Flashcards
Cell Adhesion & the Extracellular Matrix
Cards in this deck (25)
- 1What cells form connective tissues?Fibroblasts - Osteoblasts - Myofibroblasts - Adipocytes - Chondrocytes - Blood cells
- 2Composition of the ECMFibular proteins
• collagen - fibronectin - elastin - laminin
Polysaccharides glycosaminoglycans (GAGs - which when organised by specific protein make proteoglycans) - 3Function of: FibroblastsSynthesis of collagen, elastin & proteoglycans
- 4Formation of collagen• Synthesised in the RER --> released via the secretory pathway as pro collagen --> pro collagen is then trimmed & cross-linked to make a fibril
- 5What is special about collagen secretion?• Golgi packages it into specialised vesicles
• collagen fibril production by fibroblasts occurs in a membrane tube called a fibripositor
• collagen secretion occurs at specialised regions via exocytosis - 6Where is elastin made?Fibroblasts & also smooth muscle cells + chondrocytes
- 7Define: proteoglycanAssemblage of glycosaminoglycans & proteins
- 8Functions of proteoglycans• Matrix support, cushioning & hydration
• Glue-like function
• Links between proteins of ECM+ECM & ECM+cell surface
• Organisation - linking proteins allowing GAGs to combine w/ hyaluronic acid - 9What are GAG chains?Long chains of repeating disaccharide units
- 104 important GAGs• Keratan Sulfate - KS
• Chondroitin Sulfate - CS
• Dermatan Sulfate - DS
• Heparin Sulfate - HS - 11How is the ECM linked to the cytoskeleton?Collagen / proteoglycans binds fibronectin --> fibronectin binds integrins --> integrins bind via adaptors to actin cytoskeleton
- 12What are the 2 functions of myofibroblasts?1. Fibroblast-like: secrete collagen
2. Smooth muscle-like: synthesis contractile proteins (actin, myosin) & intermediate filaments (desmin) - 13Describe myofibroblast involvement in the healing of tissue damageMyofibroblasts proliferate --> secrete collagen --> form a fibrous scar, consolidating the damaged area --> contract to reduce the size of the damaged area - by expression of focal adhesion & smooth muscle actin
- 14How do we stain adipocytes in the lab?Nile red
- 15Function of: Tight junctions• Define polarity
• Selective movement between cells
• Can link to actin cytoskeleton - 16Function of: Adherens junctionsPlaque anchors actin filaments at the membrane between two cells
- 17Name 4 cadherins & the tissue they provide cell adhesion within1. E-cadherin - epithelia
2. N-cadherin - neurons & heart tissue
3. P-cadherin - placenta & epidermis
4. VE-cadherin - endothelial tissue - 18Function of: DesmosomesLink the intermediate filaments in adjacent cells
- 19Function of: Gap junctions• communication
• small molecule passage
• coordination of function
• provide a hydrophilic channel - 20Function of: Focal adhesions• link ECM via integrins to the cytoskeleton
• act as signalling platforms - 21Function of: Hemi-desmosomesLinks epithelial cells to the BM via laminin
- 22Function of: IntegrinsAct as bridges between the cytosol & ECM
- 23Describe the steps of cell adhesion in cancerCarcinoma in situ - tumour cells accumulate
Reduction in cadherin expression - cells convert to mesenchymal
Microinvasion begins - aided by MMP secretion
BM breached
Leading invading tumour cells express integrins - promote interaction w/ ECM & non-epithelial cells during movement
Autocrine motility factors increase tumour motility
Antiogenisis factors expressed - tumour cells enter blood & lymphatic circulation
Dissemination - Metastasis - 24What gene mutation causes Duchenne's Muscular DystrophyAbsence of dystrophin due to premature termination of translation
- 25AtalurenAn experimental drug thought to override the premature stop signal mutation to produce normal dystrophin production
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- MD2001 Flashcards on Cell Adhesion & the Extracellular Matrix, created by Lareyna Mcmenemy on 16/07/2018.
- Created by
- Lareyna Mcmenemy · Jul 2018
- Updated
- Jul 16, 2018
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