Lec11: Neurovascular unit Flashcards
What are the 4 components of the Neurovascular unit?
Perivascular macrophages + Astrocytes + Pericytes + Endothelial cells (PAPE)
How big are small capillaries in the neural vasculature?
20micrometers.
How big are large capillaries in the neural vasculature?
150micrometers.
All neuronal cells are within what distance of a blood vessel?
200 micrometers.
Why are endothelial cells termed “polarised”, and towards what structure does the apical side face?
Because the apical and basal aspects are quite different. Apical side faces blood.
Tight junctions in the blood brain barrier are made up of proteins that have what two functions?
- Seals vessel
2. Selective barrier
Are endothelial cells thee only cells that express tight junctions?
Yes.
Name the 5 types of proteins that make up tight junctions.
- Cadherins
- Claudins
- Occludens
- Zonula Occludens
- Junctions Adhesion Molecules
Why is it still sometimes possible for large molecules to move across endothelial cells?
Using various transporters.
Leukocyte mirgration occurs in response to two main cytokines. What are these cytokines?
IL-1, TNF-alpha
Leukocyte migration occurs in response to 5 main chemokines. What are these chemokines?
IL-8, MCP-1, MIP-1, CCLs, CXCLs
What are the four steps in leukocyte migration? Draw an accompanying diagram.
- Leukocyte-endothelial cell interaction
- Tethering/Rolling
- Strong adhesion
- Diapedesis/Extravasation
Describe the two types of Extravasation.
- Paracellular transport = moves between endothelial cells by cleaving through tight junctions
- Transcellular transport = moves through body of cell
What are the major endothelial adhesion molecules?
VCAM-1 (CD106) and ICAM-1(CD54)
Give the list of the 6 endothelial CAM and their corresponding leukocyte CAM.
- ICAM-1 = LFA-1 (heterodimeric interaction)
- VCAM-1 = VLA-1
- E-selectin
- P-selectin
- CD99 - CD99 (homodimeric interaction)
- CD31 - CD31
