Wound healing Flashcards
What facilitates leukocyte margination and rolling?
Selectins (on both vasculature and leukocyte)
Sialyl-Lewis (on leukocyte…no idea what this is…don’t really care)
What facilitates tight binding between the vasculature and leukocytes?
ICAM and VCAM (vasculature)
Integrins…like CD18 (leukocyte)
What facilitates diapedesis (transmigration) of the leukocyte through the vasculature?
PECAMs (on both vasculature and leukocyte)
What guides leukocytes to the site of the injury after entering the interstitium?
Chemotactic signals (C5a, IL-8, LTB4, kallikrein, platelet-activating factor)
Where does leukocyte extravasation usually occur?
Postcapillary venules
What are the two kinds of possible scar formations?
Hypertrophic scars (normal) Keloid scars (look like an ugly tumor)
What secretes PDGF? What does PDGF do?
PDGF is secreted by activated platelets and macrophages
It induces vascular remodeling and smooth muscle cell migration
It also stimulates fibroblast growth for collagen synthesis
What does FGF do?
Stimulates all aspects of angiogenesis
What does EGF do?
Stimulates cell growth via tyrosine kinases (like EGFR…as expressed by ERBB2)
What does TGF-β do?
Angiogenesis, fibrosis, cell cycle arrest
What do metalloproteinases do?
Tissue remodeling
What are the three phases of wound healing?
Inflammatory (immediate)
Proliferative (2-3 days post injury)
Remodeling (1 week post injury)
What mediates the inflammatory phase?
Platelets
Neutrophils
Macrophages
What happens during the inflammatory phase?
Clot formation
Increased vessel permeability and neutrophil migration
Macrophages clear debris 2 days later
What mediates the proliferative phase?
Fibroblasts, myofibroblasts, endothelial cells, keratinocytes, macrophages
