Transcript Epithelial–Mesenchymal Transition

Epithelial–Mesenchymal
Transition
魏炽炬
Origin of Epithelium and Mesenchyme
• There are two major types of cell arrangements
in the embryo:
• epithelial cells, which are tightly connected to
one another in sheets or tubes,
• and mesenchymal cells, which are unconnected
to one other and operate as independent units.
Origin of Epithelium and Mesenchyme
• Epithelia are sheets or tubes of connected cells;
they can originate from any germ layer.
• Meschymal cells are loosely packed unconnected
cells; mesenchyme contains collagen bundles and
fibroblasts; they are derived from the mesoderm or
neural crest.
In the Adult
• Epithelium is a tissue composed of cells that
line the cavities and surfaces of structures
throughout the body.
• Epithelium is classified as a primary body
tissue, the other ones being connective tissue,
muscle tissue and nervous tissue.
In the Adult
• Mesenchyme later differentiates into blood
vessels, blood-related organs, and connective
tissues.
• All organs consist of an epithelium and
an associated mesenchyme.
Hartmut Beug
Epithelial–Mesenchymal Transition
Epithelial
Mesenchymal
Actin/
DAPI
E-cadherin
Vimentin
Desmosomes
Vimentin
Jean Paul Thiery
Epithelial–Mesenchymal Transition
Jean Paul Thiery
EMT in Tissue Remodelling
The generation of three germ layers
下胚层
The migration of neural crest
Somitogenesis
The generation of glomerulus
Hartmut Beug
EMT During Tumor Progression
Paper One
Epithelial-to Mesenchymal Transition
Generates Proliferative Human Islet
Precursor Cells
• Marvin Gershengorn, Anandwardhan Hardikar,
Chiju Wei, Elizabeth Geras-Raaka, Bernice MarcusSamuels, Bruce M. Raaka
• SCIENCE VOL 306, 2004
Potential Sources of Islet Precursor Cells
Pancreatic stem
cell
Transdifferentiation
Bone Marrow
Stem Cell
Embryonic Stem
Cell
Cadaveric
human
islets
hIPC Generation and ICA Formation
A
B
C
E
D
1 hr
F
24 hr
6 day
Transition From Insulin+ to
Vimentin+ Cells
Redifferentiation From Vimentin+ to
Insulin+ Cells
Marvin Gershengorn
Islet Precursors Generated by EMT
Joel F. Habener
EMT in Progenitor Cells of The
Developing Endocrine Pancreas
Basel membrane
ECM
Epithelium


Acinar cell
Islet
Paper Two
Islet-Derived Fibroblast-Like Cells Are
Not Derived via Epithelial-Mesenchymal
Transition From Pdx-1 or InsulinPositive Cells
• Lucas G. Chase, Fernando Ulloa-Montoya, Benjamin
L. Kidder, and Catherine M. Verfaillie
• Diabetes 56:3–7, 2007
Lineage Tracing on Proliferative
Fibroblast-like Cell Populations
Fibroblast-like Cells Are Not
Generated From Insulin+/PDX1+ Cells
Nadya L. Lumelsky
About 25% of All Insulin-Expressing
Cells Coexpressed EGFP
Paper Three
In Vitro Proliferation of Cells Derived From
Adult Human -Cells Revealed By CellLineage Tracing
• Holger A. Russ, Yael Bar, Philippe Ravassard, and
Shimon Efrat
• Diabetes 57, 2008
In Vitro Lineage Tracing of Islet Beta Cells
Labeling of human islet cells with
the two-virus system