XBF-1, a winged helix transcription factor with dual activity, has a role in positioning neurogenesis in Xenopus competent ectoderm

Development ◽  
1998 ◽  
Vol 125 (24) ◽  
pp. 4889-4900 ◽  
Author(s):  
C. Bourguignon ◽  
J. Li ◽  
N. Papalopulu
Keyword(s):  
Transcription Factor ◽  
Neuronal Differentiation ◽  
Neural Plate ◽  
High Dose ◽  
Expression Domain ◽  
Dual Effect ◽  
Winged Helix ◽  
Winged Helix Transcription Factor ◽  
Anterior Neural Plate

Neuronal differentiation in the vertebrate nervous system is temporally and spatially controlled by mechanisms which are largely unknown. Here we investigate the role of XBF-1, an anterior neural plate-specific winged helix transcription factor, in controlling the pattern of neurogenesis in Xenopus ectoderm. We show that, in the anterior neural plate of normal embryos, prospective neurogenesis is positioned at the anterior boundary of the XBF-1 expression domain. By misexpressing XBF-1 in the posterior neural plate we show that a high dose of XBF-1 has a dual effect; it suppresses endogenous neuronal differentiation in high expressing cells and induces ectopic neuronal differentiation in adjacent cells. In contrast, a low dose of XBF-1 does not suppress but instead, expands the domain of neuronal differentiation in the lateral and ventral sides of the embryo. XBF-1 regulates the expression of XSox3, X-ngnr-1, X-Myt-1 and X-Δ-1 suggesting that it acts early in the cascade leading to neuronal differentiation. A fusion of XBF-1 to a strong repressor domain (EnR) mimics most of the XBF-1 effects suggesting that the wild type XBF-1 is a transcriptional repressor. However, fusion of XBF-1 to a strong activation domain (E1A) specifically suppresses neuronal differentiation suggesting that XBF-1 may also work as a transcriptional activator. Based on these findings, we propose that XBF-1 is involved in positioning neuronal differentiation by virtue of its concentration dependent, dual activity, as a suppressor and an activator of neurogenesis.

The homeodomain-containing gene Xdbx inhibits neuronal differentiation in the developing embryo

Development ◽  
2000 ◽  
Vol 127 (13) ◽  
pp. 2945-2954 ◽  
Author(s):  
A.A. Gershon ◽  
J. Rudnick ◽  
L. Kalam ◽  
K. Zimmerman
Keyword(s):  
Neuronal Differentiation ◽  
Normal Development ◽  
Early Embryo ◽  
Neural Plate ◽  
Neural Progenitors ◽  
Expression Domain ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Early Neurogenesis

The development of the vertebrate nervous system depends upon striking a balance between differentiating neurons and neural progenitors in the early embryo. Our findings suggest that the homeodomain-containing gene Xdbx regulates this balance by maintaining neural progenitor populations within specific regions of the neuroectoderm. In posterior regions of the Xenopus embryo, Xdbx is expressed in a bilaterally symmetric stripe that lies at the middle of the mediolateral axis of the neural plate. This stripe of Xdbx expression overlaps the expression domain of the proneural basic/helix-loop-helix-containing gene, Xash3, and is juxtaposed to the expression domains of Xenopus Neurogenin related 1 and N-tubulin, markers of early neurogenesis in the embryo. Xdbx overexpression inhibits neuronal differentiation in the embryo and when co-injected with Xash3, Xdbx inhibits the ability of Xash3 to induce ectopic neurogenesis. One role of Xdbx during normal development may therefore be to restrict spatially neuronal differentiation within the neural plate, possibly by altering the neuronal differentiation function of Xash3.

Winged helix transcription factor Foxb1 is essential for access of mammillothalamic axons to the thalamus

Development ◽  
2000 ◽  
Vol 127 (5) ◽  
pp. 1029-1038 ◽  
Author(s):  
G. Alvarez-Bolado ◽  
X. Zhou ◽  
A.K. Voss ◽  
T. Thomas ◽  
P. Gruss
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activity ◽  
Wild Type ◽  
Winged Helix ◽  
Targeted Mutation ◽  
Ventricular Cells ◽  
Winged Helix Transcription Factor ◽  
Mutant Cells ◽  
Correct Expression

Our aim was to study the mechanisms of brain histogenesis. As a model, we have used the role of winged helix transcription factor gene Foxb1 in the emergence of a very specific morphological trait of the diencephalon, the mammillary axonal complex. Foxb1 is expressed in a large hypothalamic neuronal group (the mammillary body), which gives origin to a major axonal bundle with branches to thalamus, tectum and tegmentum. We have generated mice carrying a targeted mutation of Foxb1 plus the tau-lacZ reporter. In these mutants, a subpopulation of dorsal thalamic ventricular cells “thalamic palisade” show abnormal persistence of Foxb1 transcriptional activity; the thalamic branch of the mammillary axonal complex is not able to grow past these cells and enter the thalamus. The other two branches of the mammillary axonal complex (to tectum and tegmentum) are unaffected by the mutation. Most of the neurons that originate the mammillothalamic axons suffer apoptosis after navigational failure. Analysis of chimeric brains with wild-type and Foxb1 mutant cells suggests that correct expression of Foxb1 in the thalamic palisade is sufficient to rescue the normal phenotype. Our results indicate that Foxb1 is essential for diencephalic histogenesis and that it exerts its effects by controlling access to the target by one particular axonal branch.

Arachidonic acid mediates dual effect of TNF-α on Ca2+ transients and contraction of adult rat cardiomyocytes

2002 ◽  
Vol 282 (6) ◽  
pp. C1339-C1347 ◽  
Author(s):  
Aïssata Amadou ◽  
Artur Nawrocki ◽  
Martin Best-Belpomme ◽  
Catherine Pavoine ◽  
Françoise Pecker
Keyword(s):  
Arachidonic Acid ◽  
Cyclooxygenase Inhibitors ◽  
High Dose ◽  
Negative Effects ◽  
Dual Effect ◽  
Rat Cardiomyocytes ◽  
Adult Rat ◽  
Tnf Α ◽  
Biphasic Effect

Tumor necrosis factor (TNF)-α has a biphasic effect on heart contractility and stimulates phospholipase A2 (PLA2) in cardiomyocytes. Because arachidonic acid (AA) exerts a dual effect on intracellular Ca2+ concentration ([Ca2+]i) transients, we investigated the possible role of AA as a mediator of TNF-α on [Ca2+]i transients and contraction with electrically stimulated adult rat cardiac myocytes. At a low concentration (10 ng/ml) TNF-α produced a 40% increase in the amplitude of both [Ca2+]i transients and contraction within 40 min. At a high concentration (50 ng/ml) TNF-α evoked a biphasic effect comprising an initial positive effect peaking at 5 min, followed by a sustained negative effect leading to 50–40% decreases in [Ca2+]i transients and contraction after 30 min. Both the positive and negative effects of TNF-α were reproduced by AA and blocked by arachidonyltrifluoromethyl ketone (AACOCF3), an inhibitor of cytosolic PLA2. Lipoxygenase and cyclooxygenase inhibitors reproduced the high-dose effects of TNF-α and AA. The negative effects of TNF-α and AA were also reproduced by sphingosine and were abrogated by the ceramidase inhibitor n-oleoylethanolamine. These results point out the key role of the cytosolic PLA2/AA pathway in mediating the contractile effects of TNF-α.

scholarly journals Graded phenotypic response to partial and complete deficiency of a brain-specific transcript variant of the winged helix transcription factor RFX4

Development ◽  
2003 ◽  
Vol 130 (19) ◽  
pp. 4539-4552 ◽  
Author(s):  
Perry J. Blackshear ◽  
Joan P. Graves ◽  
Deborah J. Stumpo ◽  
Inma Cobos ◽  
John L. R. Rubenstein ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcript Variant ◽  
Winged Helix ◽  
Specific Transcript ◽  
Phenotypic Response ◽  
Winged Helix Transcription Factor

Goosecoid suppresses cell growth and enhances neuronal differentiation of PC12 cells

2000 ◽  
Vol 113 (15) ◽  
pp. 2705-2713
Author(s):  
K. Sawada ◽  
Y. Konishi ◽  
M. Tominaga ◽  
Y. Watanabe ◽  
J. Hirano ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Neurite Outgrowth ◽  
Neuronal Differentiation ◽  
Pc12 Cells ◽  
Mammalian Cells ◽  
Homeobox Gene ◽  
S Phase ◽  
Bhlh Transcription Factor ◽  
Spemann Organizer

In all vertebrate species, the homeobox gene goosecoid serves as a marker of the Spemann organizer tissue. One function of the organizer is the induction of neural tissue. To investigate the role of goosecoid in neuronal differentiation of mammalian cells, we have introduced goosecoid into PC12 cells. Expression of goosecoid resulted in reduced cell proliferation and enhanced neurite outgrowth in response to NGF. Expression of goosecoid led to a decrease in the percentage of S-phase cells and to upregulation of the expression of the neuron-specific markers MAP-1b and neurofilament-L. Analysis of goosecoid mutants revealed that these effects were independent of either DNA binding or homodimerization of Goosecoid. Coexpression of the N-terminal portion of the ets transcription factor PU.1, a protein that can bind to Goosecoid, repressed neurite outgrowth and rescued the proliferation of PC12 cultures. In contrast, expression of the bHLH transcription factor HES-1 repressed goosecoid-mediated neurite outgrowth without changing the proportion of S-phase cells. These results suggest that goosecoid is involved in neuronal differentiation in two ways, by slowing the cell cycle and stimulating neurite outgrowth, and that these two events are separately regulated.

scholarly journals The Winged Helix Transcription Factor Foxa3 Regulates Adipocyte Differentiation and Depot-Selective Fat Tissue Expansion

2013 ◽  
Vol 33 (17) ◽  
pp. 3392-3399 ◽  
Author(s):  
Lingyan Xu ◽  
Valentine Panel ◽  
Xinran Ma ◽  
Chen Du ◽  
Lynne Hugendubler ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Adipocyte Differentiation ◽  
Tissue Expansion ◽  
Fat Tissue ◽  
Winged Helix ◽  
Winged Helix Transcription Factor

scholarly journals Nucleosome positioning by the winged helix transcription factor HNF3

1998 ◽  
Vol 12 (1) ◽  
pp. 5-10 ◽  
Author(s):  
E. Y. Shim ◽  
C. Woodcock ◽  
K. S. Zaret
Keyword(s):  
Transcription Factor ◽  
Nucleosome Positioning ◽  
Winged Helix ◽  
Winged Helix Transcription Factor
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