scholarly journals Mouse primitive streak forms in situ by initiation of epithelial to mesenchymal transition without migration of a cell population

2011 ◽  
Vol 241 (2) ◽  
pp. 270-283 ◽  
Author(s):  
Margot Williams ◽  
Carol Burdsal ◽  
Ammasi Periasamy ◽  
Mark Lewandoski ◽  
Ann Sutherland
Keyword(s):  
Cell Population ◽  
Epithelial To Mesenchymal Transition ◽  
Primitive Streak ◽  
Mesenchymal Transition ◽  
A Cell

scholarly journals Molecular mechanism of symmetry breaking in a 3D model of a human epiblast

2018 ◽  
Author(s):  
Mijo Simunovic ◽  
Jakob J. Metzger ◽  
Fred Etoc ◽  
Anna Yoney ◽  
Albert Ruzo ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Axial Symmetry ◽  
3D Model ◽  
Epithelial To Mesenchymal Transition ◽  
Embryonic Stem ◽  
Primitive Streak ◽  
Molecular Evidence ◽  
Axis Formation ◽  
Mesenchymal Transition

ABSTRACTBreaking the anterior-posterior (AP) symmetry in mammals takes place at gastrulation. Much of the signaling network underlying this process has been elucidated in the mouse, however there is no direct molecular evidence of events driving axis formation in humans. Here, we use human embryonic stem cells to generate an in vitro 3D model of a human epiblast whose size, cell polarity, and gene expression are similar to a 10-day human epiblast. A defined dose of bone mor-phogenetic protein 4 (BMP4) spontaneously breaks axial symmetry, and induces markers of the primitive streak and epithelial to mesenchymal transition. By gene knockouts and live-cell imaging we show that, downstream of BMP4, WNT3 and its inhibitor DKK1 play key roles in this process. Our work demonstrates that a model human epiblast can break axial symmetry despite no asymmetry in the initial signal and in the absence of extraembryonic tissues or maternal cues. Our 3D model opens routes to capturing molecular events underlying axial symmetry breaking phenomena, which have largely been unexplored in model human systems.

scholarly journals BMP4-induced symmetry breaking in a 3D model of the human epiblast

2019 ◽  
Author(s):  
Mijo Simunovic ◽  
Ali H. Brivanlou ◽  
Eric D. Siggia
Keyword(s):  
Live Cell Imaging ◽  
3D Model ◽  
Epithelial To Mesenchymal Transition ◽  
Cell Imaging ◽  
Embryonic Stem ◽  
Primitive Streak ◽  
Mesenchymal Transition ◽  
Pluripotency Markers ◽  
Anterior Posterior

Abstract We describe the protocol of generating a 3D stem-cell-based model of the human pre-gastrulation epiblast by culturing human embryonic stem cells in a mix of hydrogel and Matrigel. Much like the epiblast of an in vitro attached day-10 human embryo, this model is an epithelial sphere with a cavity at its center, it is expressing key pluripotency markers, and it displays apico-basal polarity. The 3D colonies can further be differentiated with morphogens and in the case of intermediate concentrations of BMP4, they break the anterior-posterior symmetry characterized by an asymmetric expression of a primitive streak marker and showing signs of epithelial to mesenchymal transition. The protocol described here is suitable for immunofluorescence staining and for live-cell imaging.

Mechanisms of Neural Crest Migration

2018 ◽  
Vol 52 (1) ◽  
pp. 43-63 ◽  
Author(s):  
András Szabó ◽  
Roberto Mayor
Keyword(s):  
Neural Crest ◽  
Cell Population ◽  
Epithelial To Mesenchymal Transition ◽  
Neural Crest Cells ◽  
Cell Types ◽  
Embryonic Cell ◽  
Mesenchymal Transition ◽  
Chain Migration ◽  
Mass Migration ◽  
Neural Crest Migration

Neural crest cells are a transient embryonic cell population that migrate collectively to various locations throughout the embryo to contribute a number of cell types to several organs. After induction, the neural crest delaminates and undergoes an epithelial-to-mesenchymal transition before migrating through intricate yet characteristic paths. The neural crest exhibits a variety of migratory behaviors ranging from sheet-like mass migration in the cephalic regions to chain migration in the trunk. During their journey, neural crest cells rely on a range of signals both from their environment and within the migrating population for navigating through the embryo as a collective. Here we review these interactions and mechanisms, including chemotactic cues of neural crest cells’ migration.

A Novel Biomimetic Model for Studying Mechanics of Embryonic Morphogenesis and Differentiation

2010 ◽  
Author(s):  
Julia A. Henkels ◽  
Evan A. Zamir
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Primitive Streak ◽  
Mitotic Cell ◽  
Embryonic Cells ◽  
Mesenchymal Transition ◽  
Genetics Research ◽  
Undifferentiated Cells ◽  
Organizing Center ◽  
Important Time ◽  
Anterior Posterior

Before the explosion of genetics research in the last century, embryonic development was largely studied from a mechanical perspective. Paired with genetic advances in understanding developmental signaling pathways and induction mechanisms, an important goal for understanding morphogenesis is to discover how the genome codes for changes in the mechanical movements of the embryonic cells. After formation of the zygote, a phase of rapid mitotic cell division is followed by epithelialization resulting in a cohesive sheet of cells termed the epiblast. During the next major phase of triploblastic development called gastrulation, a group of undifferentiated cells in the epiblast moves collectively to the embryonic midline and eventually gives rise to the three primary germ layers: endoderm, mesoderm, and ectoderm. At the primitive streak—the “organizing center” in amniotes (reptiles, birds, and mammals) which delineates anterior-posterior polarity—prospective endodermal and mesodermal precursors undergo epithelial-to-mesenchymal transition (EMT), internalization, and eventually organogenesis. “It is not birth, marriage, or death, but gastrulation which is truly the most important time in your life” (Lewis Wolpert, 1986).

scholarly journals Self-organization of a functional human organizer by combined WNT and NODAL signalling

2017 ◽  
Author(s):  
I. Martyn ◽  
T.Y. Kanno ◽  
A. Ruzo ◽  
E.D. Siggia ◽  
A.H. Brivanlou
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Embryonic Stem ◽  
Primitive Streak ◽  
Model Organisms ◽  
Detailed Characterization ◽  
Mesenchymal Transition ◽  
Neural Fate ◽  
Secondary Axis ◽  
Human Embryology ◽  
Emt Markers

In amniotes, the development of the primitive streak (PS) and its accompanying “organizer” define the first stages of gastrulation. Despite detailed characterization in model organisms, the analogous human structures remain a mystery. We have previously shown that when stimulated with BMP4, micropatterned colonies of human embryonic stem cells (hESCs) self-organize to generate early embryonic germ layers1. Here we show that in the same type of colonies WNT signalling is sufficient to induce a PS, and WNT with ACTIVIN is sufficient to induce an organizer, as characterized by embryo-like sharp boundary formation, epithelial-to-mesenchymal transition (EMT) markers, and expression of the organizer specific transcription factor GSC. Moreover, when grafted into chick embryos, WNT and ACTIVIN treated human cells induce and contribute autonomously to a secondary axis while inducing neural fate in the host. This fulfills the most stringent functional criteria for an organizer, and its discovery represents a major milestone in human embryology.

scholarly journals BMP-2 Variants in Breast Epithelial to Mesenchymal Transition and Microcalcifications Origin

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1381 ◽  
Author(s):  
Manuel Scimeca ◽  
Raffaella Giocondo ◽  
Manuela Montanaro ◽  
Annarita Granaglia ◽  
Rita Bonfiglio ◽  
...  
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Strong Association ◽  
Positive Association ◽  
Breast Cancers ◽  
Human Breast ◽  
Mesenchymal Transition ◽  
Breast Cells ◽  
E Cadherin

This study aims to investigate the possible different roles of the BMP-2 variants, cytoplasmic and nuclear variant, in both epithelial to mesenchymal transition and in microcalcifications origin in human breast cancers. To this end, the in situ expression of cytoplasmic and nuclear BMP-2 was associated with the expression of the main epithelial to mesenchymal transition biomarkers (e-cadherin and vimentin) and molecules involved in bone metabolisms (RUNX2, RANKL, SDF-1) by immunohistochemistry. In addition, the expression of cytoplasmic and nuclear BMP-2 was associated with the presence of microcalcifications. Our data showed a significant association among the number of cytoplasmic BMP-2-positive cells and the number of both vimentin (positive association) and e-cadherin (negative association) positive breast cells. Conversely, no associations were found concerning the nuclear BMP-2-positive breast cells. Surprisingly, the opposite result was obtained by analyzing the variants of BMP-2 and both the expression of RANKL and SDF-1 and the presence of microcalcifications. Specifically, the presence of microcalcifications was related to the expression of nuclear BMP-2 variant rather than the cytoplasmic one, as well as a strong association between the number of nuclear BMP-2 and the expression of the main breast osteoblast-like cells (BOLCs) biomarkers. To further corroborate these data, an in vitro experiment for demonstrating the co-expression of nBMP-2 and RANKL or vimentin or SDF-1 in breast cancer cells that acquire the capability to produce microcalcifications was developed. These investigations confirmed the association between the nBMP-2 expression and both RANKL and SDF-1. The data supports the idea that whilst cytoplasmic BMP-2 can be involved in epithelial to mesenchymal transition phenomenon, the nuclear variant is related to the essential mechanisms for the formation of breast microcalcifications. In conclusion, from these experimental and translational perspectives, the complexity of BMP-2 signaling will require a detailed understanding of the involvement of specific BMP-2 variants in breast cancers.

scholarly journals Estradiol Induces Epithelial to Mesenchymal Transition of Human Glioblastoma Cells

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1930
Author(s):  
Ana M. Hernández-Vega ◽  
Aylin Del Moral-Morales ◽  
Carmen J. Zamora-Sánchez ◽  
Ana G. Piña-Medina ◽  
Aliesha González-Arenas ◽  
...  
Keyword(s):  
Cell Migration ◽  
Epithelial To Mesenchymal Transition ◽  
Epithelial Mesenchymal Transition ◽  
Estrogen Receptor Α ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Selective Agonist ◽  
A Cell ◽  
Human Gbm ◽  
Emt Markers

The mesenchymal phenotype of glioblastoma multiforme (GBM), the most frequent and malignant brain tumor, is associated with the worst prognosis. The epithelial–mesenchymal transition (EMT) is a cell plasticity mechanism involved in GBM malignancy. In this study, we determined 17β-estradiol (E2)-induced EMT by changes in cell morphology, expression of EMT markers, and cell migration and invasion assays in human GBM-derived cell lines. E2 (10 nM) modified the shape and size of GBM cells due to a reorganization of actin filaments. We evaluated EMT markers expression by RT-qPCR, Western blot, and immunofluorescence.We found that E2 upregulated the expression of the mesenchymal markers, vimentin, and N-cadherin. Scratch and transwell assays showed that E2 increased migration and invasion of GBM cells. The estrogen receptor-α (ER-α)-selective agonist 4,4’,4’’-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT, 10 nM) affected similarly to E2 in terms of the expression of EMT markers and cell migration, and the treatment with the ER-α antagonist methyl-piperidino-pyrazole (MPP, 1 μM) blocked E2 and PPT effects. ER-β-selective agonist diarylpropionitrile (DNP, 10 nM) and antagonist 4-[2-phenyl-5,7-bis(trifluoromethyl)pyrazole[1,5-a]pyrimidin-3-yl]phenol (PHTPP, 1 μM) showed no effects on EMT marker expression. These data suggest that E2 induces EMT activation through ER-α in human GBM-derived cells.

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