Mesenchymal cells and progenitors Flashcards
What is the mesenchyme?
A group of loosely packed cells that lack polarity
What does the mesenchyme form?
Meshwork of ECM
Allow cells to invade and form tissues
What do mesenchymal cells differentiate into?
Myocytes
Skin
Astrocytes
Stromal cells
Adipocytes
Where in the skin is the mesenchyme found?
In the dermis
Which two cells formed from mesenchymal cells make up the skin?
Fibroblasts
Myofibroblasts
What is the function of epithelial cells?
Forms barrier that protects host from environment and pathogens
Regulates exchange of nutrients, hormone, ect between blood and tissue
Why are epithelial cells polarised?
They express different proteins on either side
What is the importance of polarised epithelial cells?
Important in forming a barrier and joining cells together
Found in kidney, gut and lungs
What happens when the barrier of epithelial cells is damaged?
Inflammation
Activation of underlying cells
When may leakage of the epithelial barrier be desirable?
For recruiting plasma proteins and promoting immune cell influx
What are two types of mesenchymal transition?
Epithelial - mesenchymal transition
Endothelial - mesenchymal transition
What induces epithelial-mesenchymal transition?
TGFb, GFG, EGF (endothelial growth factor)
Environmental changes - hypoxia
What do epithelial cells become in epithelial-mesenchymal transition?
Myofibroblasts
Steps of epithelial-mesenchymal transition
Loose polarity and cell-cell adhesion
Lose ability to form tight junctions - barrier loses its function
Become more migratory
Lose expression of epithelial proteins (cytokeratins)
Gain expression of mesenchymal protein cell markers
In what processes is epithelial-mesenchymal transition involved?
Essential in the development of tissues and organs - heart valve, palette formation
Important in wound healing process
Associated with development of diseases
Which diseases is the epithelial-mesenchymal transition involved in?
Cancer
Lung fibrosis
COPD
CKD
How does epithelial-mesenchymal transition contribute to cancer?
Contributes to cancer stroma
Connective, functionally supportive framework of cells
What activates endothelial-mesenchymal transition?
Inflammatory cytokines - TGFb, TNFa and IL1b
Environmental changes - hypoxia
Steps of endothelial-mesenchymal transition
Endothelial cells appearance changes into spindle
Loose their polarity and cell-cell adhesion
Become more migratory
Loss of endothelial surface markers
Gain expression of mesenchymal proteins - collagen I and fibronectin
What does endothelial mesenchymal transition form?
Myofibroblasts
What processes are associated with endothelial mesenchymak transition?
Critical process for development of tissues and organs
Forming cardiac cushions in the heart
Associated diseases
Which diseases is endothelial mesenchymal transition associated with?
Cancer
Pulmonary hypertension
Atherosclerosis
Inflammatory diseases
What is the appearance of endothelial cells?
Cobble-like arrangement
What is the appearance of epithelial cells?
Spindle-like formation
