Tissue Renewal and Repair Flashcards
What is tissue organization? What causes it?
Def: response to inflammation that involves replacement of tissue with granulation tissue
What are intestinal stem cells called?
Crypt cells
What are hepatic stem cells called? Into what types of cells do they develop? What are the methods of liver regeneration and when are they used?
Oval cells
Hepatocytes or biliary cells
Normal regeneration: hepatocyte proliferation (hyperplasia…)
Serious injury (cancer/hep): oval cells activated
Source and function of Epidermal GF (EGF)
Source: Macrophages
Function:
Stimulates granulation tissue formation
Mitogenic for:
- Fibroblasts
- Keratinocytes
- Epithelial cells
- Hepatocytes
Function of TGF-Alpha
Induce production of VEGF
Function of Hepatocyte GF (HGF)
Cell migration during embryonic development
Mitogenic for:
- Epithelial cells
- Endothelial cells
- Hepatocytes
Stimuli for and Function of VEGF (Vascular endothelial GF)
Stimuli:
- Hypoxia
- TGF-alpha
- TGF-ß
- PDGF
Function:
- Angiogenesis (inflammation, ect.) by Capillary Sprouting
- Increase vasc. permeability
- stimulate endothelial cell migration/prolif.
- Vasculogenesis (embryonic development)
Functions of Platelet-Derived GF (PDGF)
Chemotactic for neutrophils and monocytes
Stimulate VEGF production
Migration/Proliferation of:
- fibroblasts
- smooth m
- monocytes
Functions of Fibroblast GF (FGF)
Skin reorganization and healing
- Stimulate angiogenesis
- Stimulate cell migration in wounds
Hematopoiesis
Chemotactic for:
- Fibroblasts
- Keratinocytes
Function of FGF-7
Keratinocyte GF (migration and proliferation)
Functions of Transforming GF-ß (TGF-ß)
Fibrogenic Agent (Healing by fibrosis)
- Stimulate collagen, fibronectin, proteoglycans
- Inhibit collagen degradation
Functions of Insulin-like GF-1 (IGF-1)
Healing by fibrosis
- Stimulate fibroblasts
- Stimulate ECM proteins (collagen, proteoglycan)
Signal transduction mechanism of GF receptors
Tyrosine kinase activity
Signal transduction mechanism of cytokine receptors
JAK/STAT
Signal transduction mechanism of receptors for histamine, serotonin, NE, epinephrine, chemokines
G-protein