1226
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1227
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Cunningham ME, Kitajewski JK, Greene LA. Efficient generation of stable pheochromocytoma (PC12) cell lines using a recombinant retrovirus (LNC). Methods Mol Biol 2001; 169:135-47. [PMID: 11142008 DOI: 10.1385/1-59259-060-8:135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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1228
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Huang BR, Ma XM. Expression of neurotrophic factors such as GDNF in the E. coli system. Methods Mol Biol 2001; 169:101-14. [PMID: 11142006 DOI: 10.1385/1-59259-060-8:101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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1229
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Albers KM, Davis BM. Construction and analysis of transgenic animals overexpressing neurotrophins. Methods Mol Biol 2001; 169:149-66. [PMID: 11142009 DOI: 10.1385/1-59259-060-8:149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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1230
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Xian CJ, Zhou XF. Sensitive and nonradioactive in situ detection of neurotrophin mRNAs in the nervous system. Methods Mol Biol 2001; 169:91-8. [PMID: 11142023 DOI: 10.1385/1-59259-060-8:91] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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1231
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Tsuboi Y, Nakanishi T, Takano-Yamamoto T, Miyamoto M, Yamashiro T, Takigawa M. Mitogenic effects of neutrophins on a periodontal ligament cell line. J Dent Res 2001; 80:881-6. [PMID: 11379889 DOI: 10.1177/00220345010800030701] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) are three representative neurotrophins responsible for the differentiation and survival of neurons, and their high-affinity receptors are tropomyosin-receptor-kinase (TRK)A, TRKB, and TRKC, respectively. In this study, we investigated the expression of neurotrophins in a mouse periodontal ligament cell line (MPL), by reverse transcription-polymerase chain-reaction (RT-PCR) and enzyme-linked immunoabsorbent assay (ELISA). We also studied the expression of TRK receptors on MPL by immunostaining and the effects of neurotrophins on the proliferation of MPL, with a hypothesis of autocrine mechanism of neurotrophins. Each neurotrophin and TRK receptor was expressed, and neurotrophins enhanced the proliferation of MPL. These findings suggest that the MPL has functional neurotrophin receptors involved in an autocrine function of neurotrophins. The expression level of neurotrophins and TRKs showed the reverse pattern, and we propose an auto-regulatory mechanism of ligands and receptors in accordance with the level of synthesized neurotrophins.
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MESH Headings
- Alkaline Phosphatase/analysis
- Alkaline Phosphatase/genetics
- Analysis of Variance
- Animals
- Autocrine Communication
- Brain-Derived Neurotrophic Factor/analysis
- Brain-Derived Neurotrophic Factor/genetics
- Cell Differentiation/physiology
- Cell Line
- Cell Survival/physiology
- Coloring Agents
- Culture Media, Conditioned
- Enzyme-Linked Immunosorbent Assay
- Gene Expression Regulation
- Mice
- Mice, Inbred BALB C
- Mitogens/analysis
- Mitogens/genetics
- Nerve Growth Factor/analysis
- Nerve Growth Factor/genetics
- Nerve Growth Factors/analysis
- Nerve Growth Factors/genetics
- Neurons/metabolism
- Neurotrophin 3/analysis
- Neurotrophin 3/genetics
- Periodontal Ligament/cytology
- Periodontal Ligament/metabolism
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Receptor, trkA/analysis
- Receptor, trkA/genetics
- Receptor, trkB/analysis
- Receptor, trkB/genetics
- Receptor, trkC/analysis
- Receptor, trkC/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Statistics as Topic
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1232
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Winocur G, Roder J, Lobaugh N. Learning and memory in S100-beta transgenic mice: an analysis of impaired and preserved function. Neurobiol Learn Mem 2001; 75:230-43. [PMID: 11222062 DOI: 10.1006/nlme.2000.3961] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
S100-beta, a calcium-binding astrocytic protein from chromosome 21, has been implicated in CNS function generally and the hippocampus in particular. Elevated levels of S100-beta have been observed reliably in the brains of patients with Alzheimer's Disease and Down Syndrome. Groups of transgenic mice, carrying multiple S100-beta gene copies, and nontransgenic controls were administered a series of behavioral tests (delayed spatial and nonspatial non-matching-to-sample, radial arm maze, socially acquired food preference) that assessed a wide range of cognitive functions. Consistent with the widespread presence of S100-beta throughout the brain, transgenic mice exhibited learning or memory impairment on all tasks. The dementia-like cognitive profile of S100-beta mice represents a promising model for studying comparable cognitive deficits associated with neurodegenerative diseases.
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1233
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Akamatsu S, Fujii S, Escaño MF, Ishibashi K, Sekiya Y, Yamamoto M. Altered expression of genes in experimentally induced myopic chick eyes. Jpn J Ophthalmol 2001; 45:137-43. [PMID: 11313044 DOI: 10.1016/s0021-5155(00)00360-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To identify a casual pathway between the alteration in visual experience, due to form deprivation and hyperopic defocus, and the increase in eye growth, we searched for candidate genes having regulatory effects on eye growth under myopic conditions. METHODS The expression of the brain-derived neurotrophic factor, neurotrophin-3, sonic hedgehog, nerve growth factor, Six-3 and the Lh-2 group of genes in the transcriptional level after experimentally induced myopia (form-deprivation by goggles and by hyperopic defocus using negative spectacle lenses) were evaluated by semiquantitative reverse transcriptional polymerase chain reaction and Northern blot analysis. RESULTS Results showed that only the sonic hedgehog gene was differentially expressed in the experimentally induced myopic retinal samples compared with controls. CONCLUSIONS The sonic hedgehog gene may have regulatory functions in the signaling of the cascade of events that leads to axial elongation and vitreous enlargement of the eye under myopic conditions.
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1234
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Boruch AV, Conners JJ, Pipitone M, Deadwyler G, Storer PD, Devries GH, Jones KJ. Neurotrophic and migratory properties of an olfactory ensheathing cell line. Glia 2001; 33:225-9. [PMID: 11241740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Olfactory ensheathing cells (OECs) are a unique type of macroglia required for normal olfactory axonal regeneration throughout the lifetime of an individual. Recent evidence in the literature suggests that OECs transplanted into injured spinal cords may facilitate axonal regeneration. In this study, we evaluated the neurotrophic properties of OECs using a homogeneous clonal cell line (nOEC), which does not contain contaminating cell types found in all primary OEC cultures. The results indicate that nOECs express mRNA for NGF, BDNF, NT-4/5, and neuregulins, but not for NT-3 or CNTF. In addition, nOECs secrete NGF, BDNF, and neuregulin, but retain NT-4/5 intracellularly. Finally, prelabeled nOECs derived from rat survived transplantation into a dorsal hemisected region of the hamster spinal cord and migrated only in the injured, dorsal portion of the spinal cord. This migratory pattern suggests that the nOECs are viable in vivo and respond to signals originating from the injured neuronal cells and their processes.
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1235
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Ellezam B, Selles-Navarro I, Manitt C, Kennedy TE, McKerracher L. Expression of netrin-1 and its receptors DCC and UNC-5H2 after axotomy and during regeneration of adult rat retinal ganglion cells. Exp Neurol 2001; 168:105-15. [PMID: 11170725 DOI: 10.1006/exnr.2000.7589] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Netrins are a family of chemotropic factors that guide axon outgrowth during development; however, their function in the adult CNS remains to be established. We examined the expression of the netrin receptors DCC and UNC5H2 in adult rat retinal ganglion cells (RGCs) after grafting a peripheral nerve (PN) to the transected optic nerve and following optic nerve transection alone. In situ hybridization revealed that both Dcc and Unc5h2 mRNAs are expressed by normal adult RGCs. In addition, netrin-1 was found to be constitutively expressed by RGCs. Quantitative analysis using in situ hybridization demonstrated that both Dcc and Unc5h2 were down-regulated by RGCs following axotomy. In the presence of an attached PN graft, Dcc and Unc5h2 were similarly down-regulated in surviving RGCs regardless of their success in regenerating an axon. Northern blot analysis demonstrated expression of netrin-1 in both optic and sciatic nerve, and Western blot analysis revealed the presence of netrin protein in both nerves. Immunohistochemical analysis indicated that netrin protein was closely associated with glial cells in the optic nerve. These results suggest that netrin-1, DCC, and UNC5H2 may contribute to regulating the regenerative capacity of adult RGCs.
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1236
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Jomary C, Grist J, Milbrandt J, Neal MJ, Jones SE. Epitope-tagged recombinant AAV vectors for expressing neurturin and its receptor in retinal cells. Mol Vis 2001; 7:36-41. [PMID: 11239244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
PURPOSE Neurturin (NTN) is a potent neuronal survival factor in the central and peripheral nervous systems. We previously described altered expression of mRNAs for NTN and one of its receptor components, GFRa-2 in degenerative retinas of rd/rd mice. Towards assessing the potential for transfer of these genes to counteract retinal degeneration, we examined recombinant adeno-associated virus (rAAV) constructs for expression of NTN and GFRa-2 transgenes in retinal cells in vitro and for the effect of transgene expression on retinal function following intraocular delivery in rd/rd mice. METHODS The rAAV constructs incorporated epitope tags to facilitate discrimination between transgenic and endogenous expression. Expression of murine NTN was driven by a CMV promoter and a partial murine opsin promoter was used to drive expression of human GFRa-2. rAAV preparations were used to infect mouse retinal cell cultures and for intraocular injection of predegenerative rd/rd mice. Endogenous and transgene expression was analyzed by immunofluorescence. Photoreceptor function in treated mice was assessed by electroretinography. RESULTS Both vectors delivered and expressed their transgenes in vitro and in vivo. Differential targeting was achieved in vivo through the use of alternative promoters. Under the conditions examined, no functional rescue of rd photoreceptors was observed. CONCLUSIONS Therapeutic treatment of the rd model of retinal degeneration does not appear to be effected by simple modulation of the expression of NTN or GFRa-2, and may therefore depend on additional synergistic factors. Our AAV constructs will facilitate the development of combinatorial approaches to the treatment of central and peripheral neurodegenerations.
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Abstract
Smad proteins transduce transforming growth factor-beta signals from the cell surface to the nucleus, regulating a variety of physiologic processes. In the nucleus, Smads control gene expression by binding to both DNA and transcription factors. Individual Smads regulate distinct subsets of target genes. The key residues important for this specificity are thought to reside in the carboxyl-terminal MH2 domain. To further examine Smad specificity in vivo, we undertook structure-function studies in Xenopus laevis embryos and found that truncated Smads containing the MH2 domain activate gene transcription. A striking finding revealed by the in vivo analyses was that the functional truncated Smads all behaved identically and had lost wild-type specificity. For most Smads, wild-type activity required the presence of an MH1 domain, either in cis or in trans. Of note, even heterologous MH1 domains could restore wild-type signaling specificity to effector MH2 domains. We found a possible mechanism to account for these observations, as Smad MH1 domains altered the binding of pathway-specific transcription factors to the MH2 domain. Thus, Smad MH1 domains are important to the regulation of transcriptional specificity.
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Conner JM, Darracq MA, Roberts J, Tuszynski MH. Nontropic actions of neurotrophins: subcortical nerve growth factor gene delivery reverses age-related degeneration of primate cortical cholinergic innervation. Proc Natl Acad Sci U S A 2001; 98:1941-6. [PMID: 11172055 PMCID: PMC29361 DOI: 10.1073/pnas.98.4.1941] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2000] [Indexed: 11/18/2022] Open
Abstract
Normal aging is associated with a significant reduction in cognitive function across primate species. However, the structural and molecular basis for this age-related decline in neural function has yet to be defined clearly. Extensive cell loss does not occur as a consequence of normal aging in human and nonhuman primate species. More recent studies have demonstrated significant reductions in functional neuronal markers in subcortical brain regions in primates as a consequence of aging, including dopaminergic and cholinergic systems, although corresponding losses in cortical innervation from these neurons have not been investigated. In the present study, we report that aging is associated with a significant 25% reduction in cortical innervation by cholinergic systems in rhesus monkeys (P < 0.001). Further, these age-related reductions are ameliorated by cellular delivery of human nerve growth factor to cholinergic somata in the basal forebrain, restoring levels of cholinergic innervation in the cortex to those of young monkeys (P = 0.89). Thus, (i) aging is associated with a significant reduction in cortical cholinergic innervation; (ii) this reduction is reversible by growth-factor delivery; and (iii) growth factors can remodel axonal terminal fields at a distance, representing a nontropic action of growth factors in modulating adult neuronal structure and function (i.e., administration of growth factors to cholinergic somata significantly increases axon density in terminal fields). These findings are relevant to potential clinical uses of growth factors to treat neurological disorders.
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1239
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Abstract
Current knowledge of sporadic degenerative disorders suggests that, despite their multifactorial etiopathogenesis, genetics plays a primary role in orchestrating the pathological events, and even dramatically changes the disease phenotype from patient to patient. Genes may act as susceptibility factors, increasing the risk of disease development, or may operate as regulatory factors, modulating the magnitude and severity of pathogenic processes or the response to drug treatment. The goal of pharmacogenomics is the application of this knowledge to elaborate more specific and effective treatments and to tailor therapies to individual patients according to their genetic profile. Here, we outline the leading theories on the etiopathogenesis of neurodegenerative diseases, including amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer disease, and we review the potential role of genetic variations, such as gene mutations and polymorphisms, in each context. We also suggest potential targets for new therapeutic approaches and variability factors for current treatments based on genotype features. Finally, we propose a few options of preventive therapeutic interventions in patients with a high genetic risk of disease.
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1240
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Lau AO, Sacci JB, Azad AF. Host responses to Plasmodium yoelii hepatic stages: a paradigm in host-parasite interaction. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1945-50. [PMID: 11160243 DOI: 10.4049/jimmunol.166.3.1945] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The liver stage of malaria, caused by the genus Plasmodium, is clinically silent, but immunologically significant. Ample evidence exists for an effective CD8(+) T cell response to this stage as well as the involvement of gammadeltaT cells and NK1.1(int) cells in immunized animal models. In contrast, there is little information concerning responses in a naive host. Here we report that several host gene expressions in the liver, spleen, and kidney of BALB/c mice are altered during the liver stage of Plasmodium yoelii infection. Really interesting new gene 3 (Ring3), semaphorin subclass 4 member G, glutamylcysteine synthetase, and p45 NF erythroid 2 were all up-regulated 24 h after infection with P. yoelii. Semaphorin subclass 4 member G expression was elevated in the kidney, whereas Ring3 was elevated in both spleen and kidney. The expression of TNF-alpha (TNF-alpha and IFN-gamma) were down-regulated in all three tissues tested except in infected spleen where IFN-gamma was elevated. P. yoelii-related host gene changes were compared with those in Toxoplasma gondii-infected livers. Ring3 expression increased 5-fold over control values, whereas expression of the other transcripts remained unchanged. TNF-alpha and IFN-gamma expressions were increased in the Toxoplasma-infected livers. The uniform increase of Ring3 expression in both Plasmodium- and Toxoplasma-infected livers suggests an innate immune response against parasitic infections, whereas the other gene expression changes are consistent with Plasmodium parasite-specific responses. Taken together, these changes suggest the immune responses to P. yoelii infection are both parasite and organ specific.
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1241
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Adami C, Sorci G, Blasi E, Agneletti AL, Bistoni F, Donato R. S100B expression in and effects on microglia. Glia 2001; 33:131-42. [PMID: 11180510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
We evaluated the intracellular and extracellular biological role of S100B protein with respect to microglia. S100B, which belongs to the multigenic family of Ca2+-binding proteins, is abundant in astrocytes where it is found diffusely in the cytoplasm and is associated with membranes and cytoskeleton constituents. S100B protein is also secreted by astrocytes and acts on these cells to stimulate nitric oxide secretion in an autocrine manner. However, little is known about the relationship between S100B and microglia. To address this issue, we used primary microglia from newborn rat cortex and the BV-2 microglial cell line, a well-established cell model for the study of microglial properties. S100B expression was assessed by immunofluorescence in primary microglia and by RT-PCR, Western blotting, and immunofluorescence in BV-2 cells. S100B was found in microglia in the form of a filamentous network as well as diffusely in the cytoplasm and associated with intracellular membranes. S100B relocated around phagosomes during BV-2 phagocytosis of opsonized Cryptococcus neoformans. Furthermore, interferon-gamma (IFN-gamma) treatment caused cell shape changes and redistribution of S100B, and downregulation of S100B mRNA expression in BV-2 cells. Treatment of BV-2 cells with nanomolar to micromolar amounts of S100B resulted in increased IFN-gamma-induced expression of inducible nitric oxide synthase mRNA as well as nitric oxide secretion. Taken together, these data suggest a possible role for S100B in the accomplishment/regulation of microglial cell functions.
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1242
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Eggert A, Grotzer MA, Ikegaki N, Zhao H, Cnaan A, Brodeur GM, Evans AE. Expression of the neurotrophin receptor TrkB is associated with unfavorable outcome in Wilms' tumor. J Clin Oncol 2001; 19:689-96. [PMID: 11157019 DOI: 10.1200/jco.2001.19.3.689] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Neurotrophins and their receptors regulate the proliferation, differentiation, and death of neuronal cells, and they have been implicated in the pathogenesis and prognosis of neuroblastomas and medulloblastomas. Tyrosine kinase (Trk) receptors also are expressed in extraneural tissues. PATIENTS AND METHODS To study the role of neurotrophin receptors and ligands in Wilms' tumor (WT), we determined their expression by semiquantitative duplex reverse transcriptase polymerase chain reaction in 39 patients with primary WT. Comparison of mRNA expression levels with clinical variables was performed by use of Cox regression analysis. RESULTS Children with WT that expressed high levels of full-length TrkB mRNA (TrkBfull) had a significantly greater risk of death than children whose tumors had little or no TrkBfull expression (hazard ratio, 9.7; P =.02). The 5-year relapse-free survival was 100% versus 65% for patients with low versus high tumor expression of TrkBfull (P <.003). Conversely, children with tumors that expressed high mRNA levels of a functionally inactive truncated TrkB receptor (TrkBtrunc) had a greater chance of survival than children with low levels of TrkBtrunc (hazard ratio, 0.08; P =.005). The 5-year relapse-free survival was 95% versus 68% for patients with high versus low levels of TrkBtrunc (P =.01). The hazard ratios for TrkBfull and TrkBtrunc remained significant after they were adjusted for tumor stage (P =.01 and P =.017, respectively). All WTs with high levels of TrkB expression also expressed the brain-derived nerve growth factor ligand. CONCLUSION Expression of TrkBfull in WT is associated with worse outcome, perhaps because it provides an autocrine survival pathway. Conversely, TrkBtrunc expression is associated with excellent outcome, perhaps as a result of a dominant negative effect.
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MESH Headings
- Age Factors
- Brain-Derived Neurotrophic Factor/biosynthesis
- Brain-Derived Neurotrophic Factor/genetics
- Disease-Free Survival
- Gene Expression
- Gene Expression Profiling
- Humans
- Infant
- Kidney Neoplasms/genetics
- Kidney Neoplasms/metabolism
- Kidney Neoplasms/pathology
- Neoplasm Staging
- Nerve Growth Factor/biosynthesis
- Nerve Growth Factor/genetics
- Nerve Growth Factors/biosynthesis
- Nerve Growth Factors/genetics
- Neurotrophin 3/biosynthesis
- Neurotrophin 3/genetics
- Proportional Hazards Models
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptor, Nerve Growth Factor
- Receptor, trkA/biosynthesis
- Receptor, trkA/genetics
- Receptor, trkB/biosynthesis
- Receptor, trkB/genetics
- Receptor, trkC/biosynthesis
- Receptor, trkC/genetics
- Receptors, Nerve Growth Factor/biosynthesis
- Receptors, Nerve Growth Factor/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Wilms Tumor/genetics
- Wilms Tumor/metabolism
- Wilms Tumor/pathology
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Krishnamoorthy RR, Agarwal P, Prasanna G, Vopat K, Lambert W, Sheedlo HJ, Pang IH, Shade D, Wordinger RJ, Yorio T, Clark AF, Agarwal N. Characterization of a transformed rat retinal ganglion cell line. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2001; 86:1-12. [PMID: 11165366 DOI: 10.1016/s0169-328x(00)00224-2] [Citation(s) in RCA: 237] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The purpose of the present study was to establish a rat retinal ganglion cell line by transformation of rat retinal cells. For this investigation, retinal cells were isolated from postnatal day 1 (PN1) rats and transformed with the psi2 E1A virus. In order to isolate retinal ganglion cells (RGC), single cell clones were chosen at random from the transformed cells. Expression of Thy-1 (a marker for RGC), glial fibrillary acidic protein (GFAP, a positive marker for Muller cells), HPC-1/syntaxin (a marker for amacrine cells), 8A1 (a marker for horizontal and ganglion cells) and neurotrophins was studied using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoblotting and immunocytochemistry. One of the retinal cell clones, designated RGC-5, was positive for Thy-1, Brn-3C, Neuritin, NMDA receptor, GABA-B receptor, and synaptophysin expression and negative for GFAP, HPC-1, and 8A1, suggesting that it represented a putative RGC clone. The results of RT-PCR analysis were confirmed by immunocytochemistry for Thy-1 and GFAP. Upon further characterization by immunoblotting, the RGC-5 clone was positive for Thy-1, negative for GFAP, 8A1 and syntaxin. RGC 5 cells were also positive for the expression of neurotrophins and their cognate receptors. To establish the physiological relevance of RGC-5, the effects of serum/trophic factor deprivation and glutamate toxicity were analyzed to determine if these cells would undergo apoptosis. The protective effects of neurotrophins on RGC-5 after serum deprivation was also investigated. Apoptosis was studied by terminal deoxynucleotidyl transferase-mediated fluoresceinated dUTP nick end labeling (TUNEL). Serum deprivation resulted in apoptosis and supplementation with both BDNF and NT-4 in the growth media, protected the RGC-5 cells from undergoing apoptosis. On differentiation with succinyl concanavalin A (sConA), RGC-5 cells became sensitive to glutamate toxicity, which could be reversed by inclusion of ciplizone (MK801). In conclusion, a transformed rat retinal cell line, RGC-5, has certain characteristics of retinal ganglion cells based on Thy-1 and Brn-3C expression and its sensitivity to glutamate excitotoxicity and neurotrophin withdrawal. These cells may be valuable in understanding of retinal ganglion cell biology and physiology including in vitro manipulations in experimental models of glaucoma.
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1244
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Young HM, Hearn CJ, Farlie PG, Canty AJ, Thomas PQ, Newgreen DF. GDNF is a chemoattractant for enteric neural cells. Dev Biol 2001; 229:503-16. [PMID: 11150245 DOI: 10.1006/dbio.2000.0100] [Citation(s) in RCA: 228] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In situ hybridization revealed that GDNF mRNA in the mid- and hindgut mesenchyme of embryonic mice was minimal at E10.5 but was rapidly elevated at all gut regions after E11, but with a slight delay (0.5 days) in the hindgut. GDNF mRNA expression was minimal in the mesentery and in the pharyngeal and pelvic mesenchyme adjacent to the gut. To examine the effect of GDNF on enteric neural crest-derived cells, segments of E11.5 mouse hindgut containing crest-derived cells only at the rostral ends were attached to filter paper supports and grown in catenary organ culture. With GDNF (100 ng/ml) in the culture medium, threefold fewer neurons developed in the gut explants and fivefold more neurons were present on the filter paper outside the gut explants, compared to controls. Thus, in controls, crest-derived cells colonized the entire explant and differentiated into neurons, whereas in the presence of exogenous GDNF, most crest-derived cells migrated out of the gut explant. This is consistent with GDNF acting as a chemoattractant. To test this idea, explants of esophagus, midgut, superior cervical ganglia, paravertebral sympathetic chain ganglia, or dorsal root ganglia from E11.5-E12.5 mice were grown on collagen gels with a GDNF-impregnated agarose bead on one side and a control bead on the opposite side. Migrating neural cells and neurites from the esophagus and midgut accumulated around the GDNF-impregnated beads, but neural cells in other tissues showed little or no chemotactic response to GDNF, although all showed GDNF-receptor (Ret and GFRalpha1) immunoreactivity. We conclude that GDNF may promote the migration of crest cells throughout the gastrointestinal tract, prevent them from straying out of the gut (into the mesentery and pharyngeal and pelvic tissues), and promote directed axon outgrowth.
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1245
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Henttu P. Quantification of mRNA levels using ribonuclease protection assay. Methods Mol Biol 2001; 169:65-79. [PMID: 11142021 DOI: 10.1385/1-59259-060-8:65] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
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1246
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Facchinetti F, Terrazzino S, D'Arrigo A, Rinaldi L, Leon A. Neurotrophic factors in the therapy of Parkinson's disease. FUNCTIONAL NEUROLOGY 2001; 16:45-56. [PMID: 11396271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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1247
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Lin AE, Liu Q, Mannheim GB, Darras BT. Exclusion of growth factor gene mutations as a common cause of Sotos syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 2001; 98:101-2. [PMID: 11426446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Sotos syndrome is characterized by somatic overgrowth, i.e., macrocephaly and tall stature. Because the cause and pathogenesis of Sotos syndrome remain unknown, we selected nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT-3) as possible genes mutated in Sotos syndrome. In seven patients with the classic phenotype, we excluded mutations in these growth factor genes. It is possible that these three genes are not involved in the cause of Sotos syndrome, or alternatively, mutations could not be identified in the small number of patients studied.
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1248
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Liebl DJ, Huang W, Young W, Parada LF. Regulation of Trk receptors following contusion of the rat spinal cord. Exp Neurol 2001; 167:15-26. [PMID: 11161589 DOI: 10.1006/exnr.2000.7548] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Neurotrophins function through high-affinity tyrosine kinase (Trk) receptors to promote growth and survival of cells in the injured nervous system. To investigate the role of Trk receptors in the adult nervous system, we examined TrkA, TrkB, and TrkC mRNA expression in spinal cord and brain after spinal contusion. At 1 day postinjury, all Trk receptor transcripts were down regulated at and around the site of injury, a situation that persisted through the first week. By 42 days, Trk expression was absent only within the cavity. In addition, truncated TrkB expression was substantially increased in ependymal cells and astrocytes surrounding the lesion cavity of chronically injured spinal cords. Rostral and caudal to the injury site, TrkA, TrkB, and TrkC mRNA expression did not differ from that of uninjured control spinal cords. Furthermore, no changes were observed in TrkB or TrkC expression in the axotomized corticospinal and rubrospinal neurons. These studies suggest that loss of Trk receptors at the injury site may contribute to the early progressive cellular loss in injured spinal cords, while increased presence of truncated TrkB receptors in the chronic injured spinal cord may sequester and restrict BDNF availability to support axonal regeneration and neuronal survival. The persistence of Trk receptors on supraspinal neurons suggests that neurotrophin application can support growth and survival in the acute and chronic injury states.
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MESH Headings
- Animals
- Brain/cytology
- Brain/metabolism
- Disease Models, Animal
- Gene Expression Regulation
- In Situ Hybridization
- Nerve Growth Factors/biosynthesis
- Nerve Growth Factors/genetics
- Neurons/metabolism
- Neurons/pathology
- RNA, Messenger/biosynthesis
- RNA, Messenger/metabolism
- Rats
- Rats, Long-Evans
- Receptor, trkA/genetics
- Receptor, trkA/metabolism
- Receptor, trkB/genetics
- Receptor, trkB/metabolism
- Receptor, trkC/genetics
- Receptor, trkC/metabolism
- Spinal Cord/metabolism
- Spinal Cord/pathology
- Spinal Cord Injuries/metabolism
- Spinal Cord Injuries/pathology
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1249
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Wood JP, DeSantis L, Chao HM, Osborne NN. Topically applied betaxolol attenuates ischaemia-induced effects to the rat retina and stimulates BDNF mRNA. Exp Eye Res 2001; 72:79-86. [PMID: 11133185 DOI: 10.1006/exer.2000.0929] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has previously been reported that the beta(1)-adrenoceptor antagonist, betaxolol, can protect retinal neurones from ischaemia when applied topically. It has further been shown that betaxolol can reduce influx of both sodium or calcium into neurones through interaction at neurotoxin site 2 of the sodium channel and the L-type calcium channel, respectively. The present study sought to further investigate the neuroprotective mode of action of betaxolol in the rat retina. Rats were treated topically with L-betaxolol for 10, 5 and 1 min before ischaemia, induced by raising the intraocular pressure above systolic blood pressure for 45 min. This was followed by reperfusion of 3 or 5 days where L-betaxolol was applied topically twice daily. Ischaemia plus reperfusion caused both a loss of immunoreactivity for choline acetyl transferase (ChAT) and a marked reduction of the b-wave of the electroretinogram (ERG). Treatment, as described, with topical L-betaxolol, completely blunted the effects upon ChAT immunoreactivity and caused a significant reversal of the ERG changes. Furthermore, other rats treated topically with commercially available racemic betaxolol (Betoptic Solution, 0.5%) for 6 hr had raised levels of mRNA for brain derived neurotrophic factor (BDNF) but not for basic fibroblast growth factor (bFGF) in their retinas. The combined data provide further evidence that betaxolol can blunt the effects of ischaemia to the rat retina when applied topically just before the insult. Furthermore, the finding that retinal levels of BDNF mRNA are raised following topical betaxolol treatment shows that not only can this drug reach the retina but that it can also induce changes in expression of factors which are known, themselves, to provide neuroprotection to retinal neurones.
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1250
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Kochanek PM, Janesko KL, Jenkins LW, Yan HQ, Kibbe MR, Robichaud P, Wooditch AC, Clark RS, Dixon CE, Marion DW, Billiar TR. Adenovirus-mediated transfer and expression of beta-gal in injured hippocampus after traumatic brain injury in mice. J Neurotrauma 2001; 18:73-82. [PMID: 11200251 DOI: 10.1089/089771501750055785] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In models of focal cerebral ischemia, adenoviral gene transfer is often attenuated or delayed versus naive. After controlled cortical impact (CCI)-induced traumatic brain injury in mice, CA1 and CA3 hippocampus exhibit delayed neuronal death by 3 days, with subsequent near complete loss of hippocampus by 21 days. We hypothesized that adenoviral-mediated expression of the reporter gene beta-Galactosidase (beta-Gal) in hippocampus would be attenuated after CCI in mice. C57BL6 mice (n = 16) were subjected to either CCI to left parietal cortex or sham (burr hole). Adenovirus carrying the beta-Gal gene (AdlacZ; 1 x 10(9) plaque-forming units [pfu]/mL) was then injected into left dorsal hippocampus. At 24 or 72 h, beta-Gal expression was quantified (mU/mg protein). Separate mice (n = 10) were used to study beta-Gal spatial distribution in brain sections. Beta-Gal expression in left hippocampus was similar in shams at 24 h (48.4 +/- 4.1) versus 72 h (68.8 +/- 8.8, not significant). CCI did not reduce beta-Gal expression in left hippocampus (68.8 +/- 8.8 versus 88.1 +/- 7.0 at 72 h, sham versus CCI, not significant). In contrast, CCI reduced beta-Gal expression in right (contralateral) hippocampus versus sham (p < 0.05 at both 24 and 72 h). Beta-Gal was seen in many cell types in ipsilateral hippocampus, including CA3 neurons. Despite eventual loss of ipsilateral hippocampus, adenovirus-mediated gene transfer was surprisingly robust early after CCI providing an opportunity to test novel genes targeting delayed hippocampal neuronal death.
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