1. The Extracellular Matrix (ECM)
Lecture 10

2. The Extracellular Matrix (ECM)
Lecture 10

3. The spaces in between leave room for you and I to grow.
-Rush

4. Controlled Degradation of the ECM by Metalloproteases
helps Cells Migrate

5. The Extracellular Matrix is complicated

6. Extracellular Matrix contains Sugars and Proteins
GAG Glycosaminoglycans
Unbranched repeating disaccharide chains
Hydrated, gel-like ground substance
Typically sugars long
SO3
Most negatively charged (anionic) molecules produced by animal cells

7. Extracellular Matrix contains Sugars and Proteins
GAG Glycosaminoglycans
Hyaluronin
Chondroitin Sulfate
Heparin sulfate
Keratin sulfate

8. Hyaluronan is a polysaccharide
25,000 subunits
Made directly outside the cell
Most common
No SO3
Joint fluid, wound healing, development
Source of cell migration
Degraded by hyaluronidase

9. Proteoglycans are proteins attached to GAGs
Modification of the tetrasaccharide
occurs in the ER

10. Aggrecan 3,000,000 MW and 100 GAG chains
Heterogeneity in side chains

11. As big a a bacteria That’s HUGE!!!!

12. I wonder what
proteins
are in the ECM?

13. Extracellular Matrix contains proteins collagen, elastin, fibronectin, and laminin
Collagen is strong, resisting tensile forces (in abundance in the Achilles heel)
Y is usually hydroxyproline

14. Many genetic diseases are associated with collagen malfunction

17. Cells shape the extracellular matrix
These heart fibroblasts lay down an aligned collagen tract

18. Elastin

19. Glycoproteins in the matrix help guide migration
Fibronectin
Actin
Actin stimulates fibronectin formation through integrins

20. Inflammation involves cellular migration

21. For some cells, it’s a one way journey