Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.14.16.2 (tyrosine hydroxylase)
 14,760 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Environmental enrichment (EE) alleviates sensorimotor deficits after brain infarcts but the cellular correlates are not well-known. This study aimed to test the effects of postischemic EE on neocortical cell genesis. A neocortical infarct was caused by distal ligation of the middle cerebral artery in adult spontaneously hypertensive rats, subsequently housed in standard environment or EE. Bromodeoxyuridine (BrdU) was administered during the first postischemic week to label proliferating cells and BrdU incorporation was quantified 4 weeks later in the periinfarct, ipsilateral medial and contralateral cortex. Immunohistochemistry and confocal microscopy were used to analyze co-localization of BrdU with neuronal (calbindin D28k, calretinin, parvalbumin, glutamic acid decarboxylase, tyrosine hydroxylase), astrocytic (glial fibrillary acidic protein, glutamine synthetase, vimentin, nestin), microglia/macrophage (CD11b/Ox-42, CD68/ED-1), oligodendrocyte progenitor/polydendrocyte (NG2, platelet-derived growth factor alpha receptor) or mature oligodendrocyte (myelin basic protein) markers. BrdU positive cells were increased in all analyzed cortical regions in stroke EE rats compared with stroke standard environment rats. Newly born cells in the periinfarct cortex were mostly reactive astroglia. Occasionally, BrdU positive cells in the periinfarct cortex that were negative for glial or microglia/macrophage markers co-expressed markers typical for interneurons but did not express appropriate functional markers. The majority of BrdU positive cells in intact cortical regions, ipsi- and contralaterally, were identified as NG2 positive polydendrocytes. Perineuronally situated newly born cells and polydendrocytes were found to be brain-derived neurotrophic factor immunoreactive. In conclusion, EE enhanced newborn glial scar astroglia and NG2+ polydendrocytes in the postischemic neocortex which might be beneficial for brain repair and poststroke plasticity.
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PMID:Enriched environment after focal cortical ischemia enhances the generation of astroglia and NG2 positive polydendrocytes in adult rat neocortex. 1642 25

Isolation and expansion of neural stem cells (NSCs) of human origin are crucial for successful development of cell therapy approaches in neurodegenerative diseases. Different epigenetic and genetic immortalization strategies have been established for long-term maintenance and expansion of these cells in vitro. Here we report the generation of a new, clonal NSC (hc-NSC) line, derived from human fetal cortical tissue, based on v-myc immortalization. Using immunocytochemistry, we show that these cells retain the characteristics of NSCs after more than 50 passages. Under proliferation conditions, when supplemented with epidermal and basic fibroblast growth factors, the hc-NSCs expressed neural stem/progenitor cell markers like nestin, vimentin and Sox2. When growth factors were withdrawn, proliferation and expression of v-myc and telomerase were dramatically reduced, and the hc-NSCs differentiated into glia and neurons (mostly glutamatergic and GABAergic, as well as tyrosine hydroxylase-positive, presumably dopaminergic neurons). RT-PCR analysis showed that the hc-NSCs retained expression of Pax6, Emx2 and Neurogenin2, which are genes associated with regionalization and cell commitment in cortical precursors during brain development. Our data indicate that this hc-NSC line could be useful for exploring the potential of human NSCs to replace dead or damaged cortical cells in animal models of acute and chronic neurodegenerative diseases. Taking advantage of its clonality and homogeneity, this cell line will also be a valuable experimental tool to study the regulatory role of intrinsic and extrinsic factors in human NSC biology.
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PMID:Generation of human cortical neurons from a new immortal fetal neural stem cell line. 1715 76

Rat fetal ventral mesencephalic organotypic cultures have demonstrated two morphologically different dopamine nerve fiber growth patterns, in which the initial nerve fibers are formed in the absence of astrocytes and the second wave is guided by astrocytes. In this study, the presence of subpopulations of dopamine neurons, other neuronal populations, and glial cells was determined. We used "roller-drum" organotypic cultures, and the results revealed that beta-tubulin-positive/tyrosine hydroxylase (TH)-negative nerve fibers were present as early as 1 day in vitro (DIV). A similar growth pattern produced by TH-positive neurons was present from 2 DIV. These neurites grew to reach distances over 4 mm and over time appeared to be degenerating. Thin, vimentin-positive processes were found among these nerve fibers. As the first growth was retracted, a second outgrowth was initiated and formed on migrating astrocytes. TH- and aldehyde dehydrogenase-1 (ALDH1)-positive nerve fibers formed both the nonglia-associated and the glia-associated outgrowth. In cultures with membrane inserts, only the glia-associated outgrowth was found. Vimentin-positive cells preceded migration of NG2-positive oligodendrocytes and Iba-1-positive microglia. Oligodendrocytes appeared not to be involved in guiding neuritic growth, but microglia was absent over areas dense with TH-positive neurons. In conclusion, in "roller-drum" cultures, nerve fibers are generally formed in two sequences. The early-formed nerve fibers grow in the presence of thin, vimentin-positive processes. The second nerve fiber outgrowth is formed on astroglia, with no correlation to the presence of oligodendrocytes or microglia. ALDH1-positive nerve fibers, presumably derived from A9 dopamine neurons, participate in formation of both sequences of outgrowth.
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PMID:Glial influence on nerve fiber formation from rat ventral mesencephalic organotypic tissue cultures. 1724 6

Astroglial cell lines have many applications for advancing neural developmental and functional studies. However, few astroglial cell lines have been reported from fish. In this study, we report the characterization of the immortal cell line TB2 isolated from adult tilapia brain tissue. The cell line was established at 25 degrees C in L15 medium supplemented with 15% fetal bovine serum. Most of the cells displayed a fibrous morphology and were immunoreactive for A2B5 antigen, glial fibrillary acidic protein (GFAP), keratin, vimentin, and the gap junction protein connexin 43 (Cx43). They weakly expressed glutamine synthetase (GS), S100 protein, and the neural stem cell markers Sox2 and brain lipid binding protein (BLBP). In contrast to astroglia in vivo, most TB2 cells also expressed galactocerebroside (GalC), substance P (SP), and tyrosine hydroxylase (TH). By immunoblot and RT-PCR, the cells also expressed myelin basic protein (MBP), proteolipid protein (PLP), and Cx35. On a poly-L-lysine-coated substrate in vitro, TB2 cells showed increases in neuronal dopamine decarboxylase (DDC) and microtubule-associated protein 2 (MAP2), indicating that they can initiate differentiation into neurons. Taken together, the results suggest that TB2 cells are astroglial progenitor cells (neural stem cells) and may develop into oligodendrocytes and neurons in a suitable environment. The present study advances our knowledge of fish astroglia. However, the factors that affect neural development in fish remain unknown, as do the characteristics of the intermediate differentiation stages between stem cells and mature nerve cells. The TB2 cell line will promote these investigations.
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PMID:Isolation and characterization of a neural progenitor cell line from tilapia brain. 1809 21

We studied the histochemical phenotype of carotid body (CB) cells in the adult rat. In addition to tyrosine hydroxylase (TH), type I cells expressed numerous growth factors such as glial cell line-derived neurotrophic factor (GDNF), basic fibroblast growth factor (bFGF), brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), insulin-like growth factor-I (IGF-I), epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha), as well as the receptors p75, Ret, epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor-alpha (PDGFR-alpha). Type II cells expressed the glial fibrillary acid protein (GFAP), vimentin, the trophic factor bFGF and receptors p75, EGFR and PDGFR-alpha. Both types I and II cells exhibited a positive immunoreaction to markers of neural progenitor cells such as the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) and nestin, respectively, suggesting that CB contain some immature cells even at the adult stage. The possibility that these cells can be expanded and differentiated into mature neurons should be explored.
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PMID:Immunohistochemical characterization of the rat carotid body. 1828 Jul 99

A clonal cell line, GBC4, derived from grouper (Epinephelus coioides) brain is proposed to represent an immature astroglial cell line because it expresses glial fibrillary acidic protein (GFAP), cytokeratin and vimentin. In teleost brain, tanycytes are the most abundant GFAP-expressing cell type, suggesting that GBC4 cells are derived from tanycytes. To test this hypothesis, protein and mRNA expression profiles of GBC4 cells were evaluated. We detected protein and/or mRNA expression of aromatase B, brain lipid binding protein, connexin43 protein, glutamine synthetase, S100 protein and Sox2. These proteins/mRNAs are also expressed in fish tanycytes. GBC4 cells also contained oligodendroglia proteins, including A2B5, galactocerebroside, myelin basic protein, proteolipid protein and platelet-derived growth factor receptor alpha as well as certain neuronal protein markers such as connexin35 protein and tyrosine hydroxylase. Our results indicate that GBC4 cells may be multipotent neural progenitor cells similar to tanycytes. Because GBC4 expresses several neural-specific genes, this line will be useful for studies on gene expression/regulation and neural development.
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PMID:Immunochemical and molecular characterization of GBC4 as a tanycyte-like cell line derived from grouper brain. 1924 39

Amniotic epithelial cells (AEC) are thought to represent a stem-like cell population and to be an attractive cell source for regenerative medicine, because abundant cells can be obtained noninvasively at delivery. The authors investigated the neural differentiation potential of rat AEC. Rat AEC expressed vimentin and nestin, but not c-kit, oct-4, or nanog. The expression of the neural lineage markers, including betaIII-tubulin, neuron specific enolase (NSE), neurofilament-M, neuroD, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), tyrosine hydroxylase (TH), acetylcholinesterase (AChE), cholin acetyltransferase (ChAT), and mammalian achaete-scute homolog1 (MASH1), was detected by RT-PCR in the cultured rat AEC. After neural induction, rat AEC dramatically changed their shapes, projecting dendrite-like structures. Immunocytochemically, approximately 20% of the induced cells expressed an immature neuronal marker, betaIII-tubulin. Our findings suggested that rat AEC might be already committed to differentiate to various neural lineages and that they could differentiate to immature neurons in vitro.
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PMID:Neural differentiation potential of rat amniotic epithelial cells. 2045 Feb 66

The use of human embryonic stem cells (hESCs) to repair diseased or injured brain is promising technology with significant humanitarian, societal and economic impact. Parkinson's disease (PD) is a neurological disorder characterized by the loss of midbrain dopaminergic (DA) neurons. The generation of this cell type will fulfill a currently unmet therapeutic need. We report on the isolation and perpetuation of a midbrain-specified self-renewable human neural stem cell line (hNSCs) from hESCs. These hNSCs grew as a monolayer and uniformly expressed the neural precursor markers nestin, vimentin and a radial glial phenotype. We describe a process to direct the differentiation of these hNSCs towards the DA lineage. Glial conditioned media acted synergistically with fibroblastic growth factor and leukemia inhibitory factor to induce the expression of the DA marker, tyrosine hydroxylase (TH), in the hNSC progeny. The glial-derived neurotrophic factor did not fully mimic the effects of conditioned media. The hNSCs expressed the midbrain-specific transcription factors Nurr1 and Pitx3. The inductive effects did not modify the level of the glutamic acid decarboxylase (GAD) transcript, a marker for GABAergic neurons, while the TH transcript increased 10-fold. Immunocytochemical analysis demonstrated that the TH-expressing cells did not co-localize with GAD. The transplantation of these DA-induced hNSCs into the non-human primate MPTP model of PD demonstrated that the cells maintain their DA-induced phenotype, extend neurite outgrowths and express synaptic markers.
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PMID:Dopaminergic neurons from midbrain-specified human embryonic stem cell-derived neural stem cells engrafted in a monkey model of Parkinson's disease. 2281 35

The peripheral neuroblastic tumours (PNTs) include neuroblastoma, ganglioneuroblastoma and ganglioneuromas. These subtypes reflect a spectrum of differentiation of progenitor cells of the sympathetic nervous system from tumours with predominant undifferentiated neuroblasts to those consisting of neuronal cell bodies that are well differentiated. Peripheral neuroblastoma is a tumour composed of neuroblastic cells with no or limited neuronal differentiation. In dogs, peripheral neuroblastoma is rare. The present report documents nine cases of canine peripheral neuroblastoma, the majority occurring as large masses in the craniodorsal abdominal cavity of young dogs (mean age of 3 years at diagnosis). Microscopically, all of the masses consisted of round to oval cells with a scant cytoplasm and hyperchromatic nuclei. Homer-Wright rosettes and pseudorosettes were evident in three of the nine cases. Neoplastic cells were immunoreactive in varying degrees to S100, neuron-specific enolase, synaptophysin, chromogranin A, tyrosine hydroxylase (one case) and were negative for vimentin, cytokeratin, CD3 and CD79a, indicating a neurogenic nature. Four of the nine cases occurred in Labrador retrievers (44%) and two (22%) in boxers, suggesting a possible breed predisposition.
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PMID:Peripheral neuroblastomas in dogs: a case series. 2445 49

The aim of this study was to determine the possibility of immunohistochemical demonstration of various tissue antigens in paraffin sections of zinc-ethanol-formaldehyde-fixed spinal cord, surrounded by the vertebral tissues and adjacent muscles, after decalcification in formic acid, in adult (n = 5) and newborn (n = 2) Wistar rats. In the present work, the antibodies used were against: glial fibrillary acidic protein, neurofilaments, neuronal specific nuclear protein, enzyme tyrosine hydroxylase, protein of synaptic vesicles--synaptophysin and the intermediate filament protein--vimentin. Combination of fixation in zinc-ethanol-formaldehyde and decalcification in 21% formic acid solution was shown to provide an optimal preservation of the antigens studied.
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PMID:[Decalcification in formic acid after fixation in zinc-ethanol-formaldehyde does not preclude identification of neuronal and glial markers]. 2459 6


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