Mesenchymal cells progenitors Flashcards
What is the mesenchyme?
Loosely packed cells that lack polarity
Forms meshwork of ECM and allow cells to differentiate
Where is the mesenchyme found in the skin?
Dermis
What does the skin mesenchyme form during differentiation ?
Hair follicles
Blood vessels
What cell sub-types form from the mesenchymal cells?
Stromal Skin - fibroblasts and myofibroblasts Myocytes Adipocytes Astrocytes
What are the roles of the epithelial cells?
Create a filtration barrier through its tight juncitons
Protects the skin from the environment and pathogens
Regulates exchange of nutrients and hormones between tissues and blood
What are the characteristics of epithelial cells?
Polarised - express different proteins on either side
Where are epithelial cells forund?
Lungs
Kidneys
Gut
What happens when the epithelial cells become damaged?
Triggers an inflammatory response
Activation of underlying cells
What activates the differentiation of epithelial cells into myofibroblasts?
TGFb. GFG, EFG and environmental factors like hypoxia
What are the steps of Epithelial-mesenchymal transition?
- Loose polarity and cell adhesion
- Become more migratory
- Loose expression of epithelial cell surface markers
- Gain expression of myofibroblast cell surface markers
What tissues does Epithelial-mesenchymal transition form?
Heart valves
Palette formation
What diseases are associated with epithelial-mesenchymal transition?
Cancer
COPD
Lung fibrosis
CKD
What activates endothelial-mesenchymal transition?
Inflammatory chemokines, cytokines and environmental factors like hypoxia
IL 1b
TGFb
TNFa
What are the steps of endothelial-mesenchymal transition?
- Endothelial cell appearance changes to spindle-like
- Lose polarity and cell adhesion
- Become more migratory
- Lose endothelial surface markers
- Gain expression of mesenchymal proteins - collagen I and fibronectin
What beneficial processes are endothelial-mesenchymal transition associated with?
Forms heart cushions
Important mechanism for organ and tissue development