal slices. beta-Galactosidase was expressed as early as 2 h after infection in a dose-dependent manner as measured on immunoblots, and reached a maximum level after approximately 35 h. Expression of the RNA and the antigen was still evident after the longest time sampled (11-12 days), whereas no beta-galactosidase was ever detected in cultured slices infected with a control virus lacking the reporter gene. Hippocampal cells expressing the reporter gene outlined the contour of the neuronal cell body layers in fields CA3 and dentate gyrus; such correspondence was less evident in field CA1. Anatomical, morphological, and immunohistochemical criteria also confirmed that the majority of these infected cells were neurons. beta-Galactosidase was also detected in the somata and processes of infected interneurons. Tests for synaptic pathology associated with virus infection showed no changes in pre- and postsynaptic markers.
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PMID:Rapid and stable gene expression in hippocampal slice cultures from a defective HSV-1 vector. 753 3

The genomic DNA of chicken anemia virus (CAV) was cloned and sequenced from a Japanese isolate CAA82-2. The nucleotide sequence of CAA82-2 isolate was 98% identical with that of the European Cuxhaven-1 strain (Noteborn et al., J. Virol. 65, 3131-3139, 1991). Nine open reading frames (ORFs) consisting of more than 100 nucleotides were found, i.e., four ORFs (CA1-CA4) on the plus strand and five ORFs (CA1R-CA5R) on the minus strand. These ORFs with the exception of CA4 are conserved between the two CAV isolates. All of these ORFs were expressed in Escherichia coli as fusion proteins with beta-galactosidase. By Western blot analysis, the CA2 and CA3 fusion proteins were found to react with CAV-infected chicken sera. Rabbit hyperimmune sera against the CA1, CA2, and CA3 fusion proteins were produced and tested their reactivity to CAV-infected cells. Two viral proteins with the apparent size of 54 and 16 kDa reacted with the antibodies against CA1 and CA3 fusion proteins, respectively. The 16-kDa protein, CA3, was suggested to be a major immunogen on CAV infection.
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PMID:Gene organization of chicken anemia virus. 777 81

Deletion analysis of the rat CaMII promoter demonstrated that the segment from -294 to +68 bases of CaMII was efficient as a promoter in NIH3T3 by transient assay. We developed transgenic mice carrying a fusion gene of this promoter segment and a beta-galactosidase reporter gene. This short CaMII promoter mediated the transgene expression in pyramidal cells of the cerebral neocortex, the pyriformcortex and the hippocampal regions CA1 to CA3, in granule cells of the dentate gyrus, in Purkinje cells of the cerebellum, and in neurons of the lateral vestibular nucleus of pons and the spinal cord of adult transgenic mice. The expression of endogenous CaMII was precisely analyzed by in situ hybridization in the nervous tissues. The localization of transgene expression was consistent with those of the endogenous CaMII in the adult transgenic mice. In the embryos at 13.5-15.5 days of gestation, the transgene was expressed in various neurons similarly to the endogenous CaMII but certain subtle differences were observed in the localization of expression. This short promoter of rat CaMII carried two sequence stretches highly conserved in the mouse, dog, chicken and Xenopus CaMII promoters. These conserved stretches may be involved in the observed neuron-specific expression of rat CaMII gene.
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PMID:Expression of the rat calmodulin gene II in the central nervous system: a 294-base promoter and 68-base leader segment mediates neuron-specific gene expression in transgenic mice. 825 85

We have developed a novel technique using vaccinia virus for highly efficient introduction of foreign genes into viable cells of brain slice to study function of nervous system. Hippocampal slices of adult guinea pigs were infected with a vaccinia virus carrying a gene for beta-galactosidase (beta-gal) as a reporter gene. Expression of beta-galactosidase was first detected after 5 hours and reached maximum after 16 to 24 hours. Light microscopic observation revealed that beta-galactosidase was expressed uniformly in the CA1-CA3 pyramidal cell layer, granule cell layer of dentate gyrus and glial cells. Serial sections of infected slices showed that cells were uniformly infected throughout the thickness of the slice. Thus, the vaccinia virus system provides a convenient gene transfer tool for studying brain function in cultured slice system.
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PMID:A vaccinia virus vector for efficiently introducing into hippocampal slices. 851 65

RN33B cells, a CNS-derived neuronal precursor cell line, transplanted into normal adult rat hippocampus can survive and morphologically differentiate with their ultimate morphology dependent on the integration site. This study examined the differentiation and structural integration of RN33B cells transplanted into the lesioned adult hippocampus. Pyramidal neurons of the CA1-3 regions or granular neurons in the dentate gyrus were preferentially destroyed by unilateral intraventricular kainic-acid or intradentate colchicine injections, respectively. One week after the lesion, a suspension of undifferentiated beta-galactosidase (beta-gal)-labeled RN33B cells was stereotaxically transplanted into the lesioned or the contralateral hippocampus. After 5-7 weeks, sections of the recipient brains were analyzed by toluidine blue staining and immunohistochemistry for beta-gal, GFAP, and OX-42. A reactive gliosis was observed on the lesioned side which persisted up to 7 weeks postlesion (the latest time point examined). RN33b cells survived in the lesioned hippocampus and assumed variable morphologies depending on the hippocampal layer into which they integrated. Only RN33B cells located in intact or partially damaged cell layers or in the unlesioned contralateral hippocampus differentiated with morphologies similar to those of endogenous neurons characteristic of those layers. Cells located in layers completely depleted of endogenous neurons assumed bipolar morphologies or sent out multiple processes with no structural polarity, unlike the neuronal morphologies characteristically seen in intact hippocampal cell layers. These data suggest that the presence of some endogenous neurons and partially conserved cytoarchitectural organization are essential for immortalized neuroepithelial precursor cells to differentiate into region-specific neuronal cell types.
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PMID:Selective hippocampal lesions differentially affect the phenotypic fate of transplanted neuronal precursor cells. 863 69

Transgenic (NFHLacZ) mice expressing a fusion protein composed of a truncated high-molecular-weight mouse neurofilament (NF) protein (NFH) fused to beta-galactosidase (LacZ) develop inclusions in neurons throughout the CNS. These inclusions persist from birth to advanced age and contain massive filamentous aggregates including all three endogenous NF proteins and the NFHLacZ fusion protein. Further, the levels of endogenous NF proteins are selectively reduced in NFHLacZ mice. Because these inclusions resemble NF-rich Lewy bodies (LBs) in Parkinson's disease and LB dementia, we asked whether these lesions compromised the viability of affected neurons during aging. We studied hippocampal CA1 neurons, nearly all of which harbored inclusions (type I) devoid of cellular organelles, and cerebellar Purkinje cells, nearly all of which accumulated inclusions (type II) containing numerous entrapped organelles. Purkinje cells with type II inclusions began to degenerate in the NFHLacZ mice at approximately 1 year of age, and most were eliminated by 18 months of age. In contrast, there was no significant loss of type I inclusion-bearing CA1 neurons with age. These data suggest that the sequestration of cellular organelles in type II inclusions may isolate and impair the function of these organelles, thereby rendering Purkinje cells selectively vulnerable to degeneration with age as in neurodegenerative diseases of the elderly characterized by accumulation of LBs.
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PMID:Selective degeneration fo Purkinje cells with Lewy body-like inclusions in aged NFHLACZ transgenic mice. 899 61

Primary cultures of hippocampal neurons were infected with an adenovirus coding for beta-galactosidase. Expression could be detected as early as 4 h after infection and steadily increased to high levels at 24 h without evidence for a functional impairment of the infected neurons. Similarly, adenovirus-mediated gene transfer into acute hippocampal slices was detectable 4 h after infection and could be localized to discrete areas of the CA1 region by microinjection of the virus stock solution. Infected slices were still suitable for electrophysiological experiments.
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PMID:Rapid gene transfer into cultured hippocampal neurons and acute hippocampal slices using adenoviral vectors. 903 Jul 15

The human immunodeficiency virus type-1 envelope glycoprotein gp120 is shed from the virus and from infected cells and thus can diffuse and interact with a variety of central nervous system cells. Transgenic mice constitutively expressing glial fibrillary acidic protein-driven gp120 from brain astrocytes display neuronal and glial changes resembling abnormalities in human immunodeficiency virus type-1-infected human brains. To assess the neurophysiology of these transgenic mice and determine whether gp120 expression impairs synaptic plasticity, we examined CA1 population excitatory postsynaptic potentials in hippocampal slices from transgenic mice and from non-transgenic controls, using a double-blind protocol. Compared with slices from non-transgenic littermate controls, slices from gp120 transgenic mice showed four significant alterations: (i) increased mean slopes of normalized population excitatory postsynaptic potentials; (ii) larger paired-pulse facilitation after induction of long-term potentiation at 50 ms interpulse intervals; (iii) markedly elevated short-term potentiation after 10 and 20 shocks at 100 Hz; and (iv) a significant reduction in the magnitude of CA1 long-term potentiation. In slices from transgenic mice expressing Escherichia coli beta-galactosidase from the same promoter, paired-pulse facilitation and long-term potentiation were normal. These results indicate that brain slice preparations from gp120 transgenic mice can be used to assess pathophysiological effects of gp120 on neuronal networks. Because short-term potentiation involves presynaptic mechanisms, our results suggest that gp120 expression in these mice enhances either presynaptic glutamate release or postsynaptic glutamate receptor function, or both. These changes could lead to increased Ca2+ influx, thereby contributing to neuronal dysfunction and injury. As long-term potentiation is a cellular model of learning and memory, our results may be relevant to memory (cognitive) impairments seen in patients with AIDS.
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PMID:Transgenic mice with cerebral expression of human immunodeficiency virus type-1 coat protein gp120 show divergent changes in short- and long-term potentiation in CA1 hippocampus. 948 53

Mice harboring random gene-trap insertions of a lacZ (beta-galactosidase)-neomycin resistance fusion cassette (beta-geo) were analyzed for expression in the hippocampus. In 4 of 15 lines reporter gene activity was observed in the hippocampal formation. In the obn line, enzyme activity was detected in the CA1-3 hippocampal subfields, in hpk expression was restricted to CA1, but in both lines reporter activity was also present in other brain regions. In the third line, kin, reporter activity was robustly expressed throughout the stratum pyrimidale of CA1-3, with only low-level expression elsewhere. The final line (glnC) displayed ubiquitous expression of the reporter and was not analyzed further. Fusion transcripts for the first three lines were characterized; all encode polypeptides with features of membrane-associated signalling proteins. The obn fusion identified a human cDNA (B2-1) encoding a pleckstrin homology (PH) domain, while hpk sequences matched the Epstein-Barr Virus (EBV) inducible G-protein coupled receptor, EBI-1. kin identified an alternative form of the abl-related nonreceptor tyrosine kinase c-arg. Electrophysiological studies on mice homozygous for the insertions revealed normal synaptic transmission, paired pulse facilitation and paired-pulse depression at Schaffer collateral-commissural CA1 synapses, and normal long-term potentiation (LTP) in obn and kin. hpk mice displayed an increase in hippocampal CA1 long-term potentiation (LTP), suggesting a role for this receptor in synaptic plasticity.
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PMID:Gene-trapping to identify and analyze genes expressed in the mouse hippocampus. 982 57


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