EMT1 Flashcards
What are the junctions in epithelia from weakest to strongest
Gap
Desmosomal
Adherens
Tight
What is the importance of epithelium
Encloses a 3D space
Gives definition and rigidity
Gives the cell polarity
Name the 2 important embryonic processes EMT plays a role in
Gastrulation
Neural Crest Migration
Name the signalling factors that are important for the competence, induction and maintenance of EMT in gastrulation
Competence: Wnt
Induction: Nodal
Maintenance: FGF
Name the signalling factors that are important for the competence, induction and maintenance of EMT in neural crest migration
Competence: Wnt
Induction: BMP
Maintenance: Nodal and FGF
What is the key difference between what the TF converge on in neural crest EMT and gastrulation EMT
In gastrulation converges directly
in neural crest the pathways converge on Sox9 which then activates Snail
What are the 3 transcriptional regulators of EMT
Snail
Twist
Zeb
What do they transcriptional master regulators of EMT do
Repress key genes associated with epithelial characteristics e.g. e-cadherin, occludins, claudins
Activate genes that are important for mesenchymal cells (vimentin, fibronectin, N-cadherin)
What are the effects of Snail specificallu
Inhibits E Cadherin and Cyclin D
Activates RhoB, VImentin (causes BM degradation)
What miRNAs regulate the snail TFs
MiR200 - regulates Zeb
miR 34 –> regulates Snail
What alterations control the master EMT regulators
Snail - phosphorylation = degradation
Twist - phosphorylation = stabilisation
Zeb - sumolyation takes t out of the nucleus
what micro RNAs does p53 induce
miR200 –> induces this more strongly than miR34 hence most of its effects are thought to be through Zeb inhibitrion
miR34
What proteins inhibit Seb
GRHL2
MiR200 –> also stimualted production by GRHL2
What human cells can dediferentiate
Chief cells in the stomach can deifferentiate and form complete gastric units§
what type of TFs are Snail and Seb
Zinc transcription factors
