Wound Repair Flashcards
What are some of the tissues that regenerate themselves due to normal “wear and tear”?
hematopoietic system, skin epithelium, and gastrointestinal epithelium
What are labile cells?
continuously dividing cells
Which phase of the cell cycle is the cell committed to replicate or die?
S
Which phase of the cycle has cells that aren’t actively dividing?
G0
What are cyclins?
molecules that bind to cdk to form a heterodimer that phosphorylates retnoblastoma, the main controller of the G1/S transition
What cell types reside in the G0 phase?
liver, kidneys, pancreas, mesenchymal cells, resting lymphocytes, and vascular endothelial cells
What are some examples of permanent cells?
neurons, cardiac myocytes and skeletal myocytes
What is the receptor for EGF and TGF-a?
EGFR1 (ERB B1)
What is the receptor for EGF?
tyrosine-specific kinase
T/F EGF acts in paracrine fashion
F. Juxtacrine
What are the cells of origin of EGF?
macrophages, inflammatory cells, and platelets
What are the target cells of EGF?
epithelial and fibroblasts
What is the main effect of EGF?
cell proliferation
What is the function of TGF-a and what pathology is associated with it?
facilitates regeneration of epithelium; psoriasis
What is KGF?
stimulates keratinocyte division and differentiation
What is the receptor for PDGF and what receptor type is it?
PDGFa and b and tyrosine-specific kinase
What are the cells of origin for PDGF?
macrophages, endothelial cells, platelet alpha granules and fibroblasts
What is PDGF’s target cell?
mesenchymal cells
What are some of the effects of PDGF?
1) chemokine for neutrophils, macrophages, and fibroblasts
2) mitogen (increases fibroblast proliferation)
3) stimulates fibroblasts to secrete ECM and collagenase
What are the cells of origin for FGFs
macrophages and endothelial cells
What are the target cells of FGFs?
fibroblasts and endothelial cells
T/F FGF must be bound to ECM (syndecane) in order to activate the receptor
True
What are some of the effects of FGF?
1) fibroblast chemotaxis and proliferation
2) ECM deposition
3) angiogenesis
What are the target cells of VEGF?
endothelial cells
What is the cell of origin for VEGF?
mesenchymal cells
What are some of the effects of VEGF?
1) angiogenesis
2) endothelial cell proliferation and migration
3) increase vascular permeability
What is the receptor type of TGF-b?
serine/threonine kinase
What are the target cells for TGF-b?
fibroblasts and leukocytes
What are the cells of origin for TGF-b?
macrophages, endothelial, fibroblast, lymphocytes and platelets
What is the main function of TGF-b?
promotes fibrogenesis
What is the function of HGF (hepatocyte growth factor)?
mitogenic for most epithelial cells
What is the receptor for HGF?
c-MET proto-oncogene
What are the functions of IGF-1?
stimulates collagen synthesis by fibroblasts and facilitates fibroblast proliferation