ECM 2 Flashcards
What are laminins?
GLycoproteins
Cross-shaped - alpha, beta, gamma chain
Large and multi-adhesive
Interact with cell-surface receptors and other proteoglycans
What occurs as a result of a2 chain absence?
Congenital muscular dystrophy
What are fibronectins and where are they found?
Dimeric glycoprotein find in INSOLUBLE fibrillar matrix or SOLUBLE plasma protein
LArge multidomain, interacts with receptors
What are fibronectins used for?
Cell adhesion
Embryogenesis migration
Tissue repair - wound healing
Mechanical continuum - joins the cytoskeleton by acting as bridge between collagen integrin to actin.
What are proteoglycans?
Glycoslyated proteins
Have core protein with glycosaminoglycan chains
HYDRATED CHAIN
What are GAG chains?
Glycosaminoglycan - repeating chain of disaccharides
What are the families of proteoglycan?
Perlecan - BM
Aggrecan - to aggregate
Decorin - small, leucine rich
What are the types of GAG and how are they differentiated?
Diff by sugar type
- Hyaluronan
- Chondroitin, heparan, keratan sulphate
What is hyaluronan?
Carbohydrate chain - unique
Where is hyaluronan synthesised?
Cell surface, not sulfated
Where are GAGs normally synthesised?
ER and GOlgi - hyaluronan isnt as no protein
What are the repeating disaccharides in dermatan sulfate?
IDURONIC ACID
N-acetylgalactosamine-4-sulfate
What are the repeating disaccharides in chondroitin sulphate?
GLUCURONIC ACID
N-acetylgalactosamine-4-sulfate
What is the function of decorin?
Binds to collagen - essential for fibre formation
What is aggrecan? What does it constitute of?
Cartilage constituent
Core protein with CS chains,
Backbone is hyaluronan, where KS and CS join on laterally
How does it retain water?
It is negatively charged, attracting cations which allows water to move towards it and be removed upon compression.
What is osteoarthritis and why does it occur?
Degradation of aggrecan by aggrecanases
What are fibrotic disorders?
Diseases that occur as a result of excess fibrous tissue being made, with collagen replaving functional tissue
