Extracellular Matrix Flashcards
Aggrecan
The major proteoglycan in cartilage between bones
Aneurysm
Widening of artery due to weakness in vessel wall
Angiogenesis
Formation of new blood vessels
Basal lamina
Skin. Layer of ECM proteins and basement membrane secreted by epithelial cells
Basement membrane
Layer of ECM and fibrous proteins anchoring and supporting the epithelium
Epithelium
Outer layer
Extracellular matrix
3D network of proteins and carbs surrounding cells
Glomerulus
Cluster of capillaries in kidney that filter waste. Initiate urine formation
Glycosaminoglycan
Long chain of disaccharides where residues are sulfated, making it highly (-) charged
Periosteum
Dense fibrous membrane covering bones except at joints
Fibril Forming Collagens
Collagens I and III
Network Forming Collagens
Collagen IV
Anchoring fibril collagens
Collagen VII
Collagen I
Fibril forming. Connective tissue of skin, bone, tendon, cartilage, and ligaments. Surround Cornea and organs. Perpendicular
Collagen IV
Network forming. Flexible, sheet like mesh bc of BREAKS in triple helix structure.
Filtration in glomerulus
Collagen Type VII
Anchoring fibrils, keeps basement membrane intact.
Epidermis-dermis junction in skin
DEB affects these
Osteogenesis imperfecta
Weak bones.
Affects type I collagen.
Gly to serine, doesn’t correctly fold
Alpert syndrome
Affects type IV collagen.
Nephritis, hearing loss, and ocular lesions
Dystrophic Epidermolysis Bullosa (DEB)
Skin easily blisters.
Affects type VII collagen.
Cleavage site AT DERMIS
Proteoglycans
- Heterogenous. Mostly sugar, some protein.
- Regulate signaling molecules
- fibroblast growth factor (fgf) must bind yo activate its receptor
- filtering apparatus in kidneys
- aggrecan
Heparanse
Clips proteoglycan to allow growth factor to bind to blood vessel, allowing tumor growth
Fibrillin
Form micro fibers and associate w elastic fibers in ECM.
Found in skin, eye lens, aorta, periosteum
Provides scaffold
Marfan Syndrome
Gene mutation of fibrillin 1.
Long limbs, nearsighted (lens dislocation), and large heart (aneurysm)
-Growth factor stays active
Fibronectin
2 large subunits connected at carboxyl terminal by disulfide bonds.
- multiple forms from one gene that is alt. RNA spliced
- inflammatory phase blood clotting, wound healing.
- low levels = premature deliveries
Laminin
3 chains form cross shaped structure
Junctional Epidermolysis Bullosa
Defect in laminin 5 (a3, B3, y2 chain) between dermis and epidermis
MMPs (Matrix Metalloproteinases)
ECM degradation enzymes.
Require Zn or Ca
-facilitate release of cells that migrate into wound in inflammatory phase
Fibroblasts
Synthesize collagen, fibronectin in proliferative phase
Remodeling phase
Collagen 3 replaced by collagen 1
Can takes weeks to months
