Novel retinoic acid generating activities in the neural tube and heart identified by conditional rescue of Raldh2 null mutant mice

Development ◽  
2002 ◽  
Vol 129 (9) ◽  
pp. 2271-2282 ◽  
Author(s):  
Felix A. Mic ◽  
Robert J. Haselbeck ◽  
Arnold E. Cuenca ◽  
Gregg Duester
Keyword(s):  
Spinal Cord ◽  
Retinoic Acid ◽  
Neural Tube ◽  
The Novel ◽  
Vertebrate Development ◽  
Targeted Disruption ◽  
Surface Ectoderm ◽  
Eye Field ◽  
Null Mutant Mice ◽  
Dorsal Retina

Retinoid control of vertebrate development depends upon tissue-specific metabolism of retinol to retinoic acid (RA). The RA biosynthetic enzyme RALDH2 catalyzes much, but not all, RA production in mouse embryos, as revealed here with Raldh2 null mutants carrying an RA-responsive transgene. Targeted disruption of Raldh2 arrests development at midgestation and eliminates all RA synthesis except that associated with Raldh3 expression in the surface ectoderm of the eye field. Conditional rescue of Raldh2–/– embryos by limited maternal RA administration allows development to proceed and results in the establishment of additional sites of RA synthesis linked to Raldh1 expression in the dorsal retina and to Raldh3 expression in the ventral retina, olfactory pit and urinary tract. Unexpectedly, conditionally rescued Raldh2–/– embryos also possess novel sites of RA synthesis in the neural tube and heart that do not correspond to expression of Raldh1-3. RA synthesis in the mutant neural tube was localized in the spinal cord, posterior hindbrain and portions of the midbrain and forebrain, whereas activity in the mutant heart was localized in the conotruncus and sinus venosa. In the posterior hindbrain, this novel RA-generating activity was expressed during establishment of rhombomeric boundaries. In the spinal cord, the novel activity was localized in the floorplate plus in the intermediate region where retinoid-dependent interneurons develop. These novel RA-generating activities in the neural tube and heart fill gaps in our knowledge of how RA is generated spatiotemporally and may, along with Raldh1 and Raldh3, contribute to rescue of Raldh2–/– embryos by producing RA locally.

Retinoic acid establishes ventral retinal characteristics

Development ◽  
1996 ◽  
Vol 122 (1) ◽  
pp. 195-204 ◽  
Author(s):  
G.A. Hyatt ◽  
E.A. Schmitt ◽  
N. Marsh-Armstrong ◽  
P. McCaffery ◽  
U.C. Drager ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Retinoic Acid ◽  
Optic Nerve ◽  
Normal Development ◽  
Cell Content ◽  
Optic Stalk ◽  
Eye Field ◽  
Dorsal Retina ◽  
Choroid Fissure

The developing eye is known to be rich in retinoic acid (RA), and perturbations in RA levels during formation of the optic primordia, as well as RA receptor mutations, cause retinal malformations, especially in ventral eye regions. To test the hypothesis that RA plays a role in the establishment of ventral retinal characteristics, we examined several dorsal and ventral ocular markers in RA-treated zebrafish. The optic stalk represents the ventral-most region of the early eye field. During normal development, the optic stalks constrict, decreasing in width and are gradually replaced by the optic nerve. Systemic high RA levels cause an expansion in the optic stalk with an increased cell content and a patent lumen. In addition, the stalks do not constrict and persist into later stages of development indicating an enhancement of early ventral eye characteristics. Expression of the transcription factor pax[b], normally confined to the ventral retina, expands into the dorsal retina following RA treatment, whereas msh[c], normally expressed in the dorsal retinal pole, disappears. Activity of an aldehyde dehydrogenase that normally occupies the dorsal third of the retina is reduced or abolished following high systemic RA. When a localized RA source, an RA-soaked bead, is placed next to the developing eye, a fissure resembling the choroid fissure appears in the eye facing the bead. Taken together, these observations suggest that RA is involved in the determination of the ventral retina.

scholarly journals CDX4 regulates the progression of neural maturation in the spinal cord

2017 ◽  
Author(s):  
Piyush Joshi ◽  
Andrew J. Darr ◽  
Isaac Skromne
Keyword(s):  
Spinal Cord ◽  
Transcription Factors ◽  
Retinoic Acid ◽  
Gene Regulatory Network ◽  
Neural Tube ◽  
Regulatory Network ◽  
Neural Differentiation ◽  
Retinoic Acid Signaling ◽  
Gene Regulatory ◽  
Differentiation Marker

ABSTRACTThe progressive maturation of cells down differentiation lineages is controlled by collaborative interactions between networks of extracellular signals and intracellular transcription factors. In the vertebrate spinal cord, FGF, Wnt and Retinoic Acid signaling pathways regulate the progressive caudal-to-rostral maturation of neural progenitors by regulating a poorly understood gene regulatory network of transcription factors. We have mapped out this gene regulatory network in the chicken pre-neural tube, identifying CDX4 as a dual-function core component that simultaneously regulates gradual loss of cell potency and acquisition of differentiation states: in a caudal-to-rostral direction, CDX4 represses the early neural differentiation marker Nkx1.2 and promotes the late neural differentiation marker Pax6. Significantly, CDX4 prevents premature PAX6-dependent neural differentiation by blocking Ngn2 activation. This regulation of CDX4 over Pax6 is restricted to the rostral pre-neural tube by Retinoic Acid signaling. Together, our results show that in the spinal cord, CDX4 is part of the gene regulatory network controlling the sequential and progressive transition of states from high to low potency during neural progenitor maturation. Given CDX well-known involvement in Hox gene regulation, we propose that CDX factors coordinate the maturation and axial specification of neural progenitor cells during spinal cord development.

Regional differences in retinoid release from embryonic neural tissue detected by an in vitro reporter assay

Development ◽  
1992 ◽  
Vol 116 (1) ◽  
pp. 55-66 ◽  
Author(s):  
M. Wagner ◽  
B. Han ◽  
T.M. Jessell
Keyword(s):  
Spinal Cord ◽  
Retinoic Acid ◽  
Neural Tube ◽  
Neural Tissue ◽  
Floor Plate ◽  
Luciferase Reporter ◽  
Reporter Assay ◽  
Embryonic Tissues ◽  
Low Concentrations

Retinoic acid and related retinoids have been suggested to contribute to the pattern of cell differentiation during vertebrate embryonic development. To identify cell groups that release morphogenetically active retinoids, we have developed a reporter assay that makes use of a retinoic acid inducible response element (RARE) to drive lacZ or luciferase reporter genes in stably transfected cell lines. This reporter gene assay allows detection of retinoids released from embryonic tissues over a range equivalent to that induced by femtomole amounts of retinoic acid. We have used this assay first to determine whether the floor plate, a cell group that has polarizing properties in neural tube and limb bud differentiation, is a local source of retinoids within the spinal cord. We have also examined whether the effects of exogenously administered retinoic acid on anteroposterior patterning of cells in the developing central nervous system correlate with differences in retinoid release from anterior and posterior neural tissue. We find that the release of morphogenetically active retinoids from the floor plate is only about 1.5-fold that of the dorsal spinal cord, which does not have neural tube or limb polarizing activity. These results suggest that the spatial distribution of retinoid release from spinal cord tissues differs from that of the neural and limb polarizing activity. This assay has also shown that retinoids are released from the embryonic spinal cord at much greater levels than from the forebrain. This result, together with previous observations that the development of forebrain structures is suppressed by low concentrations of retinoic acid, suggest that the normal development of forebrain structures is dependent on the maintenance of low concentrations of retinoids in anterior regions of the embryonic axis. This assay has also provided initial evidence that other embryonic tissues with polarizing properties in vivo release retinoids in vitro.

scholarly journals Targeted disruption of retinoic acid receptor alpha (RAR alpha) and RAR gamma results in receptor-specific alterations in retinoic acid-mediated differentiation and retinoic acid metabolism.

1995 ◽  
Vol 15 (2) ◽  
pp. 843-851 ◽  
Author(s):  
J F Boylan ◽  
T Lufkin ◽  
C C Achkar ◽  
R Taneja ◽  
P Chambon ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Retinoic Acid Receptor ◽  
Specific Gene ◽  
Cell Type ◽  
Targeted Disruption ◽  
F9 Cells ◽  
Retinoid Receptors ◽  
Alpha Gene ◽  
Polar Derivatives ◽  
Crabp Ii

F9 embryonic teratocarcinoma stem cells differentiate into an epithelial cell type called extraembryonic endoderm when treated with retinoic acid (RA), a derivative of retinol (vitamin A). This differentiation is presumably mediated through the actions of retinoid receptors, the RARs and RXRs. To delineate the functions of each of the different retinoid receptors in this model system, we have generated F9 cell lines in which both copies of either the RAR alpha gene or the RAR gamma gene are disrupted by homologous recombination. The absence of RAR alpha is associated with a reduction in the RA-induced expression of both the CRABP-II and Hoxb-1 (formerly 2.9) genes. The absence of RAR gamma is associated with a loss of the RA-inducible expression of the Hoxa-1 (formerly Hox-1.6), Hoxa-3 (formerly Hox-1.5), laminin B1, collagen IV (alpha 1), GATA-4, and BMP-2 genes. Furthermore, the loss of RAR gamma is associated with a reduction in the metabolism of all-trans-RA to more polar derivatives, while the loss of RAR alpha is associated with an increase in metabolism of RA relative to wild-type F9 cells. Thus, each of these RARs exhibits some specificity with respect to the regulation of differentiation-specific gene expression. These results provide an explanation for the expression of multiple RAR types within one cell type and suggest that each RAR has specific functions.

Human Muse cells-derived neural precursor cells as the novel seed cells for the repair of spinal cord injury

2021 ◽  
Vol 568 ◽  
pp. 103-109
Author(s):  
Xue Chen ◽  
Xin-Yao Yin ◽  
Ya-Yu Zhao ◽  
Chen-Chun Wang ◽  
Pan Du ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Precursor Cells ◽  
Neural Precursor Cells ◽  
Neural Precursor ◽  
The Novel ◽  
Cord Injury ◽  
Seed Cells ◽  
Muse Cells

Temporally-regulated retinoic acid depletion produces specific neural crest, ocular and nervous system defects

Development ◽  
1997 ◽  
Vol 124 (16) ◽  
pp. 3111-3121 ◽  
Author(s):  
E.D. Dickman ◽  
C. Thaller ◽  
S.M. Smith
Keyword(s):  
Nervous System ◽  
Retinoic Acid ◽  
Neural Crest ◽  
Female Rats ◽  
Retinoid Receptor ◽  
Knock Out ◽  
The Face ◽  
Normal Males ◽  
Temporal Events ◽  
Null Mutant Mice

Both retinoid receptor null mutants and classic nutritional deficiency studies have demonstrated that retinoids are essential for the normal development of diverse embryonic structures (e.g. eye, heart, nervous system, urogenital tract). Detailed analysis of retinoid-modulated events is hampered by several limitations of these models, including that deficiency or null mutation is present throughout gestation, making it difficult to isolate primary effects, and preventing analysis beyond embryolethality. We developed a mammalian model in which retinoid-dependent events are documented during distinct targeted windows of embryogenesis. This was accomplished through the production of vitamin A-depleted (VAD) female rats maintained on sufficient oral retinoic acid (RA) for growth and fertility. After mating to normal males, these RA-sufficient/VAD females were given oral RA doses which allowed for gestation in an RA-sufficient state; embryogenesis proceeded normally until retinoids were withdrawn dietarily to produce a sudden, acute retinoid deficiency during a selected gestational window. In this trial, final RA doses were administered on E11.5, vehicle at E12.5, and embryos analyzed on E13.5; during this 48 hour window, the last RA dose was metabolized and embryos progressed in a retinoid-deficient state. RA-sufficient embryos were normal. Retinoid-depleted embryos exhibited specific malformations of the face, neural crest, eyes, heart, and nervous system. Some defects were phenocopies of those seen in null mutant mice for RXR alpha(−/−), RXR alpha(−/−)/RAR alpha(−/−), and RAR alpha(−/−)/RAR gamma(−/−), confirming that RA transactivation of its nuclear receptors is essential for normal embryogenesis. Other defects were unique to this deficiency model, showing that complete ligand ‘knock-out’ is required to see those retinoid-dependent events previously concealed by receptor functional redundancy, and reinforcing that retinoid receptors have separate yet overlapping contributions in the embryo. This model allows for precise targeting of retinoid form and deficiency to specific developmental windows, and will facilitate studies of distinct temporal events.

Retinoid-binding protein distribution in the developing mammalian nervous system

Development ◽  
1990 ◽  
Vol 109 (1) ◽  
pp. 75-80 ◽  
Author(s):  
M. Maden ◽  
D.E. Ong ◽  
F. Chytil
Keyword(s):  
Nervous System ◽  
Retinoic Acid ◽  
Neural Crest ◽  
Motor Neurons ◽  
Neural Tube ◽  
Binding Protein ◽  
Sympathetic Ganglia ◽  
Retinol Binding Protein ◽  
Otic Vesicle ◽  
Protein Distribution

We have analysed the distribution of cellular retinol-binding protein (CRBP) and cellular retinoic acid-binding protein (CRABP) in the day 8.5-day 12 mouse and rat embryo. CRBP is localised in the heart, gut epithelium, notochord, otic vesicle, sympathetic ganglia, lamina terminalis of the brain, and, most strikingly, in a ventral stripe across the developing neural tube in the future motor neuron region. This immunoreactivity remains in motor neurons and, at later stages, motor axons are labelled in contrast to unlabelled sensory axons. CRABP is localised to the neural crest cells, which are particularly noticeable streaming into the branchial arches. At later stages, neural crest derivatives such as Schwann cells, cells in the gut wall and sympathetic ganglia are immunoreactive. An additional area of CRABP-positive cells are neuroblasts in the mantle layer of the neural tube, which subsequently appear to be the axons and cell bodies of the commissural system. Since retinol and retinoic acid are the endogenous ligands for these binding proteins, we propose that retinoids may play a role in the development and differentiation of the mammalian nervous system and may interact with certain homoeobox genes whose transcripts have also been localised within the nervous system.

Analysis of the development of the nervous system of the zebrafish, Brachydanio rerio

Development ◽  
1968 ◽  
Vol 19 (2) ◽  
pp. 109-119
Author(s):  
Judith Shulman Weis
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Neural Crest ◽  
Neural Tube ◽  
Sympathetic Neurons ◽  
Dorsal Surface ◽  
Teleost Fishes ◽  
Brachydanio Rerio ◽  
Solid Structure ◽  
Derivatives Of

In teleost fishes, unlike many other vertebrates, the spinal cord originates as a solid structure, the neural keel, which subsequently hollows out. Unlike vertebrates in which the neural tube is formed from neural folds, and where the neural crest arises from wedge-shaped masses of tissue connecting the neural tube to the general ectoderm, teleosts do not possess a clear morphological neural crest. Initially, the dorsal surface of the keel is broadly attached to the ectoderm as described by Shepard (1961). As the neural primordia become larger and more discrete, the region of attachment narrows, and cells become loose (the ‘loose crest stage’). These cells represent the neural crest. Subsequently they begin to migrate and to differentiate into the various derivatives of neural crest. Both sensory and sympathetic neurons arise from neural crest. At the time of their migration the cells are not morphologically distinguishable.

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