scholarly journals Cadherin-6B proteolysis promotes the neural crest cell epithelial-to-mesenchymal transition through transcriptional regulation

2016 ◽  
Vol 215 (5) ◽  
pp. 735-747 ◽  
Author(s):  
Andrew T. Schiffmacher ◽  
Vivien Xie ◽  
Lisa A. Taneyhill
Keyword(s):  
Neural Crest ◽  
Epithelial To Mesenchymal Transition ◽  
Neural Crest Cell ◽  
Cranial Neural Crest ◽  
Mesenchymal Transition ◽  
Effector Genes ◽  
A Disintegrin And Metalloproteinase ◽  
And Migration ◽  
Cranial Neural Crest Cells

During epithelial-to-mesenchymal transitions (EMTs), cells disassemble cadherin-based junctions to segregate from the epithelia. Chick premigratory cranial neural crest cells reduce Cadherin-6B (Cad6B) levels through several mechanisms, including proteolysis, to permit their EMT and migration. Serial processing of Cad6B by a disintegrin and metalloproteinase (ADAM) proteins and γ-secretase generates intracellular C-terminal fragments (CTF2s) that could acquire additional functions. Here we report that Cad6B CTF2 possesses a novel pro-EMT role by up-regulating EMT effector genes in vivo. After proteolysis, CTF2 remains associated with β-catenin, which stabilizes and redistributes both proteins to the cytosol and nucleus, leading to up-regulation of β-catenin, CyclinD1, Snail2, and Snail2 promoter-based GFP expression in vivo. A CTF2 β-catenin–binding mutant, however, fails to alter gene expression, indicating that CTF2 modulates β-catenin–responsive EMT effector genes. Notably, CTF2 association with the endogenous Snail2 promoter in the neural crest is β-catenin dependent. Collectively, our data reveal how Cad6B proteolysis orchestrates multiple pro-EMT regulatory inputs, including CTF2-mediated up-regulation of the Cad6B repressor Snail2, to ensure proper cranial neural crest EMT.

scholarly journals Cadherin-6B is proteolytically processed during epithelial-to-mesenchymal transitions of the cranial neural crest

2014 ◽  
Vol 25 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Andrew T. Schiffmacher ◽  
Rangarajan Padmanabhan ◽  
Sharon Jhingory ◽  
Lisa A. Taneyhill
Keyword(s):  
Neural Crest ◽  
Epithelial To Mesenchymal Transition ◽  
Neural Crest Cell ◽  
Neural Crest Cells ◽  
Spatiotemporal Pattern ◽  
Cranial Neural Crest ◽  
Mesenchymal Transition ◽  
Crest Cell

The epithelial-to-mesenchymal transition (EMT) is a highly coordinated process underlying both development and disease. Premigratory neural crest cells undergo EMT, migrate away from the neural tube, and differentiate into diverse cell types during vertebrate embryogenesis. Adherens junction disassembly within premigratory neural crest cells is one component of EMT and, in chick cranial neural crest cells, involves cadherin-6B (Cad6B) down-regulation. Whereas Cad6B transcription is repressed by Snail2, the rapid loss of Cad6B protein during EMT is suggestive of posttranslational mechanisms that promote Cad6B turnover. For the first time in vivo, we demonstrate Cad6B proteolysis during neural crest cell EMT, which generates a Cad6B N-terminal fragment (NTF) and two C-terminal fragments (CTF1/2). Coexpression of relevant proteases with Cad6B in vitro shows that a disintegrin and metalloproteinases (ADAMs) ADAM10 and ADAM19, together with γ-secretase, cleave Cad6B to produce the NTF and CTFs previously observed in vivo. Of importance, both ADAMs and γ-secretase are expressed in the appropriate spatiotemporal pattern in vivo to proteolytically process Cad6B. Overexpression or depletion of either ADAM within premigratory neural crest cells prematurely reduces or maintains Cad6B, respectively. Collectively these results suggest a dual mechanism for Cad6B proteolysis involving two ADAMs, along with γ-secretase, during cranial neural crest cell EMT.

scholarly journals Connexin 43 impacts the chick premigratory cranial neural crest cell population without affecting the neural crest cell epithelial-to-mesenchymal transition

2019 ◽  
Author(s):  
Karyn Jourdeuil ◽  
Lisa A. Taneyhill
Keyword(s):  
Gap Junctions ◽  
Neural Crest ◽  
Gap Junction ◽  
Neural Crest Cell ◽  
Neural Crest Cells ◽  
Cranial Neural Crest ◽  
Mesenchymal Transition ◽  
Junction Protein ◽  
Cranial Neural Crest Cells ◽  
Crest Cell

ABSTRACTGap junctions are intercellular channels that allow for the diffusion of small ions and solutes between coupled cells. Connexin 43 (Cx43), also known as Gap Junction Protein α1, is the most broadly expressed gap junction protein in vertebrate development. Cx43 is strongly expressed in premigratory cranial neural crest cells and is maintained throughout the neural crest cell epithelial-to-mesenchymal transition (EMT), but its function in these cells is not known. To this end, we have used a combination of in vivo and ex vivo live imaging with confocal microscopy, immunohistochemistry, and functional assays to assess gap junction formation, and Cx43 function, in chick premigratory cranial neural crest cells. Our results demonstrate that gap junctions exist between chick premigratory and migratory cranial neural crest cells, with Cx43 depletion inhibiting the function of gap junctions. While a reduction in Cx43 levels just prior to neural crest cell EMT did not affect EMT and subsequent emigration of neural crest cells from the neural tube, the size of the premigratory neural crest cell domain was decreased in the absence of any changes in cell proliferation or death. Collectively, these data identify a role for Cx43 within the chick premigratory cranial neural crest cell population prior to EMT and migration.

scholarly journals Rho-kinase and myosin II affect dynamic neural crest cell behaviors during epithelial to mesenchymal transition in vivo

2008 ◽  
Vol 324 (2) ◽  
pp. 236-244 ◽  
Author(s):  
Jason D. Berndt ◽  
Matthew R. Clay ◽  
Tobias Langenberg ◽  
Mary C. Halloran
Keyword(s):  
Neural Crest ◽  
Epithelial To Mesenchymal Transition ◽  
Myosin Ii ◽  
Rho Kinase ◽  
Neural Crest Cell ◽  
Mesenchymal Transition ◽  
Cell Behaviors ◽  
Crest Cell

scholarly journals Dissection, Culture and Analysis of Primary Cranial Neural Crest Cells from Mouse for the Study of Neural Crest Cell Delamination and Migration

10.3791/60051 ◽  
2019 ◽  
Author(s):  
Sandra Guadalupe Gonzalez Malagon ◽  
Lisa Dobson ◽  
Anna M Lopez Muñoz ◽  
Marcus Dawson ◽  
William Barrell ◽  
...  
Keyword(s):  
Neural Crest ◽  
Neural Crest Cell ◽  
Neural Crest Cells ◽  
Cranial Neural Crest ◽  
And Migration ◽  
Cranial Neural Crest Cells ◽  
Crest Cell

scholarly journals Draxin acts as a molecular rheostat of canonical Wnt signaling to control cranial neural crest EMT

2018 ◽  
Vol 217 (10) ◽  
pp. 3683-3697 ◽  
Author(s):  
Erica J. Hutchins ◽  
Marianne E. Bronner
Keyword(s):  
Wnt Signaling ◽  
Neural Crest ◽  
Neural Tube ◽  
Epithelial To Mesenchymal Transition ◽  
Cranial Neural Crest ◽  
Canonical Wnt Signaling ◽  
Mesenchymal Transition ◽  
Molecular Rheostat ◽  
Timing Of Initiation ◽  
Canonical Wnt

Neural crest cells undergo a spatiotemporally regulated epithelial-to-mesenchymal transition (EMT) that proceeds head to tailward to exit from the neural tube. In this study, we show that the secreted molecule Draxin is expressed in a transient rostrocaudal wave that mirrors this emigration pattern, initiating after neural crest specification and being down-regulated just before delamination. Functional experiments reveal that Draxin regulates the timing of cranial neural crest EMT by transiently inhibiting canonical Wnt signaling. Ectopic maintenance of Draxin in the cranial neural tube blocks full EMT; while cells delaminate, they fail to become mesenchymal and migratory. Loss of Draxin results in premature delamination but also in failure to mesenchymalize. These results suggest that a pulse of intermediate Wnt signaling triggers EMT and is necessary for its completion. Taken together, these data show that transient secreted Draxin mediates proper levels of canonical Wnt signaling required to regulate the precise timing of initiation and completion of cranial neural crest EMT.

Inhibition of cranial neural crest cell development by vitamin A in the cultured chick embryo

Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 267-271
Author(s):  
John R. Hassell ◽  
Judith H. Greenberg ◽  
Malcolm C. Johnston
Keyword(s):  
Vitamin A ◽  
Neural Crest ◽  
Neural Crest Cell ◽  
Cell Development ◽  
Cranial Neural Crest ◽  
Cranial Neural Crest Cell ◽  
Neural Crest Cell Migration ◽  
Cranial Neural Crest Cells ◽  
Crest Cell ◽  
Whole Egg

Chick embryos at stage 8, prior to neural crest cell migration, were explanted on whole egg medium with or without vitamin A and cultured for 3 days. Sections through the head regions showed that the cranial neural crest cells had migrated into the first visceral arch in the controls but were absent from this structure in the treated embryos. These observations suggest that vitamin A inhibits neural crest cell development or migration, an effect which may in part account for the facial malformations produced by excess vitamin A.

scholarly journals A PHD12–Snail2 repressive complex epigenetically mediates neural crest epithelial-to-mesenchymal transition

2012 ◽  
Vol 198 (6) ◽  
pp. 999-1010 ◽  
Author(s):  
Pablo H. Strobl-Mazzulla ◽  
Marianne E. Bronner
Keyword(s):  
Neural Crest ◽  
Adhesion Molecule ◽  
Chromatin Immunoprecipitation ◽  
Epithelial To Mesenchymal Transition ◽  
Adaptor Protein ◽  
Unknown Mechanism ◽  
Mesenchymal Transition ◽  
Histone 3 ◽  
Active Transcription

Neural crest cells form within the neural tube and then undergo an epithelial to mesenchymal transition (EMT) to initiate migration to distant locations. The transcriptional repressor Snail2 has been implicated in neural crest EMT via an as of yet unknown mechanism. We report that the adaptor protein PHD12 is highly expressed before neural crest EMT. At cranial levels, loss of PHD12 phenocopies Snail2 knockdown, preventing transcriptional shutdown of the adhesion molecule Cad6b (Cadherin6b), thereby inhibiting neural crest emigration. Although not directly binding to each other, PHD12 and Snail2 both directly interact with Sin3A in vivo, which in turn complexes with histone deacetylase (HDAC). Chromatin immunoprecipitation revealed that PHD12 is recruited to the Cad6b promoter during neural crest EMT. Consistent with this, lysines on histone 3 at the Cad6b promoter are hyperacetylated before neural crest emigration, correlating with active transcription, but deacetylated during EMT, reflecting the repressive state. Knockdown of either PHD12 or Snail2 prevents Cad6b promoter deacetylation. Collectively, the results show that PHD12 interacts directly with Sin3A/HDAC, which in turn interacts with Snail2, forming a complex at the Cad6b promoter and thus revealing the nature of the in vivo Snail repressive complex that regulates neural crest EMT.

scholarly journals Sip1 mediates an E-cadherin-to-N-cadherin switch during cranial neural crest EMT

2013 ◽  
Vol 203 (5) ◽  
pp. 835-847 ◽  
Author(s):  
Crystal D. Rogers ◽  
Ankur Saxena ◽  
Marianne E. Bronner
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Critical Role ◽  
Embryonic Stem ◽  
Neural Crest Cell ◽  
Stem Cell Population ◽  
Mesenchymal Transition ◽  
E Cadherin

The neural crest, an embryonic stem cell population, initially resides within the dorsal neural tube but subsequently undergoes an epithelial-to-mesenchymal transition (EMT) to commence migration. Although neural crest and cancer EMTs are morphologically similar, little is known regarding conservation of their underlying molecular mechanisms. We report that Sip1, which is involved in cancer EMT, plays a critical role in promoting the neural crest cell transition to a mesenchymal state. Sip1 transcripts are expressed in premigratory/migrating crest cells. After Sip1 loss, the neural crest specifier gene FoxD3 was abnormally retained in the dorsal neuroepithelium, whereas Sox10, which is normally required for emigration, was diminished. Subsequently, clumps of adherent neural crest cells remained adjacent to the neural tube and aberrantly expressed E-cadherin while lacking N-cadherin. These findings demonstrate two distinct phases of neural crest EMT, detachment and mesenchymalization, with the latter involving a novel requirement for Sip1 in regulation of cadherin expression during completion of neural crest EMT.

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