scholarly journals Caldesmon regulates actin dynamics to influence cranial neural crest migration in Xenopus

2011 ◽  
Vol 22 (18) ◽  
pp. 3355-3365 ◽  
Author(s):  
Shuyi Nie ◽  
Yun Kee ◽  
Marianne Bronner-Fraser
Keyword(s):  
Neural Crest ◽  
Cultured Cells ◽  
Phosphorylation Site ◽  
Neural Crest Cells ◽  
Actin Dynamics ◽  
Cranial Neural Crest ◽  
Critical Function ◽  
Cranial Neural Crest Cells ◽  
Neural Crest Migration

Caldesmon (CaD) is an important actin modulator that associates with actin filaments to regulate cell morphology and motility. Although extensively studied in cultured cells, there is little functional information regarding the role of CaD in migrating cells in vivo. Here we show that nonmuscle CaD is highly expressed in both premigratory and migrating cranial neural crest cells of Xenopus embryos. Depletion of CaD with antisense morpholino oligonucleotides causes cranial neural crest cells to migrate a significantly shorter distance, prevents their segregation into distinct migratory streams, and later results in severe defects in cartilage formation. Demonstrating specificity, these effects are rescued by adding back exogenous CaD. Interestingly, CaD proteins with mutations in the Ca2+-calmodulin–binding sites or ErK/Cdk1 phosphorylation sites fail to rescue the knockdown phenotypes, whereas mutation of the PAK phosphorylation site is able to rescue them. Analysis of neural crest explants reveals that CaD is required for the dynamic arrangements of actin and, thus, for cell shape changes and process formation. Taken together, these results suggest that the actin-modulating activity of CaD may underlie its critical function and is regulated by distinct signaling pathways during normal neural crest migration.

scholarly journals Chick cranial neural crest cells migrate by progressively refining the polarity of their protrusions

2017 ◽  
Author(s):  
Miriam A. Genuth ◽  
Christopher D.C. Allen ◽  
Takashi Mikawa ◽  
Orion D. Weiner
Keyword(s):  
Neural Crest ◽  
Quantitative Imaging ◽  
Cell Movement ◽  
Neural Crest Cells ◽  
Branchial Arch ◽  
Cranial Neural Crest ◽  
Directed Movement ◽  
Morphological Polarity ◽  
Cranial Neural Crest Cells

SummaryIn vivo quantitative imaging reveals that chick cranial neural crest cells throughout the migratory stream are morphologically polarized and migrate by progressively refining the polarity of their protrusions.AbstractTo move directionally, cells can bias the generation of protrusions or select among randomly generated protrusions. Here we use 3D two-photon imaging of chick branchial arch 2 directed neural crest cells to probe how these mechanisms contribute to directed movement, whether a subset or the majority of cells polarize during movement, and how the different classes of protrusions relate to one another. We find that cells throughout the stream are morphologically polarized along the direction of overall stream movement and that there is a progressive sharpening of the morphological polarity program. Neural crest cells have weak spatial biases in filopodia generation and lifetime. Local bursts of filopodial generation precede the generation of larger protrusions. These larger protrusions are more spatially biased than the filopodia, and the subset of protrusions that power motility are the most polarized of all. Orientation rather than position is the best correlate of the protrusions that are selected for cell movement. This progressive polarity refinement strategy may enable neural crest cells to efficiently explore their environment and migrate accurately in the face of noisy guidance cues.

scholarly journals MAPRE2 mutations result in altered human cranial neural crest migration, underlying craniofacial malformations in CSC-KT syndrome

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cedric Thues ◽  
Jorge S. Valadas ◽  
Liesbeth Deaulmerie ◽  
Ann Geens ◽  
Amit K. Chouhan ◽  
...  
Keyword(s):  
Neural Crest ◽  
Induced Pluripotent Stem Cell ◽  
Neural Crest Cells ◽  
Branchial Arch ◽  
Cellular Migration ◽  
Cranial Neural Crest ◽  
Craniofacial Malformations ◽  
Neural Crest Migration

AbstractCircumferential skin creases (CSC-KT) is a rare polymalformative syndrome characterised by intellectual disability associated with skin creases on the limbs, and very characteristic craniofacial malformations. Previously, heterozygous and homozygous mutations in MAPRE2 were found to be causal for this disease. MAPRE2 encodes for a member of evolutionary conserved microtubule plus end tracking proteins, the end binding (EB) family. Unlike MAPRE1 and MAPRE3, MAPRE2 is not required for the persistent growth and stabilization of microtubules, but plays a role in other cellular processes such as mitotic progression and regulation of cell adhesion. The mutations identified in MAPRE2 all reside within the calponin homology domain, responsible to track and interact with the plus-end tip of growing microtubules, and previous data showed that altered dosage of MAPRE2 resulted in abnormal branchial arch patterning in zebrafish. In this study, we developed patient derived induced pluripotent stem cell lines for MAPRE2, together with isogenic controls, using CRISPR/Cas9 technology, and differentiated them towards neural crest cells with cranial identity. We show that changes in MAPRE2 lead to alterations in neural crest migration in vitro but also in vivo, following xenotransplantation of neural crest progenitors into developing chicken embryos. In addition, we provide evidence that changes in focal adhesion might underlie the altered cell motility of the MAPRE2 mutant cranial neural crest cells. Our data provide evidence that MAPRE2 is involved in cellular migration of cranial neural crest and offers critical insights into the mechanism underlying the craniofacial dysmorphisms and cleft palate present in CSC-KT patients. This adds the CSC-KT disorder to the growing list of neurocristopathies.

Mesodermal defects and cranial neural crest apoptosis in alpha5 integrin-null embryos

Development ◽  
1997 ◽  
Vol 124 (21) ◽  
pp. 4309-4319 ◽  
Author(s):  
K.L. Goh ◽  
J.T. Yang ◽  
R.O. Hynes
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Neural Crest ◽  
Neural Crest Cells ◽  
Cell Surface Receptor ◽  
Cranial Neural Crest ◽  
Wild Type ◽  
Surface Receptor ◽  
Cranial Neural Crest Cells

Alpha5beta1 integrin is a cell surface receptor that mediates cell-extracellular matrix adhesions by interacting with fibronectin. Alpha5 subunit-deficient mice die early in gestation and display mesodermal defects; most notably, embryos have a truncated posterior and fail to produce posterior somites. In this study, we report on the in vivo effects of the alpha5-null mutation on cell proliferation and survival, and on mesodermal development. We found no significant differences in the numbers of apoptotic cells or in cell proliferation in the mesoderm of alpha5-null embryos compared to wild-type controls. These results suggest that changes in overall cell death or cell proliferation rates are unlikely to be responsible for the mesodermal deficits seen in the alpha5-null embryos. No increases in cell death were seen in alpha5-null embryonic yolk sac, amnion and allantois compared with wild-type, indicating that the mutant phenotype is not due to changes in apoptosis rates in these extraembryonic tissues. Increased numbers of dying cells were, however, seen in migrating cranial neural crest cells of the hyoid arch and in endodermal cells surrounding the omphalomesenteric artery in alpha5-null embryos, indicating that these subpopulations of cells are dependent on alpha5 integrin function for their survival. Mesodermal markers mox-1, Notch-1, Brachyury (T) and Sonic hedgehog (Shh) were expressed in the mutant embryos in a regionally appropriate fashion. Both T and Shh, however, showed discontinuous expression in the notochords of alpha5-null embryos due to (1) degeneration of the notochordal tissue structure, and (2) non-maintenance of gene expression. Consistent with the disorganization of notochordal signals in the alpha5-null embryos, reduced Pax-1 expression and misexpression of Pax-3 were observed. Anteriorly expressed HoxB genes were expressed normally in the alpha5-null embryos. However, expression of the posteriormost HoxB gene, Hoxb-9, was reduced in alpha5-null embryos. These results suggest that alpha5beta1-fibronectin interactions are not essential for the initial commitment of mesodermal cells, but are crucial for maintenance of mesodermal derivatives during postgastrulation stages and also for the survival of some neural crest cells.

scholarly journals A monoclonal antibody against a laminin-heparan sulfate proteoglycan complex perturbs cranial neural crest migration in vivo.

1988 ◽  
Vol 106 (4) ◽  
pp. 1321-1329 ◽  
Author(s):  
M Bronner-Fraser ◽  
T Lallier
Keyword(s):  
Monoclonal Antibody ◽  
Heparan Sulfate ◽  
Neural Crest ◽  
Neural Tube ◽  
Neural Crest Cells ◽  
Heparan Sulfate Proteoglycan ◽  
Sulfate Proteoglycan ◽  
Cranial Neural Crest ◽  
Neural Crest Migration

INO (inhibitor of neurite outgrowth) is a monoclonal antibody that blocks axon outgrowth, presumably by functionally blocking a laminin-heparan sulfate proteoglycan complex (Chiu, A. Y., W. D. Matthew, and P. H. Patterson. 1986. J. Cell Biol. 103: 1382-1398). Here the effect of this antibody on avian neural crest cells was examined by microinjecting INO onto the pathways of cranial neural crest migration. After injection lateral to the mesencephalic neural tube, the antibody had a primarily unilateral distribution. INO binding was observed in the basal laminae surrounding the neural tube, ectoderm, and endoderm, as well as within the cranial mesenchyme on the injected side of the embryo. This staining pattern was indistinguishable from those observed with antibodies against laminin or heparan sulfate proteoglycan. The injected antibody remained detectable for 18 h after injection, with the intensity of immuno-reactivity decreasing with time. Embryos ranging from the neural fold stage to the 9-somite stage were injected with INO and subsequently allowed to survive for up to 1 d after injection. These embryos demonstrated severe abnormalities in cranial neural crest migration. The predominant defects were ectopic neural crest cells external to the neural tube, neural crest cells within the lumen of the neural tube, and neural tube deformities. In contrast, embryos injected with antibodies against laminin or heparan sulfate proteoglycan were unaffected. When embryos with ten or more somites were injected with INO, no effects were noted, suggesting that embryos are sensitive for only a limited time during their development. Immunoprecipitation of the INO antigen from 2-d chicken embryos revealed a 200-kD band characteristic of laminin and two broad smears between 180 and 85 kD, which were resolved into several bands at lower molecular mass after heparinase digestion. These results indicate that INO precipitates both laminin and proteoglycans bearing heparan sulfate residues. Thus, microinjection of INO causes functional blockage of a laminin-heparan sulfate proteoglycan complex, resulting in abnormal cranial neural crest migration. This is the first evidence that a laminin-heparan sulfate proteoglycan complex is involved in aspects of neural crest migration in vivo.

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