Extracellular `Matrix Flashcards
What are the macromolecules making up ECM?
- Protein
- Carbohydrates
What is ECM?
Extracellular matrix
What are the 4 functions of ECM?
- Physical support
- Tissue properties
- Influences cell growth/adhesion/differentiation
- Organogenesis
Which cells deposit ECM?
Fibroblasts
What are the 3 components of ECM?
- Collagens
- Glycoproteins (multi-adhesive)
- Proteoglycans
What are the 4 types of collagens in connective tissue?
- I
- II
- III
- IV —> basement membrane
What are the 3 types of multi-adhesive glycoproteins in connective tissue?
- Fibronectin
- Fibrinogen
- Laminins —> basement membrane
What are the 4 types of proteoglycans in connective tissue?
- Aggrecan
- Versican
- Decorin
- Perlecan —> basement membrane
What are the 3 components of the basement membrane?
- Type IV collagen
- Laminins
- Perlecan
How do matrix components interact with cells?
Bind to integrins on cell surface (receptors)
What are integrins?
Transmembrane cell adhesion receptors —> mediating cell-to-cell and cell-ECM interactions
What are the 2 properties of tendon and skin tissue?
- Tough
- Flexible
What are the 2 properties of bone tissue?
- Hard
- Dense
What are the 2 properties of cartiledge tissue?
- Resilient
- Shock-absorbing
Are connective tissue properties consistent around the body?
No —> vary depending on tissue function
How does connective tissue vary its properties?
- Different ECM components (eg. collagen types)
- Different arrangements of collagen
How do ECM abnormalities arise? (4)
- Mutations affecting ECM proteins
- Mutations affecting ECM catabolism
- Excess ECM
- Loss of ECM
What are 5 examples of disorders resulting from mutated ECM proteins?
- Osteogenesis imperfecta (Brittle bones) - collagen I
- Marfan’s syndrome - fibrillin I
- Alport’s syndrome - collagen IV
- Epidermolysis Bullosa - laminin 5
- Muscular dystrophy (congenital) - laminin 2
What is an example of a disorder resulting from ECM catabolism issues?
Hurler’s syndrome - L-α-iduronidase
What are 3 examples of disorders resulting from excess ECM deposition? (fibrosis)
- Liver cirrhosis
- Diabetic nephropathy
- IPF (idiopathic pulmonary fibrosis)
What does excess ECM deposition lead to?
Fibrosis
What is an example of a disorder resulting from loss of ECM?
Osteoarthritis
What are collagens?
Family of fibrous proteins
Which organs are collagens essential for?
- Bones
- Tendons
- Skin